The clinical significance of post-transplantation non-HLA antibodies in renal transplantation.

This study was undertaken to examine the clinical relevance of antibodies detected in the sera of patients following renal transplantation. The sera from 23 transplant recipients with acute rejection and 10 transplant recipients with diagnosed chronic rejection were tested against various epithelial, monocyte and endothelial cell lines (A549, HTB44, primary renal epithelial, U937 and Ea-hy 926). The test used for detecting binding antibodies was a simple, indirect immunofluorescence flow cytometric technique. The level of IgG antibodies directed against the test cell lines was examined in the sera of patients with mild or severe rejection and compared to those of patients showing no signs of rejection. Patients with chronic rejection were found to have increased levels of antibodies (IgG and IgM) when compared to patients with either end-stage renal failure or patients with stable post-transplant renal function. Antibodies detected by the present technique were directed against antigens found on all cell lines tested, and immunoblotting indicated that they were directed against non-HLA antigens. In conclusion, monitoring for the presence of such antibodies may provide a valuable prognostic indicator of graft rejection in renal transplant patients.