Effect of Therapeutic Plasma Exchange-Containing Regimens on Donor Specific Antibodies in Patients With Antibody Mediated Rejection of Pulmonary Transplant

Prior studies examining therapeutic plasma exchange (TPE)-containing regimens in pulmonary transplant antibody-mediated rejection (AMR) have been limited by sample size and inconsistent application of TPE. In this single-center, retrospective study, patients with pulmonary transplant AMR who received a TPE-containing treatment regimen were examined. Mean fluorescence intensity (MFI) and Class distribution of DSAs were examined before/after 5 TPE and again after 8 TPE in the subset of patients who received an extended course of TPE. Fifty-two patients who completed 5 TPE were included. Testing of serum at 1:1 and 1:16 prior to initiation of TPE demonstrated that Class II DSAs occurred more frequently and at a higher MFI compared to Class I DSAs. After completing 5 TPE, for both 1:1 and 1:16 testing, the MFI of DSAs decreased significantly regardless of Class. For 4 patients with persistent DSAs, extending the course of TPE to 8 procedures did not cause an additional significant decline in the MFI of DSAs. Four patients developed de novo DSAs during the course of 5 TPE. Development of de novo DSAs was not associated with plasma exposure during TPE and was associated with high morbidity. In conclusion, completion of 5 TPE during treatment for pulmonary transplant AMR is associated with significant declines in DSAs regardless of HLA Class. Extending the course of TPE for DSAs which persist despite 5 TPE may be of limited benefit. De novo development of DSAs during the course of 5 TPE is associated with poor outcomes.