A Prospective Study Investigating Immune Checkpoint Molecule and CD39 Expression on Peripheral Blood Cells for the Prognostication of COVID-19 Severity and Mortality.

In patients with COVID-19, broad panels of immune checkpoint molecules (ICPMs) and the purinergic signaling have not been studied in parallel. We aimed to perform in-depth immunophenotyping of major cell subsets present in human peripheral blood of COVID-19 patients and controls using PD1, TIM3, LAG3, TIGIT, and CD200R, as well as CD39, as markers for the purinergic signaling pathway. We studied 76 COVID-19 patients and 12 healthy controls using peripheral blood mononuclear cells on flow cytometry. Univariable and multivariable statistics were performed. All ICPMs studied were significantly overexpressed on different cell subsets of COVID-19 patients when compared with healthy controls. Elevated lactate dehydrogenase; C-reactive protein; age; and high expression of CD45+, CD39+CD45+, TIM3+CD39+CD4+CD45+, and TIM3+CD39+CD8+CD3+CD4+ cells were significantly associated with severe COVID-19. On multivariable analysis, however, only high expression of CD39+CD45+ (OR 51.4, 95% CI 1.5 to 1763) and TIM3+CD39+CD4+CD3+CD45+ (OR 22.6, 95% CI 1.8 to 277) cells was an independent predictor for severe COVID-19. In conclusion, numerous ICPMs are overexpressed in COVID-19 patients when compared with healthy controls, suggesting a pathophysiological role of these molecules in SARS-CoV-2 infection. However, only TIM3 in co-expression with CD39 remained as a significant independent prognostic ICPM on multivariable analysis. The flow cytometric evaluation of TIM3+CD39+CD4+CD3+CD45+, as well as CD39+CD45+, is a powerful tool for the prognostication of COVID-19 patients on hospital admission.

A Brief Communication on Circulating PD-1-positive T-Regulatory Lymphocytes in Melanoma Patients Undergoing Adjuvant Immunotherapy With Nivolumab.

Upregulation of T-regulatory lymphocytes (Tregs) is one of numerous immune escape mechanisms of malignancies. In the present pilot study we aimed to study the effect of adjuvant nivolumab during the initiation of treatment on circulating Tregs subpopulations in patients with stage III melanoma. We subsequently recruited patients with stage III melanoma who had the indication for adjuvant anti-programmed death 1 (PD-1) treatment with nivolumab. Blood collections were performed before the initiation of nivolumab and before every 2-week therapy cycle. Flow cytometry was performed for the determination of circulating CD4CD25highCD127PD-1(PD-1Tregs) and CD4CD25highCD127CTLA-4 (CTLA-4Tregs) Treg populations. Circulating PD-1Tregs [18.1% (range, 2.9%-41.7%) vs. 4.2% (0.4%-9.8%), P=0.0001] significantly decreased after the first cycle of immunotherapy and maintained decreased during a 3-month course of treatment. By contrast, CTLA-4Tregs significantly increased after the first nivolumab dose when compared with CTLA-4Tregs before the second treatment [0.75 (0-45.5) vs. 2.1 (0.1-90.8), P=0.0002]. Blood levels of PD-1Tregs and CTLA-4Tregs remained more or less decreased and increased during a 3-month therapy with nivolumab, respectively. Data of PD-1Tregs as well as CTLA-4Tregs was not significantly associated with frequencies of immune-related adverse events (P<0.05). In conclusion, we have demonstrated that circulating PD-1Tregs of melanoma patients in stage III rapidly and continuously decline after the initiation of adjuvant treatment with the PD-1 blocking antibody nivolumab. By contrast, this decline is paralleled with an increase of CTLA-4Tregs. The expression of PD-1 and CTLA-4 on Tregs might be a potential biomarker for the efficacy of immune checkpoint blockade in melanoma.

Cutaneous leukocytoclastic vasculitis: the role of lymphocytes and related immune markers.

INTRODUCTION: Apart from neutrophils, other immune cells may play a significant pathogenetic role in cutaneous leukocytoclastic vasculitis (CLV). AIM: To investigate lymphocytes and related immunological factors in patients with CLV requiring systemic glucocorticosteroid treatment. MATERIAL AND METHODS: Fourteen patients with severe idiopathic CLV were treated with systemic prednisolone in a tapered dose regimen. Ten healthy individuals served as controls. At baseline and post-treatment, we studied inducer/helper and suppressor/cytotoxic T lymphocytes, B lymphocytes, natural killer cells, CD4+CD25++CD127- cells, CD4+CD25+CD39+ cells and FOXP3, transforming growth factor ß1 (TGF-ß1) and interleukin-10 (IL-10) mRNA levels in the blood using flow cytometry and real time polymerase chain reaction (RT-PCR), respectively. On immunohistochemistry, we studied CD4, CD8, granzyme B, TGF-ß1, and IL-10. RESULTS: Flow cytometry did not show significant differences. The RT-PCR revealed that TGF-ß1 mRNA expression was significantly higher after therapy when compared to baseline and controls. On immunohistology, baseline CLV lesions showed significantly more CD4+ lymphocytes than post-treated CLV and controls. CD8+ expression was significantly higher after therapy when compared to baseline and controls. Baseline granzyme B was significantly increased when compared to treated CLV and controls. The IL-10 expression of treated CLV was significantly increased when compared to baseline CLV and; baseline CLV IL-10 expression was significantly increased as compared to controls. CONCLUSIONS: Circulating T regulatory cells do not play a significant role in the pathogenesis of CLV. T helper cells and granzyme B seem to be involved in the inflammatory cutaneous process of CLV. A resolution of CLV observed after glucocorticosteroid treatment may be mediated via up-regulation of TGF-ß1 and IL-10 in different compartments.

Towards Profiles of Resistance Development and Toxicity for the Small Cationic Hexapeptide RWRWRW-NH2.

RWRWRW-NH2 (MP196) is an amphipathic hexapeptide that targets the bacterial cytoplasmic membrane and inhibits cellular respiration and cell wall synthesis. In previous studies it showed promising activity against Gram-positive bacteria and no significant cytotoxicity or hemolysis. MP196 is therefore used as lead structure for developing more potent antibiotic derivatives. Here we present a more comprehensive study on the parent peptide MP196 with regard to clinically relevant parameters. We found that MP196 acts rapidly bactericidal killing 97% of initial CFU within 10 min at two times MIC. We were unable to detect resistance in standard 24 and 48 h resistance frequency assays. However, MP196 was effective against some but not all MRSA and VISA strains. Serum binding of MP196 was intermediate and we confirmed its low toxicity against mammalian cell lines. MP196 did neither induce NFκB activation nor cause an increase in IL8 levels at 250 µg/mL, and no IgE-dependent activation of basophil granulocytes was detected at 500 µg/mL. Yet, MP196 demonstrated acute toxicity in mice upon injection into the blood stream. Phase contrast microscopy of mouse blood treated with MP196 revealed a shrinking of erythrocytes at 250 µg/mL and severe morphological changes and lysis of erythrocytes at 500 µg/mL. These data suggest that MP196 derivatization directed at further lowering hemolysis could be instrumental in overcoming acute toxicity. The assessment of hemolysis is a critical step in the evaluation of the clinical potential of promising antimicrobial peptides and should be accompanied by microscopy-based morphological analysis of blood cells.

Severe dyslipidemia and immune activation in HIV patients with dysglycemia.

BACKGROUND AND OBJECTIVE: Diabetes mellitus (DM) is common in human immunodeficiency virus (HIV)-infected patients. However, the relationship between dysglycemia, lipid metabolism, and immune activation in HIV patients is poorly understood. METHODS: We retrospectively analyzed the clinical data of 180 HIV patients, including 153 patients undergoing highly active antiretroviral therapy (HAART) and 27 HAART-naive patients. DM was defined as fasting serum glucose levels ≥126 mg/dl, and impaired fasting glucose (IFG) was defined as serum glucose levels of 101-125 mg/dl at two different time points. Lipid metabolic indexes were measured. CD4+, CD8+, and CD8+ HLA-DR+ T cells were determined by flow cytometry. RESULTS: IFM and DM percentages were higher in the HAART group than in the HAART-naive group (59.5% vs. 48.1% and 21.6% vs. 7.4%, respectively; p < 0.01). Additionally, DM percentage was high in patients receiving HAART containing protease inhibitors. Serum levels of triglycerides and very low-density lipoprotein cholesterol were higher in IFG and DM HAART patients than in euglycemic HAART patients (p < 0.05). Serum triglyceride levels were higher in HAART-naive DM patients than in other patients (p < 0.05). CD8+ and CD8+ HLA-DR+ cell counts were higher in IFG and DM HAART patients than in euglycemic HAART patients (p < 0.05). Ordinal logistic regression analysis suggested that TRIG, VLDL, CD8, and HAART were predictors of glucose metabolic disorders. CONCLUSION: HIV patients with hyperglycemia have severe dyslipidemia and immune activation, and HAART is an important impact factor of glucose and lipid metabolic disorders.

Prevalence and Influencing Factors of Thyroid Dysfunction in HIV-Infected Patients.

Thyroid dysfunction is more common in human immunodeficiency virus (HIV) patients. But the effects of highly active antiretroviral therapy (HAART) and hepatitis B/C virus (HBV/HCV) coinfection on thyroid function is unclear. We retrospectively reviewed the data of 178 HIV patients and determined the prevalence of thyroid dysfunction and the relationship between thyroid hormone levels, CD4 cell count, HIV-1 duration, HAART duration/regimens, and HBV/HCV coinfection. Of the 178 patients, 59 (33.1%) had thyroid dysfunction, mostly hypothyroidism. Thyroid dysfunction was significantly more frequent in the HAART group (41/104, 39.4%) than in the HAART-naïve group (18/74, 24.3%; P < 0.05). The mean CD4 cell count was significantly lower in patients with hypothyroidism (372 ± 331/µL) than in the other patients (P < 0.05). The FT4 level was significantly lower in the HAART group than in the HAART-naïve group (1.09 ± 0.23 versus 1.20 ± 0.29 pg/mL, P < 0.05). FT3/FT4 levels were negatively related to HIV duration and FT3 levels were positively related to CD4 cell (P < 0.05). HBV patients had lower FT3 levels, while HCV patients had higher FT3 and FT4 levels (P < 0.05). Thyroid dysfunction is more common in HIV patients on HAART, mainly manifested as hypothyroidism. FT3/FT4 levels are correlated with HIV progression. HBV/HCV coinfection increases the probability of thyroid dysfunction.

RNA polymerase III autoantibodies may indicate renal and more severe skin involvement in systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a multiorgan autoimmune disorder characterized by sclerosis of the skin and organs as well as the presence of antinuclear autoantibodies. Several types of antinuclear autoantibodies have been described in SSc, associated with distinct disease entities and differences in prognosis. METHODS: The aim of this study was to screen for the presence of antibodies reacting with RNA polymerase III (anti-RNAP3) in a large cohort of patients with SSc treated at a tertiary referral center and to evaluate correlations with disease severity. RESULTS: Anti-RNAP3 antibodies were detected in 11 of 158 patients (7.0%). Eight of the 11 (72.7%) anti-RNAP3-positive patients had diffuse cutaneous SSc (P < 0.01). A higher modified Rodnan skin score, associated with diffuse SSc, correlated with the presence of anti-RNAP3 (P < 0.0001). The detection of anti-RNAP3 antibodies strongly correlated with the presence of renal involvement (P < 0.0001). The odds ratio of RNAP3-positive patients to develop renal involvement was 80.1 (95% CI 9.3-690.1). CONCLUSIONS: This study demonstrates that the detection of anti-RNAP3 antibodies in patients with SSc correlates with renal crisis and severe cutaneous involvement. The possibility to detect specific antibodies with a prognostic value can lead to a better risk management of patients with SSc.

Mitochondrial haplogroup H correlates with ATP levels and age at onset in Huntington disease.

Mitochondrial dysfunction has been implicated in the pathogenesis of Huntington disease (HD), a primarily neurodegenerative disorder that results from an expansion in the polymorphic trinucleotide CAG tract in the HD gene. In order to evaluate whether mitochondrial DNA (mtDNA) variation contributes to HD phenotype we genotyped 13 single nucleotide polymorphisms (SNPs) that define the major European mtDNA haplogroups in 404 HD patients. Genotype-dependent functional effects on intracellular ATP concentrations were assessed in peripheral leukocytes. In patients carrying the most common haplogroup H (48.3%), we demonstrate a significantly lower age at onset (AO). In combination with PGC-1 alpha genotypes, 3.8% additional residual variance in HD AO can be explained. Intracellular ATP concentrations in HD patients carrying the cytochrome c oxidase subunit I (CO1) 7028C allele defining haplogroup H were significantly higher in comparison to non-H individuals (mean +/- SEM, 599 +/- 51.8 ng/ml, n = 14 vs. 457.5 +/- 40.4 ng/ml, p = 0.03, n = 9). In contrast, ATP concentrations in cells of HD patients independent from mtDNA haplogroup showed no significant differences in comparison to matched healthy controls. Our data suggest that an evolutionarily advantageous mitochondrial haplogroup is associated with functional mitochondrial alterations and may modify disease phenotype in the context of neurodegenerative conditions such as HD.

Detection of clonal T cells in the circulation of patients with nephrogenic systemic fibrosis.

BACKGROUND: Nephrogenic systemic fibrosis is a sclerodermalike disease in patients with acute or chronic renal insuffiency related to administration of gadolinium-containing contrast agents. Previous studies have demonstrated clonal T-cell populations in the blood of patients with systemic sclerosis, suggesting that these cells may be involved in the pathogenesis of the disease. Facing the clinical similarities of both diseases, we hypothesized that clonal expansion of T cells could be present in nephrogenic systemic fibrosis as well. OBSERVATIONS: Findings from polymerase chain reaction and high-resolution capillary electrophoresis for T-cell receptor gamma gene rearrangement analysis showed that all 6 prospectively evaluated patients (100%) with nephrogenic systemic fibrosis had detectable clonal T cells in their peripheral blood. In contrast, only 4 of the 15 control patients (27%) with chronic renal failure and none of the 12 healthy individuals analyzed in this study had evidence for T-cell clonality using the same type of examination. Clonal T-cell-positive patients with systemic sclerosis have previously been reported to better respond to extracorporeal photopheresis. However, this was not the case in 2 of our patients with nephrogenic systemic fibrosis. Conclusion As in systemic sclerosis, clonally expanded T-cell populations could play a critical role in the pathogenesis of nephrogenic systemic fibrosis, probably as an in vivo-activated inflammatory response to gadolinium exposure.

[Effect of HIV-1 infection on apoptosis of CD4+ T lymphocytes mediated by Fas].

OBJECTIVE: To study the pathogenic role of Fas/CD95 in HIV-1 infection subjects, and to investigate the effects of HIV on plasma levels of sFas and the expression of CD95 on different CD4(+) T lymphocyte subpopulations. METHODS: Four-color flow cytometry was used to determine the expression of CD95, CD45RO, CD45RA on CD4(+ )T lymphocyte in peripheral blood from HIV-1 infection subjects and serum Fas levels were quantified by enzyme-linked immunosorbent assay (ELISA). RESULT: Compared with healthy controls, serum Fas levels were significantly increased (P<0.05) in HIV group and positively correlated with the disease progress. The expression of CD95 on naive T-lymphocyte subsets was increased whereas that on memory T-lymphocyte subsets was decreased. CONCLUSION: Fas plays an important role in the deletion of CD4(+) T-lymphocyte during HIV-1 infection. Further understanding of the relationship between Fas/CD95 and CD45RO/CD45RA may help to predict the progression of the disease and the clinical outcome.

[Expression of co-receptor on different T lymphocytes subpopulations after effective HAART].

OBJECTIVE: To measure CCR5 and CXCR4 chemokine receptor expression on CD4 and CD8 T cells in HIV-1 infection and to relate levels to the distribution of CD45RO memory and CD45RA-naive subsets after effective HAART. METHODS: Four-color cytofluorometry with appropriate conjugated monoclonal antibodies (mAbs) was performed to define CD45RA and CD45RO subsets of CD4 and CD8 T cells and measure the expression of CCR5, CXCR4 in blood from 43 received HAART patients and 5 non-treated HIV and 13 healthy controls. RESULTS: The levels of CCR5 and CXCR4 on CD4 and CD8 T cells and their CD45RO/CD45RA subsets in HIV-1-infected patients had not any statistical significance than that on control subjects and effective HAART could adjust the expression on T cells. CONCLUSION: CXCR4/CCR5 plays an important role in the progress of HIV-1 infection. The most favorable condition for treatment should be initiated before stage B.

[Evaluation of serum interleukin-18 and interleukin-10 in patients with HIV-1 and hepatitis viruses co-infected subjects].

OBJECTIVE: To study the significance of cytokines in patients with HIV and hepatitis viruses co-infection. METHODS: Serum levels of IL-18 and IL-10 were measured by enzyme-linked immunosorbent assay (ELISA). HIV-RNA levels were measured in EDTA plasma by quantitative reverse polymerase chain reaction (PCR). CD4(+) lymphocyte counts were determined by four-color Flow cytometry (FCM). RESULTS: The levels of IL-18 were significantly higher in HIV-infected persons compared with those in controls (P<0.05). With HIV disease progression, IL-18 levels increased while Il-10 levels decreased. HCV patients showed lower levels of IL-18 and IL-10 than those of the co-infection group. CONCLUSION: Univariate analyses shows significant co-variables IL-10 in co-infection. Up-regulating IL-18 activity and/or down-regulating IL-10 may be a potential therapy to patients with HIV and hepatitis viruses co-infection.

[Immune activation in AIDS related Kaposi's sarcoma].

OBJECTIVE: To study the pathogenesis role of immune system activation in AIDS related Kaposi's sarcoma(AIDS-KS). METHODS: The serum levels of sFas, beta 2-microglobin, IL-10, IL-16, IL-18, IL-6 and sIL-4R were detected by ELISA in 8 AIDS-KS patients, 28 patients with HIV infection but without Kaposi's sarcoma(HIV-NKS) and 16 normal controls. The lymphocyte and their subsets, CD38(+) CD8, HLA-DR(+)CD8 in the peripheral blood mononuclear cell (PBMCs) in 12 AIDS-KS and 32 HIV-NKS were detected by flow cytometer. RESULTS: Beta 2-MG and sIL-4R in HIV-NKS were significantly higher than those in normal controls(P<0.05), IL-16 in HIV-NKS was significantly lower than that in controls(P<0.05). IL-18 was higher in both AIDS-KS and HIV-NKS compared with normal controls. In AIDS-KS, CD3, CD4, CD8, NK and HLA-DR(+)CD8 were lower than those in HIV-NKS whereas CD19 and CD38(+)CD8 were higher than those in HIV-NKS. But the difference was not statistically(P<0.05). CONCLUSION: Although both AIDS-KS and HIV-NKS demonstrate some activation of immune system, there appears to be no significant difference between immune responses in KS and NKS patients. These data suggest that the activation of the immune system is unlikely to contribute significantly to the pathogenesis of AIDS-KS.