Profound thrombocytopenia related to G-CSF

Severe thrombocytopenia in association with G-CSF therapy is extremely rare. Here we report a case of profound thrombocytopenia in a 57-year-old male with refractory cardiac ischemia, who received G-CSF during an angiogenesis trial. After 5 days of G-CSF therapy (10 microg/kg/day) the platelet count fell progressively to a nadir of 5x10(9)/L. The patient received steroid, immunoglobulin and platelet support and recovered without sequelae. Subsequent investigations suggested an underlying immune-mediated thrombocytopenia, which we hypothesize was exacerbated by G-CSF therapy.