Mycophenolate Acid Reduce Donor Specific HLA Antibody Strength in Kidney Transplant Recipients

Abstract

Introduction: The development of donor-specific HLA antibodies (DSA) post-transplant has been associated with chronic rejection and graft failure. We hypothesized that mycophenolic acid (MPA) dose escalation will reduce DSA. Methods: Thirty stable DSA positive recipients consented to participate in this 2 year study. MPA was increased in increments of 180/250mg at baseline and at 3 month intervals as tolerated or until maximum manufacturer's recommended dose was achieved. DSA and laboratory data were collected monthly during escalation. HLA single antigen beads analyzed in the Luminex instrument were used to establish donor specificity and strength of the antibodies measured as mean fluorescence intensity (MFI). All recipients received anti-lymphocyte induction therapy. Maintenance immunosuppression consisted of a calcineurin inhibitor, prednisone and MPA. Results: Twenty of 29 (69%) recipients had a reduction or stabilization in DSA MFI within the first 6 months of the study.Figure: [Pre and Post Escalation DSA MFI]One recipient was lost to follow-up at time of submission. Twenty-one of 29 (72%) recipient's renal function improved or remained stable. Notably, DSA development occurred from 2-96 months post-transplant with a mean range of 32 months. Conclusion: MPA dose escalation appears to benefit recipients with DSA in this preliminary 6 month data. Maximum tolerated MPA should be attempted to minimize DSA formation and therefore improve graft function and long term graft survival. Longer follow- up is needed to determine significance.