ABSTRACT
The immunosuppressive effect of a major burn has been known for many years. However, a complete understanding of the effects of a burn on the immune system remains elusive. Lymphocytes immunophenotype is a reflection of the functional level of immune system. There is little knowledge concerning the expression of HLA-DR on peripheral blood [Pb] T lymphocytes. T lymphocytes of 26 major burn [25-40%] patients were analyzed in 24 hours, 1 week and 2 weeks after burn, using, monoclonal antibodies of CD3, CD4, CD8, CD25 [IL2R,] and HLA-DR by flow cytometry and comparing them with those of26 apparently healthy donors. There was statistically significant reduction in absolute number of CD3 [p<0.0001], CD4/CD8 ratio [p=0.01] in the first 24 h in comparison with controls. CD25 [IL2R] shows insignificant upregulation on T lymphocytes after burn with significant upregulation of HLA-DR. The absolute number of CD3[+] cells began to increase after 2 weeks [p=0.03]. but still reduced than controls [p=0. 08,]. CD4/CD8 ratio was more or less as healthy control after 2 weeks. Upregulation of CD25 was insignificantly increased and that of HLA-DR were marked increased after 2 weeks. The absolute number CD25 and HLA-DR[+] T lymphocyte subsets all over the time of the study are low than controls except that of HLA-DR[+] T lymphocytes after 2 weeks [p=0.009]. The data obtained suggest persistent activation of T lymphocytes 2 weeks post major burns. HLA-DR expression can reflect post burn lymphocyte activation