immune-histological assessment of sub-clinical acute and borderline rejection in renal allograft recipients : data from a transplant center in India

Abstract EN

This single-center study was carried out on living related and unrelated renal transplant recipients (RTRs) to evaluate the usefulness of surveillance biopsies in monitoring stable renal allografts using immuno-histological markers for immune-activation.

This is a prospective, longitudinal study.

Protocol biopsies of 60 RTRs with stable graft function were evaluated at three, six and 12 months post-transplant.

Immuno-histological evaluation was carried out using immune-activation markers (perforins, granzyme and interleukin-2R), phenotypic markers (CD-3 and CD-20), viral markers and C4d.

The demographic and clinical profile was recorded for each patient.

All cases of acute sub-clinical rejection (SCR) were treated and borderline SCR cases were followed-up without treatment.

SCR at three and six months post-transplant was evident in 16.7 % and 3.7 % of RTRs, respectively.

Positive statistical association of SCR was seen with HLA-DR mismatches, whereas patients receiving induction therapy and tacrolimus-based immunosuppression exhibited a lower incidence of SCR.

T cell phenotype with persistent expression of immune-activation markers exhibited positive statistical association with interstitial fibrosis and tubular atrophy at 12-month follow-up biopsy.

The mean creatinine levels were significantly lower in the protocol biopsy group than the non-protocol biopsy group.

No significant difference was found between the mean creatinine levels of the SCR group after treatment and the non-SCR cases within the protocol biopsy group.

Early treatment of sub-clinical acute rejection leads to better functional outcomes.

However, persistent immune-activation is associated with chronicity and may have implications on long-term graft survival.