Eosinophilia resulting from administration of recombinant granulocyte‐macrophage colony‐stimulating factor (rhGM‐CSF) in a patient with T‐γ lymphoproliferative disease

A therapeutic trial of recombinant human granulocyte‐macrophage colony‐stimulating factor (rhGM‐CSF) was attempted in a patient with neutropenia and frequent infections secondary to T‐γ lymphoproliferative disease (T‐γ LPD). During the 14 days of subcutaneous rhGM‐CSF (500 μg/m2/day), the absolute eosinophil count increased from 0 to 9,455/μl. By contrast, the absolute neutrophil count decreased. Toxicity related to rhGM‐CSF included arthralgia and nonspecific chest pain. The possible mechanism for the rhGM‐CSF induced selective eosinophilia is discussed.