Definition of cellular immune responses to brain antigens in human head trauma

Abstract

Cellular immune responses to brain antigens in patients with head injury were studied by applying the leukocyte adherence inhibition (LAI) assay. The investigation was conducted in 3 phases. In the initial phase, evaluation of a series of 22 test and 25 control cases obtained at random during 2-6 wk following a traumatic event indicated significant non-adherence of leukocytes (NAL) in 77% of the test group and 20% of the control group in the presence of brain antigen. In a 2nd phase, a larger test population was divided into 4 groups of different posttraumatic intervals. This study measured NAL in the presence of normal heart or normal brain antigen. Assays revealed an initial significant NAL in the presence of both antigens; however, after the 1st wk following injury the majority of cases manifested significant NAL only with brain antigen. These values of NAL persisted for 6-8 wk. As a final phase of investigation, analysis of a sequential series of assays in 12 patients over a 90 day period indicated significant NAL in the presence of brain antigen within the 1st wk of injury; this was followed by a drop in NAL in most of the cases. Studies at 7-60 days posttrauma demonstrated significant NAL with brain antigen alone, with a subsequent drop by 90 days. These observations are interpreted to represent sensitization of leukocyte subgroups to brain proteins that are immunologically recognized following the traumatic event.