Faculty Bibliography

Status 1A liver transplant candidates are given the highest medical priority for the allocation of deceased donor livers. Organ Procurement and Transplantation Network (OPTN) policy requires physicians to certify that a candidate has a life expectancy without a transplant of less than 7 days for that candidate to be given status 1A. Additionally, candidates receiving status 1A must have one of six medical conditions listed in policy. Using Scientific Registry of Transplant Recipients data from all prevalent liver transplant candidates from 2010 to 2020, we used a bias-corrected Kaplan-Meier model to calculate the survival of status 1A candidates and to determine their life expectancy without a transplant. We found that status 1A candidates have a life expectancy without a transplant of 24 (95% CI 20-46) days-over three times longer than what policy requires for status 1A designation. We repeated the analysis for subgroups of status 1A candidates based on the medical conditions that grant status 1A. We found that none of these subgroups met the life expectancy requirement. Harmonizing OPTN policy with observed data would sustain the integrity of the allocation process.

Increasing numbers of compatible pairs are choosing to enter paired exchange programs, but motivations, outcomes, and system-level effects of participation are not well described. Using a linkage of the Scientific Registry of Transplant Recipients and National Kidney Registry, we compared outcomes of traditional (originally incompatible) recipients to originally compatible recipients using the Kaplan-Meier method. We identified 154 compatible pairs. Most pairs sought to improve HLA matching. Compared to the original donor, actual donors were younger (39 vs. 50 years, p < .001), less often female (52% vs. 68%, p < .01), higher BMI (27 vs. 25 kg/m², p = .03), less frequently blood type O (36% vs. 80%, p < .001), and had higher eGFR (99 vs. 94 ml/min/1.73 m², p = .02), with a better LKDPI (median 7 vs. 22, p < .001). We observed no differences in graft failure or mortality. Compatible pairs made 280 additional transplants possible, many in highly sensitized recipients with long wait times. Compatible pair recipients derived several benefits from paired exchange, including better donor quality. Living donor pairs should receive counseling regarding all options available, including kidney paired donation. As more compatible pairs choose to enter exchange programs, consideration should be given to optimizing compatible pair and hard-to-transplant recipient outcomes.

BACKGROUND:The association between exposure to air pollution and papillary thyroid carcinoma is unknown. We sought to estimate the relationship between long-term exposure to the fine (diameter ≤ 2.5 μm) particulate matter component of air pollution and the risk of papillary thyroid cancer. METHODS:Adult (age ≥18) patients with newly diagnosed papillary thyroid carcinoma between January 1, 2013 and December 31, 2016 across a single health system were identified using electronic medical records. Data from 1,990 patients with papillary thyroid carcinoma were compared with 3,980 age- and sex-matched control subjects without any evidence of thyroid disease. Cumulative fine (diameter <2.5 μm) particulate matter exposure was estimated by incorporating patients' residential zip codes into a deep learning neural networks model, which uses both meteorological and satellite-based measurements. Conditional logistic regression was performed to assess for association between papillary thyroid carcinoma and increasing fine (diameter ≤2.5 μm) particulate matter concentrations over 1, 2, and 3 years of cumulative exposure preceding papillary thyroid carcinoma diagnosis. RESULTS:n = 0.04). Among current smokers (n = 623), the risk of developing papillary thyroid carcinoma was highest (adjusted odds ratio = 1.35, 95% confidence interval: 1.12-1.63). CONCLUSION/CONCLUSIONS:Increasing concentration of fine (diameter ≤2.5 μm) particulate matter in air pollution is significantly associated with the incidence of papillary thyroid carcinoma with 2 and 3 years of exposure. Our novel findings provide additional insight into the potential associations between risk factors and papillary thyroid carcinoma and warrant further investigation, specifically in areas with high levels of air pollution both nationally and internationally.

BACKGROUND:Tertiary hyperparathyroidism after kidney transplantation has been associated with graft dysfunction, cardiovascular morbidity, and osteopenia; however, its true prevalence is unclear. The objective of our study was to evaluate the prevalence of and risk factors for tertiary hyperparathyroidism. METHODS:A prospective cohort of 849 adult kidney transplantation recipients (December 2008-February 2020) was used to estimate the prevalence of hyperparathyroidism 1-year post-kidney transplant. Tertiary hyperparathyroidism was defined as hypercalcemia (≥10mg/dL) and hyperparathyroidism (parathyroid hormone≥70pg/mL) 1-year post-kidney transplantation. Modified Poisson regression models were used to evaluate risk factors associated with the development of both persistent hyperparathyroidism and tertiary hyperparathyroidism. RESULTS:Among kidney transplantation recipients, 524 (61.7%) had persistent hyperparathyroidism and 182 (21.5%) had tertiary hyperparathyroidism at 1-year post-kidney transplantation. Calcimimetic use before kidney transplantation was associated with 1.30-fold higher risk of persistent hyperparathyroidism (adjusted prevalence ratio = 1.30, 95% CI: 1.12-1.51) and 1.84-fold higher risk of tertiary hyperparathyroidism (adjusted prevalence ratio = 1.84, 95% CI: 1.25-2.72). Pre-kidney transplantation parathyroid hormone ≥300 pg/mL was associated with 1.49-fold higher risk of persistent hyperparathyroidism (adjusted prevalence ratio = 1.49, 95% CI = 1.19-1.85) and 2.21-fold higher risk of tertiary hyperparathyroidism (adjusted prevalence ratio = 2.21, 95% CI = 1.25-3.90). Pre-kidney transplantation tertiary hyperparathyroidism was associated with an increased risk of post-kidney transplantation tertiary hyperparathyroidism (adjusted prevalence ratio = 1.71, 95% CI = 1.29-2.27), but not persistent hyperparathyroidism. Furthermore, 73.0% of patients with persistent hyperparathyroidism and 61.5% with tertiary hyperparathyroidism did not receive any treatment at 1-year post-kidney transplantation. CONCLUSION/CONCLUSIONS:Persistent hyperparathyroidism affected 61.7% and tertiary hyperparathyroidism affected 21.5% of kidney transplantation recipients; however, the majority of patients were not treated. Pre-kidney transplantation parathyroid hormone levels ≥300pg/mL and the use of calcimimetics are associated with the development of tertiary hyperparathyroidism. These findings encourage the re-evaluation of recommended pre-kidney transplantation parathyroid hormone thresholds and reconsideration of pre-kidney transplantation secondary hyperparathyroidism treatments to avoid the adverse sequelae of tertiary hyperparathyroidism in kidney transplantation recipients.

Nondirected kidney donors can initiate living donor chains that end to patients on the waitlist. We compared 749 National Kidney Registry (NKR) waitlist chain end transplants to other transplants from the NKR and the Scientific Registry of Transplant Recipients between February 2008 and September 2020. Compared to other NKR recipients, chain end recipients were more often older (53 vs. 52 years), black (32% vs. 15%), publicly insured (71% vs. 46%), and spent longer on dialysis (3.0 vs. 1.0 years). Similar differences were noted between chain end recipients and non-NKR living donor recipients. Black patients received chain end kidneys at a rate approaching that of deceased donor kidneys (32% vs. 34%). Chain end donors were older (52 vs. 44 years) with slightly lower glomerular filtration rates (93 vs. 98 ml/min/1.73 m² ) than other NKR donors. Chain end recipients had elevated risk of graft failure and mortality compared to control living donor recipients (both p < .01) but lower graft failure (p = .03) and mortality (p < .001) compared to deceased donor recipients. Sharing nondirected donors among a multicenter network may improve the diversity of waitlist patients who benefit from living donation.

Background/UNASSIGNED:Posttransplant diabetes (PTD), a major complication after kidney transplantation (KT), is often attributable to immunosuppression. The risk of PTD may increase with more potent steroid maintenance and older recipient age. Methods/UNASSIGNED:Using United States Renal Data System data, we studied 12 488 adult first-time KT recipients (2010-2015) with no known pre-KT diabetes. We compared the risk of PTD among recipients who underwent early steroid withdrawal (ESW) versus continued steroid maintenance (CSM) using Cox regression with inverse probability weighting to adjust for confounding. We tested whether the risk of PTD resulting from ESW differed by recipient age (18-29, 30-54, and ≥55 y). Results/UNASSIGNED:). Conclusions/UNASSIGNED:The beneficial association of ESW with decreased PTD was more pronounced among recipients aged ≥55, supporting an age-specific assessment of the risk-benefit balance regarding ESW.