#33
RETROSPECTIVE ANALYSIS OF CDC (-) KIDNEY TRANSPLANTED PATIENTS: COMPARISON OF HLA CLASS I/II ALLOANTIBODIES BY ELISA AND LUMINEX BEADS.
D. Garcia, C. Alaez, R. Ceballos, R.A. Reyes, E. Bertaud, A. Rodriguez, H. Flores and C. Gorodezky. Mexico City InDRE, SS, Dept. of Immunol.
Immunogenetics; Auton. Univ. of Aguascalientes; Hosp. Miguel Hidalgo and Aguascalientes Mexico, Central Med. Quirurgica.
IgG antibodies (ab) directed against donor HLA-A, B and even DR antigens present at the time of transplant will cause hyperacute rejection in solid organ transplant patients; ab will also be harmful at the long term. We compared three techniques restrospectively in patients who received a living donor kidney. Patients were X= 36±18.7 years old (males-X=45 y; females-X= 32 y) and had at least one year survival. They (N=44) were diagnosed initially with diabetes mellitus (27.3%), amiloidosis (2.3%), chronic glomerulonefritis (40.9%), hypoplasia (2.3%), primary nephropathy (11.4%); unknown (15.9%). All were negative for c.I/II by CDC before transplant. We retrospectively analyzed patients’ sera by ELISA and Luminex. CDC w/DTT, no DTT and AHG, ELISA and Luminex were done for c.I/II ab. The Kappa test and r values were applied for concordance analysis between Luminex and ELISA, since all sera were CDC (-). The correlation between Luminex and ELISA (c.I ab) was K=0.730; r=0.732. For c.II ab, K=0.535, r=0.542. Two patients had acute rejection (4.6%), but no detectable ab, thus rejection was due to HLA incompatibility; one (2.3%) developed chronic rejection. This patient CDC(-) pre-transplant, was positive for c. I/II ab (ELISA/Luminex). Of the total, 18.9% had c.I IgG, 13.6% had c.II IgG and 2.7% showed c.I/II IgG by Luminex and were ELISA (-). These results although preliminary, emphasize the importance to understand the ab profile of the patient serum samples when interpreting the results of different techniques, particularly those measuring IgG.