CD19+CD24hiCD38hi Regulatory B cells Involved in Hepatic Alveolar Hydatid Infection in Humans

: In larval Echinococcus multilocularis infections causing alveolar echinococcosis (AE) in humans, immune tolerance and/or down-regulation of protective immunity is a marked characteristic of this chronic disease. In order to probe whether CD19+CD24hiCD38hi regulatory B cells (Bregs) took part in the immune suppression, the frequencies of these cells in peripheral blood were analyzed by flow cytometry, and the level of IL-10 and TGF-β were detected in serum through ELISA of AE patients and healthy individuals. The distribution of IL-10 and TGF-β in hepatic tissue close to or distant from the lesion of AE patients was detected by immunohistochemistry separately. The results showed that the frequencies of Bregs and the level of IL-10 and TGF-β increased significantly in AE patients compared with healthy individuals and the distribution of IL-10 and TGF-β in hepatic tissue close to the lesion was more abundant than in the hepatic tissue distant from lesion. Taken together, the Bregs frequency and the interrelated cytokines (IL-10 and TGF-β) have a positive correlation to the hepatic alveolar hydatid infection in humans.