Immunological and endocrinological disturbances in patients after prolonged coma following head injury

It has been previously reported that following severe brain damage, a deficit of cellular immunity could be detected in the early phase after the occurence of the lesion. We report here the results of a cross-sectional study on long term effects of severe brain damage on immunological and neuro-endocrine changes in patients who recovered from prolonged coma caused by head injury. Results obtained from post-comatose (PC) patients were compared with those obtained from two control groups made up of spinal-cord injury (SCI) patients and healthy subjects, respectively. The following parameters were studied: lymphomonocyte subsets; interleukin 2 (IL-2) production; natural killer (NK) activity and serum levels of adrenocorticotrophic hormone (ACTH), cortisol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, tri-iodothyronine (T3) and thyroxine (T4). With respect to healthy controls the PC1 subgroup, i.e. patients examined 3-6 months after injury, showed a statistically significant decrease in IL-2 production, NK activity and CD25 lymphocytes. Similar immunological disturbances were observed in SCI but not in the PC2 subgroup, i.e. patients examined later than 6 months after injury. The same sub-group of PC1 patients showed high serum levels of cortisol and PRL. These results could be related to the immunological status and may be interpreted as a transient but prolonged condition of chronic stress or "chronic alarm reaction"