Thrombopoietin may not play an important role in change of platelets in chronic hepatitis B patients with thrombocytopenia treated by lamivudine

초록

Background/Aims: Thrombopoietin (TPO) mainly produced in liver is an important cytokine for thrombopoiesis. In patients with chronic hepatitis B (CHB), lamivudine leads to significant biochemical and histologic improvement. However, the effect of lamivudine on peripheral blood platelets has not been reported. The aims of this study were to determine the changes of platelets and serum TPO levels in CHB patients during lamivudine therapy, and to clarify the role of TPO in the change of platelet counts. Methods: 79 CHB patients were included (Group A, baseline platelet count less than 100; B, 100-150; C, more than 150 x 103/ul). Platelet counts and serum TPO level were measured before, month 3, 6, 12 after lamivudine treatment. Results: In 79 patients, platelets (12 Mo vs baseline, 149.5 vs 127.3 x 103/ul, p = 0.000) and TPO (12 Mo vs baseline, 185.5 vs 103.9 pg/ml, p = 0.001) were increased during lamivudine treatment. These changes of platelet and serum TPO level were not different among group A, B and C. While platelets were significantly increased during the initial half of 12 months of lamivudine treatment, serum TPO level was increased during the later half of this treatment period. There was no significant difference in percentile changes of serum TPO (132% vs 125%, p > 0.05) between two groups with platelet elevation (n = 40) and without elevation (n = 39) based on median percentile change of platelets. Conclusion: Lamivudine treatment increases not only in platelets but also in serum TPO level significantly in CHB. However, serum TPO may not play an important role in changes of platelets in this situation because increase in platelet precedes increase in serum TPO level.