[Evaluation of neutropenia in children]

Many circumstances lead to discover a neutropenia in paediatric practice. In most of the cases, it is an acquired, transient neutropenia, related to a viral or a bacterial infection, a malignant haemopathy, or an acquired auto-immune neutropenia, also called benign chronic neutropenia. Constitutional disorder with neutropenia is more exceptional. Many complex genetic diseases include a neutropenia, among which several immunologic disorders that could be easily diagnosed by immunological tests. Other complex genetic diseases include Shwachman-Diamond syndrome, associating an external pancreatic insufficiency with bone and skin abnormalities; Glycogen storage disease type Ib, with metabolic disorder. Primary constitutional neutropenias are limited to very few entities. Kostmann's disease is a permanent isolated neutropenia, usually associated with a bone marrow granulopoeisis blockage; cyclic neutropenia is characterised by recurrent oscillations (every 21 days) of neutrophil count. Elastase 2 gene mutations have been observed in both diseases. Treatment and prevention of severe infections are a major concern in the management of chronic neutropenia and could be achieved by prophylactic antibiotics (like sulfamethoxazole-trimethoprime) and also G-CSF, which is regularly effective, but could facilitate various side-effects. Constitutional neutropenias, especially Kostmann's disease and Shwachman-Diamond syndrome, are associated with an increased leukemic risk.