Israel Medical Association Journal

Background: Immune cell counts in blood in severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection may be useful prognostic biomarkers of disease severity, mortality, and response to treatment.

Objectives: To analyze sub-populations of lymphocytes at hospital admission in survivors and deceased from severe pneumonia due to coronavirus disease-2019 (COVID-19).

Methods: We conducted a cross-sectional study of healthcare workers confirmed with SARS-CoV-2 in convalescents (control group) and healthy controls (HC) diagnosed with severe COVID-19. Serum samples were taken at hospital admission and after recovery. Serum samples ≥ 25 days after onset of symptoms were analyzed for lymphocyte subpopulations through flow cytometry. Descriptive statistics, Kruskall-Wallis test, receiver operating characteristic curve, calculation of sensitivity, specificity, predictive values, and Kaplan-Meier analysis were performed.

Results: We included 337 patients: 120 HC, 127 convalescents, and 90 severe COVID-19 disease patients (50 survivors, 40 deceased). For T cells, total lymphocytes ≥ 800/μL, CD3+ ≥ 400/μL, CD4+ ≥ 180/μL, CD8+ ≥ 150/μL, B cells CD19+ ≥ 80/μL, and NK ≥ 34/μL subsets were associated with survival in severe COVID-19 disease patients. All subtypes of lymphocytes had higher concentrations in survivors than deceased, but similar between HC and convalescents. Leukocytes ≥ 10.150/μL or neutrophils ≥ 10,000/μL were associated with increased mortality. The neutrophil-to-lymphocyte ratio (NLR) ≥ 8.5 increased the probability of death in severe COVID-19 (odds ratio 11.68).

Conclusions: Total lymphocytes; NLR; and levels of CD3+, CD4+, CD8+, and NK cells are useful as biomarkers of survival or mortality in severe COVID-19 disease and commonly reach normal levels in convalescents.

Background: Reference ranges for adult peripheral blood lymphocyte subsets have been established in a few countries. To the best of our knowledge no broad lymphocyte subset analysis of the Israeli population has been reported. 

Objectives: To establish reference ranges for healthy adults in Israel and to describe age- and gender-specific differences, if present.

Methods: Lymphocyte subsets CD3, CD3/CD4, CD3/CD8, CD3-/CD16+/CD56+, CD3/TCRαβ, CD3/TCRγδ, and CD19 were examined by flow cytometry in 326 subjects. Samples were subdivided according to age and gender.

Results: Women of all ages had a significantly higher percentage and absolute counts of CD3/CD4 cells than their male counterparts. Higher CD3/CD4 cells were observed also in the older population (> 50 years). CD3/CD8 and CD3-/CD16+/CD56+ were higher in males. Older males had a lower total lymphocyte percentage and CD19 cells compared to younger men. No significant gender-related differences were observed in percent and number of CD19, CD3/TCRαβ or CD3/TCRγδ at all ages.

Conclusions: These reference values could be useful in further studies for assessing changes that occur in different populations in human pathology.

 

Systemic sclerosis (SSc) is characterized by extensive collagen deposition, microvasculopathy and autoantibodies. All three features can be promoted by activation of T cells and B cells. T cells are of Th2 type producing profibrotic cytokines IL-4 and IL-13 and inducing dendritic cell maturation that promotes Th2 response. B cells are overactivated and promote fibrosis by autoantibodies that activate fibroblasts or inhibit the degradation of extracellular matrix. They also promote fibrosis by cell-cell contact with fibroblasts or dendritic cells. B cells, through autoantibodies, may promote vasoconstriction and obliterative vasculopathy. They may also sustain activation of T cells by functioning as antigen-presenting cells. An immunoregulatory subset of B cells, namely IL-10-producing Bregs, is decreased in SSc. Finally, B cells have a critical role in animal models of SSc. All this evidence suggests an important role for B cells in the pathogenesis of SSc and makes B cells a potential target for therapeutic intervention in this disease. 

 

Background: Several studies have identified associations between low vitamin D concentrations and risk of upper respiratory infections (URI). T lymphocytes have a major anti-viral role, are affected by vitamin D metabolism, and may mediate the link between vitamin D and URIs. Competitive swimmers have a relatively high rate of URIs, alongside a high prevalence of low vitamin D concentration. 

Objectives: To examine the associations linking T cell receptor excision circles (TREC, markers of thymus activity), circulating 25(OH)D concentrations and the effect of vitamin D supplementation, and URI symptoms in young competitive swimmers.

Methods: We tested 82 adolescent swimmers for serum 25(OH)D and TREC concentrations and found that 55 had vitamin D insufficiency. Randomized supplementation of either vitamin D3 or placebo was given for 12 winter weeks. URI symptoms were recorded weekly. The associations between TREC copy numbers, vitamin D and URI burden were examined.

Results: TREC concentrations decreased with the participants’ age (r = -0.346, P = 0.003), with no significant between-gender difference. TREC concentrations did not materially differ among subjects with normal, insufficient or deficient vitamin D status, and were not affected by vitamin D supplementation. No significant correlations were found between TREC levels or their changes during the study period, and mean URI severity or duration. 

Conclusions: Thymus activity, represented by higher TREC levels, was not related to vitamin D concentrations or status, and was not affected by vitamin D supplementation in adolescent swimmers. TREC concentrations were not associated with URI severity or duration in this population.

 

Current treatments for systemic lupus erythematosus (SLE) are effective in reducing morbidity and mortality but are not specific and have severe adverse effects. Based on understanding of the different dysregulated immunological pathways involved in SLE pathogenesis, specific targeted therapies were developed. This review presents the current and the near-future novel biological immune targeted treatments, such as B cell-targeted therapy, cytokine blockade, peptide-based treatments and other novel treatments for SLE.
 

Background: Metastatic melanoma is an aggressive and highly malignant cancer. The 5 year survival rate of patients with metastatic disease is less than 5% with a median survival of only 6–10 months. Drugs like dacarbazin (DTIC) as a single agent or in combination with other chemotherapy agents have a response rate of 15–30%, but the duration of response is usually short with no impact on survival. Interleukin-2-based immunotherapy has shown more promising results. The National Institutes of Health recently reported that lymphodepleting chemotherapy, followed by an adoptive transfer of large numbers of anti-tumor specific tumor-infiltrating lymphocytes, resulted in an objective regression in 51% of patients.

Objectives: To introduce the TIL[1] technology to advanced metastatic melanoma patients in Israel.

Methods: We generated TIL cultures from tumor tissue, choosing those with specific activity against melanoma and expanding them to large numbers.

Results: TIL cultures from nine patients were established and examined for their specific activity against the patients' autologous tumor cells. Twelve TIL cultures derived from 5 different patients showed the desired anti-tumor activity, making those 5 patients potential candidates for the therapy.

Conclusions: Pre-clinical studies of the TIL technology in a clinical laboratory set-up were performed successfully and this modality is ready for treating metastatic melanoma patients at the Sheba Medical Center's Ella Institute.

Background: The etiology of bone marrow failure, a prominent feature of paroxysmal nocturnal hemoglobulinuria, is presently unknown.

Objectives: To evaluate the possible influence of cellular immune mechanisms in the bone marrow failure of PNH.

Methods: We studied marrow erythroid colony formation in a patient with paroxysmal nocturnal hemoglobinuria without hypoplastic/aplastic marrow complications.

Results: In vitro assays revealed a pronounced inhibition of primitive erythroid (BFU-E) progenitor cell growth by marrow T lymphocytes. Removal of T cells prior to culture resulted in a 4.5-fold enhancement of BFU-E numbers. Reevaluation of in vitro erythropoiesis during steroid administration indicated a persistent, albeit less prominent, T cell inhibitory effect.

Conclusion: Our findings provide the first direct evidence for a cellular immune inhibitory phenomenon accompanying PNH.

_____________________________ 

PNH= paroxysmal nocturnal hemoglobinuria