Natural Killer Cell Counts Research Articles

Sphingosine phosphate lyase insufficiency syndrome as a primary immunodeficiency state

Sphingosine phosphate lyase insufficiency syndrome (SPLIS) is a genetic disease associated with renal, endocrine, neurological, skin and immune defects. SPLIS is caused by inactivating mutations in SGPL1, which encodes sphingosine phosphate lyase (SPL). SPL catalyzes the irreversible degradation of the bioactive sphingolipid sphingosine-1-phosphate (S1P), a key regulator of lymphocyte egress. The SPL reaction represents the only exit point of sphingolipid metabolism, and SPL insufficiency causes widespread sphingolipid derangements that could additionally contribute to immunodeficiency. Herein, we review SPLIS, the sphingolipid metabolic pathway, and various roles sphingolipids play in immunity. We then explore SPLIS-related immunodeficiency by analyzing data available in the published literature supplemented by medical record reviews in ten SPLIS children. We found 93% of evaluable SPLIS patients had documented evidence of immunodeficiency. Many of the remainder of cases were unevaluable due to lack of available immunological data. Most commonly, SPLIS patients exhibited lymphopenia and T cell-specific lymphopenia, consistent with the established role of the S1P/S1P1/SPL axis in lymphocyte egress. However, low B and NK cell counts, hypogammaglobulinemia, and opportunistic infections with bacterial, viral and fungal pathogens were observed. Diminished responses to childhood vaccinations were less frequently observed. Screening blood tests quantifying recent thymic emigrants identified some lymphopenic SPLIS patients in the newborn period. Lymphopenia has been reported to improve after cofactor supplementation in some SPLIS patients, indicating upregulation of SPL activity. A variety of treatments including immunoglobulin replacement, prophylactic antimicrobials and special preparation of blood products prior to transfusion have been employed in SPLIS. The diverse immune consequences in SPLIS patients suggest that aberrant S1P signaling may not fully explain the extent of immunodeficiency. Further study will be required to fully elucidate the complex mechanisms underlying SPLIS immunodeficiency and determine the most effective prophylaxis against infection.

AI fusion of multisource data identifies key features of vitiligo

Vitiligo is a skin disorder that is associated with a decreased risk of skin cancer, but it can lead to increased susceptibility to sunburn, psychological distress, and disruptions in daily life, consists of two primary subtypes: segmental and nonsegmental vitiligo, each with distinct underlying mechanisms. However, the reliable identification of diagnostic markers and the ability to differentiate between these subtypes have remained elusive challenges. This study aims to pioneer predictive algorithms for vitiligo diagnosis, harnessing the capabilities of AI (Artificial Intelligence) to amalgamate multisource data and uncover essential features for distinguishing vitiligo subtypes.An ensemble algorithm was thoughtfully developed for vitiligo diagnosis, utilizing a spectrum of machine learning techniques to evaluate the likelihood of vitiligo, whether segmental or nonsegmental. Diverse machine learning methodologies were applied to distinguish between healthy individuals and vitiligo patients, as well as to differentiate segmental from nonsegmental vitiligo. The ensemble algorithm achieved a remarkable AUC (Area Under the Curve) of 0.99 and an accuracy of 0.98 for diagnosing vitiligo. Furthermore, in predicting the development of segmental or nonsegmental vitiligo, the model exhibited an AUC of 0.79 and an accuracy of 0.73. Key parameters for vitiligo identification encompassed factors such as age, FBC (full blood count)-neutrophils, FBC-lymphocytes, LKF(liver and kidney function)-direct bilirubin, LKF-total bilirubin, and LKF-total protein levels. In contrast, vital indicators for monitoring the progression of segmental and nonsegmental vitiligo included FBC-B lymphocyte count, FBC-NK (Natural Killer) cell count, and LKF-alkaline phosphatase levels. This retrospective study underscores the potential of AI-driven analysis in identifying significant risk factors for vitiligo and predicting its subtypes at an early stage. These findings offer great promise for the development of effective diagnostic tools and the implementation of personalized treatment approaches in managing this challenging skin disorder.

Risk factors and long-term outcomes for human herpesvirus 6 encephalitis in the early period after allogeneic stem cell transplantation.

Human herpesvirus 6 (HHV6) encephalitis is a rare but life-threatening complication for patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, reports on susceptibility factors and clinical outcomes are limited. We enrolled HHV6 encephalitis patients following allo-HSCT between 2018 and 2022, then conducted a 1:4 nested case-control cohort study to evaluate risk factors and long-term outcomes. Among 1350 patients, 20 (1.48%) developed HHV6 encephalitis, with a median onset time of 25.5 days after HSCT. Patient age<30 (odds ratio [OR], 3.24, P = 0.016) and NK cell count<115/ul at 21 days (OR, 6.07, P = 0.018) were identified as independent risk factors in multivariate analysis. Moreover, the HHV6 encephalitis group was significantly associated with higher incidence of grade II-IV graft-versus-host disease (aGVHD) (hazard ratio [HR], 5.52, P < 0.001) and transplant-associated microangiopathy (HR,9.86, P < 0.001), and demonstrated a significantly higher non-relapse mortality (NRM) (HR, 5.28, P = 0.004) and a lower overall survival (HR, 4.34, P = 0.001) or progression-free survival (HR, 3.94, P = 0.001) compared to control group. In conclusion, patients <30 years old or with delayed NK cell recovery are more susceptible to HHV6 encephalitis after allo-HSCT, and patients with HHV6 encephalitis after transplantation have poorer clinical outcomes.

Peripheral NK cell count predicts response and prognosis in breast cancer patients underwent neoadjuvant chemotherapy.

The count of lymphocyte subsets in blood can reflect the immune status of the body which is closely related to the tumor immune microenvironment and the efficacy of NAT. This study aims to explore the relationship between peripheral blood lymphocyte subsets and the efficacy and prognosis of NAT in breast cancer. We retrospectively analyzed clinicopathological information and peripheral blood lymphocyte subpopulation counts of patients receiving NAT from January 2015 to November 2021 at Sun Yat-sen University Cancer Center. Kaplan-Meier curves were used to estimate the survival probability. The independent predictors of NAT response and survival prognosis were respectively analyzed by multivariate logistic regression and Cox regression, and nomograms were constructed accordingly. The prediction efficiency of three nomograms was validated separately in the training cohort and the testing cohort. 230 patients were included in the study, consisting of 161 in the training cohort and 69 in the testing cohort. After a median follow-up of 1238 days, patients with higher NK cell value showed higher pCR rates and higher OS and RFS after NAT (all P < 0.001). Multivariate analyses suggested NK cell count was an independent predictor of NAT response, OS and RFS. We then built nomograms accordingly and validated the prediction performance in the testing cohort (C index for NAT response: 0.786; for OS: 0.877, for RFS: 0.794). Peripheral blood NK cell count is a potential predictive marker for BC patients receiving NAT. Nomograms based on it might help predict NAT response and prognosis in BC.

Iron overload impact on peripheral blood cells, lymphocytes and karyotypes in newly diagnosed myelodysplastic syndromes (MDS) patients: a single-center retrospective analysis

We conducted a retrospective analysis of 68 newly diagnosed myelodysplastic syndrome (MDS) patients who were treated in the Department of Hematology at Yuncheng Central Hospital affiliated to Shanxi Medical University from October 2017 to March 2022. Based on the serum ferritin (SF) level, the newly diagnosed MDS patients were divided into two groups: iron overload (IOL) group (SF > 1000 ng/mL) and non-iron overload (NIOL) group(SF ≤ 1000 ng/mL). General clinical data, peripheral blood cells, lymphocyte subsets and marrow karyotypes were compared. We found that MDS patients with IOL had lower hemoglobin (Hb), lower reticulocyte (RET) counts, and lower absolute natural killer (NK) cell counts compared with NIOL group (p < 0.05). The correlation analysis also showed a negative correlation between the NK cell counts and SF level (r = −0.270, P = 0.026). Furthermore, we found IOL group had higher incidence of complex and poor karyotypes. In conclusion, we found that IOL is correlated with anemia in MDS patients, which may lead to a decrease in T lymphocyte cells, especially in NK cells, that play a role in the immune pathogenesis of MDS, thereby suppressing immune surveillance function. Additionally, IOL may contribute to the pathogenesis of MDS by affecting karyotypes.

Prognostic analysis of concurrent Pneumocystis jirovecii pneumonia in patients with systemic lupus erythematosus: a retrospective study

BackgroundSystemic lupus erythematosus (SLE) has been less deadly since the advent of corticosteroid-sparing medications. SLE patients still have a higher mortality rate than the general population. Infectious disease is reported as one of the major causes of death in patients with SLE. Although bacteria are the most often isolated pathogens from patients with SLE, Pneumocystis jirovecii pneumonia (PJP) is more deadly than bacterial infection.MethodsWe retrospectively enrolled consecutive patients with SLE concurrent with PJP (SLE-PJP) in our center between January 2014 and December 2022. The participants were classified into two groups: survivors and non-survivors. Cox regression models and Kaplan‒Meier survival analyses were conducted to explore prognostic factors for survival.ResultsThere were 57 patients with SLE (42.0 ± 15.8 years old, 78.9% female) complicated with PJP, 22 (38.6%) of whom died. Compared with the survival group, the non-survival group had more patients with hyperglycemia or diabetes mellitus, invasive ventilation (p < 0.01), respiratory failure, intensive care unit admission, non-invasive ventilation, and hospital-acquired pneumonia (p < 0.05). The non-survival group showed a higher neutrophil percentage, lactate dehydrogenase, D-dimer (p < 0.001), urea, high-sensitivity C-reactive protein (hsCRP), erythrocyte sedimentation rate (ESR), and ferritin (p < 0.05). It also had lower minimal albumin, hemoglobin (p < 0.001), immunoglobulin G, complement 3, peripheral lymphocyte count, platelet, NK cell count, and CD4+ T-cell count (p < 0.05). Multivariate analysis indicated that hyperglycemia or diabetes mellitus (HR = 4.25, p < 0.01, 95% CI: 1.51–11.97), thrombocytopenia (HR = 4.22, p < 0.01, 95% CI: 1.63–10.91) and lower complement 3 (C3) (HR = 4.06, p < 0.01, 95% CI: 1.60-10.33) were independent risk factors for the survival of SLE-PJP patients.ConclusionsThe mortality rate of patients with SLE-PJP is still high. Hyperglycemia, decreased C3, and thrombocytopenia are independent survival risk factors.

Recombinant Human Interleukin-2 Corrects NK Cell Phenotype and Functional Activity in Patients with Post-COVID Syndrome

Post-COVID syndrome develops in 10–20% of people who have recovered from COVID-19 and it is characterized by impaired function of the nervous, cardiovascular, and immune systems. Previously, it was found that patients who recovered from infection with the SARS-CoV-2 virus had a decrease in the number and functional activity of NK cells. The aim of the study was to assess the effectiveness of recombinant human IL-2 (rhIL-2) administered to correct NK cell phenotype and functional activity in patients with post-COVID syndrome. Patients were examined after 3 months for acute COVID-19 of varying severity. The phenotype of the peripheral blood NK cells was studied by flow cytometry. It was found that disturbances in the cell subset composition in patients with post-COVID syndrome were characterized by low levels of mature (p = 0.001) and cytotoxic NK cells (p = 0.013), with increased release of immature NK cells (p = 0.023). Functional deficiency of NK cells in post-COVID syndrome was characterized by lowered cytotoxic activity due to the decreased count of CD57+ (p = 0.001) and CD8+ (p 0.001) NK cells. In the treatment of patients with post-COVID syndrome with recombinant IL-2, peripheral blood NK cell count and functional potential were restored. In general, the effectiveness of using rhIL-2 in treatment of post-COVID syndrome has been proven in patients with low levels of NK cells.

Immune and inflammation features of severe and critical Omicron infected patients during Omicron wave in China

ObjectiveThe current study aimed to investigate the baseline immune and inflammatory features and in-hospital outcomes of patients infected with the Omicron variant (PIWO) who presented with different disease severities during the first wave of mass Omicron infections in the Chinese population has occurred.MethodA cross‐sectional study was conducted on 140 hospitalized PIWO between December 11, 2022, and February 16, 2023. The clinical features, antibodies against SARS-CoV-2, immune cells, and inflammatory cytokines among mildly, severely, and critically ill PIWO at baseline and during follow-up period were compared.ResultPatients with severe (n = 49) and critical (n = 35) disease were primarily male, needed invasive mechanical ventilation treatment, and exhibited higher mortality than those with mild disease (n = 56). During acute infection, SARS-CoV-2-specific antibody levels fluctuated with disease severity, serum antibodies increased and the incidence of severe cases decreased in critically ill PIWO over time. Antibody titers in severe or critical PIWO with no antibody responses at baseline did not increase significantly over time. Meanwhile, CD4+T cell, CD8+T cell, and natural killer cell counts were negatively correlated with disease severity, whereas interleukin (IL)-6 and IL-10 levels were positively correlated. In addition, combined diabetes, immunosuppressive therapy before infection, serum amyloid A, IL-10 and neutrophil counts were independently associated with severe and critical illness in PIWO. Among the 11 nonsurvivors, 8, 2, 1 died of respiratory failure, sudden cardiac death, and renal failure, respectively. Compared with survivors, nonsurvivors exhibited lower seropositivity of SARS-CoV-2-specific antibody, reduced CD3+T and CD4+T cell counts, and higher IL-2R, IL-6, IL-8, and IL-10 levels. Of note, lactate dehydrogenase was a significant risk factor of death in severe or critically ill PIWO.ConclusionThis present study assessed the dynamic changes of SARS-CoV-2-specific antibodies, immune cells and inflammatory indexes between severely and critically ill PIWO. Critical and dead PIWO featured compromised humoral immune response and excessive inflammation, which broadened the understanding of the pathophysiology of Omicron infection and provides warning markers for severe disease and poor prognosis.

Immune profiling and functional analysis of NK and T cells in ataxia telangiectasia.

Ataxia telangiectasia (AT) is a rare autosomal-recessive disorder characterized by profound neurodegeneration, combined immunodeficiency, and an increased risk for malignant diseases. Treatment options for AT are limited, and the long-term survival prognosis for patients remains grim, primarily due to the emergence of chronic respiratory pathologies, malignancies, and neurological complications. Understanding the dysregulation of the immune system in AT is fundamental for the development of novel treatment strategies. In this context, we performed a retrospective longitudinal immunemonitoring of lymphocyte subset distribution in a cohort of AT patients (n = 65). Furthermore, we performed FACS analyses of peripheral blood mononuclear cells from a subgroup of 12 AT patients to examine NK and T cells for the expression of activating and functional markers. We observed reduced levels of peripheral blood CD3+CD8+ cytotoxic T cells, CD3+CD4+ T helper cells, and CD19+ B cells, whereas the amount of CD3--CD56+ NK cells and CD3+CD56+ NKT-like cells was similar compared with age-matched controls. Notably, there was no association between the age-dependent kinetic of T-, B-, or NK-cell counts and the occurrence of malignancy in AT patients. Additionally, our results indicate an altered NK- and T-cell response to cytokine stimulation in AT with increased levels of TRAIL, FasL, and CD16 expression in NK cells, as well as an elevated activation level of T cells in AT with notably higher expression levels of IFN-γ, CD107a, TRAIL, and FasL. Together, these findings imply function alterations in AT lymphocytes, specifically in T and NK cells, shedding light on potential pathways for innovative therapies.

Low risk of hepatitis B virus reactivation in membranous nephropathy patients with resolved infection undergoing rituximab-based regimens without antiviral prophylaxis

IntroductionPatients with resolved hepatitis B virus infection undergoing rituximab are at risk of hepatitis B virus reactivation without antiviral prophylaxis. However, the risk in such patients treated with rituximab-based regimens for membranous nephropathy is not clear. We evaluated the risk of hepatitis B virus reactivation in membranous nephropathy patients with resolved infection undergoing rituximab-based regimens without antiviral prophylaxis. MethodsClinical data of 51 membranous nephropathy patients with resolved hepatitis B virus infection undergoing rituximab-based regimens without antiviral prophylaxis were retrospectively analyzed. Among these, 21 patients were followed for more than 1 year after rituximab discontinuation. The clinical data collected aimed to assess patients’ responses and the risk of hepatitis B virus reactivation during and after rituximab treatment. Results30/51 (58.8 %) patients reached complete or partial remission at 12 months. None of the patients experienced HBsAg seroreversion during rituximab treatment. Alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase and total bilirubin levels, as well as the numbers of patients who exceeded the upper limits of normal for alkaline phosphatase and prothrombin time, did not show any statistically significant difference during rituximab-based therapy. Neither did the anti-HBs level, the number of patients with protective anti-HBs titers exceeding 10 U/L, nor the levels of CD19+ B cells, CD4+ T cells, CD8+ T cells, and natural killer cells. Among the 21 patients followed for 12 (ranging from 12 to 19) months after rituximab discontinuation, no hepatitis B virus reactivation was observed. The mean anti-HBs level and the number of patients with anti-HBs titers over 10 U/L did not show any statistically significant difference during the extended follow-up of 33 patient-years. Neither did the CD4+ T cell, CD8+ T cell, nor the natural killer cell counts. One patient presented with an ALT level that exceeded the baseline value by three times and reached above 100 U/L, accompanied by elevations in AST, GGT, and ALP levels. Meanwhile, the anti-HBs titer was 816.09 U/L, and HBsAg was negative. ConclusionThe administration of rituximab-based regimens in membranous nephropathy patients with hepatitis B virus resolved infection leads to a low risk of hepatitis B virus reactivation without antiviral prophylaxis. Patient’s immune status, drug combination, rituximab strategy should be fully evaluated when considering antiviral prophylaxis therapy.

A novel LGALS1-depended and immune-associated fatty acid metabolism risk model in acute myeloid leukemia stem cells

Leukemia stem cells (LSCs) are recognized as the root cause of leukemia initiation, relapse, and drug resistance. Lipid species are highly abundant and essential component of human cells, which often changed in tumor microenvironment. LSCs remodel lipid metabolism to sustain the stemness. However, there is no useful lipid related biomarker has been approved for clinical practice in AML prediction and treatment. Here, we constructed and verified fatty acid metabolism-related risk score (LFMRS) model based on TCGA database via a series of bioinformatics analysis, univariate COX regression analysis, and multivariate COX regression analysis, and found that the LFMRS model could be an independent risk factor and predict the survival time of AML patients combined with age. Moreover, we revealed that Galectin-1 (LGALS1, the key gene of LFMRS) was highly expressed in LSCs and associated with poor prognosis of AML patients, and LGALS1 repression inhibited AML cell and LSC proliferation, enhanced cell apoptosis, and decreased lipid accumulation in vitro. LGALS1 repression curbed AML progression, lipid accumulation, and CD8+ T and NK cell counts in vivo. Our study sheds light on the roles of LFMRS (especially LGALS1) model in AML, and provides information that may help clinicians improve patient prognosis and develop personalized treatment regimens for AML.

Decreased Peripheral Blood Natural Killer Cell Count in Untreated Juvenile Dermatomyositis Is Associated with Muscle Weakness.

Juvenile Dermatomyositis (JDM) is the most common inflammatory myopathy in pediatrics. This study evaluates the role of Natural Killer (NK) cells in Juvenile Dermatomyositis (JDM) pathophysiology. The study included 133 untreated JDM children with an NK cell count evaluation before treatment. NK cell subsets (CD56low/dim vs. CD 56bright) were examined in 9 untreated children. CD56 and perforin were evaluated in situ in six untreated JDM and three orthopedic, pediatric controls. 56% of treatment-naive JDM had reduced circulating NK cell counts, designated "low NK cell". This low NK group had more active muscle disease compared to the normal NK cell group. The percentage of circulating CD56low/dim NK cells was significantly lower in the NK low group than in controls (0.55% vs. 4.6% p < 0.001). Examination of the untreated JDM diagnostic muscle biopsy documented an increased infiltration of CD56 and perforin-positive cells (p = 0.023, p = 0.038, respectively). Treatment-naive JDM with reduced circulating NK cell counts exhibited more muscle weakness and higher levels of serum muscle enzymes. Muscle biopsies from treatment-naive JDM displayed increased NK cell infiltration, with increased CD56 and perforin-positive cells.

Natural Killer Cell Presence in Antibody-Mediated Rejection.

Transcript analyses highlight an important contribution of natural killer (NK) cells to microvascular inflammation (MVI) in antibody-mediated rejection (ABMR), but only few immunohistologic studies have quantified their spatial distribution within graft tissue. This study included 86 kidney transplant recipients who underwent allograft biopsies for a positive donor-specific antibody (DSA) result. NK cells were visualized and quantified within glomeruli and peritubular capillaries (PTC), using immunohistochemistry for CD34 alongside CD16/T-bet double-staining. Staining results were analyzed in relation to histomorphology, microarray analysis utilizing the Molecular Microscope Diagnostic System, functional NK cell genetics, and clinical outcomes. The number of NK cells in glomeruli per mm2 glomerular area (NKglom) and PTC per mm2 cortical area (NKPTC) was substantially higher in biopsies with ABMR compared to those without rejection, and correlated with MVI scores (NKglom Spearman's correlation coefficient [SCC] = 0.55, p < 0.001, NKPTC 0.69, p < 0.001). In parallel, NK cell counts correlated with molecular classifiers reflecting ABMR activity (ABMRprob: NKglom 0.59, NKPTC 0.75) and showed a trend towards higher levels in association with high functional FCGR3A and KLRC2 gene variants. Only NKPTC showed a marginally significant association with allograft function and survival. Our immunohistochemical results support the abundance of NK cells in DSA-positive ABMR.

Increased CD56 expression after photodynamic therapy indicates an increased natural killer cell count following early photodynamic therapy for cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most common type of skin cancer. Photodynamic therapy (PDT) is a promising therapeutic method for managing cSCC due to its proven ability to target specific areas over time and its low risk of side effects. PDT may cause tissue damage and vascular shutdown, and may regulate local immunological responses. The present study aimed to investigate and compare the early lymphocyte modifications before and after PDT for SCC. A total of 10 patients with SCC were identified by pathological investigation. Initially, all wounds were treated with 20% aminolevulinic acid (ALA)-PDT as the initial stage in the therapeutic procedure. The wounds were treated by exposing them to red LED light with a wavelength of 635 nm, an energy density of 100 J/cm2 and an intensity of 80 mW/cm2. The tumor tissue was surgically removed 24 h later, and another round of PDT therapy was administered. Immunohistochemistry for CD3 and CD56 was conducted on the wound tissue post-surgery. If the wound showed granulation, necrosis or secretion, debridement was added to the therapy. All patients were monitored for 0.6-1.0 year post-treatment. ALA-PDT combination surgery fully controlled the tumor tissue in all 10 patients. The immunohistochemical analysis of the wound tissues showed that the expression of CD56 increased, while the expression of CD3 was not different after photodynamic therapy. These results also indirectly indicated that the overall count of NK cells in the 10 patients increased, nevertheless, there was no alteration in the T lymphocyte count. In conclusion, the ALA-PDT combination surgical therapy for cSCC demonstrates favorable results. An increase in CD56 expression may be a mechanism for the effective treatment of cSCC with PDT.

Impact of autologous hematopoietic stem cell transplantation on the efficacy of CAR-T treatment of relapsed/refractory multiple myeloma

Objective: To evaluate the effect of autologous hematopoietic stem cell transplantation (ASCT) on the treatment of relapsed/refractory multiple myeloma (RRMM) with chimeric antigen receptor T cell (CAR-T) therapy. Methods: A retrospective cohort study. The clinical data of 168 patients with RRMM who underwent CAR-T therapy at the Department of Hematology, Xuzhou Medical University Hospital from 3 January 2020 to 13 September 2022 were analyzed. Patients were classified into a transplantation group (TG; n=47) and non-transplantation group (NTG; n=121) based on whether or not they had undergone ASCT previously. The objective response rate (ORR), progression-free survival (PFS), overall survival (OS) and the levels of CD3, CD4, CD8, CD19, CD56 and natural killer (NK) cells before CAR-T infusion were analyzed by χ2 test, Kaplan-Meier method and independent sample t-test. Results: Among 168 patients with RRMM, 98 (58.3%) were male. The median age of onset was 57 (range 30-70) years. After CAR-T therapy, the ORR of patients was 89.3% (92/103) in the NTG and 72.9% (27/73) in the TG. The ORR of the NTG was better than that of the TG (χ2=5.71, P=0.017). After 1 year of CAR-T therapy, the ORR of the NTG was 78.1% (75/96), and that of the TG was 59.4% (19/32). The ORR of the NTG was better than that of the TG (χ2=4.32, P=0.038). The median OS and PFS in the NTG were significantly longer than those in the TG (OS, 30 vs. 20 months; PFS, 26 vs. 12 months; both P<0.05). The CD4 level before CAR-T infusion in the TG was significantly lower than that in the NTG (25.65±13.56 vs. 32.64±17.21; t=-2.15, P=0.034), and there were no significant differences in the counts of CD3, CD8, CD19, CD56, and NK cells between the TG and NTG (all P>0.05). Conclusion: Among patients suffering from RRMM who received CAR-T therapy, patients who did not receive ASCT had significantly better outcomes than those who had received ASCT previously, which may have been related to the CD4 level before receiving CAR-T therapy.

Updated results of a phase 1/2 study of AU-007, a monoclonal antibody (mAb) that binds to IL-2 and inhibits CD25 binding, in patients with advanced solid tumors.

2527 Background: AU-007 is a computationally designed human mAb that binds interleukin-2 (IL-2) on its CD25 binding epitope. AU-007 bound IL-2 cannot bind trimeric (CD25, CD122, CD132) IL-2 receptors (IL-2R) on regulatory T cells (Tregs), vascular endothelium, or eosinophils, but IL-2’s binding to dimeric IL-2R (CD122, CD132) on effector T (T eff) and NK cells is unhindered. AU-007 thus redirects IL-2 towards T eff and NK cell activation, while diminishing Treg activation and vascular leak. AU-007 uniquely redirects IL-2 generated from T eff cell expansion, converting a Treg-mediated autoinhibitory loop into an immune stimulating loop. Methods: The study consists of three dose escalation arms followed by cohort expansion. Arm 1A evaluates escalating doses (0.5 – 12 mg/kg) of AU-007 (IV every 2 weeks [Q2W]). Arm 1B evaluates AU-007 Q2W + escalating doses (15K – 270K IU/kg) of one aldesleukin subcutaneous (SC) dose. Arm 1C evaluates AU-007 + escalating doses of SC aldesleukin, both Q2W. Nineteen solid tumor types are allowed in escalation. Cohort expansion Arm 2B evaluates 9 mg/kg AU-007 + one 135K IU/kg aldesleukin dose. Results: Fifty-three patients were enrolled as of 23 January 2024: 15 in Arm 1A, 12 in Arm 1B, 25 in Arm 1C, and 1 in cohort expansion. AU-007 (+/- aldesleukin) was well-tolerated, with no dose limiting toxicities through all Arm 1A and 1B cohorts and the 3rd cohort (of 4) in 1C. Enrollment is ongoing in the final Arm 1C cohort and Arm 2B expansion. All drug related adverse events (AE) were Grade 1 or 2 except for 4 patients with transient lymphopenia (Grade 3 and 4) and 1 patient with Grade 3 anemia. The most common drug-related AEs were pyrexia (18%), fatigue (16%), nausea (14%), lymphopenia (8%), and chills (6%). Two patients had transient Grade 2 drug-related serious AEs: pyrexia Arm 1B and cytokine release syndrome Arm 1C; both patients continued therapy. A confirmed partial response (32% decrease) occurred in a nasopharyngeal carcinoma patient in Arm 1C who progressed on anti-PD-1 therapy. Tumor shrinkage occurred in patients with non-small cell lung, bladder, head and neck, colorectal (CRC), and renal cancer. A melanoma patient (Arm 1B) who progressed on anti-CTLA-4 + anti-PD-1 therapy had a 48% decrease in target tumors; a small brain metastasis was found and irradiated at week 16 and the patient remains on treatment. A patient with microsatellite stable CRC had a 26% tumor shrinkage after the first cycle (Arm 1C). Serum Tregs and eosinophils decreased in patients while NK and CD8 cell counts trended upwards. The CD8:Treg ratio trends upward in all cohorts. Conclusions: The mild toxicity profile and promising early efficacy observed in dose escalation across multiple tumor types in heavily pretreated patients, along with initial pharmacodynamic data, warrant continued evaluation of AU-007 + low dose SC aldesleukin in the Phase 2 expansion cohorts of the study. Clinical trial information: NCT05267626 .

Comparison of NK cell count between 1% and 10% FBS culture media concentration by FACS analysis

Recently, there has been a growing research interest in the application of immunotherapy for cancer treatment. Various approaches have been developed, and one of these methods involves utilizing Natural Killer (NK) cells of the immune system to specifically target cancer cells. Research on this method necessitates the mass and stable production of NK cells through culturing. For NK cell culture, Fetal Bovine Serum (FBS) is widely used in the industry at concentrations ranging from 10% to 20%. In an effort to explore a more efficient culturing technique, this study aims to investigate the effect of 1% FBS on cell viability of NK cells in cell culture. Because NK cells are usually defined by cell surface molecules, the efficacy of using a lower FBS concentration was quantitatively measured using Fluorescence-Activated Cell Sorting (FACS). The cell counts of cells cultured in 1% FBS was compared to those of cells cultured in 10% FBS. The results showed that no significant difference was found between cell count of cells cultured in 1% and 10% FBS. Thus, 1% FBS concentration culturing method was not found to be inferior. Further research is needed on the effect of replicating cancer microenvironment on NK cell viability.

A standardized combination of Terminalia chebula and Withania somnifera extracts enhances immune function in adults: a pilot randomized, double-blind, placebo-controlled clinical study.

The use of botanical medicine has been demonstrated as a potential strategy to manage or treat a variety of health issues. Terminalia chebula (Retz) fruit and Withania somnifera (L.) Dunal roots are important medicinal herbs described in Ayurveda and traditional therapy for diverse health benefits. This pilot study aimed to evaluate the immune function-enhancing potential of a unique blend of T. chebula fruit and W. somnifera root extracts, LN20189, in healthy men and women. Forty healthy volunteers (age: 35-60 years) were randomized into two groups receiving either LN20189 (500 mg per day) or a matched placebo over 28 consecutive days. The total T-cell population was the primary efficacy measure in this study. The secondary efficacy measures included counts of CD4, CD8, natural killer (NK) cells, serum levels of interleukin-2 (IL-2), interferon-gamma (IFN-γ), total immunoglobulin-G (IgG), and Immune Function Questionnaire (IFQ) scores. Safety parameter assessments were also conducted. Post-trial, in LN20189-supplemented subjects, T cells, CD4, NK cells count, and the CD4:CD8 ratio were increased by 9.32, 10.10, 19.91, and 17.43%, respectively, as compared to baseline. LN20189 supplementation increased serum IFN-γ and IgG levels by 14.57 and 27.09% from baseline and by 13.98 and 21.99%, compared to placebo, respectively. Also, the IFQ scores in the LN20189 group were 84.68% (vs. baseline) and 69.44% (vs. placebo) lower at the end of the trial. LN20189 improved the study volunteers' cellular and humoral immune functions. In summary, LN20189 supplementation was found tolerable and improved the key cellular and humoral factors of the immune system and helped improve immune function of the trial volunteers.

A Randomized Phase 2 Trial of Felzartamab in Antibody-Mediated Rejection

BackgroundAntibody-mediated rejection is a leading cause of kidney-transplant failure. The targeting of CD38 to inhibit graft injury caused by alloantibodies and natural killer (NK) cells may be a therapeutic option.MethodsIn this phase 2, double-blind, randomized, placebo-controlled trial, we assigned patients with antibody-mediated rejection that had occurred at least 180 days after transplantation to receive nine infusions of the CD38 monoclonal antibody felzartamab (at a dose of 16 mg per kilogram of body weight) or placebo for 6 months, followed by a 6-month observation period. The primary outcome was the safety and side-effect profile of felzartamab. Key secondary outcomes were renal-biopsy results at 24 and 52 weeks, donor-specific antibody levels, peripheral NK-cell counts, and donor-derived cell-free DNA levels.ResultsA total of 22 patients underwent randomization (11 to receive felzartamab and 11 to receive placebo). The median time from transplantation until trial inclusion was 9 years. Mild or moderate infusion reactions occurred in 8 patients in the felzartamab group. Serious adverse events occurred in 1 patient in the felzartamab group and in 4 patients in the placebo group; graft loss occurred in 1 patient in the placebo group. At week 24, resolution of morphologic antibody-mediated rejection was more frequent with felzartamab (in 9 of 11 patients [82%]) than with placebo (in 2 of 10 patients [20%]), for a difference of 62 percentage points (95% confidence interval [CI], 19 to 100) and a risk ratio of 0.23 (95% confidence interval [CI], 0.06 to 0.83). The median microvascular inflammation score was lower in the felzartamab group than in the placebo group (0 vs. 2.5), for a mean difference of −1.95 (95% CI, −2.97 to −0.92). Also lower was a molecular score reflecting the probability of antibody-mediated rejection (0.17 vs. 0.77) and the level of donor-derived cell-free DNA (0.31% vs. 0.82%). At week 52, the recurrence of antibody-mediated rejection was reported in 3 of 9 patients who had a response to felzartamab, with an increase in molecular activity and biomarker levels toward baseline levels.ConclusionsFelzartamab had acceptable safety and side-effect profiles in patients with antibody-mediated rejection. (Funded by MorphoSys and Human Immunology Biosciences; ClinicalTrials.gov number, NCT05021484; and EUDRACT number, 2021-000545-40.)

A Novel Homozygous RHOH Variant Associated with T Cell Dysfunction and Recurrent Opportunistic Infections.

RHOH, an atypical small GTPase predominantly expressed in hematopoietic cells, plays a vital role in immune function. A deficiency in RHOH has been linked to epidermodysplasia verruciformis, lung disease, Burkitt lymphoma and T cell defects. Here, we report a novel germline homozygous RHOH c.245G > A (p.Cys82Tyr) variant in a 21-year-old male suffering from recurrent, invasive, opportunistic infections affecting the lungs, eyes, and brain. His sister also succumbed to a lung infection during early adulthood. The patient exhibited a persistent decrease in CD4+ T, B, and NK cell counts, and hypoimmunoglobulinemia. The patient's T cell showed impaired activation upon in vitro TCR stimulation. In Jurkat T cells transduced with RHOHC82Y, a similar reduction in activation marker CD69 up-regulation was observed. Furthermore, the C82Y variant showed reduced RHOH protein expression and impaired interaction with the TCR signaling molecule ZAP70. Together, these data suggest that the newly identified autosomal-recessive RHOH variant is associated with T cell dysfunction and recurrent opportunistic infections, functioning as a hypomorph by disrupting ZAP70-mediated TCR signaling.