IgG Subtype Research Articles

Silk fibroin-based hydrogel as injectable carrier for prolonged immunization of plant-based COVID-19 subunit vaccine

Silk fibroin (SF)-based hydrogel was prepared to serve as an injectable carrier, aimed at prolonging the immunization effect of the plant-derived vaccine for the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2). This vaccine consists of the Receptor-Binding Domain (RBD) linked with the Fragment Crystallizable (Fc) region of Human Immunoglobulin G 1 (IgG1), also referred to as the RBD-Fc vaccine. The formulation also includes Aluminium hydroxide gel (Alum). Ex-vivo experiments demonstrated that both the SARS-CoV-2 RBD-Fc-loaded SF hydrogel (RBD-Fc/SF hydrogel) and the Alum-adjuvanted SARS-CoV-2 RBD-Fc-loaded SF hydrogel (Alum-RBD-Fc/SF hydrogel) indicated localized retention. This resulted in a controlled and prolonged release of 75% and 25% over a period of 60 days, respectively. This facilitated continuous interaction between the immune system and the viral peptide, specifically the RBD, which could have significant implications for geometric mean titer (GMT). In immunization studies, the RBD-Fc/SF hydrogel and Alum-RBD-Fc/SF hydrogel had induced a more prolonged and stronger immunogenic response of mouse-RBD-specific IgG titer and IgG subtypes (IgG1 and IgG2a). The specific IgG1 and IgG2a titers of RBD-Fc/SF hydrogel (with GMTs of 67,559 and 1,056, respectively) and Alum-RBD-Fc/SF hydrogel (with GMTs of 155,209 and 1,838, respectively) were superior to the RBD-Fc vaccine without SF hydrogel (with GMTs of 3200 and 200, respectively). Furthermore, they were comparable to the responses elicited by commercial Alum-adjuvants currently in use (with GMTs of 51,200 and 4,850, respectively). Additionally, a concentration of 0.1%w/v SF exhibited significant adjuvant properties by augmenting the secretion of various cytokines. For instance, it enhanced the secretion of Interleukin-6 (IL-6) to 88.02 pg/mL, which is comparable to the secretion induced by commercial Alum adjuvants (39.48 pg/mL). These findings suggest that SF hydrogel-based vaccine formulations could enhance humoral immunity and induce long-lasting immune responses. However, further investigations are required to assess the neutralizing potential of the antibodies produced against SARS-CoV-2 and its variants. The prospects and outcomes of SF hydrogel-based vaccine formulations indicate their potential as a next-generation vaccine platform. Such innovative strategies could be pivotal in the fight against COVID-19 and other infectious diseases.

Prevalence and immunopathologic characteristics of seropositive and seronegative hepatitis B virus-associated membranous nephropathy: a retrospective study of 420 biopsy-proven cases

Background This retrospective study aims to investigate the prevalence and immunopathologic characteristics of seropositive and seronegative hepatitis B virus-associated membranous nephropathy (HBV-MN). Methods Clinicopathologic and serologic records of 420 patients with histologically confirmed HBV-MN between January 2014 and July 2021 were examined to determine the prevalence of seropositive and seronegative HBV-MN. Serum anti-PLA2R antibody testing was conducted on 280 patients with HBV-associated membranous nephropathy (HBV-MN) from August 2018 to July 2021. Immunopathologic characteristics of HBV-MN patients and anti-PLA2R antibody positivity were analyzed. Results Among 420 pathologically confirmed HBV-MN patients, 230 (54.8%) were seropositive for HBV. The seropositive group exhibited higher blood creatinine values and incidence of liver function abnormalities than the seronegative group (p < .05). Serum anti-PLA2R antibody testing on 280 HBV-MN patients revealed a total positive rate of 44.6%, with the seronegative group showing a significantly higher rate (62.6%) compared to the seropositive group (32.1%) (p < .01). The anti-PLA2R antibody-positive group displayed higher levels of urine protein (p < .05), serum cholesterol (p < .01), and IgG4 subtypes (p < .05) compared to the negative group. Additionally, the positive group had significantly lower levels of serum albumin and IgG than the negative group (p < .01). Conclusions This comprehensive study reveals a significantly higher prevalence of seronegative HBV-MN than previously thought. The blood creatinine values and incidence of liver function abnormalities was higher in the serology-positive group than in the serology-negative group. Notably, the seronegative group displayed a higher positive rate of anti-PLA2R antibodies compared to the seropositive group, indicating distinctive clinical and immunopathologic features.

Anticardiolipin Antibody Plays a More Important Role Than Anti-β2-Glycoprotein I Antibody in Activating Complement in Patients with Lupus Nephritis.

This research aimed to explore the correlation between antiphospholipid antibodies (aPLs) and complement activation in lupus nephritis (LN) patients. A retrospective analysis was carried out on patients diagnosed with LN based on renal biopsy from June 2019 to June 2022. The study assessed levels of IgM, IgA, and IgG subtypes of anticardiolipin antibodies (aCLs) and anti-β2-glycoprotein I (anti-β2-GPI) antibodies. Pathological and clinical data were collected concurrently with the renal biopsy. The analysis included 76 LN patients, with 44.7% testing positive for aPLs. LN patients with positive aPLs exhibited increased hematuria, higher SLEDAI scores, reduced serum C3 and C4 levels, and more C1q deposits in the glomerulus compared to those with negative aPLs (P<0.05). Correlation analysis demonstrated the inverse relationships between IgG-aCL levels and serum C3 and C4 levels (r=-0.29, P=0.005; r=-0.24, P=0.016, respectively), as well as a positive correlation with C4 deposits in the glomerulus (r=0.20, P=0.041). This investigation suggests that aPLs, particularly IgG-aCLs, may be associated with the severity of LN and could contribute to the activation of classical complement pathways.

Fasciola hepatica infection modifies IgG1 specific immune response to foot-and-mouth disease virus induced by vaccination

Fasciola hepatica, a worldwide distributed helminth, has a robust immunoregulatory effect in the host, increasing the susceptibility to secondary infections. Foot and mouth disease (FMD) is a highly contagious acute vesicular viral disease effectively controlled by vaccination in endemic regions. Despite the evidence of immunoregulatory effects, the impact of fasciolosis on the immune response induced by FMD vaccination in cattle has never been assessed. Our objective was to evaluate whether the infection by F. hepatica in cattle influences the long-term immunity elicited by the currently used commercial FMD-inactivated vaccines. Aberdeen Angus steers negative for F. hepatica were vaccinated twice against FMD virus (FMDV) during the first 6 months of age using a commercial oil vaccine formulated with A24/Cruzeiro and O1/Campos strains. When maternal antibodies against F. hepatica were weaned (18––20 months of age) animals were divided into groups of 12 and infected or mock-infected with 500 metacercariae/animal. Individual serum samples were collected at 0-, 28-, 59-, 87- and 157-days post-infection (dpi). Indirect ELISAs were used to detect A24/Cruzeiro specific bovine IgG and IgG subtypes. The total IgG antibody levels and avidity against FMDV did not show significant differences between all the groups. The commercial vaccine induced higher IgG2 than IgG1 titers in vaccinated animals. Anti-FMDV IgG1 levels significantly decreased in the infected group at 28 dpi. In addition, the avidity of IgG1 FMDV-specific antibodies at day 28 in the infected group was reduced compared to the control. These results show that F. hepatica infection modified anamnestic responses against FMDV, reducing serum IgG1 titers and avidity. To our knowledge, this is the first report of immune-regulation of F. hepatica altering the immune response of FMD vaccines, one of the most globally used animal vaccines.

Multivalent MVA-vectored vaccine elicits EBV neutralizing antibodies in rhesus macaques that reduce EBV infection in humanized mice.

Epstein-Barr virus (EBV) is an oncogenic human herpesvirus associated with ~350,000 cases of lymphoid and epithelial malignancies every year, and is etiologically linked to infectious mononucleosis and multiple sclerosis. Despite four decades of research, no EBV vaccine candidate has yet reached licensure. Most previous vaccine attempts focused on a single viral entry glycoprotein, gp350, but recent data from clinical and pre-clinical studies, and the elucidation of viral entry mechanisms, support the inclusion of multiple entry glycoproteins in EBV vaccine design. Here we generated a modified vaccinia Ankara (MVA)-vectored EBV vaccine, MVA-EBV5-2, that targets five EBV entry glycoproteins, gp350, gB, and the gp42gHgL complex. We characterized the genetic and translational stability of the vaccine, followed by immunogenicity assessment in BALB/c mice and rhesus lymphocryptovirus-negative rhesus macaques as compared to a gp350-based MVA vaccine. Finally, we assessed the efficacy of MVA-EBV5-2-immune rhesus serum at preventing EBV infection in human CD34+ hematopoietic stem cell-reconstituted NSG mice, under two EBV challenge doses. The MVA-EBV5-2 vaccine was genetically and translationally stable over 10 viral passages as shown by genetic and protein expression analysis, and when administered to female and male BALB/c mice, elicited serum EBV-specific IgG of both IgG1 and IgG2a subtypes with neutralizing activity in vitro. In Raji B cells, this neutralizing activity outperformed that of serum from mice immunized with a monovalent MVA-vectored gp350 vaccine. Similarly, MVA-EBV5-2 elicited EBV-specific IgG in rhesus macaques that were detected in both serum and saliva of immunized animals, with serum antibodies demonstrating neutralizing activity in vitro that outperformed serum from MVA-gp350-immunized macaques. Finally, pre-treatment with serum from MVA-EBV5-2-immunized macaques resulted in fewer EBV-infected mice in the two challenge experiments than pretreatment with serum from pre-immune macaques or macaques immunized with the monovalent gp350-based vaccine. These results support the inclusion of multiple entry glycoproteins in EBV vaccine design and position our vaccine as a strong candidate for clinical translation.

Update on the outcome of M-protein screening program of multiple myeloma in China: A 7-year cohort study.

To improve the early detection rate of multiple myeloma (MM), the M-protein screening system has been performed in the hospital population at Zhongshan Hospital Fudan University since 2014, with electrophoretic-based monoclonal immunoglobulin (M-protein) screening integrated into the blood biochemistry panel. This study updated 7-year follow-up findings of MM patients diagnosed by screening-driven and symptom-driven approaches. The retrospective study compared the characteristics and outcomes of patients diagnosed through two patterns by reviewing the plasma cell disease database from January 2014 to October 2021. The screening-driven group included patients diagnosed through the screening system during workups of unrelated medical conditions or routine checkups. In contrast, patients who visited or were referred to the hematological department due to myeloma-related end-organ damage were categorized into the symptom-driven group. There were 3,110,218 serum protein electrophoresis (SPEP) tests performed during 7 years, with 1.95% (60,609) patients yielding positive SPEP results. Of 911 confirmed MM cases (excluding concurrent amyloidosis), 366 were assigned to the screening-driven group, while 545 were to the symptom-driven group. Compared to the symptom-driven group, the screening group had more IgG subtypes, earlier International Stage System stages, fewer disease-related symptoms, lower ECOG scores, less extramedullary disease, a lower percentage of bone marrow plasma cells, and a lower level of lactate dehydrogenase. Frontline response results of two groups were similar. Patients detected through screening had a significantly improved median progression-free survival (PFS) than the symptom-driven group (62.2 vs. 24.9 months, p < 0.001, HR: 2.12, 95% CIs: 1.69-2.65), with median follow-ups of 32.6 and 27.4 months. Furthermore, the median overall survival (OS) was significantly longer in patients of the screening group (not reached vs. 62.3 months, p < 0.001, HR: 2.49, 95% CIs: 1.81-3.41). After being adjusted for well-acknowledged myeloma prognostic factors, the screening-driven diagnostic pattern remained an independent prognostic factor indicating improved PFS and OS in MM patients. Routine M-protein screening for MM in the hospital population results in an earlier diagnosis and better patient outcomes.

Vdpace As Salvage Therapy in Triple Class Relapse/Refractory Multiple Myeloma

Background: Patients that have triple-class relapsed/refractory multiple myeloma (RRMM) have relapsed on each of the following classes: an immunomodulatory drugs (IMiDs), proteasome inhibitors (PI), and anti-CD38 monoclonal antibody (MoAb). RRMM poses a significant challenge with poor prognosis due to limited options. We evaluated VDPACE (bortezomib, dexamethasone, cisplatin, doxorubicin, cyclophosphamide, etoposide) for efficacy and safety as salvage therapy in heavily pre-treated RRMM. Methods: We retrospectively analyzed 54 patients who had triple-class RRMM and received at least 1 cycle of VDPACE between June 2016 - July 2023 at the University of Kansas Health System in collaboration with the U.S Myeloma Innovations Research Collaborative (USMIRC). VDPACE consisted of bortezomib 1 mg/m2 subcutaneous on days 1,4,8 and 11, doxorubicin 10 mg/m2 continuous infusion (CI) x 4 days, cisplatin 10 mg/m2 CI x 4 days, cyclophosphamide 400 mg/m2 CI x 4 days and etoposide 40 mg/m2 CI x 4 days. Descriptive analysis was performed on available data for patient characteristics, disease course, and outcomes differentiating these two groups. Adverse events were graded based on the CTCAE v5.0 criteria. Responses to therapy, including overall response rate (ORR), complete response or better (≥CR), and very good partial response (VGPR) were evaluated using the International Myeloma Working Group (IMWG) criteria. The Kaplan-Meier method was used for progression-free survival (PFS) and overall survival (OS) assessments. Results: Of the 54 patients in this study, the median age was 62 years (41-75), 81% (n=44) were Caucasian, 48% (n=26) were IgG subtype, 42% of the patients (n=23) had Stage-III disease at treatment, 74% (n=40) had high-risk cytogenetics, and extramedullary disease (EMD) was present in 50% (n=27) of patients. These patients had a median of 5 (2-10) prior lines of therapy;67% (n=36) were penta-drug exposed, 59% (n=32) were penta-RRMM and 19% (n=10) were refractory to BCMA-directory therapy. Patient characteristics are summarized in Table 1. The overall response rate (ORR) for the whole cohort was 54%, 7 (13%) patients achieved ≥ VGPR, median PFS was 4.67 months (95% CI, 2.97 to 8.40), while OS was 7.93 months (95% CI, 6.33 to 14.73), see Figure 1. Regarding efficacy on penta-RRMM (n=32) vs non-penta-RRMM subgroups (n=22), the ORR was 44% vs 68% respectively, while the median PFS was 2.67 months (95% CI, 2-7.6) in the penta-RRMM subgroup compared to 9.28 months(95% CI, 4.67-NA) in the non-penta-refractory subgroup. Treatment post salvage therapy of VDPACE included autologous/allogenic stem cell transplant (SCT), BCMA-directed therapies (CAR-T, T-cell engaging bispecific antibodies and antibody-drug conjugates), other chemotherapies, in addition to enrollment to clinical trials reported at 13%, 26%, 39% and 4%, respectively. 11% patients proceeded to hospice due to progression disease. Most patients experienced hematological adverse events (AEs), including grade III/IV lymphopenia (96%), neutropenia (93%), thrombocytopenia (87%) and anemia (76%). 69% (n=37) required a blood transfusion and 67% (n=36) required platelet transfusion. Neutropenic fever (NF) was reported in 33% (n=18), while the most common cause of infection was bacteremia in 24% of patients, followed by pneumonia in 20% of the patients. Following the initial hospitalization to receive treatment, the readmission rate within 60 days was 50% (n=27), that was mostly due to NF (52%, n=14). Treatment related mortality (TRM) in the first 30 days was reported in 6% (n=3), all due to severe sepsis. See Table 1. Conclusions: Based on our retrospective study, VDPACE is an effective salvage treatment in triple RRMM, and can be used as a bridging therapy prior to CAR-T, prior to enrollment in clinical trials or proceeding to SCT, however, due to TRM secondary to severe infections, careful selection of patients for this intensive therapy must be emphasized.

Characterization of Clonal Hematopoietic of Indeterminate Potential (CHIP) Mutations in an Imid-Naïve Multiple Myeloma (MM) Autologous Stem Cell Transplant (ASCT) Population: First Results from a Pre-Transplant Time Point in a Prospective, Longitudinal Study

Background: Clonal Hematopoiesis of Indeterminate Potential (CHIP) is defined by the acquisition of ≥ 1 somatic mutations in the blood of healthy adults, but can also be detected at higher prevalence in patients with malignancies, particularly after DNA damaging therapy. The presence of CHIP mutations in MM confers a reduced overall survival (Mouhieddine, JCO 2020) but high quality, prospective evaluation of CHIP mutation evolution over the transplant sequence, including the impact of high-dose melphalan and immunomodulatory (IMiD)-based therapy, is largely under-studied. Serial assessment of CHIP over the transplant course has been reported from the coMMpass dataset, demonstrating a 4-fold increase in mutation prevalence from 5.8% at diagnosis to 25% after 3.1 years (Mouhieddine, Blood, 2021). In this data set, most patients were exposed to prior IMiD-containing at some point during therapy. Whether the survival benefit reported with IMiD-based maintenance therapy post-transplant is associated with CHIP mutation modulation is unclear. We are therefore investigating the longitudinal evolution of CHIP in a cohort of transplant-eligible, largely IMiD-naïve patients (pts) over the pre- and post-ASCT course in an ongoing study. Here, we present preliminary findings from the pre-transplant time-point after non-IMiD-containing induction but before high-dose melphalan and ASCT. Methods: The ongoing Princess Margaret Cancer Center ARCH 001 trial is a prospective, longitudinal study evaluating evolution of CHIP in a transplant-eligible MM population. Mutation testing is performed using the highly sensitive single-molecule molecular inversion probe (SmMIP) next-generation sequencing (NGS) technique (Abelson, Bioinformatics, 2022). After sequencing with a minimum sequencing depth of 4000x, the list of mutation calls produced by smMIP-tools is subject to various filters to reduce the likelihood of false positives. Synonymous mutations, as well as any variants falling within introns or splice regions are removed. The minor allele frequency of the variant (if available) is required to be above 0.1% so as to exclude mutations that are common SNPs. VAF frequency threshold of 1-30 % is set for calling somatic mutations, with a view to minimize false positives and germ-line mutations. Multiple time points for testing pertinent to therapy include: within 1 month pre-transplant (after induction and stem cell collection), 3 months post-transplant, and two subsequent samples 12 and 24 months post-sample 2. Here we report preliminary results of CHIP mutation testing in the first 66 pts at the pre-transplant time point. Results: Patient, disease and treatment characteristics for all pts and their stratification by the presence of CHIP mutations are outlined in Table 1. The total cohort is typical for a transplant-eligible population with median age 65 years, male predominance (M 59%/F 41%), 60% IgG subtype, 23% high-risk FISH cytogenetics. Most (90%) received a non-IMiD containing induction regimen CyBorD; only 6% received an IMiD pre-ASCT. CHIP mutations were identified in 28/66 pts, for a mutation prevalence rate of 43%; 6 patients (9%) carried ≥ 1 mutation. The median age at transplant as well as other baseline demographics did not differ between those with and without mutations (Table 1). Mutation profiles are shown in Figure 1, and are consistent with those described in the literature with the most commonly mutated genes being DNMT3a, TET2, ASXL1 and PPM1D, and the mutation prevalence rate highest for DNMT3a at 21%. 6 pts (9%) had ≥ 1 mutation (range 2-3) identified, with 3 of 6 involving the DNMT3a gene. Other genes involved in patients with multiple mutations were TET2 (n=3), ASXL1 (n=2), PPM1D (n=2), SRSF2 (n=1), SF3B1 (n=1). Mean allele frequency was 4%, ranging from 1-19. Conclusion: Our results using deep SmMIP sequencing show a mutation prevalence rate of 43% in a cohort of transplant-eligible, largely IMiD-naive MM pts studied after induction. These rates are higher than those generally described in the literature, which may relate to the high sensitivity of the assay used, variation in filtering between institutions, and the deliberate use of a relatively low VAF threshold with the intent to capture clinically significant variants for longitudinal tracking during the course of this ongoing study. Further studies during lenalidomide maintenance will be forthcoming.

Significance of Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio and Monocyte-to-Lymphocyte Ratio in the Prognosis of Newly Diagnosed Multiple Myeloma Patients

Background Multiple myeloma is a cancer of the plasma cells, characterized by abnormal proliferation in the bone marrow. In 2023 about 12,590 deaths are expected to occur secondary to the disease. It is important to identify the predictors of disease progression for prognostication.Tumor microenvironment influences the growth of malignant plasma cells. Neutrophilia can enhance tumor growth, angiogenesis and provide a favorable matrix for metastasis. Lymphopenia is also suggestive of disease progression. Hence, an increased neutrophil-to-lymphocyte ratio (NLR) has been linked with a poor prognosis in many cancers. Monocytes are thought to be recruited by tumor cells for suppressing the immune cells and aiding in prolonged survival. In patients with multiple myeloma, a low platelet count is linked to a worse prognosis since a greater marrow myeloma burden leads to inhibition of thrombopoiesis.Hence, a low platelet-to-lymphocyte ratio (PLR) and high monocyte-to-lymphocyte ratio (MLR) are linked with worse prognosis.The aim of our study was to investigate the role of NLR, PLR and MLR in the prognosis of our patients. Methods This is a retrospective study that analyzed patients diagnosed with Multiple Myeloma from 2012 to 2022 at Saint Vincent Cancer Center, Worcester, Massachusetts. We performed a chart review and collected demographics including age at the time of diagnosis, gender, BMI, race. Additionally, we also collected data such as multiple myeloma type, R-ISS staging, complete blood count (cbc), chemotherapy used, auto stem cell transplant, 5-year survival. NLR, PLR and MLR were calculated based on pre-treatment cbc. Based on literature review, cutoffs for High NLR (≥2), Low NLR (&amp;lt;2), High PLR (≥120.00), low PLR (&amp;lt;120.00) and high MLR (≥0.27), and low MLR (&amp;lt;0.27) were made. SPSS was used for analysis of the data. A logistic regression was used to calculate the Odd's ratio (OR). A p value less than equal to 0.05 was considered significant. Results The total number of patients analyzed were 97. 47.4% (n=46) were females and 52.6% (n=51) were males. Mean age at diagnosis was 69.3 years. Mean BMI was 30.16 kg/m 2. 35.1% (n=34) of the patients had IgG subtype. 36.1% (n=35) of our study population belonged to R-ISS stage 2. 38.1% (n=37) of the patients were treated with lenalidomide, bortezomib, dexamethasone combination. Mean NLR was 3.4, mean PLR was 166.949 and mean MLR was 0.46. 66% (n=64) of the patients belonged to the high NLR group, 61.9% (n=60) to the high PLR group and 64.9% (n=63) to the high MLR group. Out of 97 patients, 56.7% (n=55) were alive at 5 years. High NLR (≥2) was associated with lower odds of 5-year survival with a p value of 0.037 and a 95% confidence interval (0.095-0.931). High MLR (≥0.27) was associated with lower odds of 5-year survival with a p value of 0.042 and a 95% confidence interval (0.124-0.962). PLR did not correlate with 5-year survival and was not statistically significant (p value of 0.157). Conclusions Based on our study, a high NLR (≥2) and high MLR (≥0.27) were associated with lower odds of 5-year survival. Hence NLR and MLR are independent prognostic factors in newly diagnosed multiple myeloma patients which can be economical and effective methods for early evaluation of patient prognosis.

Breast milk immune composition varies during the transition stage of lactation: characterization of immunotypes in the MAMI cohort

BackgroundBreast milk is a complex and dynamic fluid needed for infant development and protection due to its content of bioactive factors such as immunoglobulins (Igs). Most studies focus primarily on IgA, but other types of Ig and even other immune components (cytokines and adipokines) may also play significant roles in neonatal health. As a first step, we aimed to characterize the Ig profile, many cytokines, and two adipokines (leptin and adiponectin) at two sampling time points within the transitional stage, which is the least studied phase in terms of these components. The secondary objective was to identify different breast milk immunotypes in the MAMI cohort substudy, and finally, we further aimed at analyzing maternal and infant characteristics to identify influencing factors of breast milk immune composition.MethodsBreast milk samples from 75 mothers were studied between days 7 and 15 postpartum. The Igs, cytokines, and adipokine levels were determined by a multiplex approach, except for the IgA, IgM, and leptin that were evaluated by ELISA.ResultsIgA, IgM, IgE, IgG2, IL-1β, IL-5, IL-6, IL-10, and IL-17 were significantly higher on day 7 with respect to day 15. The multiple factor analysis (MFA) allowed us to identify two maternal clusters (immunotypes) depending on the breast milk immune profile evolution from day 7 to day 15, mainly due to the IgE and IgG subtypes, but not for IgA and IgM, which always presented higher levels early in time.ConclusionAll these results demonstrated the importance of the dynamics of the breast milk composition in terms of immune factors because even in the same lactation stage, a difference of 1 week has induced changes in the breast milk immune profile. Moreover, this immune profile does not evolve in the same way for all women. The dynamic compositional changes may be maternal-specific, as we observed differences in parity and exclusive breastfeeding between the two BM immunotype groups, which could potentially impact infant health.

Association between anti-cardiac autoantibodies in acute myocarditis and downstream clinical outcomes

Abstract Introduction Myocarditis is an inflammatory heart muscle disease that can result in cardiac dysfunction and arrhythmias. Its aetiology includes infectious, toxic or autoimmune causes. Myocarditis is responsible for sudden cardiac death in young adults (1) and can result in heart failure due to dilated cardiomyopathy in 20% of patients (2). The pathogenesis of myocarditis may involve immune system dysregulation leading to a cascade of inflammation and myocardial damage (3). For those patients that rapidly progress to end-stage dilated cardiomyopathy, an important dilemma is whether there is any prospect of heart function recovery. Therefore, there is an unmet need for a better understanding of key causal pathways and for developing a biological signature of disease progression. Hypothesis The progression of acute myocarditis depends on a persistent adaptive immune response against the heart, leading to ongoing inflammation, myocardial fibrosis and ultimately tissue destruction and remodelling. Aims We sought to explore anti-cardiac IgG serum levels, their temporal profile throughout follow up and their association with clinical and imaging data, in patients presenting with acute myocarditis. Methods We prospectively recruited 80 patients with a clinical diagnosis of acute myocarditis. We measured their total anti-cardiac IgG levels at admisssion, 3- and 12-months follow-up using an enzyme-linked immunosorbent assay (ELISA). We explored the association between the anti-cardiac IgG levels, cardiac MRI parameters (CMR) and clinical data. Results We detect an adaptive immune response against the heart in a subgroup of patients with acute myocarditis. 20% of patients develop high systemic titres of anti-cardiac IgG (OD threshold &amp;gt;0.65), within the first 7 days of presentation (Figure 1a). These patients continue to have persistent and significantly higher anti-cardiac IgG levels at 12 months (Figure 1b). Importantly, patients that mount a strong initial adaptive immune response against the heart, are more likely to show evidence of persistent oedema on CMR at 12 months(Figure 1c). Clinical event rates in our cohort have remained low at five-year follow-up. A small signal exists to indicate potentially higher rates of persistent symptoms (70% vs 47%), hospitalisations for heart failure (12% vs 8%) and new heart failure diagnosis (18% vs 11%), in patients that mount a strong adaptive immune response compared to those that do not. Conclusion A subset of patients with acute myocarditis develops a strong and persistent adaptive immune response against the heart. This may be associated with more myocardial oedema on cardiac MRI, persistent symptoms and higher rates of heart failure diagnoses and hospitalisations. Further work Plasma proteomics (targeted and un-targeted discovery) with validation in myocardial tissue. Analysis of CMR data with a focus on fibrosis assessment. ELISA for IgG subtypes and total IgG against myosin and troponin I.

Inadequate structural constraint on Fab approach rather than paratope elicitation limits HIV-1 MPER vaccine utility

Broadly neutralizing antibodies (bnAbs) against HIV-1 target conserved envelope (Env) epitopes to block viral replication. Here, using structural analyses, we provide evidence to explain why a vaccine targeting the membrane-proximal external region (MPER) of HIV-1 elicits antibodies with human bnAb-like paratopes paradoxically unable to bind HIV-1. Unlike in natural infection, vaccination with MPER/liposomes lacks a necessary structure-based constraint to select for antibodies with an adequate approach angle. Consequently, the resulting Abs cannot physically access the MPER crawlspace on the virion surface. By studying naturally arising Abs, we further reveal that flexibility of the human IgG3 hinge mitigates the epitope inaccessibility and additionally facilitates Env spike protein crosslinking. Our results suggest that generation of IgG3 subtype class-switched B cells is a strategy for anti-MPER bnAb induction. Moreover, the findings illustrate the need to incorporate topological features of the target epitope in immunogen design.

Monoclonal Protein Concentration and Risk of Multiple Myeloma: Is 0.5 g/DL the New 1.5?

Introduction : Monoclonal Gammopathy of Undetermined Significance (MGUS) is an asymptomatic clonal plasma cell disorder with a risk of progression to multiple myeloma (MM). To provide an accurate prognosis, monoclonal protein (M-protein) concentration has been used to assess risk of progression to myeloma. Current risk models developed from stored serum samples in a predominately white population of patients indicated a low risk of progression (less than 1% per year) in patients with M-protein of &amp;lt;1.5 g/dL. Little is known about M-protein concentration and risk of progression in patients tested during routine clinical care in a more diverse population. We assessed the outcomes of MGUS five years after diagnosis, and determined the association between baseline characteristics and the rate of progression to MM. Methods: We used data from national Veterans Health Administration system to identify patients diagnosed with MGUS from 1999-2021 and were followed from MGUS diagnosis until progression, death, or the date 7/11/2023 was reached. MGUS diagnosis and progression to MM was confirmed utilizing a natural language processing algorithm. We included patients of black and white race and those with IgG, IgA, or light chain MGUS. The exposure was M-protein concentration at MGUS diagnosis, stratified by ≤0.5, &amp;gt;0.5-≤1.0, &amp;gt;1.0-≤1.5, &amp;gt;1.5 g/dL. We plotted the cumulative incidence function curve and used a multivariable Fine-Gray sub distribution hazard model with progression at 5 years as the event of interest, and death as a competing event. Covariates included sex, race, MGUS type, age, body mass index (BMI), diabetes, renal disease, and other comorbidities summarized by Charlson Comorbidity Index at MGUS diagnosis. Results: We included 15,520 patients with MGUS. The mean age at the diagnosis was 71.1. IgG subtype was more common (83.2%) than IgA (12.7%), and light chain (4.1%). 19.6% and 39.5% of patients had renal disease and diabetes, respectively. Black veterans represented 5600 (36.1%) of the cohort. At 5 years, 26.6% of veterans with an M-protein of &amp;gt;1.5 g/dL were diagnosed with myeloma, compared to 11.7% with 1.1-1.5 g/dL, 6.9% with 0.6-1.0 g/dL, and 3.3% with ≤0.5 g/dL. In multivariable models an M-protein &amp;gt;1.5 was associated with a greater risk of progression compared to ≤0.5 (multivariable-adjusted Hazard Ratio [aHR] 9.76, 95% Confidence Interval [CI] 8.37-11.40). Overall, increasing age was shown to have lower risk of transitioning to MM at 5 years with aHR of 0.983 (95% CI 0.978-0.988). Conclusion: In this modern cohort, only an M-protein of ≤0.5 g/dL was associated with a less 1% per year risk of developing MM. Conversely, 26.6% of veterans with an M-protein level &amp;gt;1.5 g/dL developed MM at 5 years. Risk of MM in patients clinically evaluated for MGUS may be higher than previously thought and new models of MM progression should be developed.

Survival of Patients with Multiple Myeloma Treated with Bortezomib-Based Triplets and Autologous Hematopoietic Stem Cell Transplant As First Line in Latin America

Background In transplant-eligible newly diagnosed multiple myeloma (NDMM), triplet combinations including proteasome-inhibitors and immunomodulators are the backbone of induction therapy before autologous stem cell transplant (ASCT). Post-ASCT maintenance with lenalidomide is the standard of care. This approach yields deep responses and long overall survival. In Latin America (LATAM) there is scarce data about the outcome of bortezomib-based triplets and ASCT. The aim of this study was to evaluate overall survival (OS) in Latin American transplant-eligible NDMM patients induced with bortezomib-based triplets and ASCT. Methods Retrospective international multicenter cohort study. Patients older than 18 years with MM, who received bortezomib-based triplets followed by ASCT as first line, between 2010 and 2022 were analyzed. Data were collected from clinical records in a standardized report form. We analyzed clinical characteristics at diagnosis and frontline therapy outcomes. Descriptive statistics were performed. Comparisons of characteristics between groups were made using the Chi-square test, Student´s T-test and ANOVA, as appropriate. Survival analysis was performed using Kaplan-Meier curves, comparisons between groups by Log Rank method, and calculations of the risk relationships by Cox regression. Statistical analysis was performed by using IBM SPSS version 25.0. Results A total of 279 patients with NDMM were included, 124 from Argentina, 20 from Chile, 30 from Mexico, 20 from Paraguay, 43 from Peru, 33 from Uruguay, and 9 from Venezuela. Median age was 57 years (range 29-75) with a male predominance (54.8%). Most patients (58%) were treated in private centers. 56.1% were IgG subtype, 24.8% IgA and 17.3% light chain MM. According to the ISS, 69.2% were classified as ISS II or III. Bone disease was the most frequent myeloma-defining events (75.9%), followed by anemia (61.4%), renal failure (24.2%), and hypercalcemia (20.1%). Fluorescence in situ hybridation (FISH) analysis was performed in 53.4% of patients (only 41% with plasma cell sorting), del17p was the most frequent anomaly found (17.4%), followed by t(4;14) (6%), and t(14;16) (2%). The most frequently used induction regimen was cyclophosphamide-bortezomib-dexamethasone (CyBorD) (38.7%), followed by bortezomib-thalidomide-dexamethasone (VTD) (33.7%), and bortezomib-lenalidomide-dexamethasone (VRD) (27.6%). Very good partial remission (VGPR) or better was achieved in 88.3% for VRD, 81.9% for VTD, and 76.8% for CyBorD (p=0.138). Median time from diagnosis to ASCT was 261.5 days. Only 7 patients received tandem ASCT as first-line consolidation. Maintenance treatment was administered to 88.2% of patients and was based on lenalidomide, thalidomide, bortezomib, and lenalidomide+bortezomib in 67.9%, 16.3%, 8.9% and 3.3%, respectively. Treatments and responses are shown in detail in Table 1. With a median follow-up of 45 months (range 7-140), median progression-free survival (PFS) was 33 months (95% CI, 26.7 - 39.3). Median PFS according to treatment was 21 months (95% CI, 14.3 - 27.7) for VRD, 35 months (95% CI, 22.2 - 47.8) for VTD, and 36 months (95% CI, 28 - 44) for CyBorD, p=0.004. Median OS of the whole cohort was not reached (NR), and 86% at 45 months; 75 months for VRD (95% CI, 44 - 106), and NR for CyBorD and VTD (p=0.284) (Figure 1). In the multivariate analysis hypercalcemia (p=0.01) and extramedullary disease (p=0.03) were the only independent risk factors. Discussion FISH was performed only in half of our patients, and the majority without plasma cell sorting. The main used regimen was CyBorD. Although better PFS was obtained with CyBorD, no significant differences in responses or OS were found between VRD, VTD or CyBorD. The reason why VRD PFS and OS were lower merits further study. We report a high rate of maintenance treatment.

Hyposecretory Progression Pattern Indicates Inferior Survival of Multiple Myeloma

Introduction: The application of novel drugs has significantly enhanced the prognosis of patients with MM. However, most patients will inevitably experience disease progression and relapse. At progressive disease (PD), patients always exhibit distinct features characterized by varying levels of M protein and plasma cells in the bone marrow (BMPC), even in the presence of end-organ damage. Notably, a subgroup of patients initially diagnosed with secretory MM exhibits a higher proportion of BMPC but a lower level of M protein when PD, rendering identification of this subgroup challenging without conducting bone marrow evaluations, leading to many patients experiencing PD but without timely treatment. The identification and comprehension of the hyposecretion at progression remain unclear and require further investigation. Thus, in this study, we aimed to assess the impact of different patterns of disease progression according to M protein and BMPC percentage on the survival and describe the features of the subgroup. Methods: We retrospectively analyzed the baseline and progression clinical features of 268 patients in our hospital between January 1, 2013 to July 1, 2023. We classified the PD patterns into three categories based on the elevated level of M protein and clonal plasma cells in bone marrow at progression: a. hyposecretory progression (HypoP) means &amp;gt;10% increase of the absolute percentage of BMPCs but serum M-protein increase &amp;lt;5g/L (or urine M protein increase &amp;lt; 200 mg/24h) and patients with the non-secretory subtype at diagnosis were excluded.; b. extramedullary progression (EMP) means appearance of a new extramedullary lesion; c. classic progression (ClaP) means any one or more of the other PD criteria according to International Myeloma Working Group (IMWG) criteria. High burden refers to the percentage of BMPC &amp;gt; 50%. Time from the first relapse to death as overall survival (OS) after the first progression (pro-OS). Results: There were 268 patients included in the study, and according to their features of M protein and BMPC at progression, 206 (76.8%) patients were classified in the ClaP group, 39 (14.6%) patients in EMP group and 23 (8.6%) patients in HypoP group. The percentage of female in HypoP group was 52.2%, which was much higher than that in other two groups (36.5% in ClaP and 30.8% in EMP). In general, the patients with MM are predominantly of the IgG subtype. Interestingly, for patients featured by hyposecretion in progression, the M protein types were mainly IgA (47.9%) and light chain type (43.5%) ( P&amp;lt;0.001). Compared to the ClaP and EMP group, there were more patients in HypoP presenting t(11;14) (36.8% vs 16.7% vs 11.8%) and 1q21+ (70% vs 53.8% vs 53.8%) both at diagnosis and progression. And at disease progression, the proportion of patients with t(4;14) in the HypoP group was as high as 50%. Besides, in terms of clinical manifestations, HypoP patients were more likely to suffer from hypercalcemia, renal dysfunction, and lower serum M protein level and EMP experienced high level of lactate dehydrogenase (LDH) both at diagnosis and progression. The median follow-up was 67.0m (7.6-123.0m). Figure 1 demonstrates the progression-free survival (PFS), OS and pro-OS of patients with different progression patterns. Patients in ClaP and EMP groups experienced similar PFS whereas HypoP patients had significantly shorter median PFS ( P=0.003, 23.9m vs. 22.6m vs. 14.1m). We also found that patients with ClaP and HypoP feature had inferior median OS ( P=0.007, 71.4m vs. 48.0m vs. 53.9m for ClaP vs. EMP vs, HypoP) and pro-OS ( P=0.012, 34.2m vs. 17.3m vs. 23.4m for ClaP vs, EMP vs. HypoP). Then we refer to these two as non-ClaP. In the Cox-regression, multivariate analysis showed ISS-III, ASCT and non-ClaP were associated with shorter pro-OS and OS ( Figure 1). Conclusions: In conclusion, our results indicate that the hyposecretory progression pattern is a valuable indicator of inferior survival. In such cases, bone marrow testing plays a crucial role in identifying and detecting this special group. Patients presenting with EMP or HypoP features tend to have a poorer prognosis, representing unmet clinical need. Therefore, it is important to recognize these particular patients as early as possible and to intensify treatment strategies.

Salvage Transplant Versus CAR-T Cell Therapy for Relapsed Multiple Myeloma

Background: Ide-cel and cilta-cel received regulatory approval for the treatment of patients with relapsed or refractory multiple myeloma (MM) after ≥4 prior lines of therapy, and almost all eligible patients in the US and Europe have previously received at least one autologous hematopoietic cell transplant (autoHCT). Even for those who received upfront autoHCT, salvage transplant (either second autoHCT or allogeneic HCT) for patients with relapsed MM was shown to be effective and feasible. Therefore, comparing CAR-T cell therapy with salvage transplant could facilitate future selection of patients with relapsed MM, as eligibility for transplant (especially allogeneic HCT) differs significantly from that of CAR-T. Methods: We leveraged a large European dataset to identify relapsed MM patients who received either salvage autoHCT, allogeneic HCT, or CAR-T cell therapy. To minimize selection bias, we only included patients who received salvage treatment from 2018 onwards and who had documented time of relapse. Furthermore, to control for differences in patient characteristics, we applied propensity score (PS) matching for the comparison: CAR-T versus auto HCT and versus allogeneic HCT. We performed individual matching with the “nearest neighbour” method, using a caliper=0.2. The model for PS estimation included patient sex, MM classification at diagnosis, previous transplant history (single or tandem auto), interval between upfront transplant and relapse and between relapse and CAR-T/salvage transplant, age, performance status and disease status at CAR-T/salvage transplant. Endpoints of matched groups were compared by Log-Rank test or Gray test stratified on the pair. Primary endpoint was progression-free survival (PFS) at 1 year with 95% confidence interval (CI). Secondary endpoints constituted non-relapse mortality, incidence of relapse, and overall survival (OS). Results: We included 4292 patients, of whom 3858 received salvage autoHCT, 371 allogeneic HCT, and 63 CAR-T cell therapy (60% ide-cel, 33% cilta-cel, 7% other investigational). Median age at time of salvage treatment was 62 years for autoHCT, 54 years for allogeneic HCT, and 61 years for CAR-T cell therapy (P&amp;lt;0.001). More than 60% of patients were male in all groups, and IgG subtype of MM was present in 52% of autoHCT, 48% of allogeneic HCT, and 44% of CAR-T cell therapy. More patients receiving CAR-T cell therapy had a Karnofsky performance status &amp;lt;80% (41%) versus 32% of autoHCT and 29% of allogeneic HCT. In terms of response, complete response to treatment was observed in 40% for autoHCT, 63% for allogeneic HCT, and 44% for CAR-T cell therapy. Partial remission or very good partial remission was achieved 11%, 9%, and 35%, respectively (P&amp;lt;0.001). Median follow-up was 16.7 months for the entire cohort. The PS method could successfully match almost all patients for the comparison of CAR-T cell therapy versus salvage autoHCT (59 patient, respectively). The 1-year PFS for CAR-T cell therapy versus autoHCT was 68% (95% CI, 56-80%) versus 44% (95% CI, 28-59%; P=0.048; Figure 1). The 1-year non-relapse mortality was 9% (95% CI, 2-17%) versus 0% (P=0.31). Cumulative incidence of relapse at 1 year was 23% versus 57% (P=0.028), and 1-year overall survival was 81% versus 68% (P=0.059). The PS method matched 33 patients for the comparison of CAR-T cell therapy versus salvage allogeneic HCT. The 1-year PFS was 72% (95% CI, 56-88%) versus 39% (95% CI, 18-60%; P=0.346). Non-relapse mortality at 1-year was 13% (95% CI, 1-25%) versus 23% (95% CI, 7-43%; P=0.257). The 1-year cumulative incidence of relapse was 15% versus 36% (P=0.763), and the 1-year overall survival was 84% (95% CI, 71-97%) versus 60% (95% CI, 39-81%; P=0.083). Conclusion: This multicenter retrospective study compared CAR-T cell therapy with salvage transplantation strategies for relapsed MM. CAR- T cell therapy appeared to improve outcomes, especially in comparison with salvage autoHCT. The higher absolute rates of non-relapse mortality observed with CAR-T cell therapy may not counterbalance overall beneficial results, and rather highlights the need for careful selection of patients. Longer follow-up will be needed for definitive results.

Ginsenoside Rb1 enhanced immunity and altered the gut microflora in mice immunized by H1N1 influenza vaccine.

Influenza is an acute infectious respiratory disease caused by the influenza virus that seriously damages human health, and the essential way to prevent influenza is the influenza vaccine. Vaccines without adjuvants produce insufficient specific antibodies and therefore require adjuvants to boost antibody titers. Microbes and hosts are a community that needs to "promote bacteria," which could provide new value for the immune effect. (1) The H1N1 influenza vaccine, in combination with Ginsenoside Rb1, was co-injected into mice intraperitoneally (I.P.). Then, immunoglobulin G and antibody subtype levels were tested by enzyme-linked immunosorbent assay (ELISA). Moreover, mice were infected with a lethal dose of the H1N1 influenza virus (A/Michigan/45/2015), and survival status was recorded for 14 days. Lung tissues were stained by hematoxylin and eosin (H&E), and ELISA detected inflammatory factor expression levels. (2) Mice were immunized with Ginsenoside Rb1 combined with quadrivalent influenza inactivated vaccine(IIV4), and then IgG levels were measured by ELISA. (3) Fresh stool was collected for fecal 16S rDNA analysis. Ginsenoside Rb1 boosted IgG and antibody subtypes in the H1N1 influenza vaccine, improved survival of mice after virus challenge, attenuated lung histopathological damage, and reduced inflammatory cytokines expression in IL-6 and TNF-α. The results of 16S rDNA showed that Rb1 decreased species diversity but increased species richness compared to the PBS group and increased the abundance of Akkermansiaceae and Murbaculaceae at the Family and Genus levels compared with the HA+Alum group. Ginsenoside Rb1 has a boosting effect on the immune efficacy of the H1N1 influenza vaccine and is promising as a novel adjuvant to regulate the microecological balance and achieve an anti-infective effect.

Sex-Specific Immune Responses to Seasonal Influenza Vaccination in Diabetic Individuals: Implications for Vaccine Efficacy.

Seasonal influenza vaccination has different implications on the immune response depending on the comorbidities. Diabetes is one such critical disease that increases the patient's susceptibility to influenza and suppresses vaccine efficacy and immunity. The sex of the individuals also plays a definitive role in the immune responses to both the vaccine and the infection. This study aims to understand the efficacy of the seasonal vaccine against influenza in diabetic groups and undergoing immune mechanisms in different sexes (females and males). In this study, we are reporting about a switching of the immune response of the infected and vaccinated diabetic females towards stronger Th1/Th17 responses with suppressed humoral immunity. They show increased cDC1, enhanced proinflammatory activities within T cells, CD8T activation, Th17 proliferation, and the majority of IgG2 antibody subtypes with reduced neutralization potential. Males with diabetes exhibit enhanced humoral Th2-immunity than the nondiabetic group. They exhibit higher cDC2, and DEC205 levels within them with an increase in plasma B lymphocytes, higher IgG1 subtypes in plasma cells, and influenza-hemagglutinin-specific IgG titer with stronger virus neutralization potential. Males with diabetes recovered better than the females as observed from the changes in their body weight. This study highlights the critical immune mechanisms and sex-specific swapping of their preferred immune response pathways against influenza after vaccination during diabetes. We propose a need for a sex-specific customized vaccine regimen to be implemented against influenza for individuals having diabetes to exploit the manifested strength and weakness in their protective immunity.

Preliminary evaluation of immunogenicity and protective effect of multicomponent recombinant protein vaccine EPRHP014 against tuberculosis

Objective: To evaluate the immunogenicity and protective effect of a multicomponent recombinant protein vaccine EPRHP014 constructed independently and provide a scientific basis for developing new tuberculosis (TB) vaccine and effective prevention and control of TB. Methods: Three full-length Mycobacterium (M.) tuberculosis protein antigens (EsxH, Rv2628, and HspX) and two epitope-predicted and optimized epitope-dominant protein antigens (nPPE18 and nPstS1) were selected, from which five protein antigens were used to construct a protein antigen composition EPRHP014, including a fusion expression multi-component protein antigen (EPRHP014f) and a multi-component mixed protein antigen (EPRHP014m) formed with the five single protein using clone, purification, and purification respectively. Multicomponent protein vaccines EPRHP014f and EPRHP014m were prepared with aluminum adjuvant, and the BCG vaccine was used as a control. ELISA detected the titer of serum-specific antibodies, the secretion of various cytokines was detected by ELISpot and Luminex, and immune protection was observed by the M. tuberculosis growth inhibition test in vitro. The results were statistically analyzed by t-test or rank sum test, and P<0.05 was considered a statistically significant difference. Results: Mice Immunized with EPRHP014m and EPRHP014f could produce highly effective IgG antibodies and their subtypes IgG1 and IgG2a, and the antibody titers were similar to those of mice immunized with BCG, with no statistical significance (P>0.05). The number of spot-forming cells (SFC) secreting IFN-γ and IL-4 induced by EPRHP014f group was significantly higher than those by EPRHP014m group and BCG group (P<0.05), but there was no significant difference in the number of SFC for IFN-γ and IL-4 induced between EPRHP014m group and BCG group (P>0.05). The secretion levels of GM-CSF and IL-12p70 induced by the EPRHP014m group were higher than those of the BCG group (P<0.05), but there was no significant difference in the levels of IL-6 and IL-10 induced between EPRHP014m group and BCG group (P>0.05). There was no significant difference in the secretions of IL-6, IL-10, IL-12, and GM-CSF between the EPRHP014f and BCG groups (P>0.05). EPRHP014m group, EPRHP014f group, and BCG group had obvious antibacterial effects in vitro, and the difference was insignificant (P>0.05). Conclusion: Both EPRHP014f and EPRHP014m can induce strong humoral and cellular immune responses in mice after immunization, and have a strong ability to inhibit the growth of M. tuberculosis in vitro, indicating that the antigen composition EPRHP014 has good potential in the development and application of TB vaccine.

Role of complement in myasthenia gravis.

Myasthenia gravis is a prototypic neuroimmune disorder with autoantibodies targeting the acetylcholine receptor complex at the neuromuscular junction. Patients present with mainly ocular muscle weakness and tend to have a generalized muscle weakness later in the clinical course. The weakness can be severe and fatal when bulbar muscles are heavily involved. Acetylcholine receptor antibodies are present in the majority of patients and are of IgG1 and IgG3 subtypes which can activate the complement system. The complement involvement plays a major role in the neuromuscular junction damage and the supporting evidence in the literature is described in this article. Complement therapies were initially studied and approved for paroxysmal nocturnal hemoglobinuria and in the past decade, those have also been studied in myasthenia gravis. The currently available randomized control trial and real-world data on the efficacy and safety of the approved and investigational complement therapies are summarized in this review.