ACQUIRED AND CONSTITUTIONAL NEUTROPENIA I N CHILDHOOD

The evaluation of a neutropenia first must document its etiology. Besi des the particular etiological aspects in the newborn, neutropenia in a child may be 1) acquired, 2) constitutional, part of a complex genet ic disease, 3) constitutional, isolated. Primary acquired neutropenia, also called benign chronic neutropenia is the most frequent cause of chronic neutropenia in children; it is usually well tolerated and has a frequent favorable outcome in 12-14 months. Many complex genetic dis eases include a neutropenia, among which several immunologic disorders that must be ruled out before considering the diagnosis of isolated c onstitutional neutropenia. Infantile agranulocytosis is the main prima ry constitutional neutropenia. It may be sporadic or hereditary (autos omal recessive or dominant inheritance) and is present at birth. It is profound, usually < 0,5 G/l (< 500/mm(3)) and exposes to severe pyoge nic and fungal infections. In the neonatal period neutropenia must pri marily suggest a bacterial infection, although other etiologies have t o be known, particularly neonatal neutropenia caused by passive transf er of maternal antibodies and neutropenia related to gravidic maternal hypertension. The treatment of severe chronic neutropenia is directed towards the prevention of infections. It includes prophylactic antibi otherapy, the most commonly used one being the trimetroprim-sulfametho xazole association, and granulocyte colony stimulating factor (G-CSF). G-CSF has considerably improved the condition of patients; it is usua lly well tolerated, but secondary effects have been reported (hyperspl enism, glomerulonephritis, osteoporosis, vasculitis), and a potential leukemogenic risk has been evoked.