Regulatory T cells and CD20 + B cells in pediatric very severe aplastic anemia: possible clinical markers for evaluating the therapeutic efficacy and prognosis.

OBJECTIVES: To investigate the immune status of children with very severe aplastic anemia (VSAA), and evaluate the frequencies of CD20+ B cells and Regulatory T cells (Tregs) as potential markers for evaluating the therapeutic efficacy and prognosis.

METHODS: We systematically analyzed CD20+ B cells and Tregs using Flow Cytometry in 36 children with VSAA (14 newly diagnosed cases and 22 cases in remission after therapy with HDIVIG + r-ATG + CSA).

RESULTS: In newly diagnosed VSAA patients, the percentage of CD20+ B cells was higher than that in healthy children (P < .01), whereas the percentage of Tregs was lower than that in healthy children (P < .001). After treatment with HDIVIG + r-ATG + CSA, the percentage of CD20+ B cells in peripheral blood was decreased obviously, and the percentage of Tregs was significantly increased.

CONCLUSION: There is a moderate negative correlation between the percentage of Tregs and CD20+ B cells in our study. Our results shed light on the roles of Tregs and CD20+ B cells as therapeutic efficacy and prognostic markers of pediatric VSAA. Moreover, the mechanism underlying the decrease of blood Tregs and increase of CD20+ B cells in pediatric VSAA patients have been discussed, indicating that Tregs may suppress B cell responses.