Human Leukocyte Antigen Mismatch and Steroid Maintenance in Kidney Transplantation.

Background: This study aimed to analyze the impact of chronic steroid maintenance (CSM) vs early steroid withdrawal (ESW) in kidney transplant recipients (KTRs) stratified by the level of human leukocyte antigen (HLA) mismatch.

Methods: Adult KTRs between 2001 and 2011 who received antibody induction followed by calcineurin inhibitor (CNI)/mycophenolate mofetil (MMF) maintenance with or without steroid were identified from the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) database. Using multivariate analysis, graft and patient outcomes were compared for CSM vs ESW in KTRs stratified by HLA mismatch levels separately for depleting and nondepleting antibody-induced patients.

Results: Among 43,096 study patients, 26,582 received depleting induction (zero HLA mismatch = 5324 [CSM = 3416; ESW = 1908]; 5-6 HLA mismatch = 21,258 [CSM = 13,739; ESW = 7519]) and 16,514 patients received nondepleting induction (zero HLA mismatch = 4109 [CSM = 3453; ESW = 656]; 5-6 HLA mismatch = 12,405 [CSM = 10,890; ESW = 1515]). Adjusted graft failure risks for CSM vs ESW groups for zero HLA mismatch patients were as follows: HR 1.13, P = .07 (depleting induction); HR 1.30, P = .01 (nondepleting induction). Graft outcomes were similar for CSM vs ESW in 5-6 HLA mismatch groups for both induction types. Adjusted patient death risks were significantly higher for CSM vs ESW with depleting (HR 1.3, P = .003) and nondepleting (HR 1.45, P = .006) induction in zero HLA mismatch patients and only with depleting induction in 5-6 HLA mismatch groups (HR 1.16, P < .001).

Conclusions: Our study supports the feasibility of ESW regardless of the level of HLA mismatch in KTRs selected for antibody induction and CNI/MMF maintenance.