PB1993 EFFICACY OF ANTI-NEUTROPHIL ANTIBODIES TESTING IN PREDICTING CLINICAL OUTCOMES AND SPONTANEOUS RESOLUTION OF NEUTROPENIA IN CHILDREN: A SINGLE CENTER EXPERIENCE

Abstract

Background: Autoimmune neutropenia (AIN) is common form of neutropenia in children. AIN presents with absolute neutrophil count (ANC) of less than 0.5 x 109/L, but mild infection and spontaneous resolution. AIN is caused by anti-neutrophil antibodies (ANA). Detection of ANA is usually helpful in the diagnosis of AIN, but is controversy about the exclusion of congenital neutropenia or the prediction of outcome. Aims: The purpose of this study was to demonstrate the efficacy of the ANA testing for predicting clinical outcomes and spontaneous resolution of neutropenia in children with neutropenia. Methods: We reviewed the records of 62 patients with neutropenia of less than 1.5 x 109/L who were tested for ANA (positive or negative) in Department of Pediatrics, Pusan National University Children's Hospital, from February 2013 to January 2018. Patients with ANC > 1.5 x 109/L at presentation, alternative clinical diagnosis such as marrow failure or malignancy, and patients who were lost to follow-up were excluded. Blood samples for immunoglobulin G (IgG) and immunoglobulin M (IgM) ANA were tested by immunofluorescent flow cytometric technique. Results: For total of 62 pediatric patients with neutropenia, the mean age was 18.69 months (range, 3-96 months), 31 of the patients were boys and 31 was girl. All 62 patients had neutropenia, the mean ANC was 0.38 x 109/L (range, 0-1.39 x 109/L). Positive ANA were detected in 18 cases (29.0%) and absent in 44 (71.0%). Fifteen of 18 patients (83.3%) in ANA positive and 23 of 44 patients (52.3%) in ANA negative showed recovery from neutropenia, statistically significant (P = 0.022). The median age at recovery for those with resolving neutropenia was 26.8 months for the ANA positive and 20.48 months for ANA negative patients, respectively. The frequency of admission to the tertiary hospital with recurrent fevers and infections after the ANA testing (2.52, range, 0–23) in ANA negative was significantly higher than those (0.72, range, 0–3) in ANA positive (P = 0.008). Summary/Conclusion: Our study documents that ANA testing in children with neutropenia is helpful in establishing the diagnosis of AIN and effective in predicting clinical prognosis and spontaneous resolution of neutropenia. We also recommend that you consider to the results of ANA testing when treat of neutropenic children with recurrent fever and infection.