An isologous antigen-antibody reaction with human neutrophiles, related to neonatal neutropenia.

Development of methods for detection of leukocyte antigens has made possible the classification of human leukocytes into different antigenic types, distinct from those of erythrocytes. To date several such antigen systems have been described (1-4). Studies on the distribution of some of these antigens in various blood cells have indicated that they are present in both granulocytic and nongranulocytic cells, as well as in platelets (5, 6). It has been shown that these antigens are also present in certain nonhematopoietic tissues, such as placenta, kidney, and lung (5, 7). This study concerns a new leukocyte antigen, the first that appears to be specific for neutrophiles. In 2 unrelated families, this antigen was responsible for maternal immunization during pregnancy, and the subsequent transplacental transfer of the antibody appeared to be responsible for neonatal neutropenia.