Comparison of de novo donor-specific antibodies between living and cadaveric lung transplantation

Background: Despite growing interest in donor-specific antibodies (DSAs) and antibody-mediated rejection (AMR) in lung transplantation (LTx), no study evaluating the outcomes in recipients with de novo DSAs (dnDSAs) in living-donor lobar LTx (LDLLT) exists. We compared various characteristics of DSAs in LDLLT with those in cadaveric LTx (CLT) based on prospectively collected data.

Methods: Between October 2009 and September 2019, 211 recipients underwent LTx (128 CLTs and 83 LDLLTs). We reviewed 108 CLTs and 74 LDLLTs to determine the characteristics and clinical impact of dnDSAs. Eighteen data-deficient cases, 7 cases with preformed DSAs, and 4 re-transplants were excluded.

Results: There were significant differences between CLT and LDLLT patients in age, primary disease, ischemic time, and number of human leukocyte antigen mismatches per donor. The dnDSA incidence in LDLLT (6.8%) was significantly lower than that in CLT (19.4%, p = 0.02). The dnDSAs appeared later in LDLLT (mean 1,256 days) than in CLT (mean 196 days, p = 0.003). According to Cox models analyzed using dnDSA as a time-dependent covariate, dnDSA positivity was significantly associated with a poor overall survival (OS; hazard ratio [HR] 3.46, 95% confidence interval [CI] 1.59-7.57, p = 0.002) and poor CLAD-free survival in case of CLT (HR: 2.23, 95% CI: 1.08-4.63, p = 0.003). However, no such significant associations were noted in case of LDLLT.

Conclusions: The dnDSA occurrence was significantly lower and later in LDLLT than in CLT. Furthermore, dnDSA-positivity was significantly associated with worse OS and CLAD-free survival after CLT but not after LDLLT.