RFX6 Maintains Gene Expression and Function of Adult Human Islet α-Cells.

Mutations in the gene encoding the transcription factor regulatory factor X-box binding 6 (RFX6) are associated with human diabetes. Within pancreatic islets, RFX6 expression is most abundant in islet α-cells, and α-cell RFX6 expression is altered in diabetes. However, the roles of RFX6 in regulating gene expression, glucagon output, and other crucial human adult α-cell functions are not yet understood. We developed a method for selective genetic targeting of human α-cells and assessed RFX6-dependent α-cell function. RFX6 suppression with RNA interference led to impaired α-cell exocytosis and dysregulated glucagon secretion in vitro and in vivo. By contrast, these phenotypes were not observed with RFX6 suppression across all islet cells. Transcriptomics in α-cells revealed RFX6-dependent expression of genes governing nutrient sensing, hormone processing, and secretion, with some of these exclusively expressed in human α-cells. Mapping of RFX6 DNA-binding sites in primary human islet cells identified a subset of direct RFX6 target genes. Together, these data unveil RFX6-dependent genetic targets and mechanisms crucial for regulating adult human α-cell function.

HNF1α maintains pancreatic α and ß cell functions in primary human islets.

HNF1A haploinsufficiency underlies the most common form of human monogenic diabetes (HNF1A-maturity onset diabetes of the young [HNF1A-MODY]), and hypomorphic HNF1A variants confer type 2 diabetes risk. But a lack of experimental systems for interrogating mature human islets has limited our understanding of how the transcription factor HNF1α regulates adult islet function. Here, we combined conditional genetic targeting in human islet cells, RNA-Seq, chromatin mapping with cleavage under targets and release using nuclease (CUT&RUN), and transplantation-based assays to determine HNF1α-regulated mechanisms in adult human pancreatic α and ß cells. Short hairpin RNA-mediated (shRNA-mediated) suppression of HNF1A in primary human pseudoislets led to blunted insulin output and dysregulated glucagon secretion after transplantation in mice, recapitulating phenotypes observed in patients with diabetes. These deficits corresponded with altered expression of genes encoding factors critical for hormone secretion, including calcium channel subunits, ATPase transporters, and extracellular matrix constituents. Additionally, HNF1A loss led to upregulation of transcriptional repressors, providing evidence for a mechanism of transcriptional derepression through HNF1α. CUT&RUN mapping of HNF1α DNA binding sites in primary human islets imputed a subset of HNF1α-regulated genes as direct targets. These data elucidate mechanistic links between HNF1A loss and diabetic phenotypes in mature human α and ß cells.

Assessment of Hormonal Contraceptive Utilization and Associated Odds of Hypercoagulopathy in Patients with Venous Malformations Using a National Claims Database.

BACKGROUND: Vascular anomalies that exhibit a slow velocity of blood flow, specifically venous malformations (VM), are associated with hypercoagulability. There is limited literature on the utilization of hormonal contraceptives (HCs) and the development of clotting events in female individuals diagnosed with VM. OBJECTIVE: We aimed to characterize HC utilization and associated odds of hypercoagulopathy in patients with VM of child-bearing age. METHODS: Using a national administrative claims database, we identified female patients with VM aged 15-49 years and a control population, matched for age and length of insurance enrollment, from 2016 to 2021. Multivariable logistic regression was used to estimate the odds of hypercoagulation events associated with HC use. RESULTS: Two hundred and sixty-seven (47.2%) patients with VM and 1284 (45.4%) control patients utilized HCs during the study period. Oral contraceptives were the most common HC for patients with and without VM (73.8% and 76.9% of those taking HCs, respectively), and estrogen-containing combination HCs (70.4% in patients with VM and 75.9% in controls) were more prevalent than progestin-only HCs in both populations. Despite a heightened baseline odds of hypercoagulopathy in patients with VM relative to patients without VM (odds ratio = 12.54; 95% confidence interval 7.73-20.3), HC use was not associated with an increased odds of hypercoagulation in the VM subpopulation (odds ratio = 0.82; 95% confidence interval 0.46-1.46). In contrast, tobacco use (odds ratio = 2.12; 95% confidence interval 1.09-4.12) and a history of coagulopathy (odds ratio = 3.92; 95% confidence interval 1.48-10.36) were predictive of thromboembolic events in the VM cohort. CONCLUSIONS: These findings suggest that patients with VM may safely use HCs with careful consideration of other risk factors for thromboses.

Health Care Utilization and Costs in Systemic Therapies for Metastatic Melanoma from 2016 to 2020.

BACKGROUND: Widespread implementation of immune checkpoint inhibitors (ICI) and targeted therapies for metastatic melanoma has led to a decline in melanoma-related mortality but increased healthcare costs. We aimed to determine how healthcare utilization varied by systemic, non-adjuvant melanoma treatment from 2016 to 2020. PATIENTS AND METHODS: Adults with presumed stage IV metastatic melanoma receiving systemic therapy from 2016 to 2020 were identified in Optum, a nationwide commercial claims database. Treatment groups were nivolumab, pembrolizumab, ipilimumab+nivolumab (combination-ICI), or BRAF+MEK inhibitor (BRAFi+MEKi) therapy. Outcomes included hospitalizations, days hospitalized, emergency room (ER) visits, outpatient visits, and healthcare costs per patient per month (pppm). Multivariable regression models were used to analyze whether cost and utilization outcomes varied by treatment group, with nivolumab as reference. RESULTS: Among 2018 adult patients with metastatic melanoma identified, mean (SD) age was 67 (15) years. From 2016 to 2020, nivolumab surpassed pembrolizumab as the most prescribed systemic melanoma therapy while combination-ICI and BRAFi+MEKi therapies remained stable. Relative to nivolumab, all other therapies were associated with increased total healthcare costs (combination-ICI: ß = $47 600 pppm, 95%CI $42 200-$53 100; BRAFi+MEKi: ß = $3810, 95%CI $365-$7260; pembrolizumab: ß = $6450, 95%CI $4420-$8480). Combination-ICI and BRAFi+MEKi therapies were associated with more inpatient hospital days. CONCLUSIONS: Amid the evolving landscape of systemic therapy for advanced melanoma, nivolumab monotherapy emerged as the most used and least costly systemic treatment from 2016 to 2020. Its sharp increase in use in 2018 and lower costs relative to pembrolizumab may in part be due to earlier adoption of less frequent dosing intervals.

Assessment of Comorbidities Associated With Allergic Contact Dermatitis in the United States: A Retrospective Claims-Based Study.

BACKGROUND: Allergic contact dermatitis (ACD) is a common dermatologic disease. Patch testing remains the criterion standard for diagnosis. In clinical practice, avoidance may be limited by patient occupation or noncompliance, the pervasive nature of the culprit agent, or barriers to expert care because of socioeconomic, cultural, or geographic factors. Thus, ACD is frequently chronic and/or recurrent; however, the comorbidities associated with ACD are not well characterized. OBJECTIVE: The aim of the study is to identify associations between ACD and psychiatric, sleep health, cardiovascular, and infectious conditions. METHODS: In this study, we used a large US claims database to identify comorbidities associated with ACD diagnosed after patch testing, including psychiatric, sleep health, cardiovascular, and infectious conditions. We also stratified these associations by chronicity of disease. RESULTS: We identified associations between ACD and psychiatric, sleep-related, cardiovascular, and infectious comorbidities. We also found that more chronic ACD was associated with more infectious comorbidities. All of these associations remained significant on further subanalysis when patients with AD and venous stasis were excluded. CONCLUSIONS: Allergic contact dermatitis is associated with multiple comorbidities. Further study is required to corroborate these findings, determine causality, and to explore the impact of possible interventions in the workup and management of this common and often debilitating disease.

Gorlin Syndrome: Assessing Genotype-Phenotype Correlations and Analysis of Early Clinical Characteristics as Risk Factors for Disease Severity.

PURPOSE: Gorlin syndrome (GS) is a rare genetic disorder characterized by lifetime risk of basal cell carcinomas (BCCs), skeletal anomalies (SAs), and other extracutaneous neoplasms. There is great variation in disease severity, and a genotype-phenotype correlation has not been well established. Here, we investigate whether patients' clinical characteristics predict disease severity to inform clinical decision making. METHODS: Data of 248 patients with GS were collected between 2014 and 2021 from three institutions. Multivariable regression analyses were performed to investigate whether clinical characteristics predicted disease burden. Genotype-phenotype correlations were investigated in 40 patients. RESULTS: Patients with SAs had a mean increase of 120 lifetime BCCs (95% CI, 27.1 to 213) relative to patients without SAs. Those with ≥ 2 SAs had 2.45 increased odds (95% CI, 1.01 to 5.91) of advanced or metastatic BCCs. Moreover, the presence of multiple SAs was associated with 5.00 increased odds of having a keratocystic odontogenic tumor (95% CI, 2.22 to 11.3) and 2.79 increased odds of an ovarian fibroma (95% CI, 1.05 to 7.40). Genotype-phenotype analyses showed that missense/in-frame mutations were more likely to be hereditary compared with severe deleterious mutation types (100% v 27%; P = .004). In addition, heat map visualization illustrated that those with more deleterious variants, like large deletions, trended toward increased burden of SAs and BCCs per year. CONCLUSION: GS patients with SAs may be at greater risk for developing more numerous and severe BCCs and other neoplastic growths including keratocystic odontogenic tumors and ovarian fibromas. Current clinical guidelines suggest yearly follow-up in individuals with GS. Since SAs are usually recognized at the time of diagnosis, our results suggest that more vigilant lifetime multidisciplinary surveillance should be considered for these patients starting in childhood.