Preliminary report: effects of interleukin-1 on platelet counts.

Recombinant human interleukin-1 beta was given in 5 daily intravenous infusions to ten patients with metastatic malignant disorders as part of an antineoplastic trial. All ten patients experienced transient increases in heart rate, low-grade fevers, and rigors. A neutrophil-dominated 100% rise in leucocyte counts occurred 4-8 h after treatment. Leucocyte counts returned to baseline levels within 24 h of interleukin-1 beta infusion. A 50% rise in platelets occurred in response to interleukin-1 beta; the increase in platelet counts was first noted 6 days after treatment began and was sustained for 24 days after treatment. Interleukin-1 beta may therefore be beneficial in the treatment of conditions of thrombocytopenia associated with haematological disorders and chemotherapy for malignant disorders.