T lymphocytes expressing human Ia-like antigens in infectious mononucleosis (IM).

In six patients with Epstein-Barr virus (EBV) induced infectious mononucleosis (IM) and in two patients with IM-like syndrome, peripheral blood lymphocytes in the acute and convalescent phase were tested for human la-like antigens as well as other cell surface markers. The major population of T lymphocytes in the acute phase showed la-like antigens, as detected by indirect immunofluorescence with heteroantisera, and the number of la-like antigen-positive T lymphocytes decreased with convalescence. The crossabsorption study indicated that the amount of la-like antigen on the surface of IM T cells was less than that of Raji cells.