Background-Angiomyolipomas in patients with the tuberous sclerosis complex or sporadic lymphangioleiomyomatosis are associated with mutations in tuberous sclerosis genes resulting in constitutive activation of the mammalian target of rapamycin (mTOR). The drug sirolimus suppresses mTOR signaling.

Background Pulmonary hypertension (PH) is associated with increased morbidity across the cardiopulmonary disease spectrum. Based largely on expert consensus opinion, PH is defined by a mean pulmonary artery pressure (mPAP) ≥25 mmHg. Although mPAP levels below this threshold are common among populations at risk for PH, the relevance of mPAP <25 mmHg to clinical outcome is unknown. Methods and Results We analyzed retrospectively all US veterans undergoing right heart catheterization (RHC)(2007–2012) in the Veterans Affairs health care system (N=21,727; 908 day median follow-up). Cox proportional hazards models were used to evaluate the association between mPAP and outcomes of all-cause mortality and hospitalization, adjusted for clinical covariates. When treating mPAP as a continuous variable, the mortality hazard increased beginning at 19 mmHg (HR=1.183, 95% CI [1.004–1.393]) relative to 10 mmHg. Therefore, patients were stratified into three groups: referent (≤18 mmHg; N=4,207), borderline PH (19–24 mmHg; N=5,030), and PH (≥25 mmHg; N=12,490). The adjusted mortality hazard was increased for borderline PH (HR=1.23, 95% CI [1.12–1.36], P<0.0001) and PH (HR=2.16, 95% CI [1.96–2.38], P<0.0001) compared to the referent group. The adjusted hazard for hospitalization was also increased in borderline PH (HR=1.07, 95% CI [1.01–1.12], P=0.0149) and PH (HR=1.15, 95% CI [1.09–1.22], P<0.0001). The borderline PH cohort remained at increased risk for mortality after excluding the following high-risk subgroups: patients with pulmonary artery wedge pressure >15 mmHg, pulmonary vascular resistance ≥3.0 Wood units, or inpatient status at the time of RHC. Conclusions These data illustrate a continuum of risk according to mPAP level, and that borderline PH is associated with increased mortality and hospitalization. Future investigations are needed to test the generalizability of our findings to other populations and study the effect of treatment on outcome in borderline PH.

Summary Background Rare genetic variants cause pulmonary arterial hypertension, but the contribution of common genetic variation to disease risk and natural history is poorly characterised. We tested for genome-wide association for pulmonary arterial hypertension in large international cohorts and assessed the contribution of associated regions to outcomes. Methods We did two separate genome-wide association studies (GWAS) and a meta-analysis of pulmonary arterial hypertension. These GWAS used data from four international case-control studies across 11 744 individuals with European ancestry (including 2085 patients). One GWAS used genotypes from 5895 whole-genome sequences and the other GWAS used genotyping array data from an additional 5849 individuals. Cross-validation of loci reaching genome-wide significance was sought by meta-analysis. Conditional analysis corrected for the most significant variants at each locus was used to resolve signals for multiple associations. We functionally annotated associated variants and tested associations with duration of survival. All-cause mortality was the primary endpoint in survival analyses. Findings A locus near SOX17 (rs10103692, odds ratio 1·80 [95% CI 1·55–2·08], p=5·13 × 10 –15 ) and a second locus in HLA-DPA1 and HLA-DPB1 (collectively referred to as HLA-DPA1/DPB1 here; rs2856830, 1·56 [1·42–1·71], p=7·65 × 10 –20 ) within the class II MHC region were associated with pulmonary arterial hypertension. The SOX17 locus had two independent signals associated with pulmonary arterial hypertension (rs13266183, 1·36 [1·25–1·48], p=1·69 × 10 –12 ; and rs10103692). Functional and epigenomic data indicate that the risk variants near SOX17 alter gene regulation via an enhancer active in endothelial cells. Pulmonary arterial hypertension risk variants determined haplotype-specific enhancer activity, and CRISPR-mediated inhibition of the enhancer reduced SOX17 expression. The HLA-DPA1/DPB1 rs2856830 genotype was strongly associated with survival. Median survival from diagnosis in patients with pulmonary arterial hypertension with the C/C homozygous genotype was double (13·50 years [95% CI 12·07 to >13·50]) that of those with the T/T genotype (6·97 years [6·02–8·05]), despite similar baseline disease severity. Interpretation This is the first study to report that common genetic variation at loci in an enhancer near SOX17 and in HLA-DPA1/DPB1 is associated with pulmonary arterial hypertension. Impairment of SOX17 function might be more common in pulmonary arterial hypertension than suggested by rare mutations in ...

No abstract