Alloimmune Neutropenia in a Neonate: Case Report and Review of Literature

Abstract

Neonatal alloimmune neutropenia, variably referred to in the literature as NAIN, FNAIN or NIN, is a disorder of neutrophil destruction in newborns similar to better-known conditions such as hemolytic disease of the newborn and neonatal alloimmune thrombocytopenia (FNAIT). Infants affected by this self-limiting condition can present asymptomatically or have a wide range of symptoms, from skin manifestations and mucositis to severe infections such as sepsis and pneumonia. In our case, we report an otherwise asymptomatic term infant born with severe neutropenia to a mother affected by COVID-19 in the 3rd trimester. However, it is unclear if COVID-19 contributed to our patients’ neutropenia. Diagnostic testing eventually revealed the presence of anti-neutrophil antibodies, confirming the diagnosis of alloimmune neutropenia. The infant was conservatively managed with early discharge prior to resolution of neutropenia and close post-discharge follow up.

World human neutrophil antigens investigation survey

“…NAIN is a disorder of the foetus that results from maternal alloimmunization against paternal HNA expressed on fetal neutrophils [4,10]. NAIN is analogous to haemolytic disease of the foetus/ newborn (HDFN) which affects red blood cells and foetal/neonatal alloimmune thrombocytopenia (FNAIT) which affects platelets [11].…”