IDIOPATHIC THROMBOCYTOPENIA AND NEUTROPENIA IN CHILDHOOD

Purpose: Between 1975 and 1990, 13 patients seen at The Hospital for S ick Children, Toronto, Ontario, were noted to have concurrent idiopath ic thrombocytopenia and neutropenia (ITN; platelet count < 150 X 10(9) /L; absolute neutrophil count <1.5 X 10(9)/L). These patients all had normal marrow function and no evidence of systemic disease. Patients a nd Methods: A detailed chart review was performed to define the clinic al and laboratory features of these patients. Results: Although this w as a heterogeneous group of patients, they shared several common chara cteristics. The disease followed a chronic course with thrombocytopeni a or neutropenia or both that persisted or recurred over the entire pe riod of follow-up in all patients (18 months to 15 years). The disease was associated with splenomegaly in eight patients and lymphadenopath y in nine patients. Boys were affected more frequently than were girls (ratio 11:2). Thrombocytopenia improved temporarily during treatment with corticosteroids, i.v. immunoglobulin G, RhoGAM, and a variety of immunosuppressive agents; however, neutropenia tended to be much more resistant to these therapies. Splenectomy was ineffective in two child ren in whom the procedure was performed. Platelet and neutrophil antib odies or both were detected in five of six patients who were tested, s uggesting an autoimmune cause for the cytopenias. Conclusions: These f indings suggest that ITN in childhood is distinct from immune thromboc ytopenic purpura, particularly in terms of its chronicity and poor res ponse to therapy.