RELEVANCE OF HLA Abs PRE AND POST RENAL TRANSPLANT.

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RELEVANCE OF HLA Abs PRE AND POST RENAL TRANSPLANT.
Ronald Kerman, Ph.D., Noriel Acorda, B.S., Natalie Guidry, B.S., Hermangshu Podder, M.D., Richard Knight, M.D., Charles Van Buren, M.D., Stephen Katz, M.D. and Barry Kahan, Ph.D., M.D.. Houston TX, USA, Univ. of Texas Medical School, 77030, Surgery.

IgG HLA Abs in pre-Tx sera of renal allograft recips are correlated with acute rejections (AR). Little is known about post-Tx HLA Abs. It would be important to understand the impact of specific suppressants on the presence of post-Tx HLA Abs. We studied the pre and post-Tx sera of 133 Sirolimus treated primary recips of a deceased-donor renal allograft for HLA Ab. Results were correlated with AR and chronic rejection (CR). Pre-Tx, 58% (77/133) of the recips had no (0%) HLA Ab and had 8% (6/77) ARs within 12 months post-Tx. Post-Tx, 15.6% (12/71) of these recips had de novo HLA Abs. In contrast, 18% (24/133) of recips had class I HLA Ab only and more ARs (29% vs 8%, p<0.02) than the 0% HLA Ab recips. Post-Tx, 50% (12/24) of these recips continued presenting class I HLA Ab, 8% (2/24) now had class II Ab, however, 42% (10/24) converted to 0% Ab. Only 8% (11/133) of recips had class II HLA Abs only and had 18% (2/11) ARs (18% vs 8%, p<0.05). Post-Tx 45% (5/11) remained the same, 1 was positive for class I HLA Ab, and 5 converted to 0% HLA Ab. Finally, 16% (21/133) of recips had both class I and II HLA Abs and more ARs (43% vs 8%, p<0.01) than 0% HLA Ab recips. Post-Tx, 67% (14/21) of recips remained positive for both class I and II HLA Abs, 3 were class II only and 3 lost class I and 4 lost both class I and II HLA Abs. The mean time to CR for recips with pre-Tx 0% HLA Ab was 32 ± 14 mos, for recips with class I, II or both pre-Tx, but who lost HLA Ab post-Tx, the time was a similar 30 ± 11 mos. In contrast, recips with class I, II or both HLA Abs pre and/or post-Tx had chronic rejection within 11 ± 8 mos (32±14 vs 11 ± 8, p<0.02). The presence of HLA Ab pre and/or post-Tx was a risk factor for AR and CRs.