Publications

BACKGROUND

Peripheral arterial disease (PAD) is a global health problem that is frequently underdiagnosed and undertreated. Noninvasive tools to predict the presence and severity of PAD have limitations including inaccuracy, cost, or need for intravenous contrast and ionizing radiation.

HYPOTHESIS

A clinical/biomarker score may offer an attractive alternative diagnostic method for PAD.

METHODS

In a prospective cohort of 354 patients referred for diagnostic peripheral and/or coronary angiography, predictors of ≥50% stenosis in ≥1 peripheral vessel (carotid/subclavian, renal, or lower extremity arteries) were identified from >50 clinical variables and 109 biomarkers. Machine learning identified variables predictive of obstructive PAD; a score derived from the final model was developed.

RESULTS

The score consisted of 1 clinical variable (history of hypertension) and 6 biomarkers (midkine, kidney injury molecule-1, interleukin-23, follicle-stimulating hormone, angiopoietin-1, and eotaxin-1). The model had an in-sample area under the receiver operating characteristic curve of 0.85 for obstructive PAD and a cross-validated area under the curve of 0.84; higher scores were associated with greater severity of angiographic stenosis. At optimal cutoff, the score had 65% sensitivity, 88% specificity, 76% positive predictive value (PPV), and 81% negative predictive value (NPV) for obstructive PAD and performed consistently across vascular territories. Partitioning the score into 5 levels resulted in a PPV of 86% and NPV of 98% in the highest and lowest levels, respectively. Elevated score was associated with shorter time to revascularization during 4.3 years of follow-up.

CONCLUSIONS

A clinical/biomarker score demonstrates high accuracy for predicting the presence of PAD.

BACKGROUND AND OBJECTIVES

Black Americans with and without kidney disease risk variants face high risk of ESKD. Soluble urokinase-type plasminogen activator receptor (suPAR), a circulating signaling protein and marker of immune activation, constitutes a promising biomarker of CKD-associated risks. We aimed to quantify the associations between serum suPAR concentration and adverse outcomes in Black Americans with and without kidney disease risk variants, over and above iodine-125 iothalamate measured GFR and proteinuria.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Using data from the African-American Study of Kidney Disease and Hypertension, a multicenter clinical trial followed by a cohort phase with a median total follow-up of 9.7 years (interquartile range, 6.5-10.9 years), we examined the associations of suPAR with CKD progression (defined as doubling of serum creatinine or ESKD), ESKD, worsening proteinuria (defined as pre-ESKD doubling of 24-hour urine protein-to-creatinine ratio to ≥220 mg/g), and all-cause death.

RESULTS

At baseline, the median suPAR was 4462 pg/ml, mean measured GFR was 46 ml/min per 1.73 m, and median 24-hour urine protein-to-creatinine ratio was 80 mg/g. After controlling for baseline demographics, randomization arm, GFR, proteinuria, risk status, and clinical risk factors, there was a 1.26-times higher risk for CKD progression per SD higher baseline log-transformed suPAR (hazard ratio [HR], 1.26; 95% confidence interval [95% CI], 1.11 to 1.43; <0.001). Higher suPAR was also independently associated with risk of ESKD (HR, 1.36; 95% CI, 1.17 to 1.58; <0.001) and death (HR, 1.25; 95% CI, 1.08 to 1.45; =0.003). suPAR was only associated with worsening proteinuria in patients with two risk alleles (HR, 1.46; 95% CI, 1.08 to 1.99; =0.02).

CONCLUSIONS

Higher suPAR was associated with various adverse outcomes in Black Americans with CKD, with and without kidney disease risk variants, independently of proteinuria and GFR.

Using integrative genomic analysis of 360 metastatic castration-resistant prostate cancer (mCRPC) samples, we identified a novel subtype of prostate cancer typified by biallelic loss of CDK12 that is mutually exclusive with tumors driven by DNA repair deficiency, ETS fusions, and SPOP mutations. CDK12 loss is enriched in mCRPC relative to clinically localized disease and characterized by focal tandem duplications (FTDs) that lead to increased gene fusions and marked differential gene expression. FTDs associated with CDK12 loss result in highly recurrent gains at loci of genes involved in the cell cycle and DNA replication. CDK12 mutant cases are baseline diploid and do not exhibit DNA mutational signatures linked to defects in homologous recombination. CDK12 mutant cases are associated with elevated neoantigen burden ensuing from fusion-induced chimeric open reading frames and increased tumor T cell infiltration/clonal expansion. CDK12 inactivation thereby defines a distinct class of mCRPC that may benefit from immune checkpoint immunotherapy.

Germline mutations involving small mothers against decapentaplegic-transforming growth factor-β (SMAD-TGF-β) signaling are an important but rare cause of pulmonary arterial hypertension (PAH), which is a disease characterized, in part, by vascular fibrosis and hyperaldosteronism (ALDO). We developed and analyzed a fibrosis protein-protein network (fibrosome) in silico, which predicted that the SMAD3 target neural precursor cell expressed developmentally down-regulated 9 (NEDD9) is a critical ALDO-regulated node underpinning pathogenic vascular fibrosis. Bioinformatics and microscale thermophoresis demonstrated that oxidation of Cys in the SMAD3 docking region of NEDD9 impairs SMAD3-NEDD9 protein-protein interactions in vitro. This effect was reproduced by ALDO-induced oxidant stress in cultured human pulmonary artery endothelial cells (HPAECs), resulting in impaired NEDD9 proteolytic degradation, increased NEDD9 complex formation with Nk2 homeobox 5 (NKX2-5), and increased NKX2-5 binding to Up-regulation of NEDD9-dependent collagen III expression corresponded to changes in cell stiffness measured by atomic force microscopy. HPAEC-derived exosomal signaling targeted NEDD9 to increase collagen I/III expression in human pulmonary artery smooth muscle cells, identifying a second endothelial mechanism regulating vascular fibrosis. ALDO-NEDD9 signaling was not affected by treatment with a TGF-β ligand trap and, thus, was not contingent on TGF-β signaling. Colocalization of NEDD9 with collagen III in HPAECs was observed in fibrotic pulmonary arterioles from PAH patients. Furthermore, ablation or inhibition prevented fibrotic vascular remodeling and pulmonary hypertension in animal models of PAH in vivo. These data identify a critical TGF-β-independent posttranslational modification that impairs SMAD3-NEDD9 binding in HPAECs to modulate vascular fibrosis and promote PAH.