Immune and idiopathic neutropenia.

Neutropenia is often attributed to immunologically mediated injury to mature neutrophils or their precursors. Clinically it is useful to classify immune mediated neutropenias as isoimmune, autoimmune (including some drug-associated neutropenias), and idiopathic (cases possibly with an immune mechanism). Isoimmune neutropenia occurs in infancy and the antigen and is an isoform of CD16. This condition usually resolves spontaneously. For other forms of immune neutropenia the antigens are not yet well defined and the diagnosis is usually based on clinical criteria. In these patients availability of granulocyte macrophage colony-stimulating factor is a major advance; most respond quickly to treatment with this growth factor.