The immune system and the histiocytosis syndromes.

The histiocytosis syndromes consist of a heterogeneous group of disorders referred to as histiocytosis X or differentiated histiocytosis. Although a large proportion of cases of histiocytosis remains to be of an idiopathic nature, there are cases in which the etiologic mechanism appears to be a defect in the immune system. Provided is a brief review of the literature regarding the immune system in histiocytic disease and a review of the experience at the University of Minnesota with immunologic evaluation of children with histiocytic reactions. Two general hypotheses on the relationship between the immune system and histiocytosis syndromes are discussed.