Clinical outcomes and complications of recipients of HLA matched living donor kidney transplants at UCLA: A retrospective chart review

Background

Kidney transplantation between HLA matched siblings results in superior graft survival. It has been hypothesized that the degree of HLA matching in these cases reduces the risk of organ rejection, allowing for reduced immunosuppression exposure. Current tolerance protocols are successful in permitting immunosuppression withdrawal, but require initial exposure to high levels of immunosuppression. Long term data on immunosuppressive complications has not been well studied in this population, and are needed to fully evaluate current tolerance protocols.

Methods

In this retrospective cohort, we aimed to evaluate immunosuppression regimens among HLA-matched living kidney transplant recipients. We screened living kidney donor transplant donors-recipient pairs from 2013 to 2019 and found 28 recipients meeting criteria. A retrospective chart review using the electronic medical record was performed evaluating for preoperative clinical factors, cause of ESRD, maintenance immunosuppression regimen, short and long term sequelae of immunosuppression exposure as well as graft outcomes.

Results

Median age was 49, half were women and half were non-White (25% Hispanic, 14% Asian/Pacific Islander, 7% other and 4% African American). Median follow up was 3.5 years. Most common causes of ESRD were glomerulonephritis, diabetes and polycystic kidney disease. Over 80% of patients were on calcineurin inhibitor based dual therapy, with approximately 50% on prednisone and the remainder on an anti-metabolite. 14% of first time HLA matched kidney transplant recipients were on 3 immunosuppressive medications. 43% of recipients experienced immunosuppression-related complications, the most common of which was infection, occurring in almost a third of all patients. Graft and overall survival was 100% for this cohort with an average serum creatinine between 1.1 and 1.3 mg/dL at the end of the study period. One patient experienced acute rejection (4%).

Conclusions

In our single institution study, a large proportion of HLA matched living kidney transplant recipients experienced complications related to immunosuppression. The majority of patients were on CNI based therapy with a second agent. Additional studies are necessary to determine minimal effective dosing of immunosuppression in HLA matched living donor kidney transplants.