Cytotoxic antibodies monitoring in kidney transplantation--their clinical relevance and challenges.

Introduction: The key of the successful renal transplantation is the ability to identify the best immunological match between donor and recipient considering the possibility of rejection phenomenon. The aim was to identify class I and/or class II cytotoxic antibodies in renal-transplanted patients in order to assess the immunological potential for prevention of subclinical or acute rejection episodes.

Patients And Methods: We have evaluated ninety-two patients who had kidney transplantation in 2010 in Fundeni Clinical Institute, Bucharest, Romania, concerning HLA matching and anti-HLA immunization status. For HLA genotyping were used molecular biology methods--PCR-SSP (Invitrogen, USA). For cytotoxic antibodies, the methods used were ELISA (GTI Diagnostics, USA) and Luminex (One Lambda, USA). Crossmatch tests between donor cells and recipient serum were performed by ELISA (GTI Diagnostics, USA). Rejection diagnosis was supported by renal biopsy.

Results: In the 20 presensitized cases, the rate of acute rejection was 30% while in the 72 unsensitized cases the rejection was 19.4%. The incidence of acute rejection was higher in anti-HLA class I presensitized patients compared with anti-HLA class II (20% and 14.3%, respectively) but there was no significant difference compared to pre-transplant unsensitized patients (19.4%). Sequential post-transplantation monitoring of anti-HLA antibodies has shown in pre-transplant sensitized patients group a constantly increasing of PRA value, while in the pre-transplant unsensitized patients group, 32% developed de novo cytotoxic antibodies.

Conclusions: More sensitive and specific methods to detect anti-HLA antibodies before transplantation and sequential post-transplantation monitoring of these antibodies would be useful to identify patients who are at higher risk for allograft failure.