Prevalence of anti-lymphocyte IgM autoantibodies driving complement activation in COVID-19 patients.

Introduction: COVID-19 patients can develop autoantibodies against a variety of secreted and membrane proteins, including some expressed on lymphocytes. However, it is unclear what proportion of patients might develop anti-lymphocyte antibodies (ALAb) and what functional relevance they might have. Methods: We evaluated the presence and lytic function of ALAb in the sera of a cohort of 85 COVID-19 patients (68 unvaccinated and 17 vaccinated) assigned to mild (N=63), or moderate/severe disease (N=22) groups. Thirty-seven patients were followed-up after recovery. We also analyzed in vivo complement deposition on COVID-19 patients' lymphocytes and examined its correlation with lymphocyte numbers during acute disease. Results: Compared with healthy donors (HD), patients had an increased prevalence of IgM ALAb, which was significantly higher in moderate/severe disease patients and persisted after recovery. Sera from IgM ALAb+ patients exhibited complement-dependent cytotoxicity (CDC) against HD lymphocytes. Complement protein C3b deposition on patients' CD4 T cells was inversely correlated with CD4 T cell numbers. This correlation was stronger in moderate/severe disease patients. Discussion: IgM ALAb and complement activation against lymphocytes may contribute to the acute lymphopenia observed in COVID-19 patients.

Clinical impact of transient lymphopenia.

Transient or persistent immunosuppression is a known risk factor for morbidity and mortality in critically ill patients. Aim of the present study is to evaluate the lymphopenia in patients admitted to the Emergency Unit of AOU Policlinico Umberto I, to investigate its prevalence at admission and the persistence during hospitalization until discharge. Possible correlations were evaluated between lymphopenia, diagnosis of admission, comorbidities and chronic treatments. In this study, 240 patients (142 men; 98 female; mean age 75.1 ± 15.1) were enrolled. Patients were divided into two groups according to the lymphocytes count at hospital admission, namely "Group A" with lymphopenia and "Group B" with values in the normal range. Moreover, the patients in group A were distinguished in relation to the regression or persistence of the lymphopenia assessed at the time of hospital discharge (Group A1: persistence; Group A2: normalization). Prevalence of lymphopenia at admission was 57%; Group A showed higher mean age and percentage of patients over 65 years of age; and none differences were observed regarding gender. Prevalence of lymphopenia at admission was 57%; Group A showed higher mean age and percentage of patients over 65 years of age; no differences were observed regarding gender. All subsets of the lymphocytes (CD4+, CD8+, NK) were equally reduced. Persistent lymphopenia was found in 19% of patients. Lymphopenia should be valued at the time of hospital admission as a factor influencing the prognosis, the management and the treatment of these patients.

Risk factors for COVID-19 associated pulmonary aspergillosis and outcomes in patients with acute respiratory failure in a respiratory sub-intensive care unit.

BACKGROUND: COVID-19-associated pulmonary aspergillosis (CAPA) is burdened by high mortality. Data are lacking about non-ICU patients. Aims of this study were to: (i) assess the incidence and prevalence of CAPA in a respiratory sub-intensive care unit, (ii) evaluate its risk factors and (iii) impact on in-hospital mortality. Secondary aims were to: (i) assess factors associated to mortality, and (ii) evaluate significant features in hematological patients. MATERIALS AND METHODS: This was a single-center, retrospective study of COVID-19 patients with acute respiratory failure. A cohort of CAPA patients was compared to a non-CAPA cohort. Among patients with CAPA, a cohort of hematological patients was further compared to another of non-hematological patients. RESULTS: Three hundred fifty patients were included in the study. Median P/F ratio at the admission to sub-intensive unit was 225 mmHg (IQR 155-314). 55 (15.7%) developed CAPA (incidence of 5.5%). Eighteen had probable CAPA (37.3%), 37 (67.3%) possible CAPA and none proven CAPA. Diagnosis of CAPA occurred at a median of 17 days (IQR 12-31) from SARS-CoV-2 infection. Independent risk factors for CAPA were hematological malignancy [OR 1.74 (95%CI 0.75-4.37), p = 0.0003], lymphocytopenia [OR 2.29 (95%CI 1.12-4.86), p = 0.02], and COPD [OR 2.74 (95%CI 1.19-5.08), p = 0.014]. Mortality rate was higher in CAPA cohort (61.8% vs 22.7%, p < 0.0001). CAPA resulted an independent risk factor for in-hospital mortality [OR 2.92 (95%CI 1.47-5.89), p = 0.0024]. Among CAPA patients, age > 65 years resulted a predictor of mortality [OR 5.09 (95% CI 1.20-26.92), p = 0.035]. No differences were observed in hematological cohort. CONCLUSION: CAPA is a life-threatening condition with high mortality rates. It should be promptly suspected, especially in case of hematological malignancy, COPD and lymphocytopenia.

Early predictors of intensive care unit admission among COVID-19 patients in Qatar.

Background: COVID-19 is associated with significant morbidity and mortality. This study aimed to explore the early predictors of intensive care unit (ICU) admission among patients with COVID-19. Methods: This was a case-control study of adult patients with confirmed COVID-19. Cases were defined as patients admitted to ICU during the period February 29-May 29, 2020. For each case enrolled, one control was matched by age and gender. Results: A total of 1,560 patients with confirmed COVID-19 were included. Each group included 780 patients with a predominant male gender (89.7%) and a median age of 49 years (interquartile range = 18). Predictors independently associated with ICU admission were cardiovascular disease (adjusted odds ratio (aOR) = 1.64, 95% confidence interval (CI): 1.16-2.32, p = 0.005), diabetes (aOR = 1.52, 95% CI: 1.08-2.13, p = 0.016), obesity (aOR = 1.46, 95% CI: 1.03-2.08, p = 0.034), lymphopenia (aOR = 2.69, 95% CI: 1.80-4.02, p < 0.001), high AST (aOR = 2.59, 95% CI: 1.53-4.36, p < 0.001), high ferritin (aOR = 1.96, 95% CI: 1.40-2.74, p < 0.001), high CRP (aOR = 4.09, 95% CI: 2.81-5.96, p < 0.001), and dyspnea (aOR = 2.50, 95% CI: 1.77-3.54, p < 0.001). Conclusion: Having cardiovascular disease, diabetes, obesity, lymphopenia, dyspnea, and increased AST, ferritin, and CRP were independent predictors for ICU admission in patients with COVID-19.

Long-term outcomes of two-dose alemtuzumab induction in pediatric kidney transplantation.

BACKGROUND: Alemtuzumab is a lymphocyte depleting agent used for induction in kidney transplant, but long-term information on its use in pediatric recipients remains sparse. METHODS: We performed a single-center retrospective cohort study of 57 pediatric kidney transplant recipients receiving alemtuzumab 20 mg/m2/dose ×2 doses for induction immunosuppression. All patients underwent surveillance biopsies, and 91.3% underwent steroid withdrawal by day 4 post-transplant. Outcomes of interest included graft survival, development of donor specific antibodies (DSA), incidence of viremia and PTLD, and duration of lymphopenia. RESULTS: Median follow-up time was 7.9 years (IQR 5-13.6 years). Median graft survival was 16.5 years (95% CI 11.6-unknown). DSA developed in 36.5% at a median of 944 days (IQR 252-2113 days). Incidences of BK polyomavirus DNAemia (BKPyV-DNAemia), CMV DNAemia, and EBV DNAemia were 38.6%, 22.8%, and 14%, respectively; one patient developed PTLD at 13.3 years post-transplant. Median duration of lymphopenia was 365 days (IQR 168-713 days); 19.3% of patients remained lymphopenic at 3 years post-transplant. There was no association between duration of lymphopenia and graft survival, rejection, DSA detection, or viremia. CONCLUSIONS: A two-dose alemtuzumab induction protocol can have excellent outcomes with a steroid-free maintenance immunosuppression regimen. More comprehensive, multicenter, comparative studies of pediatric kidney transplant are needed to improve long-term outcomes.

[Immunophenotyping by spectral cytometry reveals a profile of lymphopenia associated with deregulation with an increase in effector memory lymphocytes in a patient with a mutation in the ITPR3 gene]. / Inmunofenotipo por citometría espectral, revela un perfil de linfopenia asociado a desregulación con aumento de linfocitos de memoria efectora en paciente con mutación en el gen ITPR3.

BACKGROUND: Variants in intracellular calcium transport genes have been associated with syndromic immunodeficiencies with a SCID phenotype. CASE REPORT: Seven-year-old girl of non-consanguineous parents, in Cartagena-Colombia. At two months of age, he presented hematochezia and was diagnosed with alimentary proctolitis without improvement with restriction to milk, wheat and eggs, and malnutrition developed. At eight months, a colon biopsy shows chronic lymphoid hyperplasia, presenting with anemia, eosinophilia, but total and specific IgE to normal foods. After four years, the Immunology Service found her asymptomatic, nutritionally recovered and without allergic sensitization, but eosinophilia and elevated calprotectin persisted, suggesting an early-onset inflammatory bowel disease. Immunoglobulins were normal, lymphocyte populations with CD3, CD4 and CD8 lymphopenia. At six years old, she presented atopic dermatitis, still had elevated calprotectin and was lymphopenic. Immunophenotyping by spectral cytometry using Cytek®cFluor®Immunoprofiling-Kit14 showed lymphopenia and CD4/CD8 inversion. Naïve CD4+ and CD8+ T lymphocytes were decreased, while T-CD8+CD45RA-CCR7- and T-CD8+CD45RA+CCR7- effector memory populations were expanded. Effector and central memory CD4+ T-lymphocytes were also increased1 (Image 1). The exome revealed a heterozygous variant in the ITPR3 gene (carrier father), c.7571G>A, p.(Arg2524His); predictors classify it as having a potential eliminating effect. CONCLUSIONS: The clinical features and immunophenotype of this candidate variant differ from others related to intracellular calcium transport. They are functional studies necessary to validate their causality. A patient with a potentially deleted variant presents an immunophenotype with CD3 lymphopenia and persistent lymphocyte activation.

ANTECEDENTES: Las variantes en genes del transporte de calcio intracelular han sido asociadas a inmunodeficiencias sindrómicas con un fenotipo IDCG. REPORTE DE CASO: Niña de siete años, de padres no consanguíneos, en Cartagena-Colombia. A los dos meses de vida, presenta hematoquecia y se diagnostica con proctolitis alimentaria sin mejoría con restricción a leche, trigo y huevo, desarrollando desnutrición. A los ocho meses, una biopsia de colon muestra hiperplasia linfoide crónica, cursa con anemia, eosinofilia, pero IgE total y específica a alimentos normales. A los cuatro años, el Servicio de Inmunología la encuentra asintomática, recuperada nutricionalmente y sin sensibilización alérgica, pero persiste eosinofilia y calprotectina elevada, sugiriendo una enfermedad inflamatoria intestinal de inicio temprano. Las inmunoglobulinas fueron normales, poblaciones linfocitarias con linfopenia CD3, CD4 y CD8. A los seis años, presenta dermatitis atópica, sigue con calprotectina elevada y linfopénica. El inmunofenotipo por citometría espectral mediante Cytek®cFluor®Immunoprofiling-Kit14, mostró linfopenia e inversión CD4/CD8. Los linfocitos T-vírgenes CD4+ y CD8+ estaban disminuidos, en cambio las poblaciones de memoria efectora T-CD8+CD45RA-CCR7- y T-CD8+CD45RA+CCR7­ estaban expandidas. Los linfocitos T-CD4+ de memoria efectora y central, también estaban aumentados1 (Imagen 1). El exoma reveló una variante heterocigótica en el gen ITPR3 (padre portador), c.7571G>A, p.(Arg2524His); los predictores la clasifican como de potencial efecto deletéreo. CONCLUSIONES: La clínica y el inmunofenotipo de esta variante candidata difiere de otras relacionadas con el transporte del calcio intracelular. Son necesarios estudios funcionales para validar su causalidad. Una paciente con una variante potencialmente deletérea, presenta un inmunofenotipo con linfopenia CD3 y activación persistente de los linfocitos.

Patients with STAT1 Gain-of-function Mutations Display Increased Apoptosis which is Reversed by the JAK Inhibitor Ruxolitinib.

INTRODUCTION: The signal transducer and activator of transcription (STAT1) gain-of-function (GOF) syndrome accounts for most cases of chronic mucocutaneous candidiasis but is characterized by a broader clinical phenotype that may include bacterial, viral, or invasive fungal infections, autoimmunity, autoinflammatory manifestations, vascular complications, or malignancies. The severity of lymphopenia may vary and influence the infectious morbidity. METHODS: In our cohort of seven STAT1-GOF patients, we investigated the mechanisms that may determine T lymphopenia, we characterized the interferon gene signature (IGS) and analyzed the effect of ruxolitinib in reverting the immune dysregulation. RESULTS: STAT1-GOF patients exhibited increased T lymphocyte apoptosis that was significantly augmented in both resting conditions and following stimulation with mitogens and IFNα, as evaluated by flow cytometry by Annexin V/ Propidium iodide assay. The JAK inhibitor ruxolitinib significantly reduced the IFNα-induced hyperphosphorylation of STAT1 and reverted the stimulation-induced T-cell apoptosis, in vitro. In two adult STAT1-GOF patients, the JAKinib treatment ameliorated chronic mucocutaneous candidiasis and lymphopenia. Most STAT1-GOF patients, particularly those who had autoimmunity, presented increased IGS that significantly decreased in the two patients during ruxolitinib treatment. CONCLUSION: In STAT1-GOF patients, T lymphocyte apoptosis is increased, and T lymphopenia may determine higher risk of severe infections. The JAKinib target therapy should be evaluated to treat severe chronic candidiasis and lymphopenia, and to downregulate the IFNs in patients with autoinflammatory or autoimmune manifestations.

Newborn Screening for Severe T and B Cell Lymphopenia Using TREC/KREC Detection: A Large-Scale Pilot Study of 202,908 Newborns.

Newborn screening (NBS) for severe inborn errors of immunity (IEI), affecting T lymphocytes, and implementing measurements of T cell receptor excision circles (TREC) has been shown to be effective in early diagnosis and improved prognosis of patients with these genetic disorders. Few studies conducted on smaller groups of newborns report results of NBS that also include measurement of kappa-deleting recombination excision circles (KREC) for IEI affecting B lymphocytes. A pilot NBS study utilizing TREC/KREC detection was conducted on 202,908 infants born in 8 regions of Russia over a 14-month period. One hundred thirty-four newborns (0.66‰) were NBS positive after the first test and subsequent retest, 41% of whom were born preterm. After lymphocyte subsets were assessed via flow cytometry, samples of 18 infants (0.09‰) were sent for whole exome sequencing. Confirmed genetic defects were consistent with autosomal recessive agammaglobulinemia in 1/18, severe combined immunodeficiency - in 7/18, 22q11.2DS syndrome - in 4/18, combined immunodeficiency - in 1/18 and trisomy 21 syndrome - in 1/18. Two patients in whom no genetic defect was found met criteria of (severe) combined immunodeficiency with syndromic features. Three patients appeared to have transient lymphopenia. Our findings demonstrate the value of implementing combined TREC/KREC NBS screening and inform the development of policies and guidelines for its integration into routine newborn screening programs.

Autoimmune hemolytic anemia and thrombocytopenia in a Chinese patient with heterozygous NBAS mutations: Case report.

RATIONALE: Neuroblastoma amplified sequence (NBAS)-associated disease is an autosomal recessive disorder and a broad spectrum of clinical symptoms has been reported. However, autoimmune mediated hemolytic anemia (AIHA) is rarely reported in NBAS disease. PATIENT CONCERNS: A now 21-year-old male harbors heterozygous variants of c.6840G>A and c.335 + 1G>A and was found had retarded growth, hypogammaglobulinemia, B lymphopenia, optic atrophy, horizontal nystagmus, slight splenomegaly and hepatomegaly since childhood. This case had normal hemoglobin level and platelet count in his childhood. He developed AIHA first in his adulthood and then thrombocytopenia during the treatment of AIHA. The mechanism underlying a case with pronounced hypogammaglobulinemia and B lymphopenia is elusive. In addition to biallelic NBAS mutations, a germline mutation in the ANKRD26 (c.2356C>T) gene was also detected. So either autoimmune or ANKRD26 mutation-mediated thrombocytopenia is possible in this case. INTERVENTION AND OUTCOME: He was initially managed with steroid and intermittent intravenous immunoglobulin supplement. After treatment, he responded well with a normalization of hemoglobin and serum bilirubin. But the patient subsequently experienced severe thrombocytopenia in addition to AIHA. He was then given daily avatrombopag in addition to steroid escalation. He responded again to new treatment, with the hemoglobin levels and platelet counts went back to the normal ranges. Now he was on de-escalated weekly avatrombopag and low-dose steroids maintenance. CONCLUSION: The phenotype of this case indicates that c.335 + 1G>A NBAS variant is probably a pathogenic one and c.2356C>T ANKRD26 variant is improbably a pathogenic one. AIHA may respond well to steroid even when happened in patients with NBAS disease.

COVID-19 in patients with Down syndrome: A systematic review.

INTRODUCTION: Down syndrome (DS) is associated with multiple comorbid conditions and chronic immune dysfunction. Persons with DS who contract COVID-19 are at high risk for complications and have a poor prognosis. We aimed to study the clinical symptoms, laboratory and biochemical profiles, radiologic findings, treatment, and outcomes of patients with DS and COVID-19. METHOD: We systematically searched PubMed, MEDLINE, Web of Science, Scopus, and the Cochrane Library using the keywords COVID-19 or coronavirus or SARS-CoV-2 and DS or trisomy 21. Seventeen articles were identified: eight case reports and nine case series published from December 2019 through March 2022, with a total of 55 cases. RESULTS: Patients averaged 24.8 years (26 days to 60 years); 29 of the patients were male. The most common symptoms were fever, dyspnea, and cough. Gastrointestinal and upper respiratory tract symptoms were commonly reported for pediatric patients. The most common comorbidities present in patients with DS were obesity (49.0%), hypothyroidism (21.6%) and obstructive sleep apnea (15.6%). The patients were hospitalized for a mean of 14.8 days. When the patients were compared with the general COVID-19 population, the mean number of hospitalized days was higher. Most patients had leukopenia, lymphopenia, and elevated inflammatory markers (d-dimer and C-reactive protein). Bilateral infiltrations and bilateral ground-glass opacifications were frequently seen in chest radiographs and chest computed tomographic imaging. Most of the patients were treated with methylprednisolone, macrolides, and hydroxychloroquine. Of the 55 patients, 22 died. The mean age of the patients who died was 42.8 years. Mortality rate was higher in individuals with DS over 40 years of age. CONCLUSION: More studies are needed to better understand COVID-19 infections among persons with DS. In addition, the study was limited by a lack of statistical analyses and a specific comparison group.

Lymphopenia is associated with broad host response aberrations in community-acquired pneumonia.

OBJECTIVES: Lymphopenia at hospital admission occurs in over one-third of patients with community-acquired pneumonia (CAP), yet its clinical relevance and pathophysiological implications remain underexplored. We evaluated outcomes and immune features of patients with lymphopenic CAP (L-CAP), a previously described immunophenotype characterized by admission lymphocyte count <0.724 × 109 cells/L. METHODS: Observational study in 149 patients admitted to a general ward for CAP. We measured 34 plasma biomarkers reflective of inflammation, endothelial cell responses, coagulation, and immune checkpoints. We characterized lymphocyte phenotypes in 29 patients using spectral flow cytometry. RESULTS: L-CAP occurred in 45 patients (30.2%) and was associated with prolonged time-to-clinical-stability (median 5 versus 3 days), also when we accounted for competing events for reaching clinical stability and adjusted for baseline covariates (subdistribution hazard ratio 0.63; 95% confidence interval 0.45-0.88). L-CAP patients demonstrated a proportional depletion of CD4 T follicular helper cells, CD4 T effector memory cells, naïve CD8 T cells and IgG+ B cells. Plasma biomarker analyses indicated increased activation of the cytokine network and the vascular endothelium in L-CAP. CONCLUSIONS: L-CAP patients have a protracted clinical recovery course and a more broadly dysregulated host response. These findings highlight the prognostic and pathophysiological relevance of admission lymphopenia in patients with CAP.

Kaplan lecture 2023: lymphopenia in particle therapy.

PURPOSE: Lymphopenia is now generally recognized as a negative prognostic factor in radiotherapy. Already at the beginning of the century we demonstrated that high-energy carbon ions induce less damage to the lymphocytes of radiotherapy patients than X-rays, even if heavy ions are more effective per unit dose in the induction of chromosomal aberrations in blood cells irradiated ex-vivo. The explanation was based on the volume effect, i.e. the sparing of larger volumes of normal tissue in Bragg peak therapy. Here we will review the current knowledge about the difference in lymphopenia between particle and photon therapy and the consequences. CONCLUSIONS: There is nowadays an overwhelming evidence that particle therapy reduces significantly the radiotherapy-induced lymphopenia in several tumor sites. Because lymphopenia turns down the immune response to checkpoint inhibitors, it can be predicted that particle therapy may be the ideal partner for combined radiation and immunotherapy treatment and should be selected for patients where severe lymphopenia is expected after X-rays.

Early effects of different brain radiotherapy modalities on circulating leucocyte subpopulations in rodents.

PURPOSES: Lymphopenia is extensively studied, but not circulating leucocyte subpopulations, which however have distinct roles in tumor tolerance. Proton therapy has been shown to have a lesser impact on the immune system than conventional X-ray radiotherapy through lower dose exposure to healthy tissues. We explored the differential effects of brain X-ray and proton irradiation on circulating leucocyte subpopulations. MATERIALS AND METHODS: Leucocyte subpopulation counts from tumor-free mice were obtained 12 hours after 4 fractions of 2.5 Gy. The relationships between irradiation type (X-rays or protons), irradiated volume (whole-brain/hemi-brain) and dose rate (1 or 2 Gy/min) with circulating leucocyte subpopulations (T-CD4+, T-CD8+, B, and NK-cells, neutrophils, and monocytes) were investigated using linear regression and tree-based modeling approaches. Relationships between dose maps (brain, vessels, lymph nodes (LNs)) and leucocyte subpopulations were analyzed and applied to construct the blood dose model, assessing the hypothesis of a direct lymphocyte-killing effect in radiation-induced lymphopenia. RESULTS: Radiation-induced lymphopenia occurred after X-ray but not proton brain irradiation in lymphoid subpopulations (T-CD4+, T-CD8+, B, and NK-cells). There was an increase in neutrophil counts following protons but not X-rays. Monocytes remained unchanged under both X-rays and protons. Besides irradiation type, irradiated volume and dose rate had a significant impact on NK-cell, neutrophil and monocyte levels but not T-CD4+, T-CD8+, and B-cells. The dose to the blood had a heterogeneous impact on leucocyte subpopulations: neutrophil counts remained stable with increasing dose to the blood, while lymphocyte counts decreased with increasing dose (T-CD8+-cells > T-CD4+-cells > B-cells > NK-cells). Direct cell-killing effect of the dose to the blood mildly contributed to radiation-induced lymphopenia. LN exposure significantly contributed to lymphopenia and partially explained the distinct impact of irradiation type on circulating lymphocytes. CONCLUSIONS: Leucocyte subpopulations reacted differently to X-ray or proton brain irradiation. This difference could be partly explained by LN exposure to radiation dose. Further researches and analyses on other biological processes and interactions between leucocyte subpopulations are ongoing. The various mechanisms underlying leucocyte subpopulation changes under different irradiation modalities may have implications for the choice of radiotherapy modalities and their combination with immunotherapy in brain cancer treatment.

Low CD4 + T cell count is related to specific anti-nuclear antibodies, IFNα protein positivity and disease activity in systemic lupus erythematosus pregnancy.

BACKGROUND: Lymphopenia, autoantibodies and activation of the type I interferon (IFN) system are common features in systemic lupus erythematosus (SLE). We speculate whether lymphocyte subset counts are affected by pregnancy and if they relate to autoantibody profiles and/or IFNα protein in SLE pregnancy. METHODS: Repeated blood samples were collected during pregnancy from 80 women with SLE and 51 healthy controls (HC). Late postpartum samples were obtained from 19 of the women with SLE. Counts of CD4 + and CD8 + T cells, B cells and NK cells were measured by flow cytometry. Positivity for anti-nuclear antibodies (ANA) fine specificities (double-stranded DNA [dsDNA], Smith [Sm], ribonucleoprotein [RNP], chromatin, Sjögren's syndrome antigen A [SSA] and B [SSB]) and anti-phospholipid antibodies (cardiolipin [CL] and ß2 glycoprotein I [ß2GPI]) was assessed with multiplexed bead assay. IFNα protein concentration was quantified with Single molecule array (Simoa) immune assay. Clinical data were retrieved from medical records. RESULTS: Women with SLE had lower counts of all lymphocyte subsets compared to HC throughout pregnancy, but counts did not differ during pregnancy compared to postpartum. Principal component analysis revealed that low lymphocyte subset counts differentially related to autoantibody profiles, cluster one (anti-dsDNA/anti-Sm/anti-RNP/anti-Sm/RNP/anti-chromatin), cluster two (anti-SSA/anti-SSB) and cluster three (anti-CL/anti-ß2GPI), IFNα protein levels and disease activity. CD4 + T cell counts were lower in women positive to all ANA fine specificities in cluster one compared to those who were negative, and B cell numbers were lower in women positive for anti-dsDNA and anti-Sm compared to negative women. Moreover, CD4 + T cell and B cell counts were lower in women with moderate/high compared to no/low disease activity, and CD4 + T cell count was lower in IFNα protein positive relative to negative women. Finally, CD4 + T cell count was unrelated to treatment. CONCLUSION: Lymphocyte subset counts are lower in SLE compared to healthy pregnancies, which seems to be a feature of the disease per se and not affected by pregnancy. Our results also indicate that low lymphocyte subset counts relate differentially to autoantibody profiles, IFNα protein levels and disease activity, which could be due to divergent disease pathways.

A large single-center cohort of bare lymphocyte syndrome: Immunological and genetic features in Turkey.

Major histocompatibility complex class II (MHC-II) deficiency or bare lymphocyte syndrome (BLS) is a rare, early-onset, autosomal recessive, and life-threatening inborn error of immunity. We aimed to assess the demographic, clinical, laboratory, follow-up, and treatment characteristics of patients with MHC-II deficiency, together with their survival. We retrospectively investigated 21 patients with MHC-II deficiency. Female/male ratio was 1.63. The median age at diagnosis was 16.3 months (5 months-9.7 years). Nineteen patients (90.5%) had parental consanguinity. Pulmonary diseases (pneumonia, chronic lung disease) (81%), diarrhoea (47.6%), and candidiasis (28.6%) were common. Four (19%) had autoimmunity, two developed septic arthritis, and three (14%) developed bronchiectasis in the follow-up. Three patients (14%) had CMV viraemia, one with bilateral CMV retinitis. Eight (38.1%) had lymphocytopenia, and four (19%) had neutropenia. Serum IgM, IgA, and IgG levels were low in 18 (85.7%), 15 (71.4%), and 11 (52.4%) patients, respectively. CD4+ lymphocytopenia, a reversed CD4+/CD8+ ratio, and absent/low HLA-DR expressions were detected in 93.3%, 86.7%, and 100% of the patients, respectively. Haematopoietic stem cell transplantation (HSCT) was performed on nine patients, and four died of septicaemia and ARDS after HSCT. The present median age of patients survived is 14 years (1-31 years). Genetic analysis was performed in 10 patients. RFX5 homozygous gene defect was found in three patients (P1, P4 and P8), and RFXANK (P2 and P14) and RFXAP (P18 and P19) heterozygous gene defects were found in each two patients, respectively. This large cohort showed that BLS patients have severe combined immunodeficiency (SCID)-like clinical findings. Flow cytometric MHC-II expression study is crucial for the diagnosis, differential diagnosis with SCID, early haematopoietic stem cell transplantation (HSCT), and post-HSCT follow-up. Genetic studies are required first for matched family donor evaluation before HSCT and then for genetic counselling.

Frequency of Dimethyl Fumarate-Induced Lymphopenia among Omani Patients with Multiple Sclerosis.

Objectives: Dimethyl fumarate (DMF) is known to cause lymphopenia when used to treat patients with multiple sclerosis (MS). However, research on DMF therapy in the Arab world, especially in Oman, is scarce. This study aimed to analyse the prevalence of lymphopenia among Omani patients with MS and their reasons for discontinuing DMF therapy. Methods: In this retrospective study, the medical records of Omani patients with MS who were treated using DMF at two tertiary hospitals in Muscat, Oman, from February 2017 to February 2023 were reviewed. Their demographic, clinical and laboratory data were retrieved and analysed. Absolute lymphocyte count values at baseline and at the last follow-up, as well as the reasons for discontinuing DMF therapy, were collected. Descriptive and inferential statistical techniques were used for data analysis. Binary-logistic regression analysis was used to identify the risk factors for DMF-induced lymphopenia. Results: A total of 64 Omani patients with MS were included in this study. The majority of the study participants (n = 40; 63%) were female. All included patients started DMF therapy at the mean age of 33 ± 7.7 years. After administration of DMF, 14 (21.9%) patients developed grades 1-3 of lymphopenia. The DMF therapy was discontinued for 23 (36.0%) patients, mainly in response to adverse events or confirmed pregnancy. Female gender was the only significant predictor of DMF-induced lymphopenia (P = 0.037). Conclusions: Most Omani patients with MS had mild lymphopenia (grades 1-2). Early adverse events and pregnancy were the main reasons provided for discontinuing DMF therapy.

Neoadjuvant chemoradiotherapy combined with sequential perioperative toripalimab in locally advanced esophageal squamous cell cancer.

BACKGROUND: Programmed death 1 (PD-1) inhibitor demonstrated durable antitumor activity in advanced esophageal squamous cell carcinoma (ESCC), but the clinical benefit of perioperative immunotherapy in ESCC remains unclear. This study evaluated the efficacy and safety of neoadjuvant chemoradiotherapy (nCRT) combined with the PD-1 inhibitor toripalimab in patients with resectable ESCC. METHODS: From July 2020 to July 2022, 21 patients with histopathologically confirmed thoracic ESCC and clinical staged as cT1-4aN1-2M0/cT3-4aN0M0 were enrolled. Eligible patients received radiotherapy (23 fractions of 1.8 Gy, 5 fractions a week) with concurrent chemotherapy of paclitaxel/cisplatin (paclitaxel 45 mg/m2 and cisplatin 25 mg/m2) on days 1, 8, 15, 22, 29 and two cycles of toripalimab 240 mg every 3 weeks after nCRT for neoadjuvant therapy before surgery, four cycles of toripalimab 240 mg every 3 weeks for adjuvant therapy after surgery. The primary endpoint was the major pathological response (MPR) rate. The secondary endpoints were safety and survival outcomes. RESULTS: A total of 21 patients were included, of whom 20 patients underwent surgery, 1 patient refused surgery and another patient was confirmed adenocarcinoma after surgery. The MPR and pathological complete response (pCR) rates were 78.9% (15/19) and 47.4% (9/19) for surgery ESCC patients. 21 patients (100.0%) had any-grade treatment-related adverse events, with the most common being lymphopenia (100.0%), leukopenia (85.7%), neutropenia (52.4%). 14 patients (66.7%) had adverse events of grade 3 with the most common being lymphopenia (66.7%). The maximum standardized uptake value and total lesion glycolysis of positron emission tomography/CT after neoadjuvant therapy well predicted the pathological response. The peripheral CD4+%, CD3+HLA-DR+/CD3+%, CD8+HLA-DR+/CD8+%, and IL-6 were significant differences between pCR and non-pCR groups at different times during neoadjuvant therapy. Three patients had tumor relapse and patients with MPR have longer disease-free survival than non-MPR patients. CONCLUSIONS: nCRT combined with perioperative toripalimab is effective and safe for locally advanced resectable ESCC. Long-term survival outcomes remain to be determined. TRIAL REGISTRATION NUMBER: NCT04437212.

T-cell count and T-cell telomere length in patients with severe COVID-19.

Lymphocyte telomere length (TL) is highly variable and shortens with age. Short telomeres may impede TL-dependent T-cell clonal expansion with viral infection. As SARS-CoV-2 infection can induce prolonged and severe T-cell lymphopenia, infected adults, and particularly older adults with short telomeres, may display severe T-cell lymphopenia. To examine the relationship between T-cell TL parameters and T-cell counts, we studied 40 patients hospitalized with severe COVID-19. T-cells were isolated from lymphocytes, counted using flow cytometry, and their TL parameters were measured using the Telomere Shortest Length Assay. The cohort (median age = 62 years, 27% female) was racially and ethnically diverse (33% White, 35% Black, and 33% Other). On intensive care unit study day 1, T-cell count (mean=1.03 x109/L) was inversely related to age (p=0.007) and higher in females than males (p=0.025). Mean TL was 3.88 kilobases (kb), and 45.3% of telomeres were shorter than 3 kb. Using multiple regression analysis and adjusting for age and sex, T-cell count decreased with increased proportion of T-cell telomeres shorter than 3 kb (p=0.033) and increased with mean TL (p=0.052). Our findings suggest an association between the buildup of short telomeres within T-cells and explain in part reduced peripheral blood T-cell counts in patients with severe COVID-19. Shortened T-cell telomeres may be a risk factor for COVID-19-associated T-cell lymphopenia.

Systematic review and pooled analysis of the impact of treatment-induced lymphopenia on survival of glioblastoma patients.

PURPOSE/OBJECTIVE(S): Treatment related lymphopenia is a known toxicity for glioblastoma (GBM) patients and several single-institution studies have linked lymphopenia with poor survival outcomes. We performed a systematic review and pooled analysis to evaluate the association between lymphopenia and overall survival (OS) for GBM patients undergoing chemotherapy and radiation therapy (RT). MATERIALS/METHODS: Following PRISMA guidelines, a systematic literature review of the MEDLINE database and abstracts from ASTRO, ASCO, and SNO annual meetings was conducted. A pooled analysis was performed using inverse variance-weighted random effects to generate a pooled estimate of the hazard ratio of association between lymphopenia and OS. RESULTS: Ten of 104 identified studies met inclusion criteria, representing 1,718 patients. The lymphopenia cutoff value varied (400-1100 cells/uL) and as well as the timing of its onset. Studies were grouped as time-point (i.e., lymphopenia at approximately 2-months post-RT) or time-range (any lymphopenia occurrence from treatment-start to approximately 2-months post-RT. The mean overall pooled incidence of lymphopenia for all studies was 31.8%, and 11.8% vs. 39.9% for time-point vs. time-range studies, respectively. Lymphopenia was associated with increased risk of death, with a pooled HR of 1.78 (95% CI 1.46-2.17, P < 0.00001) for the time-point studies, and a pooled HR of 1.38 (95% CI 1.24-1.55, P < 0.00001) for the time-point studies. There was no significant heterogeneity between studies. CONCLUSION: These results strengthen observations from previous individual single-institution studies and better defines the magnitude of the association between lymphopenia with OS in GBM patients, highlighting lymphopenia as a poor prognostic factor.

Lymphopenia associated with survivin and its downstream pathway in COVID-19 serving as a potential route in COVID-19 pathogenesis.

PURPOSE: Starting in 2019, coronavirus disease 2019 (COVID-19) caused an epidemic that was growing rapidly and has harmed millions of people globally. It has been demonstrated that survivin regulates lymphocyte survival, a main route involved in COVID-19 pathogenesis. Survivin belongs to the inhibitor of apoptosis protein (IAP) family, and its primary functions comprise regulating mitosis and inhibiting apoptosis. Since lower survivin expression has been shown to increase the sensitivity of lymphocytes to apoptotic induction, we looked into the function of survivin and its corresponding pathways in COVID-19 pathogenesis. MATERIALS AND METHODS: The expression of survivin, X-linked inhibitor of apoptosis protein (XIAP), caspases 3, 7, 9, and poly (ADP-ribose) polymerase (PARP) was evaluated at both mRNA and protein levels in peripheral blood mononuclear cells (PBMCs) derived from healthy donors and patients with severe and moderate COVID-19 by qRT-PCR and Western blotting, respectively. Then, we enforced apoptosis to COVID-19 patient-derived lymphocytes, and the percent was assessed by flow cytometry. RESULTS: Survivin and XIAP were less expressed in PBMCs derived from COVID-19 patients as apoptosis inhibitors than PARP, cleaved-PARP, caspase 9, and cleaved caspases 3 and 7, according to the results of real-time PCR and Western blot analysis. Additionally, according to the flow cytometry results, the down-regulation of survivin served as a potential factor in the lymphocyte depletion observed in patients with COVID-19. CONCLUSION: The role of survivin and its related pathway was first discovered in the development of COVID-19 and may serve as a potential prognostic and therapeutic target.