RESUMO
CLINICAL IMPLICATIONS: Female X-linked chronic granulomatous disease (XL-CGD) carriers may develop severe clinical disease including infections with CGD-defining pathogens and inflammatory disorders. Similar to males with XL-CGD, female carriers warrant ongoing evaluation and prophylaxis where indicated.
RESUMO
BACKGROUND: B-cell affinity maturation in germinal center relies on regulated actin dynamics for cell migration and cell-to-cell communication. Activating mutations in the cytoskeletal regulator Wiskott-Aldrich syndrome protein (WASp) cause X-linked neutropenia (XLN) with reduced serum level of IgA. OBJECTIVE: We investigated the role of B cells in XLN pathogenesis. METHODS: We examined B cells from 6 XLN patients, 2 of whom had novel R268W and S271F mutations in WASp. By using immunized XLN mouse models that carry the corresponding patient mutations, WASp L272P or WASp I296T, we examined the B-cell response. RESULTS: XLN patients had normal naive B cells and plasmablasts, but reduced IgA+ B cells and memory B cells, and poor B-cell proliferation. On immunization, XLN mice had a 2-fold reduction in germinal center B cells in spleen, but with increased generation of plasmablasts and plasma cells. In vitro, XLN B cells showed reduced immunoglobulin class switching and aberrant cell division as well as increased production of immunoglobulin-switched plasma cells. CONCLUSIONS: Overactive WASp predisposes B cells for premature differentiation into plasma cells at the expense of cell proliferation and immunoglobulin class switching.
Assuntos
Linfócitos B , Neutropenia , Proteína da Síndrome de Wiskott-Aldrich , Animais , Linfócitos B/citologia , Divisão Celular , Doenças Genéticas Ligadas ao Cromossomo X , Humanos , Imunoglobulina A , Camundongos , Neutropenia/genética , Plasmócitos/patologia , Proteína da Síndrome de Wiskott-Aldrich/metabolismoRESUMO
We performed a retrospective study of coronavirus disease 2019 (COVID-19) in people with human immunodeficiency virus (PWH). PWH with COVID-19 demonstrated severe lymphopenia and decreased CD4+ T cell counts. Levels of inflammatory markers, including C-reactive protein, fibrinogen, D-dimer, interleukin 6, interleukin 8, and tumor necrosis factor α were commonly elevated. In all, 19 of 72 hospitalized individuals (26.4%) died and 53 (73.6%) recovered. PWH who died had higher levels of inflammatory markers and more severe lymphopenia than those who recovered. These findings suggest that PWH remain at risk for severe manifestations of COVID-19 despite antiretroviral therapy and that those with increased markers of inflammation and immune dysregulation are at risk for worse outcomes.