CD19 and eosinophilic granulomatosis with polyangiitis: Tsurikisawa et al. (49) showed a significant increase in the proportion of B lymphocytes positive for CD80, CD27, and CD95 in the blood of EGPA patients with frequent relapses, while those with the seldom-relapsing disease had higher CD19-positive B-cell counts and higher serum IgG levels, suggesting that frequently relapsing EGPA is associated with induced B-cell apoptosis.