Purposes: Clinical course and treatment outcome of childhood chronic ITP are quite variable in the literature. We report in the current paper our observation on the clinical behavior of chronic ITP in Chinese children.
Patients and methods: We performed a retrospective review (Jan. 1990 to Dec. 2000) of children having low platelet count (plt <150 x 10(9)/L) for more than 6 months without identifiable cause. The indication for treatment was plt < or =20 x 10(9)/L. Remission is defined as plt > or =150 x 10(9)/L.
Results: Thirty-four children were identified within these 11 years. Their median age at diagnosis was 6.7 years (range from 0.4 to 16.8 years). The M:F ratio was 16:18. Bone marrow aspiration was performed in 30/34 cases. The median plt count at presentation was 24 x 10(9)/L (range 2 to 135 x 10(9)/L). Fourteen of 34 (41%) children eventually achieved durable remission. The chance of remission at 5 years was 66.62% with a median follow-up time of 5.86 years (range 0.72 to 10.41 years). Concerning therapy, 17/34 (50%) required no treatment while for the remaining 17, treatment included steroid (n = 16), IVIG (n = 7) or splenectomy (n = 3). In spite of temporary improvement in most, treatment induced prolonged complete remission (plt >150 x 10(9)/L) in only 2 patients. Twenty of 31 tested had abnormal immune marker(s) at presentation but none evolved into specific autoimmune disease later on. There was no correlation between the remission status, response to treatment, and the presence of autoimmune markers.
Conclusion: About half of our chronic ITP patients achieved remission within 5 years. Medical treatment does not seem to alter the natural course of the disease but induced a transient response in most cases. Positive autoimmune markers are common among chronic ITP patients and have no significance in predicting outcome.