P199 A successful lung transplantation in two patients with positive donor specific antibodies and positive crossmatch

Introduction Sensitization to HLA antibodies has been associated with worse outcome in lung transplant recipients. Many lung transplant centers avoid transplanting patients with positive flow cytometry crossmatch (FCXM). However, delaying the transplant in these patients may increase their mortality on the waiting list. We are reporting two cases of crossmatch positive lung transplantation. Case scenario A 37-year old lady diagnosed with pulmonary fibrosis. Patient sensitized to HLA class I and II at time of transplant.The FCXM was positive T-cell (+78 MCS) and B-cell (+165 MCS). She had multiple DSA: Anti A2 (2795 MFI), Anti DR51 (2215 MFI), Anti DR52 (2088 MFI), Anti DQB1:05:02 (655 MFI), Anti DR14 (1411 MFI), anti DP2 (813 MFI). Second case is a 58-year old lady with pulmonary fibrosis secondary to Sjogren’s syndrome. Patient sensitized to HLA class II only at the time of transplant. The T-cell crossmatch was negative while, B-cell was positive (+318 MCS). She had multiple DSA: Anti DRB1∗10:01(14776 MFI), Anti-DR53 (4796 MFI), Anti-DP1 (1942 MFI), Anti- DQB1∗05:01(3384 MFI), Anti-DP2 (790 MFI). In view of patients’ deterioration, lung transplantation was preceded despite of positive crossmatch results, using combination of plasmapheresis, Intravenous immunoglobulin (IVIG) and Thymoglobulin. Both patients did well with no evidence of graft rejection. However, the repeated HLA antibodies screening during follow up showed persistent DSA. in the first patient: Anti-A2(1377 MFI), Anti-DRB1∗14 (4864 MFI), Anti-DR52 (3044 MFI), Anti-DR51 (1708 MFI), Anti-DP2 (1993 MFI). In the second patient: Anti-A1 (3561 MFI), AntiA24 (712 MFI), Anti-DQB1∗05:01(5837 MFI), Anti-DP1 (692 MFI), Anti-DRB1∗10:01 (643 I). Conclusion Lung transplantation is possible in patients with crossmatch positive, using perioperative desensitization protocol. Desensitization treatment did neither eliminate DSA nor prevent de novo DSA formation. However, follow up of these patients showed no evidence of graft rejection. Long-term data is needed.