New Biomarker VEA195 as Early Serologic Indication of Organ Transplant Rejection: Validation Study in Comparison With Histomorphologic Data.

Abstract

Background: The identification of new bio-marker to predict and to monitor the renal graft loss is a challenge to overcome, in spite of emerging roles attributed to alloantibodies to identify recipients at risk of rejection. The aim of this study is to evaluate the detection and the quantification of a 30 kD immune protein using its partial sequence, VEA195, considered as a serologic monitoring marker in kidney-allograft failure. Materials and Methods: 1- Residual serum specimens of 31 allografted patients and 17 controls; including 15 blood donors based on ABO system and 2 non transplanted kidney failure patients. All sera were stored at -20°C after completion of routine biological analyses. All the patients were HLA-I and HLA-II total or partial mismatched recipients (living donors). An experienced renal pathologist independently confirmed the rejection stage according to the Banff 05-07 criteria. 2- The detection of VEA195 was blindly performed by colloidal gold immunochromatography assay on membrane using two specific monoclonal antibodies 7G9 and 10E5. 3- The reactivity on a strip test was displayed by the presence of purple red test-band, visually appreciated at 40 ng/ml serum and automatically quantified with lower limits of 2 ng/ml serum. This was completed in comparison with a standard curve previously established with serial dilutions of the VEA195 peptide on densitometer.Table: No Caption available.Conclusions: 1- VEA195 is an early serologic marker of prediction in graft loss. Five of nine non-rejection patients were found VEA-reactive 6 to 9 months before rejection confirmation by patho-histology assay. 2- In situ VEA 195 staining by specific monoclonal antibodies was also shown in glomerule and peritubular capillaries similarly to immunochemical staining of rejection on biopsies. 3- VEA195, circulating and staining on biopsy, is to be considered as molecular biomarker with potential development in the future therapeutic strategies in post-transplant rejection. DISCLOSURES:Agbalika, F.: Stockholder, Biovialife inc.