Alloimmune Neonatal Neutropenia with Fetomaternal Transfusion Syndrome

Abstract

The causes of production of a granulocyte-specific allo-antibody cannot be identified in most cases of alloimmune neutropenia. We report here a case of a neonate presenting with anemia (Hb 8.2 g/dl) and neutropenia (neutrophil counts 240/, ul). Her anemia was normocytic and normochromic with a high reticulocyte count, requiring blood transfusion. Her neutropenia responded to G-CSF treatment, and spontaneous increase was noted after 2 months. We diagnosed the neonate as having fetomaternal transfusion syndrome, because of elevated maternal alfa-fetoprotein levels, and also alloimmune neutropenia, because of the presence of an anti-NA2 antibody in the serum of her mother. This is the first case suggesting that fetomaternal transmission via the placenta could cause alloimmune neutropenia by neutrophil-specific antigen sensitization.