Purpose: To determine the effect of intravenous immunoglobulin (IVIG) on neutrophil count, the authors studied patients with idiopathic thrombocytopenic purpura (ITP).
Patients and methods: Thirty-one of 40 patients with ITP were treated with an IVIG regimen (400 mg/kg/daily for 5 days), while the other 9 were observed without any medications. Peripheral samples were examined during the clinical course.
Results: The absolute neutrophil count in 22 patients with no fever as a side effect decreased significantly by day 2 after the start of IVIG, but in most patients it began to increase soon after the last IVIG. There was also a significant difference between the decreased level of the absolute neutrophil count in patients with and without IVIG. However, re-administration of IVIG within 2 weeks did not significantly suppress the neutrophil count. In contrast, the neutrophil count increased in every patient with a fever as a side effect of IVIG.
Conclusions: IVIG induced a decrease in peripheral blood neutrophil count in patients with ITP.