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#38-OR
DONOR SPECIFIC HLA ANTIBODY REDUCTION, REBOUND, THEN DISAPPEARANCE (PERMANENT ?) IN PATIENTS TREATED WITH IVIG AND PLASMAPHORESIS PRIOR TO KIDNEY TRANSPLANTATION.
Wlliam LeFor Ph.D. 1, Mayra Lopez-Cepero Ph.D. 1, Donna Becker CHS 1 and John Leone M.D. Ph.D. 2. 1 Transplant Immunology Lab., LifeLink Foundation, Tampa, FL and 2 LifeLink Health Care Institute, LifeLink Foundation, Tampa, FL .
Thirteen patients with a T+ or B+ FC-XM vs a live kidney donor got IVIG plus mycophenolate for 1 month, then plasmaphoresis (PP) until T-B- FC-XM was achieved. The transplant was performed with induction therapy. Pre and post-transplant flow cytometry determined: (1) Class I and II PRA with multiple antigen coated beads; (2) Ab specificity and relative quantity with single antigen coated beads; and (3) the T and B cell FC-XM strengh using quantitative linear MESF units. IVIG decreased the quantity of most Abs and strength of FC-XM but had no effect on PRA. When a T-B- FC-XM was achieved the average PRA was 85% of its initial value. About 1 week post-transplant > 90% of patients had a rebound back to prior values for: PRA; Ab quantity/ specificity; and FC-XM. Following additional PP donor-specific Ab became and remained negative while non-donor Ab remained strongly positive. This pattern was seen with Ab to HLA-A , B, Cw, Bw, DR, DRw, DQ and DP. Specificity patterns include: Ab to a B44 mismatch became and remained negative but for other Bw4 antigens remained strongly positive; Ab to a B35 mismatch became and remained negative while that for Bw6 antigens remained strongly positive; and Ab to a B7 mismatch became and remained negative while that for other B7 CREG antigens remained strongly positive. This suggests the presence of the kidney is modulating the immune response. New Ab was seen in 2 patients,one to a mismatch from 10 years previously, and one to a mismatch in the current transplant. Actual graft survival at 3-24 months is 100%.