Peri-Operative Desensitization for Highly Sensitized Lung Transplant Recipients Following COVID-19 Acute Respiratory Distress Syndrome (ARDS) - Report of Two Cases

INTRODUCTION: Sensitized lung transplant (LTx) candidates have longer waiting times, decreased likelihood of transplant, and increased risk of death while on the waitlist. Patients with SARS-Cov-2 ARDS on ECMO support due to end-stage lung disease have a short window of opportunity for LTx. We report two cases in which the Toronto LTx peri-operative strategy was performed with good outcomes in highly sensitized Covid-19 patients. CASE REPORT: Case 1: 31-yo female patient with Covid-19 ARDS, transferred for LTx evaluation after 46 days on VV-ECMO. She was pregnant when she presented with Covid -19 acute respiratory failure, and underwent an urgent C-section due to fetal distress. She required blood transfusions during ICU stay. At LTx assessment: PRA class I: 95%; class II: 0%. A decision to proceed with LTx with perioperative desensitization was made considering the low probability of finding a suitable donor. After seven days on the waiting list, she underwent bilateral LTx. Virtual crossmatch (XM) positive (B35); CDC-XM negative. Desensitization protocol was performed with perioperative plasma exchange (PLEX) without basiliximab induction, followed by five sessions of PLEX and intravenous immunoglobulin 1 mg/kg. Due to postoperative acute cholecystitis with positive cultures after biliary drainage, anti thymocyte globulin (ATG) infusion (3 mg/kg) was held, and infusion postponed until four weeks post LTx. Tacrolimus, mycophenolate, and prednisone were used as maintenance immunosuppression. The patient was discharged home on PO day 53 with excellent graft function. Case 2: 35-yo female patient with Covid-19 ARDS, transferred for LTx after 69 days on VV-ECMO. History of 3 previous pregnancies and multiple blood transfusions due to transitory coagulopathy during her ICU stay. PRA class I: 83%; class II: 94%. VCM positive (B7, Cw7, DRB1*11:01, DR52, DQA1*05/DQB1*03). Desensitization protocol was performed, but ATG infusion was held due to C. albicans bloodstream infection and colonization with pan-resistant K. pneumoniae. DSAs at six weeks were negative. She remains hospitalized for mechanical ventilation withdrawal and inpatient rehabilitation. SUMMARY: In selected cases, peri-operative desensitization is feasible and can be safely implemented in highly sensitized patients with Covid-19 ARDS.