Head and neck squamous cell carcinoma (HNSCC) in solid organ transplant recipients - Results from the scientific registry of transplant recipients (SRTR) database.

BACKGROUND: Solid organ transplant recipients have an elevated risk of cancer following organ transplantation than the age-adjusted general population. We assessed incidence of head and neck squamous cell carcinoma (HNSCC) in heart, lung, and liver recipients. BASIC PROCEDURES/METHODS: This retrospective cohort study included 124,966 patients from the United States Scientific Registry of Transplant Recipients (SRTR) database who received heart, lung, or liver transplantation between 1991 and 2010. Follow-up data were available until 2018. Patients with prevalent HNSCC at transplantation were excluded. Incident cases of HNSCC post organ transplantation were identified, and incidence rates (per 100,000 person-years) were reported by gender, race, organ type, year and age at organ transplantation. MAIN FINDINGS: The majority of patients received liver transplantation (58.64 %), followed by heart (28.64 %), and lung (12.72 %) transplantation. During follow-up, 4.14 % patients developed HNSCC. Overall incidence rate of HNSCC was 426.76 per 100,000 person-years. Male recipients had a higher HNSCC incidence rate than female recipients (571.8 and 177.0 per 100,000 person-years, respectively). Lung recipients had the highest overall HNSCC incidence rate (1273.6 per 100,000 person-years), followed by heart (644.2 per 100,000 person-years), and liver recipients (207.1 per 100,000 person-years). Overall, an increase in HNSCC incidence rate was observed with increase in age at organ transplantation. An increase in incidence rates of HNSCC over time was observed in lung recipients; however, incidence rates decreased over time in heart recipients. CONCLUSION: Solid organ transplant recipients have a high incidence of HNSCC following organ transplantation, and the incidence varies by type of organ received.

Trends in Black-White Differences of Antihypertensive Treatment in Individuals With and Without History of Stroke.

BACKGROUND: Recent hypertension guidelines for the general population have included race-specific recommendations for antihypertensives, whereas current stroke-specific recommendations for antihypertensives do not vary by race. The impact of these guidelines on antihypertensive regimen changes over time, and if this has varied by prevalent stroke status, is unclear. METHODS: The use of antihypertensive medications was studied cross-sectionally among self-identified Black and White participants, aged ≥45 years, with and without history of stroke, from the REGARDS study (Reasons for Geographic and Racial Differences in Stroke). Participants completed an in-home examination in 2003-2007 (visit 1) with/without an examination in 2013-2016 (visit 2). Stratified by prevalent stroke status, logistic regression mixed models examined associations between antihypertensive class use for visit 2 versus visit 1 and Black versus White individuals with an interaction adjusted for demographics, socioeconomic status, and vascular risk factors/vital signs. RESULTS: Of 17 244 stroke-free participants at visit 1, Black participants had greater adjusted odds of angiotensin-converting enzyme inhibitor usage than White participants (odds ratio [OR], 1.51 [95% CI, 1.30-1.77]). This difference was smaller in the 7476 stroke-free participants at visit 2 (OR, 1.16 [95% CI, 1.08-1.25]). In stroke-free participants at visit 1, Black participants had lower odds of calcium channel blocker (CCB) usage than White participants (OR, 0.47 [95% CI, 0.41-0.55]), but CCB usage did not differ significantly between Black and White stroke-free participants at visit 2 (OR, 1.02 [95% CI, 0.95-1.09]). Among 1437 stroke survivor participants at visit 1, Black participants had lower odds of CCB use than White participants (OR, 0.34 [95% CI, 0.26-0.45]). In 689 stroke survivor participants at visit 2, CCB use did not differ between Black and White participants (OR, 0.80 [95% CI, 0.61-1.06]). CONCLUSIONS: Racial differences in the use of guideline-recommended antihypertensives decreased between 2003-2007 and 2013-2016 in stroke-free individuals. In stroke survivors, racial differences in CCB usage narrowed over the time periods. These findings suggest there is still a mismatch between race-specific hypertension guidelines and recent clinical practice.

Population-average mediation analysis for zero-inflated count outcomes.

Mediation analysis is an increasingly popular statistical method for explaining causal pathways to inform intervention. While methods have increased, there is still a dearth of robust mediation methods for count outcomes with excess zeroes. Current mediation methods addressing this issue are computationally intensive, biased, or challenging to interpret. To overcome these limitations, we propose a new mediation methodology for zero-inflated count outcomes using the marginalized zero-inflated Poisson (MZIP) model and the counterfactual approach to mediation. This novel work gives population-average mediation effects whose variance can be estimated rapidly via delta method. This methodology is extended to cases with exposure-mediator interactions. We apply this novel methodology to explore if diabetes diagnosis can explain BMI differences in healthcare utilization and test model performance via simulations comparing the proposed MZIP method to existing zero-inflated and Poisson methods. We find that our proposed method minimizes bias and computation time compared to alternative approaches while allowing for straight-forward interpretations.

Application of marginalized zero-inflated models when mediators have excess zeroes.

Mediation analysis has become increasingly popular over the last decade as researchers are interested in assessing mechanistic pathways for intervention. Although available methods have increased, there are still limited options for mediation analysis with zero-inflated count variables where the distribution of response has a "cluster" of data at the zero value (i.e. distribution of number of cigarettes smoked per day, where nonsmokers cluster at zero cigarettes). The currently available methods do not obtain unbiased population average effects of mediation effects. In this paper, we propose an extension of the counterfactual approach to mediation with direct and indirect effects to scenarios where the mediator is a count variable with excess zeroes by utilizing the Marginalized Zero-Inflated Poisson Model (MZIP) for the mediator model. We derive direct and indirect effects for continuous, binary, and count outcomes, as well as adapt to allow mediator-exposure interactions. Our proposed work allows straightforward calculation of direct and indirect effects for the overall population mean values of the mediator, for scenarios in which researchers are interested in generalizing direct and indirect effects to the population. We apply this novel methodology to an application observing how alcohol consumption may explain sex differences in cholesterol and assess model performance via a simulation study comparing the proposed MZIP mediator framework to existing methods for marginal mediator effects.

Pharmacogenomics of intravenous immunoglobulin response in Kawasaki disease.

Introduction: Kawasaki disease (KD) is a diffuse vasculitis in children. Response to high dose intravenous gamma globulin (IVIG), the primary treatment, varies according to genetic background. We sought to identify genetic loci, which associate with treatment response using whole genome sequencing (WGS). Method: We performed WGS in 472 KD patients with 305 IVIG responders and 167 non-responders defined by AHA clinical criteria. We conducted logistic regression models to test additive genetic effect in the entire cohort and in four subgroups defined by ancestry information markers (Whites, African Americans, Asians, and Hispanics). We performed functional mapping and annotation using FUMA to examine genetic variants that are potentially involved IVIG non-response. Further, we conducted SNP-set [Sequence] Kernel Association Test (SKAT) for all rare and common variants. Results: Of the 43,288,336 SNPs (23,660,970 in intergenic regions, 16,764,594 in introns and 556,814 in the exons) identified, the top ten hits associated with IVIG non-response were in FANK1, MAP2K3:KCNJ12, CA10, FRG1DP, CWH43 regions. When analyzed separately in ancestry-based racial subgroups, SNPs in several novel genes were associated. A total of 23 possible causal genes were pinpointed by positional and chromatin mapping. SKAT analysis demonstrated association in the entire MANIA2, EDN1, SFMBT2, and PPP2R5E genes and segments of CSMD2, LINC01317, HIVEPI, HSP90AB1, and TTLL11 genes. Conclusions: This WGS study identified multiple predominantly novel understudied genes associated with IVIG response. These data can serve to inform regarding pathogenesis of KD, as well as lay ground work for developing treatment response predictors.