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Correlation of kidney graft rejection occurrence with PRA-STAT and CDC-PRA
72
Abstracts
6.1 #59
ABSORPTION OF PATIENT SERA TO ACHIEVE SPECIFICITY IN THE FINAL CROSSMATCH. II. CLINICAL RELEVANCE. W LeFor, M LopezCepero, C Wright, V Bowers. LifeLink Foundation, Tampa, FL Current cross match (XM) methods do not show if positive reactions are specific for the donor. We have developed a new methodology (Part I) of absorbing aliquots of patient sera with specific donor lymphoid cells or pooled platelets. The procedure adds only 45 min to the final XM and identifies true and false positive flow cytometry crossmatch (FCXM) reactions. Absorbed and untreated sera are FCXMed vs donor and autologous T and B cells. Of 31 patients with a strong + FCXM, 19 (61 %) converted to T neg-B neg or had >80% reduction in antibody (defined by MCF shift changes) following donor cell absorption. These reactions were thus more easily identified as true positives and transplants were not performed. The remaining 12 patients (39%) remained FCXM + or had <30% reduction in antibody following absorption with donor cells. These XMs were interpreted as false positives and transplants were performed. Of these 12,4(33%) had a PRA >90 and 5 (42%) were regrafts. Actual graft survival is 100% at 1-14 months. Absorption of sera with pooled platelets to remove Class I activity facilitates the interpretation of true or false positive XM results. This easily performed protocol applies equally well to Iymphocytotoxicity XMing and renders the final XM specific.
6.1 #60
CORRELATION OF KIDNEY GRAFT REJECTION OCCURRENCE WITH PRASTAT and CDC-PRA. LM Bow, LS Krisiunas, DS Shapiro, LK Roper and RT Schweizer, Transplant Service, Hartford Hospital, Hartford, CT. The clinical relevance of the existence of preformed antibody as detected by PRASTAT and CDC was evaluated by a retrospective analysis of 177 serum specimens from consecutive 1st transplant kidney allograft recipients (140 cadaver, 37 living related). The follow-up time was at least 6 months. Sera \vere evaluated prospectively by CDC prior to transplant by testing against purified T cells with antiglobulin addition, long incubation. PRA-ST AT retrospective results were performed by Sangstat on blinded sera. Clinical transplant data collected included time and number of rejection episodes, time to first rejection and overall graft survival. PRA's (CDC and PRA-STAT) were considered positive if;::: 7%. Results were as follows: Patients who tested positive by PRA-ST AT experienced rejection more frequently compared to those that tested negative (24/32 (75%) pos rej/pos PRA-STAT vs 861145 (59%) pos rej/neg PRA-ST:\T). however the difference was not statistically significant (p=O.II). When PRA-ST AT results were compared with the occurrence of rejection within the 1st 6 months following transplant, the correlation was statistically significant (p=0.037). In patients with pos PRA-STAT, 78% (18/23) experienced rejection within the 1st 6 months. In contrast, 54% (611114) patients with neg PRA-STAT had a rejection episode during that time. No correlation of CDC vs. occurrence of rej episode was observed during the 1st 30, 60, 90, 180, or 360 days post transplant.
Abstracts
6.1 #59
ABSORPTION OF PATIENT SERA TO ACHIEVE SPECIFICITY IN THE FINAL CROSSMATCH. II. CLINICAL RELEVANCE. W LeFor, M LopezCepero, C Wright, V Bowers. LifeLink Foundation, Tampa, FL Current cross match (XM) methods do not show if positive reactions are specific for the donor. We have developed a new methodology (Part I) of absorbing aliquots of patient sera with specific donor lymphoid cells or pooled platelets. The procedure adds only 45 min to the final XM and identifies true and false positive flow cytometry crossmatch (FCXM) reactions. Absorbed and untreated sera are FCXMed vs donor and autologous T and B cells. Of 31 patients with a strong + FCXM, 19 (61 %) converted to T neg-B neg or had >80% reduction in antibody (defined by MCF shift changes) following donor cell absorption. These reactions were thus more easily identified as true positives and transplants were not performed. The remaining 12 patients (39%) remained FCXM + or had <30% reduction in antibody following absorption with donor cells. These XMs were interpreted as false positives and transplants were performed. Of these 12,4(33%) had a PRA >90 and 5 (42%) were regrafts. Actual graft survival is 100% at 1-14 months. Absorption of sera with pooled platelets to remove Class I activity facilitates the interpretation of true or false positive XM results. This easily performed protocol applies equally well to Iymphocytotoxicity XMing and renders the final XM specific.
6.1 #60
CORRELATION OF KIDNEY GRAFT REJECTION OCCURRENCE WITH PRASTAT and CDC-PRA. LM Bow, LS Krisiunas, DS Shapiro, LK Roper and RT Schweizer, Transplant Service, Hartford Hospital, Hartford, CT. The clinical relevance of the existence of preformed antibody as detected by PRASTAT and CDC was evaluated by a retrospective analysis of 177 serum specimens from consecutive 1st transplant kidney allograft recipients (140 cadaver, 37 living related). The follow-up time was at least 6 months. Sera \vere evaluated prospectively by CDC prior to transplant by testing against purified T cells with antiglobulin addition, long incubation. PRA-ST AT retrospective results were performed by Sangstat on blinded sera. Clinical transplant data collected included time and number of rejection episodes, time to first rejection and overall graft survival. PRA's (CDC and PRA-STAT) were considered positive if;::: 7%. Results were as follows: Patients who tested positive by PRA-ST AT experienced rejection more frequently compared to those that tested negative (24/32 (75%) pos rej/pos PRA-STAT vs 861145 (59%) pos rej/neg PRA-ST:\T). however the difference was not statistically significant (p=O.II). When PRA-ST AT results were compared with the occurrence of rejection within the 1st 6 months following transplant, the correlation was statistically significant (p=0.037). In patients with pos PRA-STAT, 78% (18/23) experienced rejection within the 1st 6 months. In contrast, 54% (611114) patients with neg PRA-STAT had a rejection episode during that time. No correlation of CDC vs. occurrence of rej episode was observed during the 1st 30, 60, 90, 180, or 360 days post transplant.