[Chronic and recurrent immune thrombocytopenic purpura]

Immune thrombocytopenic purpura (ITP) is characterized by a drop in platelet count usually accompanied by hemorrhagic diathesis. In chronic forms the platelet count remains low for six months after diagnosis and in recurrent forms the drop in platelet count appears after a period of normality.

To asses outcome and treatment response in patients with chronic or recurrent ITP.

We performed a retrospective, descriptive study of patients attended in the pediatric hematology outpatient clinic between January 1999 and December 2001.

Of 38 patients with chronic ITP, 16 (42 %) presented chronic forms and 22 (58 %) presented recurrent forms. No significant differences were found between the two groups in age, sex, diagnosis, duration of follow-up, previous viral infection, or antiplatelet antibodies. In recurrent forms, the most effective treatment was intravenous immune gamma-globulin (77 % favorable responses) but response time was short (mean: 22.1 weeks). Splenectomy produced complete remission in 63 % of the chronic forms. Good results were obtained in six patients from both groups treated with intravenous anti-D immune globulin. During the study period, 4.5 % of patients with recurrent forms and 31.5 % of those with chronic forms showed spontaneous remission without treatment.

In our experience, the most effective treatment for recurrent forms of ITP was intravenous immune globulin, but none of the treatments achieved long-term responses. In chronic forms, splenectomy is an effective alternative when the risk of hemorrhage is high, while a watchful attitude seems to be the best option when this risk is absent. Although the number of patients treated with intravenous anti-D immune globulin was low, good results were achieved.