Chronic autoimmune neutropenia due to anti-NA1 antibody

A 12-month-old child neutropenic since the age of 8 months, was referred to our institute for a sepsis from Candida albicans. On exploring the cause of neutropenia, an anti-NA1 antibody could be detected in the patient's serum. This antibody seemed to be responsible for the neutropenia because the child's PMN type was NA1+. The reactivity of the autoantibody with the patient's own granulocytes was confirmed by direct and indirect immunofluorescence studies performed on blood and marrow cells. A reduced number of T lymphocytes with poor PHA responsivity has been interpreted as the possible cause of the autoimmune disease. Steroid therapy did not cure the neutropenia but the child's general condition improved.