ELECTIVE PHAGOCYTOSIS OF NEUTROPHILS BY M ARROW MACROPHAGES IN CHILDHOOD AUTOIMMUNE NEUTROPENIA

Autoimmune neutropenia (AIN) is a frequent cause of chronic neutropeni a especially in youngest children. Its diagnosis is established by imm unological proof of the autoimmune mechanism. The aim of this study is to better describe this autoimmune process and to show the contributi on of bone marrow smears to this diagnosis. Patients and methods. - Te n children, six girls and four boys, were examined between 1990 and 19 95. Eight of them had typical AIN, confirmed by the presence of antibo dies against neutrophils. Two other patients were included on the basi s of bone marrow pictures. Five non-neutropenic children with normal b one marrow smears were chosen as controls. Bone marrow analysis was al ways performed by the same cytologist according to a reproducible tech nique. Results. - Six out of ten patients had important features of el ective phagocytosis of neutrophils by marrow macrophages (unlike contr ols) without signs of dysgranulopoiesis or hemophagocytosis. Antibodie s against neutrophils were detected in six patients with phagocytosis and in four patients without these cytological features. In two other children presenting the same bone marrow picture and clinical profile, an autoimmune process was probable, even in the absence of antibodies against neutrophils. Some patients had several infections and were gi ven immunoglobulins and/or granulocytes colony-stimulating factor (G-C SF) therapy. The efficacy of Immunoglobulin was not constant, whereas G-CSF was effective at low doses and shortened the duration of infecti ons. Conclusion. - Prolonged neutropenia in childhood must lead to loo k for phagocytosis by marrow macrophages in bone marrow smears, as a p ossible sign of autoimmunity. Growth factors may temporarily be used a ssociated with antibiotics therapy in severe and prolonged infections.