Objective: To explore the relationship between the hematopoietic inhibitor and apoptosis of CD34+ cells in patients with severe aplastic anemia (SAA).
Methods: The inhibiting activity to the growth of both BFU-E and CFU-GM was analysed by in vitro methylcellulose culture and CD34+ cell apoptosis was assayed with a kit of programmed cell death assay and flow cytometry.
Results: Sera from two SAA patients suppressed the growth of normal hematopoietic progenitor cells and induced CD34+ cell apoptosis. Serum immunoglobulin fraction assay showed that the inhibiting activity was in the IgG fraction which bound specifically to CD34+ cells.
Conclusion: There was an inhibitive IgG fraction, which induced CD34+ cell apoptosis, in the serum of SAA patients and CD34+ cell apoptosis might be a part of the pathogenesis of SAA.