Recombinant interleukin-6 in the treatment of congenital thrombocytopenia associated with absent radii

Purpose: The role of interleukin-6 (IL-6) in the treatment of congenital thrombocytopenias is unknown. The purpose of this case report is to describe the efficacy of IL-6 in a child with thrombocytopenia with absent radii (TAR) syndrome. Methods: A 23-month-old girl with TAR syndrome was treated with recombinant IL-6 (Sigosix; Serono Laboratories, Norwell, MA) at a dose of 7 mu g/kg subcutaneously daily. Complete blood counts were monitored weekly. The child was closely monitored for any toxicity. Results: After 3 weeks of therapy, the patient had an increase in platelet count from a baseline of 5,000 to 8,000/mu l to a maximal level of 33,000/mu l. She was platelet transfusion-independent during IL-6 therapy. Fevers and chills, the main toxicities encountered, were controlled with acetaminophen and ibuprofen. An increase in the IL-6 dose caused anemia with no further increase in platelet count. After discontinuation of the drug, her hemoglobin rose to baseline and the platelet count returned to pretreatment levels. Conclusions: We conclude that IL-6 may benefit some children with TAR syndrome. The role of IL-6 and other thrombopoietic agents in the treatment of TAR and other congenital thrombocytopenias deserves further clinical study.