Phenotyping of P105-Negative B Cell Subsets in Patients with Systemic Lupus Erythematosus

This study aimed to investigate phenotype of RP105(−) B cell subsets in patients with systemic lupus erythematosus (SLE). Flow cytometry was used for phenotyping RP105-negaive B cell subsets. Based on CD19, RP105, and CD138 expression, RP105(−) B cells consist of at least 5 subsets of late B cells, including CD19(+)RP105(int), CD19(+) RP105(−), CD19(low) RP105(−) CD138(−), CD19(low) RP105(−)CD138(int), and CD19(low) RP105(−) CD138(++) B cells. Especially, CD19(+)RP105(int) and CD19(low) RP105(−)CD138(int) B cells are significantly larger than other RP105(−) B cell subsets in SLE. By comparison of RP105(−) B cell subsets between patients with SLE and normal subjects, these subsets were detectable even in normal subjects, but the percentages of RP105(−) B cell subsets were significantly larger in SLE. The phenotypic analysis of RP105(−) B cell subsets suggests dysregulation of later B cell subsets in SLE and may provide new insights into understanding regulation of B cells in human SLE

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

Additional file 1: of The balance between Foxp3 and Ror-Îłt expression in peripheral blood is altered by tocilizumab and abatacept in patients with rheumatoid arthritis

The expression levels of master regulator genes and clinical responses to ABT or TCZ. (XLSX 47 kb

Beneficial use of serum ferritin and heme oxygenase-1 as biomarkers in adult-onset Still’s disease: A multicenter retrospective study

<p><b>Background:</b> Heme oxygenase (HO)-1 is a heme-degrading enzyme highly expressed in monocyte/macrophage, serum levels of which may be promising biomarker for adult-onset Still’s disease (AOSD). We here report data on the use of serum ferritin and HO-1 levels in AOSD.</p> <p><b>Methods:</b> Under the Hypercytokinemia Study Group collaboration, we collected sera from a total of 145 AOSD patients. Three independent experts judged whether the patients were definite AOSD depending on the clinical information. These 91 ‘definite AOSD’ patients were further divided into active, remission, and relapse groups. Forty-six cases of systemic vasculitis, sepsis, etc. were included as disease controls. Serum ferritin and HO-1 levels were measured using ELISA. Associations between clinical symptoms, serum ferritin, and HO-1 were explored. Multivariate regression analysis was performed to identify independent variables associated with definite AOSD diagnosis.</p> <p><b>Results:</b> Serum ferritin and HO-1 levels were significantly higher in active and relapsed AOSD cases compared to disease controls, and were reduced by the treatment. Although a significant correlation was found between serum ferritin and HO-1 levels, a discrepancy was found in some cases such as iron-deficiency anemia. Receiver operating characteristic analysis identified optimal levels of serum ferritin (>819 ng/ml; sensitivity 76.1% and specificity 73.8%), and serum HO-1 (>30.2 ng/ml; sensitivity 84.8% and specificity 83.3%) that differentiated AOSD from controls. Interestingly, 88.9% of patients with AOSD who relapsed exceeded the cut-off value of serum HO-1 > 30.2 ng/ml, but only 50.0% exceeded serum ferritin >819 ng/ml (<i>p</i> = .013), suggesting that serum HO-1 levels may be a convenient indicator of AOSD disease status. Multivariate analysis identified neutrophilia, RF/ANA negativity, sore throat, and elevated serum HO-1 as independent variables associated with AOSD diagnosis.</p> <p><b>Conclusion:</b> We confirmed that serum ferritin and HO-1 serve as highly specific and sensitive biomarkers for AOSD. A future prospective study with large sample size is necessary to determine whether these biomarkers could be included in Yamaguchi’s Criteria.</p