Date: Sunday, June 6, 2021
Session Time: 6:00pm-7:00pm
Presentation Time: 6:05pm-6:10pm
*Purpose: Development of donor‐specific antibodies (DSA) is associated with poor outcomes in lung transplantation. Patients who are presented with at least probable AMR require treatment; however, currently there are no guidelines on which treatment regiment to use. We investigated how DSA characteristics measured by Single antigen bead assay (SAB) such as antibody titers, C1q-binding, and mean fluorescence intensity (MFI) values in undiluted and diluted sera may be used to predict a response to therapeutic plasma exchange (TPE) and inform patient’s prognosis after treatment.
*Methods: Out of 357 consecutively transplanted patients without detectable pre-existing DSA between 01/01/16 and 12/31/18, 10 patients were identified treated with 5 sessions of TPE/IVIG. DSA characteristics were collected before and after treatment. The statistical analyses including log-linear regression, two-way ANOVA, and Kaplan-Meier survival were performed. All P < 0.05 were considered to indicate statistical significance.
*Results: There was no significant difference in mean MFI, titers, or C1q-binding after treatment, suggesting that single-modality TPE treatment was not always effective. Also, there was no significant difference in titers and MFI or response to treatment between early and late DSAs. When post-treatment MFI were expressed as a percentage of pre-treatment levels and divided into 3 groups as responders (MFI levels decreased by more than 70%), partial responders (MFI decreased by 30-70%), and non-responders (MFI decreased by less than 30%), Kaplan-Meier Survival analyses showed a statistically significant difference between responders vs. partial responders and vs. non-responders (p= 0.0127). Linear regression test and Kaplan-Meyer survival analyses showed that percent of MFI reduction in 1:16 diluted pre-TPE sera was predictive of a response to standard TPE treatment (Figure A) and patient survival (Figure B).
*Conclusions: Our data suggest that effective AMR treatment improves patient survival. Using 1:16 dilution can help identify patients likely to respond to a standard protocol vs those who require a more aggressive treatment to help guide clinicians as to which patients would be expected to respond to standards protocol or require more aggressive treatment.
To cite this abstract in AMA style:Timofeeva OA, Choe J, Alsammak M, Yoon EJ, Geier S, Carney K, Au J, Diamond A, Galli JA, Shenoy K, Mamary A, Seghal S, Mullhal P, Toyoda Y, Shigemura N, Cordova F, Criner G, Brown J. Guiding Therapeutic Plasma Exchange for Amr Treatment in Lung Transplant Recipients Using Serial Dilution in Single Antigen Bead Assay [abstract]. Am J Transplant. 2021; 21 (suppl 3). https://atcmeetingabstracts.com/abstract/guiding-therapeutic-plasma-exchange-for-amr-treatment-in-lung-transplant-recipients-using-serial-dilution-in-single-antigen-bead-assay/. Accessed September 24, 2021.
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