Abstract
A 7-year-old boy with prolonged and marked leukopenia diagnosed at 6 months of age is described. The polymorphonuclear cells presented no hypersegmented nuclei or concentrated nuclear chromatin, although vacuolated myeloid cells appeared in bone marrow smears. Neutrophils reversed in response to administration of G-CSF. His leukocyte counts were 400-1000/muL during afebrile periods and increased to 2000-3000/muL in response to infections. The increased leukocyte was usually neutrophils, but lymphocytes also increased at EB-virus infection. The serum IgG decreased gradually and was 364 mg/dL at 7 years of age. Antibody responses were normal and recurrent otitis media has been the patient's only problem. Granulocytopenia with hypogammaglobulinemia of this patient mimics myelokathexis with hypogammaglobulinemia, and lymphocytes also increased at viral infections.