Recombinant human granulocyte colony‐stimulating factor therapy for cyclic neutropenia associated with common variable immunodeficiency

A 14 year old boy with common variable immunodeficiency (CVID) had regularly recurring episodes of severe infections independently of the serum γ-globulin level. Serial blood counts revealed that this patient also had cyclic neutropenia. Recently, recombinant human granulocyte colony-stimulating factor (rhG-CSF) was reported to be an effective treatment for this disease. We tried rhG-CSF therapy for this patient and a prompt increase in the neutrophil count was noted. However, the cyclic alterations and duration of the nadir of the neutrophil count were not altered, which suggested that rhG-CSF has a variable efficacy in at least some patients with cyclic neutropenia.