Neonatal alloimmune neutropaenia: Experience from an Australian paediatric health service

Abstract

Aim: To describe the presenting features and investigation findings in infants diagnosed with neonatal alloimmune neutropaenia (NAIN) within an Australian paediatric health network. The secondary aim was to describe the management and resolution of neutropaenia in infants with NAIN. Methods: A retrospective cohort study was conducted at Monash Children's Hospital, Melbourne, Australia. Infants referred to the Victorian Transplantation and Immunogenetics Service for evaluation of NAIN were identified and medical records were reviewed. Descriptive statistical analysis of infants' clinical outcomes, investigation findings and management was performed. Results: Nine infants were diagnosed with NAIN between December 2004 and June 2017. Overall incidence of NAIN was around 1 per 10 000 births. Median gestational age was 38 (range 35-40) weeks and birthweight was 2920 (2300-4445) g. Median age at NAIN work-up was 7 (2-33) days. Prior to investigation for NAIN, median absolute neutrophil count was 0.2 (0.01-0.6) × 10 9 cells/L. The post-natal ward was the source of presentation in most infants (78%). All except one infant were admitted to a neonatal unit and commenced on intravenous antibiotics (89%). Six infants were asymptomatic but received antibiotics for risk of infection (75%). Granulocyte-colony stimulating factor was administered to 44% of infants due to neutropaenia with presumed or confirmed infection. NAIN resolved at median age of 32 (6-200) days. Conclusions: Infants with NAIN frequently presented with severe, unexpected neutropaenia without major infection. Intravenous antibiotic therapy and granulocyte-colony stimulating factor use was common in this cohort. †Three pairs of siblings were observed: cases 2 and 4, and cases 6 and 7, respectively. Cases 8 and 9 were MCDA twins. EOI, early-onset infection, suspected or confirmed within 72 h of age; G-CSF, granulocyte-colony stimulating factor; ITR, immature-to-total neutrophil ratio (elevated if >0.2); LOI, late-onset infection, suspected or confirmed at or beyond 72 h of age; PROM, prolonged rupture of membranes (duration of rupture greater than 18 h); SCN, special care nursery.Neonatal alloimmune neutropaenia J Doan et al.

Combined Neonatal Alloimmune Neutropenia and Thrombocytopenia in Dizygotic Twins Conceived After Oocyte Donation

“…Neonatal alloimmune thrombocytopenia (NAIT) and neonatal alloimmune neutropenia (NAIN) are caused by maternal exposure to paternally inherited human platelet antigens (HPA) and human neutrophil antigens (HNA), respectively, expressed on the surface of fetal platelets and neutrophils that cross the placenta [ 1 - 3 ].…”