Immunosuppression Protocols For Renal Transplantation

MCT West, WYT Tse, RJS McGonigle, JA Akoh, J Shaw, H Cramp, S Shaw, PA Rowe

Derriford Hospital, Plymouth

Before 2001 all patients receiving renal allografts at the South West Transplant Centre were given standard triple therapy immunosuppression with cyclosporin, azathioprine and prednisolone regardless of individual factors that could influence the risk of acute rejection (Group 1).

In 2000 a 5 year audit of outcome was used to identify pre-existing variables that had a significant effect on the risk of rejection, using Cox’s proportional hazards regression model, employing backward elimination. Four significant variables (Lymphocytoxic antibodies, mismatch at B locus, mismatch at Dr locus and delayed/immediate function) were identified and used to divide patients into three risk categories (low, medium and high risk) in order to individualise immunosuppression from April 2001 (Group 2).

In April 2002 all de novo uncomplicated renal transplant patients in the low risk group were given cyclosporin, azathioprine and prednisolone, measured by cyclosporin concentration at 2 hours after administration (C2). Those in the medium risk group were also given basiliximab (Group 3)

Following an audit of early outcome data of C2 monitoring the initial dose of 8mg/kg was increased to 10mg/kg from Jan 2003 (Group 4).

The incidence of acute rejection in Group 1 (n=53), group 2 (n=26), group 3 (n=30) and group 4 (n=46) respectively was 49%, 27%, 27% and 26% respectively (p<0.05, Kruskal-Wallis). Graft survival was 90%, 88%, 96% and 93% at one year, not significant by log rank test.

Acute rejection remains a costly consequence of transplantation and may influence long-term outcome. By individualising the immunosuppression therapy with C2 monitoring it is possible to reduce the acute rejection rate and may increase graft survival at 1 year.