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Background The relationship between mitochondrial DNA copy number (mtDNA CN) and cardiovascular disease remains elusive. Methods and Results We performed cross‐sectional and prospective association analyses of blood‐derived mtDNA CN and cardiovascular disease outcomes in 27 316 participants in 8 cohorts of multiple racial and ethnic groups with whole‐genome sequencing. We also performed Mendelian randomization to explore causal relationships of mtDNA CN with coronary heart disease (CHD) and cardiometabolic risk factors (obesity, diabetes, hypertension, and hyperlipidemia). P <0.01 was used for significance. We validated most of the previously reported associations between mtDNA CN and cardiovascular disease outcomes. For example, 1‐SD unit lower level of mtDNA CN was associated with 1.08 (95% CI, 1.04–1.12; P <0.001) times the hazard for developing incident CHD, adjusting for covariates. Mendelian randomization analyses showed no causal effect from a lower level of mtDNA CN to a higher CHD risk (β=0.091; P =0.11) or in the reverse direction (β=−0.012; P =0.076). Additional bidirectional Mendelian randomization analyses revealed that low‐density lipoprotein cholesterol had a causal effect on mtDNA CN (β=−0.084; P <0.001), but the reverse direction was not significant ( P =0.059). No causal associations were observed between mtDNA CN and obesity, diabetes, and hypertension, in either direction. Multivariable Mendelian randomization analyses showed no causal effect of CHD on mtDNA CN, controlling for low‐density lipoprotein cholesterol level ( P =0.52), whereas there was a strong direct causal effect of higher low‐density lipoprotein cholesterol on lower mtDNA CN, adjusting for CHD status (β=−0.092; P <0.001). Conclusions Our findings indicate that high low‐density lipoprotein cholesterol may underlie the complex relationships between mtDNA CN and vascular atherosclerosis.

Introduction: As interest in metastasis-directed therapy (MDT) for prostate cancer (PCa) grows, exploring indications and patient selection is increasingly more important. Thus far, few studies have described long-term outcomes after surgical MDT in those with disease recurrence involving the lung. The objective of our study was to compare the cumulative incidence of cancer-related death by treatment modality in men with metachronous pulmonary metastases from PCa. Methods: In a single-institution retrospective study, we identified 75 men from the prospectively maintained Mayo Clinic C-11 Positron Emission Tomography Choline PCa registry with recurrent prostate cancer involving the lung but no other visceral organs. Patients were categorized into 3 groups based on treatment modalities: wedge resection ± hormonal therapy, chemohormonal therapy, and hormonal therapy alone. The risk of cancer-related death after treatment at the time of lung metastases was reported as cumulative incidence estimates. Non–cancer-related deaths were treated as a competing risk of death. A univariate Cox regression model was conducted to assess the impact of treatment modality on the risk of cancer-related death. Results: At the time of lung metastasis, the median age was 69.5 years, and the median (IQR) prostate-specific antigen was 4 (1.3-8.6) ng/ml. Forty-seven patients (62.7%) had hormone-sensitive disease, and 28 patients (37.3%) had hormone-resistant disease. A total of 26 patients (34.7%) were treated with wedge resection ± hormonal therapy, 27 (36%) with chemohormonal therapy, and 22 (29.3%) with hormonal therapy alone. The median (IQR) follow-up time was 50.3 (31.1-78.4) months, and 21 patients (28%) died. Patients who were treated with wedge resection ± hormonal therapy had lower rated of cancer-related death compared with those who received chemohormonal therapy (Hazard Ratio [HR]: 4.14, 95% CI: 1.01-16.96, P = .048) or hormonal therapy alone (HR: 6.37, 95% CI: 1.72-23.54, P = .005). Conclusion: This exploratory analysis supports the safety and feasibility of surgical metastasis-directed therapy in select patients with recurrent prostate cancer involving the lung. Favorable long-term survival provides justification for further evaluation of this approach.

Abstract Disclosure: S. Paknikar: None. J. McHugh: None. K. Rachmasari: None. I. Bancos: None. Introduction: Ectopic secretion of adrenocorticotropic hormone (ACTH) is a rare and severe form of Cushing Syndrome (CS) that requires an urgent specialized approach for diagnosis and management. Clinical Case: A 50-year-old woman was referred to endocrinology due to concern for CS. Over the previous year she had developed progressive weakness, edema, weight gain with abdominal fat redistribution, hypertension, and multiple compression fractures. On exam, she had a profound proximal myopathy, reported 10/10 pain along the spine, and was hypertensive (170/105 mm Hg) with normal other vitals. The patient's sodium was 141mmol/L [reference range 135-145 mmol/ L], potassium 4.1 mmol/L [3.6-5.2 mmol/L] while on spironolactone, and creatinine was 0.57 mg/dL [0.59-1.04 mg/dL]. Due to the severity of her symptoms, she was admitted to the hospital. Hormonal work up was consistent with an ACTH dependent CS: ACTH was 121pg/mL [7.2-63 pg/mL] and 24-hour urine cortisol was 645 mcg/24 hr [3.5-45 mcg/24 hr]. Workup for ACTH secreting tumor included a pituitary MRI which showed a 3 mm area of delayed enhancement in the pituitary gland, felt to be artifactual. A chest computed tomography (CT) showed a 1.3 cm low-density nodule in the right upper lobe concerning for a neuroendocrine tumor. A Gallium-68 DOTATATE Positron emission tomography/CT scan was performed and demonstrated that the nodule was highly DOTATATE avid (Krenning score of 3, scale of 0-4). These findings supported a diagnosis of ectopic CS caused by an ACTH secreting lung neuroendocrine tumor. Management of ectopic CS was twofold: addressing the underlying ACTH secreting lesion and urgent treatment of hypercortisolism and its consequences. In this case, this was achieved with CT-guided cryoablation of the right upper lobe nodule. The ACTH levels were monitored postoperatively, and when decreased (9.3pg/mL [ 7.2-63 pg/mL], glucocorticoid replacement therapy was initiated. As a result of prolonged hypercortisolism, the patient experienced multiple compression fractures and debility. Physical therapy was recommended for recovery from the compression fractures as well as proximal myopathy. Enoxaparin was initiated due to risk of venous thromboembolism from CS. From an osteoporosis standpoint, she was continued on calcium and vitamin-D supplementation and treated with weekly alendronate. Her hypertension improved allowing medication reduction. Postoperatively, she received education on adrenal insufficiency and biochemical monitoring for adrenal insufficiency recovery was implemented. Conclusion: Ectopic ACTH secreting tumors represent a rare cause of CS and effective management requires consideration of medical comorbidities to determine the approach: surgical, cryoablative, or medical therapy alone, mitigation of Cushing syndrome sequelae, and prompt recognition and treatment of glucocorticoid withdrawal. Presentation: Thursday, June 15, 2023

Abstract Disclosure: S.M. Alheraki: None. M.H. Horani: None. F.Z. Alharraki: None. Cushing syndrome is one of the endocrine diseases that is mainly due to the high levels of cortisol. An overproduction of adrenocorticotropic hormone (ACTH) by a pituitary adenoma or an ectopic, paraneoplastic foci (small cell lung cancer) is the primary cause of secondary hypercortisolism. While small cell lung cancer and carcinoids cause the majority of ectopic ACTH syndromes, in this article, we describe a case of Cushing syndrome secondary to lung adenocarcinoma. It is highly likely that patients with malignancies are suffering from ectopic ACTH syndrome if they exhibit clinical signs such as weakness, hypertension, or lab values indicating hyperglycemia, hypokalemia, or metabolic alkalosis. Presentation: Friday, June 16, 2023

Abstract Rationale Constantly exposed to the external environment and mutagens such as tobacco smoke, human lungs have one of the highest somatic mutation rates among all human organs. However, the relationship of these mutations to lung disease and function is not known. Objectives To identify the prevalence and significance of clonal somatic mutations in chronic lung diseases. Methods We analyzed the clonal somatic mutations from 1,251 samples of normal and diseased noncancerous lung tissue RNA sequencing with paired whole-genome sequencing from the Lung Tissue Research Consortium. We examined the associations of somatic mutations with lung function, disease status, and computationally deconvoluted cell types in two of the most common diseases represented in our dataset, chronic obstructive pulmonary disease (COPD; 29%) and idiopathic pulmonary fibrosis (IPF; 13%). Measurements and Main Results Clonal somatic mutational burden was associated with reduced lung function in both COPD and IPF. We identified an increased prevalence of clonal somatic mutations in individuals with IPF compared with normal control subjects and individuals with COPD independent of age and smoking status. IPF clonal somatic mutations were enriched in disease-related and airway epithelial–expressed genes such as MUC5B in IPF. Patients who were MUC5B risk variant carriers had increased odds of developing somatic mutations of MUC5B that were explained by increased expression of MUC5B. Conclusions Our identification of an increased prevalence of clonal somatic mutation in diseased lung that correlates with airway epithelial gene expression and disease severity highlights for the first time the role of somatic mutational processes in lung disease genetics.

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.

Pulmonary auscultation is essential for detecting abnormal lung sounds during physical assessments, but its reliability depends on the operator. Machine learning (ML) models offer an alternative by automatically classifying lung sounds. ML models require substantial data, and public databases aim to address this limitation. This systematic review compares characteristics, diagnostic accuracy, concerns, and data sources of existing models in the literature. Papers published from five major databases between 1990 and 2022 were assessed. Quality assessment was accomplished with a modified QUADAS-2 tool. The review encompassed 62 studies utilizing ML models and public-access databases for lung sound classification. Artificial neural networks (ANN) and support vector machines (SVM) were frequently employed in the ML classifiers. The accuracy ranged from 49.43% to 100% for discriminating abnormal sound types and 69.40% to 99.62% for disease class classification. Seventeen public databases were identified, with the ICBHI 2017 database being the most used (66%). The majority of studies exhibited a high risk of bias and concerns related to patient selection and reference standards. Summarizing, ML models can effectively classify abnormal lung sounds using publicly available data sources. Nevertheless, inconsistent reporting and methodologies pose limitations to advancing the field, and therefore, public databases should adhere to standardized recording and labeling procedures.

Abstract Multiple myeloma (MM) is a malignancy that is often driven by MYC and that is sustained by IRF4, which are upregulated by super-enhancers. IKZF1 and IKZF3 bind to super-enhancers and can be degraded using immunomodulatory imide drugs (IMiD). Successful IMiD responses downregulate MYC and IRF4; however, this fails in IMiD-resistant cells. MYC and IRF4 downregulation can also be achieved in IMiD-resistant tumors using inhibitors of BET and EP300 transcriptional coactivator proteins; however, in vivo these drugs have a narrow therapeutic window. By combining IMiDs with EP300 inhibition, we demonstrate greater downregulation of MYC and IRF4, synergistic killing of myeloma in vitro and in vivo, and an increased therapeutic window. Interestingly, this potent combination failed where MYC and IRF4 expression was maintained by high levels of the AP-1 factor BATF. Our results identify an effective drug combination and a previously unrecognized mechanism of IMiD resistance. Significance: These results highlight the dependence of MM on IKZF1-bound super-enhancers, which can be effectively targeted by a potent therapeutic combination pairing IMiD-mediated degradation of IKZF1 and IKZF3 with EP300 inhibition. They also identify AP-1 factors as an unrecognized mechanism of IMiD resistance in MM. See related article by Neri, Barwick, et al., p. 56. See related commentary by Yun and Cleveland, p. 5. This article is featured in Selected Articles from This Issue, p. 4

Context.— Respiratory infections complicate lung transplantation and increase the risk of allograft dysfunction. Allograft lungs may have different susceptibilities to infection than native lungs, potentially leading to different disease severity in lungs of single lung transplant recipients (SLTRs). Objective.— To study whether infections affect allograft and native lungs differently in SLTRs but similarly in double LTRs (DLTRs). Design.— Using an institutional database of LTRs, medical records were searched, chest computed tomography studies were systematically reviewed, and histopathologic features were recorded per lung lobe and graded semiquantitatively. A multilobar-histopathology score (MLHS) including histopathologic data from each lung and a bilateral ratio (MLHSratio) comparing histopathologies between both lungs were calculated in SLTRs and compared to DLTRs. Results.— Six SLTRs died of infection involving the lungs. All allografts showed multifocal histopathologic evidence of infection, but at least 1 lobe of the native lung was uninvolved. In 4 of 5 DLTRs, histopathologic evidence of infection was seen in all lung lobes. On computed tomography, multifocal ground-glass and/or nodular opacities were found in a bilateral distribution in all DLTRs but in only 2 of 6 SLTRs. In SLTRs, the MLHSAllograft was higher than MLHSNative (P = .02). The MLHSratio values of SLTR and DLTR were significantly different (P &lt; .001). Conclusions.— Allograft and native lungs appear to harbor different susceptibilities to infections. The results are important for the management of LTRs.

Summary HLA evolutionary divergence reflects the ability to recognize diverse neoantigens as non-self, and as a biomarker is conceptually distinct from programmed cell death ligand 1 expression and tumor mutation burden. HLA-based assays to predict benefit from immunotherapy in lung cancer require prospective validation. See related article by Jiang et al., p. 4830