Familial erythrophagocytic lymphohistiocytosis: surface marker analysis using monoclonal antibodies.

Surface marker analysis of atypical cells, present at elevated levels in the peripheral blood of a 2-yr-old patient with familial erythrophagocytic lymphohistiocytosis (FEL), was performed with monoclonal antibodies. The atypical cells expressed T11, T8, Ia and LeuM2 antigens, markers of suppressor/cytotoxic T lymphocyte and monocyte. The monoclonal antibody-defined surface markers were thus distinguishable from those of other lymphoproliferative disorders clinically resembling FEL.