Increased frequency of IgD-CD27(hi)CD38(hi) B cells and its association with the renal involvement in ANCA-associated vasculitis

BACKGROUND: B cells have been highlighted in the pathogenesis of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) by the identification of activated B cells in granulomatous lesions and the efficacy of B cell depletion in treatment of AAV patients in the current study; we aimed to investigate the frequency of a specific B cell subset, IgD-CD27(hi)CD38(hi) B cells in AAV patients, and its association with the disease severity of AAV. METHODS: Blood samples of patients with AAV in active stage and in remission were collected. The frequency of IgD-CD27(hi)CD38(hi) B cells was detected by flow cytometry, and its correlation with clinicopathological parameters was analyzed. RESULTS: Our results showed a significant increase of circulating IgD-CD27(hi)CD38(hi) B cells in AAV patients in active stage compared with patients in remission and healthy donors, and the frequency of IgD-CD27(hi)CD38(hi) B cells correlated with the severity of renal involvement, including serum creatinine, estimated glomerular filtration rate, and percentages of total crescents in renal biopsies. CONCLUSIONS: The results indicated that IgD-CD27(hi)CD38(hi) B cells could reflect disease severity of renal involvement in AAV. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13075-022-02796-9.