Autoimmune neutropenia in Sheboygan County, Wisconsin

Autoimmune neutropenia is thought to be an uncommon disorder in adults. Over a 2-year period, however, autoimmune neutropenia was diagnosed in seven adults in a county with a population of approximately 105,000 people. The median age of the patients was 52 years old (range of 22 to 81 years), and five of the seven patients were women. All seven patients had at least one other symptom of autoimmune disease. Three patients had splenomegaly, three patients had positive direct antiglobulin tests, and two patients had immune thrombocytopenia. Antibodies reacting to neutrophils were detected by either granulocyte agglutination (GA) or granulocyte immunofluorescence (GIF) testing in five of the seven patients. Antibodies in four patients reacted with an 80 kd neutrophil membrane glycoprotein, and antibodies from two people reacted with a 60 kd membrane glycoprotein. Three patients were given treatment with splenectomy, which resulted in only transient improvement in the neutrophil counts. Serious infections occurred in only three patients over the 2 years of observation. In summary, autoimmune neutropenia in adults may occur more often than appreciated. Most cases of autoimmune neutropenia in adults appear to be associated with other autoimmune phenomena.