Faculty Bibliography

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.

UNLABELLED:Automation of deceased donor referrals with standardized clinical triggers allows organ procurement organizations to be rapidly aware of medically eligible potential donors without the need for manual reporting and subjective decision-making of otherwise very busy hospital staff. In October 2018, 3 Texas hospitals (pilot hospitals) began using an automated referral system; our goal was to evaluate the impact of this system on eligible donor referral. METHODS/UNASSIGNED:We studied ventilated referrals (n = 28 034) in a single organ procurement organization from January 2015 to March 2021. We estimated the change in referral rate in the 3 pilot hospitals due to the automated referral system using a difference-in-differences analysis with Poisson regression. RESULTS/UNASSIGNED:). CONCLUSIONS/UNASSIGNED:Following deployment of an automated referral system that did not require any actions by the referring hospital, referrals, authorizations, and organ donors increased substantially in the 3 pilot hospitals. Broader deployment of automated referral systems may lead to increases in the deceased donor pool.

Estimating the total coronavirus disease 2019 (COVID-19) mortality burden of solid organ transplant recipients (SOTRs), both directly through COVID-19 infection and indirectly through other impacts on the healthcare system and society, is critical for understanding the disease's impact on the SOTR population. Using SRTR data, we modeled expected mortality risk per month pre-COVID (January 2015-February 2020) for kidney/liver/heart/lung SOTRs, and compared monthly COVID-era deaths (March 2020-March 2021) to expected rates, overall and among subgroups. Deaths above expected rates were designated "excess deaths." Between March 2020 and March 2021, there were 3739/827/265/252 excess deaths among kidney/liver/heart/lung SOTRs, respectively, representing a 41.2%/27.4%/18.5%/15.0% increase above expected deaths. 93.0% of excess deaths occurred in patients age≥50. The observed:expected ratio was highest among Hispanic SOTRs (1.82) and lowest among White SOTRs (1.20); 56.0% of excess deaths occurred among Black or Hispanic SOTRs. 64.7% of excess deaths occurred among patients who had survived ≥5 years post-transplant. Excess deaths peaked in January 2021; geographic distribution of excess deaths broadly mirrored COVID-19 incidence. COVID-19 likely caused over 5000 excess deaths among SOTRs in the US in a 13-month period, representing 1 in 75 SOTRs and a substantial proportion of all deaths among SOTRs during this time. SOTRs will remain at elevated mortality risk until the COVID-19 pandemic can be controlled.

BACKGROUND:Medicaid expansion has led to earlier stage diagnoses in several cancers but has not been studied in hepatocellular carcinoma (HCC), a disease with complex risk factors. We examined the effect of Medicaid expansion on the diagnosis of HCC and associations with county-level social vulnerability. METHODS:Patients with HCC <65 years of age were identified from the SEER database (2010-2016). County-level social vulnerability factors were obtained from the CDC SVI and BRFSS. A Difference-in-Difference analysis evaluated change in early-stage diagnoses (stage I-II) between expansion and non-expansion states. A Difference-in-Difference-in-Difference analysis evaluated expansion impact among counties with higher proportions of social vulnerability. RESULTS:Of 19,751 patients identified, 81.5% were in expansion states. Uninsured status decreased in expansion states (6.3%-2.4%, p < 0.0001) and remained unchanged in non-expansion states (12.7%-14.8%, p = 0.43). There was no significant difference in the incidence of early-stage diagnoses between expansion states and non-expansion states. Results were consistent when accounting for social vulnerability. CONCLUSION/CONCLUSIONS:Medicaid expansion was not associated with earlier stage diagnoses in patients with HCC, including those with higher social vulnerability. Unlike other cancers, expanded access did not translate into higher utilization of care in HCC, suggesting barriers on a multitude of levels.

BACKGROUND:Hurricanes are severe weather events that can disrupt power, water, and transportation systems. These disruptions may be deadly for patients requiring maintenance dialysis. We hypothesized that the mortality risk among patients requiring maintenance dialysis would be increased in the 30 days after a hurricane. METHODS:Patients registered as requiring maintenance dialysis in the United States Renal Data System who initiated treatment between January 1, 1997 and December 31, 2017 in one of 108 hurricane-afflicted counties were followed from dialysis initiation until transplantation, dialysis discontinuation, a move to a nonafflicted county, or death. Hurricane exposure was determined as a tropical cyclone event with peak local wind speeds ≥64 knots in the county of a patient's residence. The risk of death after the hurricane was estimated using time-varying Cox proportional hazards models. RESULTS:The median age of the 187,388 patients was 65 years (IQR, 53-75) and 43.7% were female. There were 27 hurricanes and 105,398 deaths in 529,339 person-years of follow-up on dialysis. In total, 29,849 patients were exposed to at least one hurricane. Hurricane exposure was associated with a significantly higher mortality after adjusting for demographic and socioeconomic covariates (hazard ratio, 1.13; 95% confidence interval, 1.05-1.22). The association persisted when adjusting for seasonality. CONCLUSIONS:Patients requiring maintenance dialysis have a higher mortality risk in the 30 days after a hurricane.