ABSTRACT
To investigate the relationship between the soluble HLA-G [sHLA-G] and the appearance of acute renal rejection [AR] episodes we have quantify in this study the level of sHLA-G by enzyme-linked immunosorbent assay in 42 kidney transplant patients classified in two groups: G1: 17 patients with acute rejection [AR+] and G2: 25 patients without AR [AR-]. To establish our normal sHLA-G ranges, serum samples from 18 healthy controls were tested. Pre-transplantation sHLA-G levels were significantly increased in patients [mean +/- standard error of the mean, 60.48 +/- 12.18 Units/ml] than healthy subjects [19.11 +/- 4.9 Units/ml] [p=0.001]. Although the difference was not statistically significant, G1 patients [AR+] revealed lower levels of sHLA-G [mean +/- standard error of the mean, 31.25 +/- 6.71 Units/ml] compared to G2 patients [AR-] [53.43 +/- 17.21 Units/ml]. Nevertheless, the course of total sHLA-G levels was nearly identical in patients with and without rejection. Nonparametric analysis revealed that pre-transplantation levels of sHLA-G < 18.00 Units/ ml [sensitivity: 87.8% and specificity of 72.2%] were not related to rejection. Also, multivariate analysis regarding anti-HLA antibody status, recipient age and gender showed that sHLA-G could not be an independent risk factor for renal graft rejection. However, a higher sera levels of sHLA-G seemed to contribute to better kidney allograft survival rate after 10 years of follow-up [significance tendency: p=0.091] as shown by the survival analysis. Because of the small number of subjects studied, these results must be treated with caution. A much larger cohort of kidney transplant patients according to acute rejection would seem necessary to confirm these findings