Low IgG Levels Research Articles

High Respiratory Tract Infection Rate in Patients With Familial Mediterranean Fever.

Background Familial Mediterranean fever (FMF) is a systemic autoinflammatory disease genetically transmitted with the autosomal recessive trait. Although the pathogenesis is not certain, it is known that there is a deficiency in the regulation of the natural immune system. In this study, we aimed to search whether patients with FMF are predisposed to respiratory tract infections and whether mannose-binding lectin (MBL), as a natural immune system member, contributes to it. Methods Fifty FMF patients and 20 control groups were enrolled in the study. First, the frequencies of upper respiratory tract infection (URTI) within the previous year of both patient and control groups were evaluated retrospectively. Then, both groups were followed up for URTI for one year after starting the study. The patient's immunoglobulin A (IgA), IgM, IgG, C-reactive protein (CRP), hemogram parameters, and mannose-binding lectin were evaluated. Results The median frequency of annual URTI with a retrospective evaluation of patients was higher than that of the control group. Also, the median frequency of URTI with the prospective evaluation of patients with FMF was higher than the control group.The rate of patients with low serum IgG levels was higher in the patient group than in the control group. However, serum IgG levels of FMF patients with frequent URTI were not different from those without. The median MBL levels of both groups were similar (1312 vs. 1534 ng/mlfor the patient and control group, respectively). The rate of patients having low serum MBL levels was also similar between the groups. Conclusions In the present study, we found that patients with FMF had more URTI than healthy controls. However, the underlying cause is not fully explained. There is a need for further studies with a higher number of patients evaluating URTI in patients with FMF.

Factors influencing the immune response over 15 months after SARS-CoV-2 infection: A longitudinal population-wide study in the Faroe Islands.

BackgroundThe durability of SARS‐CoV‐2 antibody response and the resulting immunity to COVID‐19 is unclear.ObjectivesTo investigate long‐term humoral immunity to SARS‐CoV‐2.MethodsIn this nationwide, longitudinal study, we determined antibody response in 411 patients aged 0–93 years from two waves of infections (March to December 2020) contributing 1063 blood samples. Each individual had blood drawn on 4–5 occasions 1–15 months after disease onset. We measured total anti‐SARS‐CoV‐2 receptor‐binding domain (RBD) antibody using a qualitative RBD sandwich ELISA, IgM, IgG and IgA levels using an quantitative in‐house ELISA‐based assay and neutralizing antibodies (NAbs) using an in‐house ELISA‐based pseudoneutralizing assay. IgG subclasses were analyzed in a subset of samples by ELISA‐based assay. We used nonlinear models to study the durability of SARS‐CoV‐2 antibody responses and its influence over time.ResultsAfter 15 months, 94% still had detectable circulating antibodies, mainly the IgG isotype, and 92% had detectable NAbs. The distribution of IgG antibodies varied significantly over time, characterized by a biphasic pattern with an initial decline followed by a plateau after approximately 7 months. However, the NAbs remained relatively stable throughout the period. The strength of the antibody response was influenced by smoking and hospitalization, with lower IgG levels in smokers and higher levels in hospitalized individuals. Antibody stability over time was mainly associated with male sex and older age with higher initial levels but more marked decrease.ConclusionsThe humoral immune response to SARS‐CoV‐2 infection varies depending on behavioral factors and disease severity, and antibody stability over 15 months was associated with sex and age.

Exploring the microbial composition of Holstein Friesian and Belgian Blue colostrum in relation to the transfer of passive immunity.

For centuries, multicellular organisms have lived in symbiosis with microorganisms. The interaction with microorganisms has been shown to be very beneficial for humans and animals. During a natural birth, the initial inoculation with bacteria occurs when the neonate passes through the birth canal. Colostrum and milk intake are associated with the acquisition of a healthy gut flora. However, little is known about the microbial composition of bovine colostrum and the possible beneficial effects for the neonatal calf. In this prospective cohort study, the microbial composition of first-milking colostrum was analyzed in 62 Holstein Friesian (HF) and 46 Belgian Blue (BB) cows by performing amplicon sequencing of the bacterial V3-V4 region of the 16S rRNA gene. Calves received, 3 times, 2 L of their dam's colostrum within 24 h after birth. Associations between colostral microbial composition and its IgG concentration, as well as each calf's serum IgG levels, were analyzed. Colostrum samples were dominated by the phyla Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria. The 10 most abundant genera in the complete data set were Acinetobacter (16.2%), Pseudomonas (15.1%), a genus belonging to the Enterobacteriaceae family (4.9%), Lactococcus (4.0%), Chryseobacterium (3.9%), Staphylococcus (3.6%), Proteus (1.9%), Streptococcus (1.8%), Enterococcus (1.7%), and Enhydrobacter (1.5%). The remaining genera (other than these top 10) accounted for 36.5% of the counts, and another 8.7% were unidentified. Bacterial diversity differed significantly between HF and BB samples. Within each breed, several genera were found to be differentially abundant between colostrum of different quality. Moreover, in HF, the bacterial composition of colostrum leading to low serum IgG levels in the calf differed from that of colostrum leading to high serum IgG levels. Results of the present study indicate that the microbes present in colostrum are associated with transfer of passive immunity in neonatal calves.

Diagnosis of Oestrus ovis infestation in sheep by PCR and enzyme-linked immunosorbent assay

The aim of this study was to assess the suitability of PCR and ELISA as diagnostic method in young sheep naturally infested by Oestrus ovis larvae. The experiment was carried out from December 2020 to April 2021 with 39 lambs divided into two groups: infested (n = 26) and control treated group (n = 13). The infested group did not receive treatment against oestrosis, and the control group was treated with closantel (10 mg/kg orally) every 28 days in order to keep the animals as free as possible of O. ovis infestation. The clinical signs varied among animals regardless of the number of recovered larvae of each lamb, however, the thick mucus and mucopurulent nasal discharge scores were less frequent in lambs from treated group. There was no correlation between the nasal discharge score and the number of O. ovis recovered larvae (R² = 0.012, P = 0.165). Three control treated animals only presented first instar larvae (L1) (1 – 4 larvae/animal) which were smaller than L1 found in the lambs of the infested group. Ninety-two percent of the lambs from infested group (24/26) were parasitized by O. ovis with number ranging from 1 to 54 larvae per animal. A gradual increase in plasma IgG (anti-antigen of O. ovis larvae) levels of animals from infested group after the third week of the trial was observed, whereas the control lambs had low levels of IgG until the end of the experiment. The PCR had low sensitivity (26 %) and high specificity (100 %), and it presented poor agreement (k = 0.177) with the larvae detection after the lamb slaughter. The oestrosis clinical signs were not related to larvae infestation intensity and ELISA showed a greater advantage over the PCR technique in identifying animals that are carrying O. ovis.

Three-month follow-up of durability of response to the third dose of the SARS-CoV-2 BNT162b2 vaccine in adults aged 60 years and older: a prospective cohort study

ObjectiveTo evaluate the durability of response 3 months after the third BNT162b2 vaccine in adults aged 60 years and older.DesignProspective cohort study.SettingSingle tertiary centre.ParticipantsHealthcare workers/family members aged ≥60 years old...

Common Variable Immune Deficiency: An Outpatient Experience

Common variable immunodeficiency (CVID) is one of the most common primary immunodeficiencies encountered by physicians, yet it is still poorly described and vastly underdiagnosed and underreported. It is characterized by low levels of immunoglobulins IgG, IgM, and IgA, recurrent infections, and an increased incidence of autoimmune conditions and malignancies. Diverse clinical presentation, poor understanding of its true prevalence, and the daunting, rarely ordered, diagnostic testing make this disease incredibly difficult to diagnose in a primary care setting. Our objectives in this study were to establish a simple marker that can be used in a primary care setting to raise suspicion of CVID and prompt further diagnostic testing and to demonstrate that the true prevalence of CVID is much higher than previously reported. Data on 441 patients who underwent Ig electrophoresis testing during a 4-year period were analyzed retrospectively for the presence of hypogammaglobulinemia and number of clinic visits for infectious processes. The average number of clinic visits before testing in patients with no identified antibody deficiency was 1.89 and in patients with any deficiency 2.22. The odds ratio for each additional visit was 1.089, which was not statistically significant (P = 0.103). When the data were recoded to be capped at 6 clinic visits, the odds ratio for each visit up to 6 was 1.119, which was marginally significant (P = 0.058). Patients with Ig deficiencies tend to have a higher number of office visits related to infectious processes. This difference, however, was not statistically significant in our study, likely because of the small number of participants. Our study also demonstrated that the prevalence of CVID is likely much higher than currently reported, and it highlights the difficulties related to the convoluted diagnostic process of this disease.

Supplementary Role of Immunological Indicators in the Diagnosis and Prognosis of Pneumocystis Pneumonia in Non-HIV Immunocompromised Patients.

BackgroundPneumocystis pneumonia (PCP) has a high mortality in HIV-negative immunocompromised patients. The occurrence and development of PCP are believed to be correlated with the level of lymphocytes and their subsets. The aim of this study was to determine if the levels of lymphocyte subpopulations and immunoglobulin are associated with PCP.MethodsA total of 74 immunocompromised patients were enrolled in this single-center cohort study. Diagnosis of PCP was based on the relevant pulmonary symptoms and radiological imaging, and the detection of Pneumocystis jirovecii in BAL fluid or biopsy tissue by metagenomic next-generation sequencing (mNGS). All patients were divided into two groups (PCP group and non-PCP group) and the patients in PCP group were then divided into two groupsbased on the outcome of the disease during the hospitalization.ResultsWe observed a significant lower level of IgG (p=0.000) and B lymphocyte counts (p=0.017) in the PCP group comparing to that in the non-PCP group. CD4+ T cell counts, as well as the ratio of CD4+/CD8+ T cells in circulation and BAL fluid were also lower in the PCP group comparing to those in the non-PCP group. Lactate dehydrogenase (LDH) in the PCP group was significantly higher than that in the non-PCP group (p=0.029). In the PCP group, a lower level of total lymphocytes (p=0.004), T cells (p=0.001), CD4+ cells (p=0.001), and CD8+ cells (p=0.007), as well as the proportion of lymphocytes in BAL fluid (p=0.000) were found in deceased patients comparing to those in the survived group.ConclusionOur study revealed an important role of humoral immunity in the infection of Pneumocystis jirovecii. The level of B cells and IgG could be used as a supplement to predict the occurrence of PCP. The level of CD4+ and CD8+ lymphocytes was significantly correlated with the outcome of PCP.

Neutralizing antibody responses against SARS-CoV-2 in patients with plasma cell disorders who are on active treatment after two doses of mRNA vaccination.

Many patients with plasma cell disorder (PCD) on active treatment with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) require hospitalization, with an increased mortality rate over healthy adults. The FDA approved two mRNA vaccines against SARS‐CoV‐2: BNT162b2 and mRNA‐1273. To assess the efficacy of vaccination in patients with PCD, retrospectively, we identified all patients on active treatment. A total of 149 patients were included. Neutralizing antibodies (NAbs) levels against SARS‐CoV‐2 adequate, intermediate, and no response were observed in 42%, 32%, and 26%, respectively. Low NAbs were seen in patients on daratumumab combinations or anti‐BCMA therapy, low lymphocytes, and low IgG levels. Twenty‐three (15%) patients have SARS CoV‐2, while 8% required hospitalization, majority of these patients had intermediate or no response based on NAbs levels. Therefore, checking NAbs may be clinically helpful in identifying patients' responses. Further prospective studies should ascertain the value of a third vaccine dose in this population.

Detection of SARS-CoV-2 Specific Antibodies in Saliva Samples.

Molecular assays on nasopharyngeal swabs act as a confirmatory test in coronavirus disease (COVID-19) diagnosis. However, the technical requirements of nasopharyngeal sampling and molecular assays limit the testing capabilities. Recent studies suggest the use of saliva for the COVID-19 diagnostic test. In this study, 44 patients diagnosed with COVID-19 in The Third People’s Hospital of Shenzhen were enrolled. Saliva and serum specimens were obtained at different time points and the immunoglobulins against SARS-CoV-2 were measured. The results showed that saliva IgA presented a higher COI value than IgG and IgM. In matched saliva and serum samples, all saliva samples presented lower IgG levels than serum samples, and only one saliva sample presented a higher IgM level. The conversion rates of saliva IgA and the detection of viral nucleic acids were analyzed in the first and second weeks after hospitalization. The positive rates increased when combining saliva IgA and viral nucleic acid detection. In conclusion, our results provide evidence that saliva IgA could serve as a useful index for the early diagnosis of COVID-19.

Research note: effects of different anticoccidial regimens on the growth performance, hematological parameters, immune response, and intestinal coccidial lesion scores of yellow-feathered broilers

Yellow-feathered broiler chickens generally have a longer growth cycle than white broilers and therefore face different coccidiosis challenges. General single vaccine and drug regimens struggle to prevent coccidiosis for yellow broilers. In this study, a single vaccine, and a combination of coccidiostat regimens was employed to explore the preventative and control effects of different pilot regimens on coccidiosis in yellow-feathered broilers. A total of 2,000 one day old Chinese Huang Youma female broilers were allocated into 4 experimental groups, each with 5 replicates. All birds were fed the same starter feed from Days 1 to 25, and all groups were inoculated with a vaccine on Day 4. After Day 26, the groups were then fed as follows: (1) Negative control group: basal diet + vaccine (NC); (2) NC + maduramycin (NCMD); (3) NC + narasin (NCNR); and (4) NC + salinomycin (NCSL). From Days 26 to 75, the NCNR group had a lower FCR than the other groups. The 75-d BW was higher in the NCNR group than in the NCSL group but was not significantly higher than that in the NC and NCMD groups. The growth performance followed the same trend during the whole experiment (Days 1–75). Compared to the NC group, the NCNR and NCSL groups had higher intestinal mucosa SIgA concentrations at Day 40 and Day 60 (P < 0.001); however the NCMD group had lower IgG levels at Day 40 and Day 60 (P = 0.036, P = 0.006 respectively). The combination groups had significantly reduced AKP levels and urine acid concentrations at Day 60 in comparison to those of the NC group (P = 0.004). The NCNR and NCMD groups had less severe intestinal coccidiosis lesion scores than the NC and NCSL groups in older birds. Thus, a single vaccine and/or combinations with different coccidiostats had different effects on broilers. The NCNR group showed comparatively better growth performance, blood biochemical indices, immune response, and coccidiosis lesion scores.

Vaccination with BNT162b2 and ChAdOx1 nCoV-19 Induces Cross-Reactive Anti-RBD IgG against SARS-CoV-2 Variants including Omicron.

SARS-CoV-2 variants of concern (VOCs) have caused a significant increase in infections worldwide. Despite high vaccination rates in industrialized countries, the fourth VOC, Omicron, has outpaced the Delta variant and is causing breakthrough infections in individuals with two booster vaccinations. While the magnitude of morbidity and lethality is lower in Omicron, the infection rate and global spread are rapid. Using a specific IgG multipanel-ELISA with the spike protein’s receptor-binding domain (RBD) from recombinant Alpha, Gamma, Delta, and Omicron variants, sera from health-care workers from the Medical University of Vienna were tested pre-pandemic and post-vaccination (BNT162b2; ChAdOx1 nCoV-19). The cohort was continuously monitored by SARS-CoV-2 testing and commercial nucleocapsid IgG ELISA. RBD IgG ELISA showed significantly lower reactivity against the Omicron-RBD compared to the Alpha variant in all individuals (p < 0.001). IgG levels were independent of sex, but were significantly higher in BNT162b2 recipients <45 years of age for Alpha, Gamma, and Delta (p < 0.001; p = 0.040; p = 0.004, respectively). Pre-pandemic cross-reactive anti-Omicron IgG was detected in 31 individuals and was increased 8.78-fold after vaccination, regardless of vaccine type. The low anti-RBD Omicron IgG level could explain the breakthrough infections and their presence could also contribute to a milder COVID-19 course by cross-reactivity and broadening the adaptive immunity.

Comparison of BNT162b2-, mRNA-1273- and Ad26.COV2.S-Elicited IgG and Neutralizing Titers against SARS-CoV-2 and Its Variants.

Because the vaccine-elicited antibody and neutralizing activity against spike protein of SARS-CoV-2 are associated with protection from COVID-19, it is important to determine the levels of specific IgG and neutralization titers against SARS-CoV-2 elicited by the vaccines. While three widely used vaccine brands (Pfizer-BNT162b2, Moderna-mRNA-1273 and Johnson-Ad26.COV2.S) are effective in preventing SARS-CoV-2 infection and alleviating COVID-19 illness, they have different efficacy against COVID-19. It is unclear whether the differences are due to varying ability of the vaccines to elicit a specific IgG antibody response and neutralization activity against spike protein of the virus. In this study, we compared the plasma IgG and neutralization titers against spike proteins of wild-type SARS-CoV-2 and eight variants in healthy subjects who received the mRNA-1273, BNT162b2 or Ad26.COV2.S vaccine. We demonstrated that subjects vaccinated with Ad26.COV2.S vaccine had significantly lower levels of IgG and neutralizing titers as compared to those who received the mRNA vaccines. While the linear regression analysis showed a positive correlation between IgG levels and neutralizing activities against SARS-CoV-2 WT and the variants, there was an overall reduction in neutralizing titers against the variants in subjects across the three groups. These findings suggest that people who received one dose of Ad26.COV2.S vaccine have a more limited IgG response and lower neutralization activity against SARS-CoV-2 WT and its variants than recipients of the mRNA vaccines. Thus, monitoring the plasma or serum levels of anti-SARS-CoV-2 spike IgG titer and neutralization activity is necessary for the selection of suitable vaccines, vaccine dosage and regimens.

Clinical Efficacy of Gandakang Tablets plus Methylprednisolone in Patients with Systemic Lupus Erythematosus.

Objective To evaluate the clinical efficacy of Gandakang tablets plus methylprednisolone in patients with systemic lupus erythematosus (SLE). Methods From February 2015 to February 2019, 60 eligible patients with SLE were recruited and assigned via the random number table method at a ratio of 1 : 1 to receive either methylprednisolone (control group) or Gandakang tablets plus methylprednisolone (observation group). The primary endpoint was clinical efficacy, and the secondary endpoints included Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score, immunoglobulin (Ig), inflammatory factor levels, and adverse events. Results Gandakang tablets plus methylprednisolone were associated with a significantly higher treatment efficacy versus methylprednisolone alone (P < 0.05). Gandakang tablets plus methylprednisolone resulted in significantly lower SLEDAI scores and lower levels of IgG, IgM, IgA, tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4), and interleukin-6 (IL-6) versus single medication of methylprednisolone (P < 0.05). The two groups showed a similar incidence of adverse events (P > 0.05). Patients given Gandakang tablets plus methylprednisolone had higher mental health, emotional role, physical role, social functioning, and bodily pain scores versus those receiving the monotherapy of methylprednisolone (P < 0.05). Conclusion Gandakang tablets plus methylprednisolone is effective in the treatment of SLE by enhancing the patients' immunity, mitigating the inflammatory response, eliminating negative emotions, and improving their quality of life.

Transient low IgG4 levels cause recurrent wheezing requiring multiple hospitalizations in infancy.

To investigate whether the immunoglobulin G (IgG4) subclass is associated with recurrent wheezing and/or asthma in infants. From April 2015 to March 2016, 77 infants under 3 years old who attended our hospital were enrolled in four groups (Group 1, controls; Group 2, infants with recurrent wheezing and multiple hospitalizations despite starting inhaled corticosteroids [ICS]; Group 3, infants with recurrent wheezing and without hospitalization after starting ICS; Group 4, allergic infants without wheezing). The relationship between IgG subclasses, especially IgG4, and recurrent wheezing resistant to ICS and requiring multiple hospitalizations in infants was examined. The serum IgG, IgM, IgA, IgG1, IgG2, and IgG3 levels did not differ significantly among the four groups. The IgG4 level in Group 2 infants (3.1 ± 0.2 mg/dl) was significantly lower than in Groups 1,3, and 4 (9.9 ± 8.0, 8.4 ± 6.1, and 23.4 ± 18.0 mg/dl). Of the 16 infants in Group 2, 10 could be followed to age 6 years. Nine of them had no recurrent wheezing at 6 years without medication. In addition, their IgG4 levels at age 6 years (16.1 ± 7.1 mg/dl) were significantly increased from those in infancy (3.0 ± 0.1 mg/dl). A transient low IgG4 level in infancy might cause recurrent wheezing and/or asthmatic symptoms in infants, and it may be one of the types of early transient wheezing.

Bronchial inflammation biomarker patterns link humoral immunodeficiency with bronchiectasis-related small airway dysfunction.

The progression of chronic destructive lung disease in patients with humoral immunodeficiency (ID) and concomitant development of bronchiectasis is difficult to prevent. Lung function tests in these patients typically show bronchial obstruction of the small airways in combination with increased air trapping in the distal airways, which is consistent with small airway dysfunction. The objective was to assess the grade of chronic lower airway inflammation and small airway dysfunction from induced sputum and the corresponding local pro-inflammatory mediator pattern to discriminate patients affected by bronchiectasis-related Small Airway Dysfunction (SAD). In a prospective design, 22 patients with ID (14 CVID, 3 XLA, 3hyper-IgM syndrome, 1hyper-IgE syndrome and low IgG levels due to treatment with rituximab and 1 SCID after BMT and persistent humoral defect) and 21healthy controls were examined. Lung function, Fraction Expiratory Nitric Oxide (FeNO) and pro-inflammatory cytokine levels were compared in subsets of patients with (ID+BE) and without bronchiectasis (ID) pre-stratified using high-resolution computed tomography (HRCT) scans and control subjects. Analysis of induced sputum showed significantly increased total cell counts and severe neutrophilic inflammation in ID. The concomitant SAD revealed higher total cell numbers compared to ID. Bronchial inflammation in ID is clearly mirrored by pro-inflammatory mediators IL-1β, IL-6 and CXCL-8, whilst TNF-α revealed a correlation with lung function parameters altered in the context of bronchiectasis-related Small Airway Dysfunction. In spite of immunoglobulin substitution, bronchial inflammation was dominated by neutrophils and was highly increased in patients with ID+BE. Notably, the pro-inflammatory cytokines in patients with ID were significantly increased in induced sputum. The context-dependent cytokine pattern in relation to the presence of concomitant bronchiectasis associated with SAD in ID patients could be helpful in delimiting ID patient subgroups and individualizing therapeutic approaches.

Immunoglobulin G passive transfer from mothers to infants: total IgG, IgG subclasses and specific antipneumococcal IgG in 6-week Malawian infants exposed or unexposed to HIV

BackgroundThe impaired transplacental passage of IgG from mothers living with HIV to their infants could be one of the causes of the high vulnerability to infections of HIV-exposed uninfected (HEU) infants, but controversial results have been obtained in different settings. The aim of this study was to assess in 6-week old HEU and HIV-unexposed, uninfected (HUU) Malawian infants the total IgG levels, the subclasses profile and the concentrations of global anti-pneumococcal capsular polysaccharide (anti-PCP) IgG and IgG2.MethodsDried blood spots were collected from 80 infants (40 HEU, 40 HUU) and antibodies concentrations determined by nephelometric method (total IgG and subclasses), or using ELISA (anti-PCP total IgG and IgG2). Results are expressed as median levels with IQR, while the proportions of each subclass out of the total IgG are used to describe the subclasses profile.ResultsAt 6 weeks HEU infants had higher median levels of total IgG and IgG1 and a significantly lower level of IgG2 [0.376 (0.344–0.523) g/l vs 0.485 (0.374–0.781) g/l, p = 0.037] compared to the HUU counterparts. The IgG subclasses distribution confirmed the underrepresentation of IgG2 (IgG2 represented 5.82% of total IgG in HEU and 8.87% in HUU). The anti-PCP IgG and IgG2 levels were significantly lower in HEU infants [8.9 (5.4–15.1) mg/l vs 16.2 (9.61–25.8) mg/l in HUU, p < 0.001, and 2.69 (1.90–4.29) mg/l vs 4.47 (2.96–5.71) mg/l in HUU, p = 0.001, respectively].ConclusionCompared to HUU infants, HEU infants have IgG abnormalities mainly represented by low IgG2 levels, suggesting that despite maternal antiretroviral therapy, the mechanisms of IgG transplacental passage continue to be impaired in women living with HIV. HEU infants also showed a significantly lower level of specific anti-PCP IgG, possibly favouring a high vulnerability to S. pneumoniae infection at an age when protection is mostly depending on maternal IgG.

Intravenous Immunoglobulin is Associated with Lower Rates of Reinfection in Solid Organ Recipients with Infection and Secondary Antibody Deficiency: A Multicenter Randomized Clinical Trial

<h3>Purpose</h3> In a multicenter randomized clinical trial we evaluated the safety and efficacy of an intravenous immunoglobulin (IVIG) protocol to decrease the rate of reinfection in solid organ recipients with severe infections and secondary antibody deficiency. <h3>Methods</h3> Distribution: Heart 20, Lung 15, Kidney 5, Liver transplantation 4 were randomized. Patients with post transplant severe infections and secondary antibody deficiency (defined as IgG < 600 mg/dL) were included. IVIG protocol: Two doses of 15 grams (interval between doses 7-15 days) followed by another 3 doses of 20 grams (interval between doses 15-30 days) of a 5% IVIG product. 39 patients that completed the protocol were analysed [IVIG in combination with conventional antimicrobial therapy (n=21) versus conventional antimicrobial therapy alone (n=18)]. Specific antibodies were tested at inclusion in the clinical trial (V1) and 30-45 days after last IVIG dose (last-visit, V7) in a subgroup of patients to assess the kinetics of humoral immunity reconstitution. <h3>Results</h3> The primary outcome measure (rate of reinfection) was significantly lower in patients randomized to receive IVIG as compared with patients receiving only conventional antimicrobial therapy (28.6 vs 66.7%, chi-square test, p=0.017). Mean number of reinfections tended to be lower in IVIG group (0.47, interval 1-3, versus 0.89, interval 1-4, Mann-Whitney test, p=0.056). IVIG recipients tended to have lower IgG levels in V1 but disclosed significantly higher IgG concentrations at distinct visits during follow-up. Significantly higher levels of specific IgG anti-cytomegalovirus, IgG anti-clostridium difficile toxins A and B and IgG1 anti-tetanus toxoid antibodies was demonstrated at V7 in patients who received IVIG as compared with patient that were treated with antimicrobial therapy alone. A significant decrease of serum IL6 and BAFF levels (V1 versus V7) was demostrated in IVIG treated patients. IVIG infusions were well tolerated. <h3>Conclusion</h3> In a multicenter randomized clinical trial we have demonstrated that IVIG is associated with a lower rate of reinfection in solid organ transplantation with severe infection and secondary IgG hypogammaglobulinemia.

Outcomes of blinatumomab based therapy in children with relapsed, persistent, or refractory acute lymphoblastic leukemia: a multicenter study focusing on predictors of response and post-treatment immunoglobulin production

The management of Refractory/Relapsed B-cell Acute Lymphoblastic Leukemia (R/R ALL) remains challenging. Incorporating blinatumomab in R/R ALL treatment has shown encouraging results. We describe the outcome and predictors of response in children receiving blinatumomab as a bridge to definitive therapy. Immunoglobulin (Ig) G and viral serology before and after therapy were evaluated. Thirty-three patients that failed standard first-line treatments due to relapsed ALL (n = 22), persistent minimal residual disease (MRD) (n = 8), or refractory disease (n = 3) received blinatumomab. Grade 2 toxicity occurred in 27.2% of patients. MRD remission (<0.01%) was achieved in 72.7% of patients. Pre-blinatumomab absolute lymphocyte count (ALC) and MRD/ALC ratio significantly associated with MRD-response. Patients with t(1;19) translocation had lower response rate, compared to all other cytogenetic categories (p = 0.013). One-year event-free survival (EFS) and overall survival (OS) were 69.2% and 79.7%, respectively. Analysis of OS and EFS showed pre-blinatumomab MRD level, ALC, MRD/ALC ratio, t(1;19), and post-blinatumomab MRD remission associated with survival. Following blinatumomab, 83% (15/18) of tested patients had low IgG levels. IgG seronegative status was observed in 83% (12/15) for varicella zoster, 35% (6/17) for herpes zoster, 18% (3/17) for cytomegalovirus, and 26% (5/17) for Epstein Barr virus. Blinatumomab produced encouraging results in children with R/R ALL and low disease burden bridging to definitive therapy. Incorporating baseline genetics and biomarkers may help identify subgroups likely to be responsive/resistant to therapy. Viral serological testing pre- and post-blinatumomab is recommended to optimize supportive and preemptive therapy. Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2022.2049936 .

Anti-SARS-CoV-2 antibody decay after vaccination and immunogenicity of the booster dose of the BNT162b2 mRNA vaccine in patients with psoriatic arthritis on TNF inhibitors.

Scanty data on the anti- SARS-CoV-2 IgG level decay after two-dose BNT162b2 vaccination have been published in patients with psoriatic arthritis (PsA) on TNF inhibitors (TNFi). Similarly, no reports on the immunogenicity of a booster dose in such patients have been provided yet.We aimed to investigate the IgG level decay after two-dose BNT162b2 vaccination and the immunogenicity and safety of the booster dose in PsA patients on TNFi. Forty patients with classified PsA on TNFi undergoing booster dose with the BNT162b2 mRNA SARS- CoV-2 vaccine (BioNTech/Pfizer) were enrolled. Fifteen days after the third shot, serum IgG levels against SARS-CoV-2 (Abbott®ARCHITECT i2000SR, positivity cut-off 50 AU/mL) were assayed in all patients. Clinimetrics and treatment data were gathered. TNFi treatment was not discontinued. Sera from healthcare professionals were considered as healthy controls for 1:1 propensity score-matching. Student's t-test and logistic regression were used for investigating differences in immunogenicity between groups and predictors of antibody response. Even though the decay of IgG levels showed similar magnitude between groups, PsA patients had a lower IgG level than matched controls at 4 months after two-dose vaccination (2009.22±4050.22 vs. 6206.59±4968.33 AU/mL, respectively p=0.0006). Booster dose restored IgG levels to a similar extent in both groups (15846.47±12876.48 vs. 20374.46±12797.08 AU/ml p=0.20, respectively). Clinical Disease Activity Index (CDAI) did not change before and after vaccination (6.68±4.38 vs. 4.95±4.20, p=0.19). A BNT162b2 booster dose should be recommended in PsA patients on TNFi as its administration restores anti-SARS-CoV-2 IgG levels similar to healthy individuals.

Pediatric Prediction Model for Low Immunoglobulin G Level Based on Serum Globulin and Illness Status.

Hypogammaglobulinemia is a condition that requires prompt diagnosis and treatment. Unfortunately, serum immunoglobulin (Ig) measurements are not widely accessible in numerous developing countries. Serum globulin is potentially the best candidate for screening of low IgG level (IgGLo) due to its high availability, low cost, and rapid turnover time. However, multiple factors may influence the probability of prediction. Our study aimed to establish a simple prediction model using serum globulin to predict the likelihood of IgGLo in children. For retrospective data of patients who were suspected of having IgGLo, both serum IgG and globulin were simultaneously collected and measured. Potential factors interfering with serum globulin and IgG levels were investigated for their impact using bivariate binary logistic regression. A multivariate binary logistic regression was used to generate a formula and score to predict IgGLo. We obtained 953 samples from 143 pediatric patients. A strong positive correlation between serum globulin and IgG levels was observed (r=0.83, p < 0.001). A screening test model using serum globulin and illness status was constructed to predict IgGLo. The formula for predicting IgGLo was generated as follows; Predicted score = (2 x globulin (g/dl)) – illness condition score (well=0, sick=1). When the score was <4, the patient has the probability of having IgGLo with a sensitivity of 0.78 (0.71, 0.84), a specificity of 0.71 (0.68, 0.74), PPV of 0.34 (0.29, 0.40) and NPV of 0.94 (0.92, 0.96). This formula will be useful as rapid and inexpensive screening tool for early IgGLo detection, particularly in countries/locations where serum IgG measurement is inaccessible.