[Primary and secondary neutropenia]

Severe chronic neutropenia (SCN) comprises a heterogeneous group of disorders with a common hematological and clinical phenotype characterized by absolute neutrophil counts (ANC) below 0,5 • 10(9)/l and increased risk of severe bacterial infections. The differentiation between primary and secondary neutropenia and the identification of causative gene mutations is of great importance for the estimation of prognosis. During childhood primary autoimmune neutropenia is the most frequent diagnosis, while secondary neutropenia predominates in adulthood. Despite the rarity, congenital, genetic neutropenias are of great value for research on normal and pathological hematopoiesis and have a fundamental impact on the current knowledge on hematopoiesis. To date mutations in more than 10 genes have been described which are mainly associated with an increased risk for leukemia.The treatment with hematopoietic growth factors has improved the long-term prognosis of SCN patients dramatically: Bacterial infections can be prevented and a normal participation in everyday life is possible.