Immune neutropenias. Clinical and biological implications

Techniques for the detection of neutrophil antibodies include leukoagglutination, cytotoxic assays, antiglobulin consumption tests, immunofluorescence, quantitation of cell-bound IgG, and opsonization assays. Employment of the various methodologies have led to the identification of neutropenic states associated with decreased survival of neutrophils in the circulation because of immune-mediated distribution of the neutrophils or excessive sequestration of their cells by reticuloendothelial cells. The immune clinical syndromes predisposing to selective neutropenia include isoimmune neonatal neutropenia, autoimmune neutropenia, drug-induced neutropenia, and complement-mediated neutropenia. Selective immune-mediated neutropenia occurs because the neutrophil contains unique antigens often not shared by other blood cells. Like incompatible red cell transfusions, incompatible neutrophil transfusions can result in clinical manifestations including fever and hypoxemia arising from pulmonary sequestration of neutrophils. Potentially therapeutic benefits derived from neutrophil transfusions and from bone marrow transplantations may be influenced by neutrophil antigen-antibody reactions. Newer techniques for detecting and identifying neutrophil antibodies may now provide a tool to answer these questions.