Faculty Bibliography

Donation after circulatory determination of death (DCDD) has increased organ donation rates in the US over the past decade within an established legal framework, which is consistent with and supports individual and family decisions regarding organ donation in the context of end-of-life care. A new application, controlled DCDD donation utilizing thoracoabdominal normothermic regional perfusion (NRP) protocols (cDCDD-NRP), provides the opportunity to maximize a donation decision by recovering additional organs for transplant, including the heart, and to limit the detrimental impact of warm ischemic time by perfusing organs in situ following the declaration of circulatory death. In this viewpoint, we narrate our rationale for why cDCDD-NRP is consistent within the existing legal framework for organ donation in the United States and recommend no changes to the Uniform Determination of Death Act.

Heterologous vaccination ("mixing platforms") for the third (D3) dose of SARS-CoV-2 vaccine is a potential strategy to improve antibody responses in solid organ transplant recipients (SOTRs), but data are mixed regarding potential differential immunogenicity. We assessed for differences in immunogenicity and tolerability of homologous (BNT162b2 or mRNA-1273; D3-mRNA) versus heterologous (Ad.26.COV2.S; D3-JJ) D3 among 377 SARS-CoV-2-infection naïve SOTRs who remained seronegative after two mRNA vaccines. We measured anti-spike titers and used weighted Poisson regression to evaluate seroconversion and development of high-titers, comparing D3-JJ to D3-mRNA, at 1-, 3-, and 6 month post-D3. 1-month post-D3, seroconversion (63% vs. 52%, p = .3) and development of high-titers (29% vs. 25%, p = .7) were comparable between D3-JJ and D3-mRNA recipients. 3 month post-D3, D3-JJ recipients were 1.4-fold more likely to seroconvert (80% vs. 57%, weighted incidence-rate-ratio: wIRR = _1.10 1.40_1.77 , p = .006) but not more likely to develop high-titers (27% vs. 22%, wIRR = _0.44 0.92_1.93 , p = .8). 6 month post-D3, D3-JJ recipients were 1.41-fold more likely to seroconvert (88% vs. 59%, wIRR = _1.04 1.41_1.93 , p = .029) and 2.63-fold more likely to develop high-titers (59% vs. 21%, wIRR = _1.38 2.63_5.00 , p = .003). There was no differential signal in alloimmune events or reactogenicity between platforms. SOTRs without antibody response after two mRNA vaccines may derive benefit from heterologous Ad.26.COV2.S D3.