Hypereosinophilic syndrome treated with alpha-interferon and granulocyte colony-stimulating factor but complicated by nephrotoxicity

A 34-year-old male with hypereosinophilic syndrome (HES) and cardiac complications was treated with recombinant human alpha-interferon (rhIFN) and recombinant human granulocyte colony-stimulating factor (rhG-CSF) in the attempt to suppress the eosinophilic cell clones and stimulate the neutrophil myelopoiesis in the bone marrow, respectively. After 1 month of pretreatment with rhIFN, rhG-CSF was administered daily for 22 days. Within a few days the combined treatment with rhIFN and rhG-CSF was followed by a marked increase in absolute neutrophil count but complicated by abdominal pain and an increase in plasma creatinine and blood urea nitrogen. The renal failure persisted when rhIFN therapy was stopped but resolved after discontinuing rhG-CSF. The pathogenesis of this reversible renal involvement needs further investigation. In that hematological improvement in vivo as well as in vitro followed the administration of rhIFN and rhG-CSF, a role for combined therapy with these cytokines may be advocated. However, caution with regard to kidney function should be taken with this combination therapy.