LABORATORY IMMUNOLOGY AND KIDNEY TRANSPLANTATION

R.J. Knight¹, S.J. Patel², K. Achkar³, G. Land⁴, S. Dilioglou⁵, J. Hamilton⁶, P. Barretto⁷, A.O. Gaber^1
1Department Of Surgery, The Methodist Hospital, Houston/TX/UNITED STATES OF AMERICA, ²Department Of Pharmacy, The Methodist Hospital, Houston/TX/UNITED STATES OF AMERICA, ³Internal Medicine, The Methodist Hospital, Houston/UNITED STATES OF AMERICA, ⁴Pathology, The Methodist Hospital, Houston/UNITED STATES OF AMERICA, ⁵Pathology, The Methodist Hospital, Houston/TX/UNITED STATES OF AMERICA, ⁶Transplant Center, The Methodist Hospital, Houston/TX/UNITED STATES OF AMERICA, ⁷Transplant Center, The Methodist Hospital, Houston/UNITED STATES OF AMERICA

Body: Introduction: There is controversy regarding the appropriate management of living donor (LD) recipients with donor specific antibody (DSA). To control cost and prevent over-immunosuppression, weintroduced a treatment protocol for the selective management of LD recipients with increasing degrees of DSA. Methods: Prospective LD renal transplant candidates with DSA were stratified into one of3 treatment protocols based on DSA titer. Group A: negative flow cross-match (FCXM) and DSA detected by single antigen bead testing, Group B: positive FCXM with DSA, and Group C: positive AHGcross-match with DSA. Post-transplant monitoring included serial measurement of DSA and protocol renal biopsies. Results: From January 2008 through December 2009, 39 of 111 (35%) LD recipients werefound to have pre-transplant DSA and enrolled in a graded desensitization regimen. Twenty-nine recipients received thymoglobulin induction +/- rituximab (group A), 6 received thymoglobulin, rituximaband immunoglobulin (IVIG) (group B), and 4 received thymoglobulin, rituximab, IVIG, and pre-transplant plasmapheresis (group C). Maintenance immunosuppression consisted of tacrolimus, mycophenolatemofetil, and prednisone. At a median follow-up of 9 months (range 1-25 months) only one patient (group B) has suffered an acute rejection episode. One patient with a post-transplant increase in DSAtiter was treated with plasmapheresis. A second recipient with persistently high-titer of DSA and a C4D positive protocol biopsy received bortezomib. All 3 recipients remain with stable and goodrenal function. Infectious complications to date have included BK viremia in 5 recipients (13%) but no BK nephropathy, CMV gastritis in one recipient and urinary tract infections in 2 recipients.Mean serum creatinine values at one, 3 months, and 6 months were 1.2±0.4, 1.2±0.04, and 1.2±0.05 mg/dl respectively. Conclusion: A desensitization treatmentprotocol stratified by degree of DSA resulted in excellent short-term graft outcomes with an acceptable incidence of BK viremia. Recipients with low levels of pre-transplant DSA may be successfullymanaged with standard immunosuppression.

Disclosure: All authors have declared no conflicts of interest.