Diminishing Significance of HLA Matching in Kidney Transplantation

Abstract

To determine trends in the significance of HLA matching and other risk factors in kidney transplantation, we analyzed data on graft survival in a consecutive sample of 33 443 transplant recipients who received deceased donor kidneys from December 1994 to December 1998 with a mean follow-up time of 2.2 years. HLA matching and other risk factors (peak panel reactive antibody, donor age, sex and cause of death, cold ischemia time, donor and recipient body size) were examined. Mean likelihood ratios of models, fit with and without each variable of interest, were calculated by generating bootstrapped samples from each single year cohort. Pooled censored and uncensored graft survival rates were 90.6% and 89.9% at 1 year, 85.8% and 84.5% at 2 years, and 80.7% and 78.6% at 3 years. HLA matching declined in significance while other factors retained similar levels of statistical significance over the four yearly cohorts. With evolving clinical practice, including the provision of safer and more potent immunosuppressive therapy, the significance of HLA matching has diminished. Non-immunologic factors continue to impede more marked improvements in long-term graft survival. Recognizing these trends, organ allocation algorithms may need to be revised.

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“…17 A previous study noted that if immunosuppression had improved to a degree that enabled transplant of well-and poorly HLAmatched kidneys with identical success rates, then HLA typing and matching would be abolished from kidney allocation algorithms. 24 We believe that optimization of induction and maintenance immunosuppression might be responsible for such results among our patients. This observation matched the results of a previous study that included 672 renal transplant recipients with different HLA-DR mismatch status and treated with antithymocyte globulin as induction therapy followed by tacrolimus, prednisone, and mycophenolate mofetil for maintenance immunosuppression.…”

Outcome of Multipair Donor Kidney Exchange by a Web-Based Algorithm

“…In contrast, kidney grafts from living donors show superior survival compared with cadaver grafts, regardless of HLA mismatches between recipients and donors. Therefore, HLA mismatches frequently are ignored in kidney transplantation from living donors (19,20). However, there also are reports that HLA mismatch between recipient and donor affects the incidence of acute rejection or subclinical rejection on protocol biopsy, which has a potential to affect the outcome of the kidney graft (21,22).…”

HLA‐matched kidney transplantation in the era of modern immunosuppressive therapy

“…14 A recent analysis suggested that the impact of HLA match on graft survival has steadily declined. 12 All of our patients received modern triple immunosuppressive agents as maintenance therapy. Our data indicated that HLA-matched deceased-donor kidney transplants still had signifi cantly better 5-year graft survival than the mismatched deceased-donor transplants.…”

“…[7][8][9][10][11] However, a recent analysis indicated that the impact of HLA matching has steadily declined as more potent immunosuppressive agents have been used. 12 It has also been suggested that the mandatory sharing beyond the local allocation area for low sensitized patients with a panel reactive antibody (PRA) level less than 20% created logistical ineffi ciencies and tended to benefi t white patients more than African American patients. 13 In January 2009, UNOS updated its policy that HLA-matched kidneys continue to be nationally shared for sensitized adult patients with PRA levels greater than 20%, and the locally matched patients have the highest priority regardless of PRA level.…”