[Colony formation of bone marrow hematopoietic progenitor cells in patients with severe aplastic anemia and its relation to the results of immunosuppressive therapy].

OBJECTIVE: To explore the defect of hematopoietic stem cell and analyze the relationship between the colony formation capacity of bone marrow hematopoietic progenitor cells and the results of immunosuppressive therapy (IST) in severe aplastic anemia (SAA) patients. METHODS: Methylcellulose semisolid culture was used. RESULTS: Thirty patients with SAA at diagnosis were studied. In 90% of the patients, the CFU-E and CFU-GM yields were strikingly decreased and in 56.7% of the patients there was no colony formation at all. Nevertheless, there was still 10% of the patients having normal CFU-E, BFU-E or/ and CFU-GM yields. After IST, 59.1% of the patients showed colony formation improvement. The difference between the results obtained pre- and post-IST(for CFU-E and BFU-E, P < 0.01, for CFU-GM, P < 0.05) was significant. In the majority of the patients, the colony formation capacities were still under the normal post-IST. Moreover, 22.7% of the patients remained no colony formation post-IST. The IST response rates between the patients with or without colony formation had no statistically difference (80% versus 50%, P < 0.05). The increment of colony formation appeared later than the therapeutic effect did, but frequently concurred with the appearance of magkaryocytes in the bone marrow smear. CONCLUSION: In the majority of SAA patients, the hematopoietic stem cells or progenitors were defective perhaps caused by immune damage; IST can improve the hematopoiesis in vitro and in vivo of SAA patients.