Introduction:
Immune thrombocytopaenia (ITP), previously known as idiopathic thrombocytopaenic purpura, is an acquired autoimmune disorder characterised by immune-mediated platelet destruction. It has been observed that some paediatric patients with ITP treated with intravenous immunoglobulin (IVIG) developed neutropaenia. The aim of the study was to investigate the association between IVIG therapy and neutropaenia in paediatric ITP.

Material and methods:
The retrospective cohort study involved 123 children (79 girls, 44 boys) with immune thrombocytopaenia, aged 8.03 ±4.55 (0.8–17.9) years (mean ± standard deviation; range) who underwent IVIG in the Department of Haematology and Paediatric Oncology in Zabrze between April 2014 and December 2021. Correlations between age, sex, weight of patients, total IVIG dose, and neutrophil/platelet counts on administration day and 1, 2, and 3 days after IVIG treatment from official medical records were analysed.

Results:
The mean total dose of IVIG was 1.7 ±0.48 g/kg BW. A significant increase in platelet level was observed usually on the first (67.5%) or second (20.3%) day after initial administration of intravenous immunoglobulins. After the course of IVIG, neutropaenia was observed in 50 subjects (40.7%). The neutropaenia occurred mostly (54%) on the first day after administration of IVIG. There was a positive correlation between the onset of neutropaenia and lower age of patients (p < 0.05). What is more, the decrease in the neutrophil count was more distinct in the group of subjects with neutropaenia.

Conclusions:
Intravenous immunoglobulin therapy in children with ITP can lead to neutropaenia. However, patients benefit noticeably from IVIG therapy, and neutropaenia in this case tends to be a transient, self-limiting condition.