Primary autoimmune neutropenia of infancy and childhood in a cohort of patients from western Romania

Neutropenia is commonly diagnosed in pediatric clinics. Due to the special vulnerability of neutropenic patients, the assessment of the etiopathogenic background of neutropenia is mandatory. In this retrospective cross-sectional cohort study, we aimed to establish the status of primary autoimmune neutropenia (AIN) from the point of view of its clinical and biological features and its outcome in a cohort of pediatric patients. We recorded all of the 3,488 cases consecutively admitted to our hospital for different diagnoses but presenting neutropenia, during a period of 3 years (January 2016 to December 2018). We had to exclude 224 patients from the analysis due to incomplete data. Our study focused on patients with AIN or chronic benign neutropenia of infancy and childhood. In these patients, a granulocyte antibody screening by granulocyte immunofluorescence test (GIFT) and the granulocyte agglutination test (GAT) were performed. Regarding their pathogenic background, 0.1% of the patients presenting neutropenia were congenital forms, the rest being acquired forms. Primary AIN was encountered in 18 cases, representing approximately 0.5%. The median age at onset for primary AIN was 7.5 months. Male/female ratio in AIN was 1.94. In 72% of the patients with AIN, neutropenia was severe during the course of disease. In 3 patients, both GIFT and GAT were positive and in 8 patients, only GIFT was positive. For the remaining 7 patients (39%), both GIFT and GAT revealed negative results. 50% of the patients needed hospitalization, but only 3 patients presented severe infections. On-demand G-CSF was administered in 22% of the patients. Our study provides insight with regard to neutropenia, showing the high frequency and etiological diversity in childhood. Primary AIN is usually diagnosed by exclusion of the other causes of neutropenia. GIFT and GAT are useful, but rarely available diagnostic tools for the confirmation of primary AIN.