IMMUNOPHENOTYPIC STUDIES ON ATYPICAL LYMPHOCYTES IN PSYCHIATRIC-PATIENTS

By using phase-contrast microscopy combined with a fluorescent stainin g technique, the frequency of blast-type atypical lymphocytes (BTALs) appearing in peripheral blood and the phenotypic expression of their s urface antigens were studied in 24 patients with schizophrenia, 16 wit h mood disorder and 14 healthy controls. BTALs were classified as bein g stimulated or activated cells, morphologically characterized by thei r large size, dark cytoplasm, a hollow perinuclear containing a few gr anules and finely dispersed chromatin structures with a few evident nu cleoli. A significantly higher number of BTALs were found in the schiz ophrenic patients compared with healthy control subjects or patients w ith mood disorder. Further, there was a significant difference in the frequency of BTALs between patients with mood disorder and healthy con trol subjects. No significant difference in the frequency of BTALs was found between the schizophrenic patients with and without medication. Immunostaining of BTALs revealed that these cells consisted of B, T a nd non-B, non-T cell subpopulations. Contrary to our expectations, the T cell was only one third of the BTAL population. HLA-DR and CD38 wer e expressed on most BTALs (> 70%), while CD25, an early activation mar ker of T cells was rarely found on BTALs (< 0.3%). The differences in activated lymphocyte populations which appeared as morphologically aty pical in the circulation among some psychiatric patients and infectiou s or autoimmune diseases are discussed. This is the first report on po pulations of BTALs. (C) 1998 Elsevier Science Ireland Ltd.