The diagnosis of acute renal allograft rejection using T-lymphocyte subsets in the peripheral blood : a better test now ?

Measuring the T-lymphocyte subsets CD4/CD8 ratio is known to be useful in the early diagnosis of acute rejection. A ratio of 1.3 or more is said to indicate the presence of acute rejection, but the sensitivity and specificity rates of the test are too low to render it of diagnostic value. We revisited this test on twenty-three renal allograft recipients who developed graft dysfunction within the first three months following transplantation. All cases were investigated thoroughly to identify the cause of graft dysfunction. Two groups of patients were identified. Group 1: patients confirmed to have acute rejection as the cause of graft dysfunction (13 patients); and group 2: patients found to have other causes of graft dysfunction (10 patients). Results of subsets with cluster of differentiation ratio CD4/CD8 were correlated with incidence of acute rejection. Of the 13 patients with acute rejection 10 revealed a CD4/CD8 ratio more than 1.7, while in the other three CD4/CD8 ratio was less than 1.7. In the second group of 10 patients in whom the cause of graft dysfunction was not acute rejection, the CD4/CD8 ratio was less than 1.7 in all cases. Our study indicates that T-lymphocyte subset ratio is useful in diagnosing acute rejection with a sensitivity and specificity of 81% and 100% respectively when the cutoff point is taken as 1.7. Studies with larger series of patients are needed to confirm this observation.