Browsing by Author "Hill, Nicholas S."

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    Clinical Characteristics and Transplant-Free Survival Across the Spectrum of Pulmonary Vascular Disease
    (Elsevier, 2022) Hemnes, Anna R.; Leopold, Jane A.; Radeva, Milena K.; Beck, Gerald J.; Abidov, Aiden; Aldred, Micheala A.; Barnard, John; Rosenzweig, Erika B.; Borlaug, Barry A.; Chung, Wendy K.; Comhair, Suzy A. A.; Desai, Ankit A.; Dubrock, Hilary M.; Erzurum, Serpil C.; Finet, J. Emanuel; Frantz, Robert P.; Garcia, Joe G. N.; Geraci, Mark W.; Gray, Michael P.; Grunig, Gabriele; Hassoun, Paul M.; Highland, Kristin B.; Hill, Nicholas S.; Hu, Bo; Kwon, Deborah H.; Jacob, Miriam S.; Jellis, Christine L.; Larive, A. Brett; Lempel, Jason K.; Maron, Bradley A.; Mathai, Stephen C.; McCarthy, Kevin; Mehra, Reena; Nawabit, Rawan; Newman, John H.; Olman, Mitchell A.; Park, Margaret M.; Ramos, Jose A.; Renapurkar, Rahul D.; Rischard, Franz P.; Sherer, Susan G.; Tang, W. H. Wilson; Thomas, James D.; Vanderpool, Rebecca R.; Waxman, Aaron B.; Wilcox, Jennifer D.; Yuan, Jason X-J; Horn, Evelyn M.; PVDOMICS Study Group; Medicine, School of Medicine
    Background: PVDOMICS (Pulmonary Vascular Disease Phenomics) is a precision medicine initiative to characterize pulmonary vascular disease (PVD) using deep phenotyping. PVDOMICS tests the hypothesis that integration of clinical metrics with omic measures will enhance understanding of PVD and facilitate an updated PVD classification. Objectives: The purpose of this study was to describe clinical characteristics and transplant-free survival in the PVDOMICS cohort. Methods: Subjects with World Symposium Pulmonary Hypertension (WSPH) group 1-5 PH, disease comparators with similar underlying diseases and mild or no PH and healthy control subjects enrolled in a cross-sectional study. PH groups, comparators were compared using standard statistical tests including log-rank tests for comparing time to transplant or death. Results: A total of 1,193 subjects were included. Multiple WSPH groups were identified in 38.9% of PH subjects. Nocturnal desaturation was more frequently observed in groups 1, 3, and 4 PH vs comparators. A total of 50.2% of group 1 PH subjects had ground glass opacities on chest computed tomography. Diffusing capacity for carbon monoxide was significantly lower in groups 1-3 PH than their respective comparators. Right atrial volume index was higher in WSPH groups 1-4 than comparators. A total of 110 participants had a mean pulmonary artery pressure of 21-24 mm Hg. Transplant-free survival was poorest in group 3 PH. Conclusions: PVDOMICS enrolled subjects across the spectrum of PVD, including mild and mixed etiology PH. Novel findings include low diffusing capacity for carbon monoxide and enlarged right atrial volume index as shared features of groups 1-3 and 1-4 PH, respectively; unexpected, frequent presence of ground glass opacities on computed tomography; and sleep alterations in group 1 PH, and poorest survival in group 3 PH. PVDOMICS will facilitate a new understanding of PVD and refine the current PVD classification.
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    Kynurenine pathway metabolism evolves with development of preclinical and scleroderma-associated pulmonary arterial hypertension
    (American Physiological Society, 2023) Simpson, Catherine E.; Ambade, Anjira S.; Harlan, Robert; Roux, Aurelie; Aja, Susan; Graham, David; Shah, Ami A.; Hummers, Laura K.; Hemnes, Anna R.; Leopold, Jane A.; Horn, Evelyn M.; Berman-Rosenzweig, Erika S.; Grunig, Gabriele; Aldred, Micheala A.; Barnard, John; Comhair, Suzy A. A.; Tang, W. H. Wilson; Griffiths, Megan; Rischard, Franz; Frantz, Robert P.; Erzurum, Serpil C.; Beck, Gerald J.; Hill, Nicholas S.; Mathai, Stephen C.; Hassoun, Paul M.; Damico, Rachel L.; PVDOMICS Study Group; Medicine, School of Medicine
    Understanding metabolic evolution underlying pulmonary arterial hypertension (PAH) development may clarify pathobiology and reveal disease-specific biomarkers. Patients with systemic sclerosis (SSc) are regularly surveilled for PAH, presenting an opportunity to examine metabolic change as disease develops in an at-risk cohort. We performed mass spectrometry-based metabolomics on longitudinal serum samples collected before and near SSc-PAH diagnosis, compared with time-matched SSc subjects without PAH, in a SSc surveillance cohort. We validated metabolic differences in a second cohort and determined metabolite-phenotype relationships. In parallel, we performed serial metabolomic and hemodynamic assessments as the disease developed in a preclinical model. For differentially expressed metabolites, we investigated corresponding gene expression in human and rodent PAH lungs. Kynurenine and its ratio to tryptophan (kyn/trp) increased over the surveillance period in patients with SSc who developed PAH. Higher kyn/trp measured two years before diagnostic right heart catheterization increased the odds of SSc-PAH diagnosis (OR 1.57, 95% CI 1.05-2.36, P = 0.028). The slope of kyn/trp rise during SSc surveillance predicted PAH development and mortality. In both clinical and experimental PAH, higher kynurenine pathway metabolites correlated with adverse pulmonary vascular and RV measurements. In human and rodent PAH lungs, expression of TDO2, which encodes tryptophan 2,3 dioxygenase (TDO), a protein that catalyzes tryptophan conversion to kynurenine, was significantly upregulated and tightly correlated with pulmonary hypertensive features. Upregulated kynurenine pathway metabolism occurs early in PAH, localizes to the lung, and may be modulated by TDO2. Kynurenine pathway metabolites may be candidate PAH biomarkers and TDO warrants exploration as a potential novel therapeutic target. NEW & NOTEWORTHY: Our study shows an early increase in kynurenine pathway metabolism in at-risk subjects with systemic sclerosis who develop pulmonary arterial hypertension (PAH). We show that kynurenine pathway upregulation precedes clinical diagnosis and that this metabolic shift is associated with increased disease severity and shorter survival times. We also show that gene expression of TDO2, an enzyme that generates kynurenine from tryptophan, rises with PAH development.