Serum G-CSF levels are not increased in patients with antibody-induced neutropenia unless they are suffering from infectious diseases.

By the use of a G-CSF-specific ELISA we determined the serum granulocyte-colony stimulating factor (G-CSF) levels in 63 patients with antibody-induced neutropenia including neonatal immune neutropenia, autoimmune neutropenia, and drug-induced immune neutropenia, In the sera of 20 patients. elevated G-CSF levels of 60-1006 pg/ml (normal <39 pg/ml) were observed. These patients suffered from infectious diseases at the time of blood collection, G-CSF levels normalized after successful antibiotic treatment, indicating that increased G-CSF production in patients with immune neutropenia may be primarily the result of infection and not of neutropenia.