Increased frequency of activated lymphocytes in the cerebrospinal fluid ofpatients with acute schizophrenia

We compared the cerebrospinal fluid (CSF) cytology of 30 acutely psychotic patients at the initial phase of their hospital treatment with that of 46 c ontrol individuals with no psychiatric disorder or central nervous system ( CNS) disease. The cytological profile of May-Grunwald-Giemsa stained CSF ce ll slides of the patients was significantly different from that of the cont rol population. The most striking finding was a significantly increased fre quency of lymphoid cells showing morphological features of activation/stimu lation and a decreased proportion of normal small lymphocytes. Many of the cells with aberrant morphology displayed structural details similar to thos e of the 'P cells' previously described in the blood of schizophrenic patie nts. The patients' CSF also contained elevated proportions of monocytes/mac rophages, some of which were found in 'rosettes' with activated lymphocytes indicating an increased intercellular adhesion. Possible pathogenic mechan isms behind lymphocyte activation and macrophage dominance in the CSF of ac utely ill psychotic patients are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.