Immune consequences of stroke and cerebral palsy in adults

The possibility that brain damage results in a sustained dysregulation of l ymphocyte responsiveness to the lymphokine, interleukin-2 (IL-2), was inves tigated in individuals who had experienced a unilateral stroke in adulthood or who presented with spastic hemiparesis since childhood. Following verif ication of unilateral brain damage via neuromotor assessment, and determina tion of their health status, blood samples were obtained to evaluate a pane l of immune measures. Soluble interleukin-2 receptor (sIL-2R) and lymphocyt e proliferative and cytolytic responses in the subjects with stroke or cere bral palsy were compared to age- and gender-matched controls. In addition, lymphocyte populations were enumerated via flow cytometry, and lymphocyte c yclic AMP (cAMP) levels were determined. Circulating blood levels of sIL-2R were significantly elevated in all individuals that had experienced unilat eral brain damage. Cytolytic activity also failed to be stimulated to the n ormal level by in vitro treatment of lymphocytes with IL-2. Further, lympho cytes from the stroke subjects proliferated significantly less after mitoge n and IL-2 stimulation. These functional differences were not accounted for by an abnormal leukocyte profile, although phenotypic analyses revealed su btle differences in the natural killer cell subsets. Overall, the findings indicate that individuals with brain damage may mot respond appropriately w hen immune activation is required. These immune differences appear to be a stable trait given that they were manifested after both perinatal and adult brain insult in otherwise healthy, independently living individuals. (C) 1 998 Elsevier Science B.V. All rights reserved.