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(+)CD24(hi)CD38(hi) 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-beta were detected in serum through ELISA of AE patients and healthy individuals. The distribution of IL-10 and TGF-beta 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-beta increased significantly in AE patients compared with healthy individuals and the distribution of IL-10 and TGF-beta 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-beta) have a positive correlation to the hepatic alveolar hydatid infection in humans.