Elevated Le(y) antigen expression on T-lymphocytes in schizophrenic patients.

Le(y) is a carbohydrate determinant of membrane glycoconjugates and is expressed in some tumor and embryonic cells. On T lymphocytes, it is known that human immunodeficiency virus (HIV)-infected human lymphocyte T-cell lines express elevated Le(y) antigen and AIDS patients show the highest Le(y) expression in T lymphocytes at lower CD4/CD8 ratio. Later, a comparative elevation of Le(y) expression on T-cell subsets has been noticed to be mainly present in patients with viral diseases, such as acute and chronic hepatitis, implying an association of the highest Le(y) expression with viral infection. We found that Le(y) antigen was most expressed in both CD4+ and CD8+ subsets of peripheral T lymphocytes in hospitalized schizophrenic patients. On the other hand, atypical lymphocytes with stimulated morphology are known to appear in the blood circulation of schizophrenic patients. Similar atypical lymphocytes have also been described in viral and autoimmune diseases. Two possibilities have been discussed: viral association in the pathology in some schizophrenic patients; and immunological abnormalities including environmental effects under hospitalization on immune status, since normal controls (staff in psychiatric hospitals) showed higher Le(y) expression than normal controls under non-psychiatric circumstances.