Ig surface receptors and erythrophagocytic activity of histiocytosis X cells in vitro.

Membrane receptors for Ig and IgG and receptors for immune complexes (C3) have been identified on the surface of histiocytosis X cells by direct immunofluorescence and by rosette formation. Histiocytosis X cells also avidly phagocytose human RBC and latex particles. The cells studied originated from three eosinophilic granulomas of bone and were maintained in culture for 12 days. These immunological characteristics suggest that histiocytosis X cells represent a neoplastic variant of a cellular subpopulation (Langerhans lineage) which probably belongs to the mononuclear phagocyte system.