[Apoptosis and proliferation of CD34 positive bone marrow cells in patients with polycythemia vera].

Objective: To study the apoptosis and proliferation of CD(34) positive (CD(34)(+)) bone marrow cells (BMC) in patients with polycythemia vera (PV).

Methods: The expression of Annexin V and Ki67 of the CD(34)(+) BMC in 20 PV patients and control cases [10 essential thrombocythemia (ET), 12 normal persons] were assessed by bicolor flow cytometry (FCM), and the correlation between apoptosis and clinical situation was analysed in PV patients.

Results: The Annexin V expressions of CD(34)(+) BMC were (15.96 +/- 1.45)% in PV patients and (15.53 +/- 1.76)% in ET patients which were lower than that in normal subjects [(23.61 +/- 3.89)%, (P < 0.05)]. The Ki67 expression of CD(34)(+) BMC was (48.79 +/- 11.68)% in PV patients and (49.60 +/- 9.98)% in ET patients, which were significantly higher than that in normal controls (33.87 +/- 6.82)%. The ratio of apoptosis/proliferation in PV patients was 0.33 +/- 0.10 and in ET patients 0.32 +/- 0.02 which were significantly lower than that in normal controls 0.72 +/- 0.11 (P < 0.01). The apoptosis of CD(34)(+) BMC was negatively correlated with the hemoglobin (Hb) levels (r = -0.481, P = 0.037), white blood cells (WBC) (r = -0.538, P = 0.026) and the numbers of endogenous erythroid colony (EEC) (r = -0.632, P = 0.50), and the ratio of apoptosis/proliferation was negatively correlated with the Hb (r = -0.537, P = 0.018) and WBC (r = -0.667, P = 0.003) in PV patients.

Conclusion: There were lower apoptosis and higher proliferation in CD(34)(+) BMC of PV patients. Lower apoptosis was correlated with the severity of the disease.