Immunodeficiency in familial erythrophagocytic lymphohistiocytosis.

4 children with familial erythrophagocytic lymphohistiocytosis and hyperlipidaemia were found to have a previously unrecognised immunological deficiency syndrome which included defects in both humoral and cellular immunity and a plasma inhibitor of in-vitro lymphocyte blastogenesis. The inhibitory activity was proportional to the increase in the triglyceride concentration in the patients' plasma. Immunological deficiency, to which hyperlipidaemia may be a contributing factor, appears to be a significant feature of familial erythrophagocytic lymphohistiocytosis.