Toll-like Receptor 9 Inhibition Mitigates Fibroproliferative Responses in Translational Models of Pulmonary Fibrosis.

RATIONALE: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease for which current treatment options only slow clinical progression. Previously, we identified a subset of patients with IPF with an accelerated disease course associated with fibroblast expression of Toll-Like Receptor 9 (TLR9) mediated by interactions with its ligand mitochondrial DNA (mtDNA). OBJECTIVES: We aimed to show that TLR9 activation induces fibroproliferative responses that are abrogated by its antagonism by using two commercially-available indirect inhibitors and a proprietary, selective direct small molecule inhibitor. METHODS: We employed two independent cohorts of patients with IPF, multiple in vitro fibroblast cell culture platforms, an in vivo mouse model, and an ex vivo human precision cut lung slices system to investigate the clinical and biologic significance of TLR9 in this disease. MEASUREMENTS AND MAIN RESULTS: In two independent IPF cohorts, plasma mtDNA activates TLR9 in a manner associated with the expression of MCP-1, IL-6, TNFα, and IP-10 and worsened transplant-free survival. Our cell culture platform showed that TLR9 mediates fibroblast activation via TGFß1 and stiff substrates, and that its antagonism, particularly direct inhibition, ameliorates this process, including production of these TLR9 associated pharmacodynamic endpoints. We further demonstrated that direct TLR9 inhibition mitigates these fibroproliferative responses in our in vivo and ex vivo models of pulmonary fibrosis. CONCLUSIONS: In this novel study, we found that direct TLR9 inhibition mitigates fibroproliferative responses in preclinical models of pulmonary fibrosis. Our work demonstrates the therapeutic potential of direct TLR9 antagonism in IPF and related fibrotic lung diseases.

Prevalence of Occult Ovarian Cancer and Metastatic Breast Cancer in Ovarian Ablation Specimens of Patients With Hormone Receptor-Positive Breast Cancer: Implications for Tissue Sampling Strategies, Early Ovarian Cancer Detection and Resource Utilization.

Bilateral oophorectomy is one method of hormone suppression for premenopausal patients with hormone receptor-positive breast cancer. Such specimens could, in theory, harbor occult early ovarian cancer and/or metastatic breast cancer but guidelines for tissue sampling for pathologic examination remain to be addressed. Therefore, we evaluated oophorectomy specimens from 166 patients who underwent ovarian ablation for hormone receptor-positive breast cancer. Results of germline genetic testing were documented by the surgeon in only 31.3% of the pathology specimen requisition forms, whereas that information was available for 81.3% of patients elsewhere in the electronic medical records. All but 5.2% tested negative for a hereditary ovarian cancer gene pathogenic variant before oophorectomy. Complete tissue sampling was performed in 77.1% of the cases and representative sampling in the remainder. No cases of ovarian cancer were observed. Ovarian metastasis of breast cancer was identified in 9.6% of patients, all of whom were already known to have advanced-stage disease. The number of tissue cassettes per ovary required for complete tissue submission was on average three times higher than that for representative tissue sampling (P < 0.01) and ranged up to 20 cassettes per ovary when multiple follicle cysts were present. We propose that guidelines for tissue sampling in this context be defined by a combination of hereditary risk and macroscopic examination; representative sampling is reasonable for macroscopically normal ovaries in hormone receptor-positive breast cancer patients whose germline genetic testing is negative. Positive genetic test results merit complete tissue submission even if macroscopically normal. This strategy balances the goals of early ovarian cancer detection and optimal resource utilization. However, it depends on clear documentation of genetic test results. Our study demonstrates that many opportunities remain to close gaps in the communication of genetic test results by clinicians submitting oophorectomy specimens for pathologic evaluation.

Antibias Efforts in United States Maternity Care: A Scoping Review of the Publicly Funded Health Equity Intervention Pipeline.

Antibias training is increasingly identified as a strategy to reduce maternal health disparities. Evidence to guide this work is limited. We conducted a community-guided scoping review to characterize new antibias research. Four of 508 projects met our criteria: US-based, publicly funded, initiated from January 1, 2018 to June 30, 2022, and featuring an intervention to reduce bias or racism in maternal health care providers. Training was embedded in multicomponent interventions in 3 projects, limiting its evaluation as a stand-alone intervention. Major public funders have sponsored few projects to advance antibias training research in maternal health. More support is needed to develop a rigorous and scalable evidence base.

Plasma mitochondrial DNA is associated with extrapulmonary sarcoidosis.

Sarcoidosis is an unpredictable granulomatous disease in which African Americans disproportionately experience aggressive phenotypes. Mitochondrial DNA (mtDNA) released by cells in response to various stressors contributes to tissue remodelling and inflammation. While extracellular mtDNA has emerged as a biomarker in multiple diseases, its relevance to sarcoidosis remains unknown. We aimed to define an association between extracellular mtDNA and clinical features of sarcoidosis.Extracellular mtDNA concentrations were measured using quantitative PCR for the human MT-ATP6 gene in bronchoalveolar (BAL) and plasma samples from healthy controls and patients with sarcoidosis from The Yale Lung Repository; associations between MT-ATP6 concentrations and Scadding stage, extrapulmonary disease and demographics were sought. Results were validated in the Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis cohort.Relative to controls, MT-ATP6 concentrations in sarcoidosis subjects were robustly elevated in the BAL fluid and plasma, particularly in the plasma of patients with extrapulmonary disease. Relative to Caucasians, African Americans displayed excessive MT-ATP6 concentrations in the BAL fluid and plasma, for which the latter compartment correlated with significantly higher odds of extrapulmonary disease.Enrichments in extracellular mtDNA in sarcoidosis are associated with extrapulmonary disease and African American descent. Further study into the mechanistic basis of these clinical findings may lead to novel pathophysiologic and therapeutic insights.

Readmission Rates After Expedited Postpartum Discharge.

OBJECTIVE: To characterize national trends in expedited postpartum discharge and, secondarily, to identify predictors of expedited postpartum discharge and assess whether expedited postpartum discharge was associated with postpartum readmissions within 60 days of delivery hospitalization discharge. METHODS: Birth hospitalizations and subsequent 60-day postpartum readmissions were extracted from the 2016-2020 Nationwide Readmissions Database for this retrospective cohort study. Postpartum discharge was categorized as expedited (less than 2 days after vaginal birth or less than 3 days after cesarean birth), routine (2 days after vaginal birth or 3 days after cesarean birth), or prolonged (more than 2 days after vaginal birth or more than 3 days after cesarean birth). Trends in expedited discharge were assessed over the study period with joinpoint regression. Unadjusted and adjusted logistic regression models were performed to assess clinical, hospital, and demographic predictors of expedited postpartum discharge. Sixty-day postpartum readmission risk was calculated, and adjusted regression models were performed to evaluate the association between expedited postpartum discharge and readmission. RESULTS: Of 17.9 million birth hospitalizations, 32.9% had expedited postpartum discharge. The overall 60-day postpartum readmission rate after delivery hospitalization discharge was 1.7% for all patients, 1.4% for expedited postpartum discharge, 1.6% for routine discharge, and 3.3% for prolonged discharge. Rates of expedited postpartum increased from 29.1% in 2016 to 31.4% in 2019 and to 43.8% in 2020. This trend was not significant (average annual percent change: 9.9%, 95% CI, -1.6% to 23.7%), although rates of expedited discharge were significantly higher in 2020 than in 2016-2019 ( P <.01). Younger and older age, chronic comorbid conditions, mental health conditions, and obstetric complications (eg, transfusion, chorioamnionitis or endometritis) were associated with lower likelihood of expedited postpartum discharge. Expedited postpartum discharge was associated with 14% lower adjusted odds of 60-day postpartum readmission compared with routine discharge (adjusted odds ratio 0.86, 95% CI, 0.85-0.88). CONCLUSION: Rates of expedited postpartum discharge increased significantly in 2020 compared with 2016-2019 and were not associated with 60-day postpartum readmission. These findings suggest that broader use of expedited postpartum discharge has not resulted in increased risk of postpartum readmissions.

cGAS Expression is Enhanced in Systemic Sclerosis Associated Interstitial Lung Disease and Stimulates Inflammatory Myofibroblast Activation.

Objective: The lungs of patients with Systemic Sclerosis Associated Interstitial Lung Disease (SSc-ILD) contain inflammatory myofibroblasts arising in association with fibrotic stimuli and perturbed innate immunity. The innate immune DNA binding receptor Cyclic GMP-AMP synthase (cGAS) is implicated in inflammation and fibrosis, but its involvement in SSc-ILD remains unknown. We examined cGAS expression, activity, and therapeutic potential in SSc-ILD using cultured fibroblasts, precision cut lung slices (PCLS), and a well-accepted animal model. Methods: Expression and localization of cGAS, cytokines, and type 1 interferons were evaluated in SSc-ILD lung tissues, bronchoalveolar lavage (BAL), and isolated lung fibroblasts. CGAS activation was assessed in a publicly available SSc-ILD single cell RNA sequencing dataset. Production of cytokines, type 1 interferons, and αSMA elicited by TGFß1 or local substrate stiffness were measured in normal human lung fibroblasts (NHLFs) via qRT-PCR, ELISA, and immunofluorescence. Small molecule cGAS inhibition was tested in cultured fibroblasts, human PCLS, and the bleomycin pulmonary fibrosis model. Results: SSc-ILD lung tissue and BAL are enriched for cGAS, cytokines, and type 1 interferons. The cGAS pathway shows constitutive activation in SSc-ILD fibroblasts and is inducible in NHLFs by TGFß1 or mechanical stimuli. In these settings, and in human PCLS, cGAS expression is paralleled by the production of cytokines, type 1 interferons, and αSMA that are mitigated by a small molecule cGAS inhibitor. These findings are recapitulated in the bleomycin mouse model. Conclusion: cGAS signaling contributes to pathogenic inflammatory myofibroblast phenotypes in SSc-ILD. Inhibiting cGAS or its downstream effectors represents a novel therapeutic approach.

Mode of delivery and neonatal outcomes with early preterm severe preeclampsia: does fetal growth restriction matter?

OBJECTIVE: Severe preeclampsia diagnosed at or prior to 34 weeks is an indication for preterm delivery. Many patients with severe preeclampsia develop fetal growth restriction as a result of the placental dysfunction associated with both conditions. The ideal mode of delivery in cases of preterm severe preeclampsia with fetal growth restriction remains controversial, with providers often proceeding directly to cesarean delivery rather than attempting a trial of labor due to theoretic concerns about the harms of labor in the face of placental dysfunction. There are limited data supporting this approach. This study evaluates whether the presence of fetal growth restriction affects the ultimate mode of delivery or neonatal outcomes among pregnancies with severe preeclampsia undergoing induction of labor at or before 34 weeks. METHODS: This was a retrospective cohort study of singletons with severe preeclampsia undergoing induction of labor ≤ 34 weeks at a single center between January 2015 and April 2022. The primary predictor was fetal growth restriction, defined as estimated fetal weight < 10th percentile for gestational age on ultrasound. Mode of delivery and neonatal outcomes were compared between those with and without fetal growth restriction using Fisher's exact and Kruskal-Wallis tests, and multivariate logistic regression was used to obtain adjusted odds ratios. RESULTS: 159 patients were included (N = 117 without fetal growth restriction, N = 42 with fetal growth restriction). There was no difference in vaginal delivery between the groups (70% vs 67%, p = .70). While those with fetal growth restriction had a higher incidence of respiratory distress syndrome and longer neonatal hospital stay, these differences were not statistically significant after adjusting for gestational age at delivery. There were no significant differences in other neonatal outcomes, including Apgar score, cord blood gases, intraventricular hemorrhage, necrotizing enterocolitis, neonatal sepsis, and neonatal demise. CONCLUSION: For pregnancies complicated by severe preeclampsia that require delivery ≤ 34 weeks, the likelihood of successful vaginal delivery following induction of labor does not differ based on presence of fetal growth restriction. Furthermore, fetal growth restriction is not an independent risk factor for adverse neonatal outcomes in this population. Induction of labor should be considered a reasonable approach and should be routinely offered to patients with concurrent preterm severe preeclampsia and fetal growth restriction.

Macrophage-derived netrin-1 drives adrenergic nerve-associated lung fibrosis.

Fibrosis is a macrophage-driven process of uncontrolled extracellular matrix accumulation. Neuronal guidance proteins such as netrin-1 promote inflammatory scarring. We found that macrophage-derived netrin-1 stimulates fibrosis through its neuronal guidance functions. In mice, fibrosis due to inhaled bleomycin engendered netrin-1-expressing macrophages and fibroblasts, remodeled adrenergic nerves, and augmented noradrenaline. Cell-specific knockout mice showed that collagen accumulation, fibrotic histology, and nerve-associated endpoints required netrin-1 of macrophage but not fibroblast origin. Adrenergic denervation; haploinsufficiency of netrin-1's receptor, deleted in colorectal carcinoma; and therapeutic α1 adrenoreceptor antagonism improved collagen content and histology. An idiopathic pulmonary fibrosis (IPF) lung microarray data set showed increased netrin-1 expression. IPF lung tissues were enriched for netrin-1+ macrophages and noradrenaline. A longitudinal IPF cohort showed improved survival in patients prescribed α1 adrenoreceptor blockade. This work showed that macrophages stimulate lung fibrosis via netrin-1-driven adrenergic processes and introduced α1 blockers as a potentially new fibrotic therapy.

A 50-Year-Old Woman With Limited Scleroderma Presenting With Shortness of Breath.

CASE PRESENTATION: A 50-year-old woman with a medical history significant for limited scleroderma (SSc) complicated by interstitial lung disease (ILD) and pulmonary arterial hypertension presented to our institution with acute on chronic shortness of breath. Ten years before presentation, she was diagnosed with SSc. Two years before presentation, she was found to have ILD, for which she was started on mycophenolate mofetil and low-dose prednisone. One year before presentation, she noted worsening dyspnea on exertion (New York Heart Association Functional Class III) and required supplemental oxygen, up to 5 L, despite findings of stable ILD on a maintenance dose of mycophenolate mofetil. A subsequent right heart catheterization showed findings consistent with severe pulmonary arterial hypertension: right atrial pressure of 19 mm Hg, pulmonary arterial pressure of 98/39 mm Hg with a mean pulmonary arterial pressure of 58 mm Hg, right ventricular pressure of 59/6 mm Hg, pulmonary arterial wedge pressure of 10 mm Hg, cardiac output of 4.2 L/min with a cardiac index of 2.7 L/min/m2, and a calculated pulmonary vascular resistance of 11.43 Wood units. She had no significant vasoreactivity on inhaled nitric oxide challenge. She was started on IV treprostinil that had been up-titrated over the course of 6 months before presentation. On admission, she denied any cough, fevers, chills, chest pains, palpitations, or lower extremity edema. She denied any sick contacts or any recent travel. She denied any periods of prolonged immobility.

Bioactive Plasma Mitochondrial DNA Is Associated With Disease Progression in Scleroderma-Associated Interstitial Lung Disease.

OBJECTIVE: Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is characterized by variable clinical outcomes, activation of innate immune pattern-recognition receptors (PRRs), and accumulation of α-smooth muscle actin (α-SMA)-expressing myofibroblasts. The aim of this study was to identify an association between these entities and mitochondrial DNA (mtDNA), an endogenous ligand for the intracellular DNA-sensing PRRs Toll-like receptor 9 (TLR-9) and cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING), which has yet to be determined. METHODS: Human lung fibroblasts (HLFs) from normal donors and SSc-ILD explants were treated with synthetic CpG DNA and assayed for α-SMA expression and extracellular mtDNA using quantitative polymerase chain reaction for the human MT-ATP6 gene. Plasma MT-ATP6 concentrations were evaluated in 2 independent SSc-ILD cohorts and demographically matched controls. The ability of SSc-ILD and control plasma to induce TLR-9 and cGAS/STING activation was evaluated with commercially available HEK 293 reporter cells. Plasma concentrations of type I interferons (IFNs), interleukin-6 (IL-6), and oxidized DNA were measured using electrochemiluminescence and enzyme-linked immunosorbent assay-based methods. Extracellular vesicles (EVs) precipitated from plasma were evaluated for MT-ATP6 concentrations and proteomics via liquid chromatography mass spectrometry. RESULTS: Normal HLFs and SSc-ILD fibroblasts developed increased α-SMA expression and MT-ATP6 release following CpG stimulation. Plasma mtDNA concentrations were increased in the 2 SSc-ILD cohorts, reflective of ventilatory decline, and were positively associated with both TLR-9 and cGAS/STING activation as well as type I IFN and IL-6 expression. Plasma mtDNA was not oxidized and was conveyed by EVs displaying a proteomics profile consistent with a multicellular origin. CONCLUSION: These findings demonstrate a previously unrecognized connection between EV-encapsulated mtDNA, clinical outcomes, and intracellular DNA-sensing PRR activation in SSc-ILD. Further study of these interactions could catalyze novel mechanistic and therapeutic insights into SSc-ILD and related disorders.