(1244) Outcomes of Flow Cytometry Crossmatch Positive Lung Transplant Recipients

• Published in: The Journal of heart and lung transplantation Vol. 42; no. 4; p. S531
• Main Authors: Menachem, B.M., Ali, H.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.04.2023
• ISSN: 1053-2498; 1557-3117
• DOI: 10.1016/j.healun.2023.02.1454

With the availability of perioperative desensitization centers have reported acceptable outcomes in sensitized recipients with positive virtual cross matches. However, there is limited data regarding outcomes for subjects with positive flow cytometry cross matches (FXM). We reviewed the significance of a positive FXM on transplant outcomes. A retrospective chart review was conducted at a high-volume lung transplant center. From 7/15/16 - 4/8/21 542 lung transplants were performed. We identified those with positive FXM at transplant and created two cohorts; false positive FXM (FPFXM) due to prior rituximab exposure and true positive FXM (TPFXM) without exposure. Data collected until 10/15/21 is reported. Basic demographic, clinical characteristics, and outcomes were collected, normalized ACR scores were calculated (sum of A grades/number of biopsies). T-Tests used for comparison where appropriate. We identified 16 subjects with a positive FXM: 8 TPFXM and 8 FPFXM. See table 1. 7/16 subjects developed at least 1 episode of ACR, with a total of 18 ACR episodes during the follow up period. Only 1 subject in the TPFXM group had 1 episode of ACR vs 6 subjects with 17 episodes of ACR in the FPFXM group. The average rate of ACR/months of follow up was .077 vs .102 respectively. The average normalized ACR scores were .024 vs .322 respectively, p = .033. 4 subjects had 4 episodes of AMR, 3 TPFXM vs 1 FPFXM. 3 subjects developed CLAD, all 3 were in the FPFXM cohort. In this cohort sensitized recipients who had a positive flow cross match had acceptable short to medium term outcomes. Accepting donors with HLA antigens previously considered unacceptable may be a viable strategy to increase access for sensitized patients at centers experienced with perioperative desensitization. This strategy may be useful in patients with highest acuity on ECMO or ventilator support without the luxury of time. Multicenter studies are needed.