Perioperative Desensitization for Sensitized Lung Transplant Candidates

Purpose Sensitized lung transplant (LTx) candidates have longer waiting times, decreased likelihood of transplant, and increased risk of death while on waitlist. To mitigate this and to increase the access to donor pool, for sensitized candidates, we modified and implemented The Toronto perioperative strategy to treat DSA-positive recipients with positive virtual crossmatch (VCM) donor offers. We hypothesize that such perioperative desensitization strategy can be safely implemented with acceptable outcomes and help decrease the waitlist mortality. Methods We performed a retrospective chart review of sensitized candidates who underwent LTx between June 2017 - June 2020 and required perioperative desensitization. We collected the baseline demographics and post-transplant variables. The protocol was implemented if the calculated panel reactive antibody (cPRA) was > 30 % and had positive VCM. Desensitization protocol included preoperative plasma exchange (PLEX) with 1.5 volume, intra operative basiliximab induction, followed by five sessions of PLEX, intravenous immunoglobulin (IvIg, 1 gm / kg) and Anti Thymocyte globulin (dose 3 mg/kg for VCM positive vs 5 mg/kg for positive actual crossmatch (ACM)). We used tacrolimus (12 - 15 ng/ml), mycophenolate and prednisone for maintenance immunosuppression. Results 25 patients required desensitization. 76% (n=19) of them are females. Median LAS score is 41.3 (IQR 33.87-60.33). Median wait time was 28.9 days (IQR 12.6-65). All patients underwent bilateral lung transplantation. ACM was positive in 24% of patients (n=6). 76% (n=19) completed the protocol. Incidence of Primary graft dysfunction at any time point was 12% (n=3). Acute cellular rejection >= grade 2 was 8% (n=2). 8% (n=2) had chronic lung allograft dysfunction. Overall survival of this cohort is 96% with a median follow up of 17 months (IQR 5 - 25.5). Conclusion Perioperative desensitization can be safely implemented with acceptable outcomes in sensitized LTx candidates. On comparison of our SRTR data, before and after desensitization implementation, we noted a decline in the waitlist mortality (11.4% to 7.6%) and 50th percentile median wait times (8.5 months to 1.3 months).