[T lymphocytes functions in mercuric chloride-induced membranous glomerulonephritis in man. Evidence for a defect of presentation of the histocompatibility class II molecules at the cell surface (author's transl)].

Membranous glomerulonephritis (MGN) is one of the well documented manifestations of autoimmunity during chronic mercuric chloride (HgCl2) intoxication. We have carried out immunological investigation of the T cell functions in a patient presenting an HgC12-induced MGN. Circulating auto-antibodies and immune complexes were absent from the serum. Lymphocyte transformation with HgCl2 over a wide range of doses (10(-3) to 10(-8) M) was negative. E rosettes, mitogen reactivity, allogeneic reactivity evidenced by a one way mixed lymphocyte culture gave slightly diminished results. These findings contrasted with a severe impairment of the stimulative ability of lymphocytes. This defect might be related to the inability of D, DR products to be exposed at the cell surface and impeding the allogeneic recognition by foreign lymphocytes. This lymphocyte defect in the course of an HgC12 MGN in man would be correlated with lymphocyte abnormalities found in experimental HgC12-treated rats. The results of this study would favour the hypothesis of a direct role of HgC12 on lymphocyte rather than a direct action on glomerular basement membrane.