Biochem Pharmacol. 2023 Mar 2:115475. doi: 10.1016/j.bcp.2023.115475. Online ahead of print.

ABSTRACT

Pulmonary fibrosis (PF) is a type of fatal respiratory diseases with limited therapeutic options and poor prognosis. The chemokine CCL17 plays crucial roles in the pathogenesis of immune diseases. Bronchoalveolar lavage fluid (BALF) CCL17 levels are significantly higher in patients with idiopathic PF (IPF) than in healthy volunteers. However, the source and function of CCL17 in PF remain unclear. Here, we demonstrated that the levels of CCL17 were increased in the lungs of IPF patients and mice with bleomycin (BLM)-induced PF. In particular, CCL17 were upregulated in alveolar macrophages (AMs) and antibody blockade of CCL17 protected mice against BLM-induced fibrosis and significantly reduced fibroblast activation. Mechanistic studies revealed that CCL17 interacted with its receptor CCR4 on fibroblasts, thereby activating the TGF-β/Smad signaling pathway to promote fibroblast activation and tissue fibrosis. Moreover, the knockdown of CCR4 by CCR4-siRNA or blockade by CCR4 antagonist C-021 was able to ameliorate PF pathology in mice. In summary, the CCL17-CCR4 axis is involved in the progression of PF, and targeting of CCL17 or CCR4 inhibits fibroblast activation and tissue fibrosis and may benefit patients with fibroproliferative lung diseases.

PMID:36870575 | DOI:10.1016/j.bcp.2023.115475

Mol Cell Proteomics. 2023 Mar 2:100524. doi: 10.1016/j.mcpro.2023.100524. Online ahead of print.

ABSTRACT

The heterogeneity of idiopathic pulmonary fibrosis (IPF) limits its diagnosis and treatment. The association between the pathophysiological features and the serum protein signatures of IPF currently remains unclear. The present study analyzed the specific proteins and patterns associated with the clinical parameters of IPF based on a serum proteomic dataset by Data-Independent Acquisition (DIA) using mass spectrometry. Differentiated proteins in sera distinguished in IPF patients into three subgroups in signal pathways and overall survival. Aging-associated signatures by WGCNA coincidently provided clear and direct evidence that aging is a critical risk factor for IPF rather than a single biomarker. LDHA and CCT6A expression, which were associated with glucose metabolic reprogramming, were correlated with high serum lactic acid content in the patients with IPF. Cross-model analysis and machine learning showed that a combinatorial biomarker accurately distinguished IPF patients from healthy subjects with an AUC of 0.848 (95% CI = 0.684-0.941) and validated from another cohort and ELISA assay. This serum proteomic profile provides rigorous evidence that enables understanding of the heterogeneity of IPF and protein alterations that could help in its diagnosis and treatment decisions.

PMID:36870568 | DOI:10.1016/j.mcpro.2023.100524

Chest. 2023 Mar 2:S0012-3692(23)00308-2. doi: 10.1016/j.chest.2023.02.038. Online ahead of print.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with a high burden of both pulmonary and extrapulmonary comorbidities.

RESEARCH QUESTION: Do these comorbidities have causal relationships with IPF?

STUDY DESIGN AND METHODS: We searched PubMed to pinpoint possible IPF-related comorbid conditions. Bidirectional Mendelian randomization (MR) was performed using summary statistics from the largest genome-wide association studies for these diseases to date in a two-sample setting. Findings were verified using multiple MR approaches under different model assumptions, replication datasets for IPF, and secondary phenotypes.

RESULTS: A total of 22 comorbidities with genetic data available were included. Bidirectional MR analyses showed convincing evidence for two comorbidities and suggestive evidence for four comorbidities. Gastroesophageal reflux disease, venous thromboembolism, and hypothyroidism were causally associated with an increased risk of IPF, while chronic obstructive pulmonary disease was causally associated with a decreased risk of IPF. For the reverse direction, IPF showed causal associations with a higher risk of lung cancer but a reduced risk of hypertension. Follow-up analyses of pulmonary function parameters and blood pressure measures supported the causal effect of chronic obstructive pulmonary disease on IPF and the causal effect of IPF on hypertension.

INTERPRETATION: The present study suggests the causal associations between IPF and certain comorbidities from a genetic perspective. Further research is needed to understand the mechanisms of these associations.

PMID:36870387 | DOI:10.1016/j.chest.2023.02.038

Respir Investig. 2023 Mar 1;61(3):314-320. doi: 10.1016/j.resinv.2023.01.009. Online ahead of print.

ABSTRACT

BACKGROUND: Validating the information recorded in administrative databases is essential. However, no study has comprehensively validated the accuracy of Japanese Diagnosis Procedure Combination (DPC) data on various respiratory diseases. Therefore, this study aimed to evaluate the validity of diagnoses of respiratory diseases in the DPC database.

METHODS: We conducted chart reviews of 400 patients hospitalized in the departments of respiratory medicine in two acute-care hospitals in Tokyo, between April 1, 2019 and March 31, 2021, and used them as reference standards. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of DPC data on 25 respiratory diseases were determined.

RESULTS: Sensitivity ranged from 22.2% (aspiration pneumonia) to 100% (chronic eosinophilic pneumonia and malignant pleural mesothelioma) and was <50% for eight diseases, while specificity was >90% for all diseases. PPV ranged from 40.0% (aspiration pneumonia) to 100% (coronavirus disease 2019, bronchiectasis, chronic eosinophilic pneumonia, pulmonary hypertension, squamous cell carcinoma, small cell carcinoma, lung cancer of other histological types, and malignant pleural mesothelioma) and was >80% for 16 diseases. Except for chronic obstructive pulmonary disease (82.9%) and interstitial pneumonia (other than idiopathic pulmonary fibrosis) (85.4%), NPV was >90% for all diseases. These validity indices were similar in both hospitals.

CONCLUSIONS: The validity of diagnoses of respiratory diseases in the DPC database was high in general, thereby providing an important basis for future studies.

PMID:36868080 | DOI:10.1016/j.resinv.2023.01.009

Respir Investig. 2023 Mar 1;61(3):306-313. doi: 10.1016/j.resinv.2023.01.008. Online ahead of print.

ABSTRACT

BACKGROUND: Acute exacerbation of fibrosing interstitial lung diseases, including idiopathic pulmonary fibrosis, is associated with poor prognosis. Accordingly, tracheal intubation and invasive mechanical ventilation are generally avoided in such patients. However, the efficacy of invasive mechanical ventilation for acute exacerbation of fibrosing interstitial lung diseases remains unclear. Therefore, we aimed to investigate the clinical course of patients with acute exacerbation of fibrosing interstitial lung diseases who were treated with invasive mechanical ventilation.

METHODS: We retrospectively analyzed 28 patients with acute exacerbation of fibrosing interstitial lung diseases who underwent invasive mechanical ventilation at our hospital.

RESULTS: Of the 28 included patients (20 men, 8 women; mean age, 70.6 years), 13 (46.4%) were discharged alive and 15 died. Ten patients (35.7%) had idiopathic pulmonary fibrosis. Univariate analysis revealed that longer survival was significantly associated with lower partial pressure of arterial carbon dioxide (hazard ratio [HR] 1.04 [1.01-1.07]; p = 0.002) and higher pH (HR 0.0002 [0-0.02] levels; p = 0.0003) and less severe general status according to the Acute Physiology and Chronic Health Evaluation II score (HR 1.13 [1.03-1.22]; p = 0.006) at the time of mechanical ventilation initiation. In addition, the univariate analysis indicated that patients without long-term oxygen therapy use had significantly longer survival (HR 4.35 [1.51-12.52]; p = 0.006).

CONCLUSIONS: Invasive mechanical ventilation may effectively treat acute exacerbation of fibrosing interstitial lung diseases if good ventilation and general conditions can be maintained.

PMID:36868079 | DOI:10.1016/j.resinv.2023.01.008

Breathe (Sheff). 2022 Dec;18(4):220147. doi: 10.1183/20734735.0147-2022. Epub 2023 Jan 10.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a progressive disease of pulmonary scarring. New treatments slow disease progression and allow pulmonary fibrosis patients to live longer. Persistent pulmonary fibrosis increases a patient's risk of developing lung cancer. Lung cancer in patients with IPF differs from cancers that develop in the non-fibrotic lung. Peripherally located adenocarcinoma is the most frequent cell type in smokers who develop lung cancer, while squamous cell carcinoma is the most frequent in pulmonary fibrosis. Increased fibroblast foci in IPF are associated with more aggressive cancer behaviour and shorter doubling times. Treatment of lung cancer in fibrosis is challenging because of the risk of inducing an exacerbation of fibrosis. In order to improve patient outcomes, modifications of current lung cancer screening guidelines in patients with pulmonary fibrosis will be necessary to avoid delays in treatment. 2-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) computed tomography (CT) imaging can help identify cancer earlier and more reliably than CT alone. Increased use of wedge resections, proton therapy and immunotherapy may increase survival by decreasing the risk of exacerbation, but further research will be necessary.

PMID:36865932 | PMC:PMC9973524 | DOI:10.1183/20734735.0147-2022

Front Pharmacol. 2023 Feb 14;14:1111393. doi: 10.3389/fphar.2023.1111393. eCollection 2023.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease (ILD) without an identifiable cause. If not treated after diagnosis, the average life expectancy is 3-5 years. Currently approved drugs for the treatment of IPF are Pirfenidone and Nintedanib, as antifibrotic drugs, which can reduce the decline rate of forced vital capacity (FVC) and reduce the risk of acute exacerbation of IPF. However these drugs can not relieve the symptoms associated with IPF, nor improve the overall survival rate of IPF patients. We need to develop new, safe and effective drugs to treat pulmonary fibrosis. Previous studies have shown that cyclic nucleotides participate in the pathway and play an essential role in the process of pulmonary fibrosis. Phosphodiesterase (PDEs) is involved in cyclic nucleotide metabolism, so PDE inhibitors are candidates for pulmonary fibrosis. This paper reviews the research progress of PDE inhibitors related to pulmonary fibrosis, so as to provide ideas for the development of anti-pulmonary fibrosis drugs.

PMID:36865908 | PMC:PMC9973527 | DOI:10.3389/fphar.2023.1111393

Eur Respir J. 2023 Mar 2;61(3):2202355. doi: 10.1183/13993003.02355-2022. Print 2023 Mar.

NO ABSTRACT

PMID:36863732 | DOI:10.1183/13993003.02355-2022

Immunol Cell Biol. 2023 Mar 2. doi: 10.1111/imcb.12637. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrotic interstitial lung disease of unknown etiology. The accumulation of macrophages is associated with disease pathogenesis. The unfolded protein response (UPR) has been linked to macrophage activation in pulmonary fibrosis. To date, the impact of activating transcription factor 6 alpha (ATF6α), one of the UPR mediators, on the composition and function of pulmonary macrophage subpopulations during lung injury and fibrogenesis is not fully understood. We began by examining the expression of Atf6α in IPF patients' lung single-cell RNA sequencing dataset, archived surgical lung specimens, and CD14+ circulating monocytes. To assess the impact of ATF6α on pulmonary macrophage composition and pro-fibrotic function during tissue remodelling, we conducted an in vivo myeloid-specific deletion of Atf6α. Flow cytometric assessments of pulmonary macrophages were carried out in C57BL/6 and myeloid specific ATF6α-deficient mice in the context of bleomycin-induced lung injury. Our results demonstrated that Atf6α mRNA was expressed in pro-fibrotic macrophages found in IPF patient lung and in CD14+ circulating monocytes obtained from IPF patient blood. After bleomycin administration, the myeloid-specific deletion of Atf6α altered pulmonary macrophage composition, expanding CD11b+ subpopulations with dual polarized CD38+ CD206+ expressing macrophages. Compositional changes were associated with an aggravation of fibrogenesis including increased myofibroblast and collagen deposition. Further mechanistic ex vivo investigation revealed that ATF6α was required for CHOP induction and the death of bone marrow-derived macrophages. Overall, our findings suggest a detrimental role for the ATF6α-deficient CD11b+ macrophages which had altered function during lung injury and fibrosis.

PMID:36862017 | DOI:10.1111/imcb.12637

Int J Med Sci. 2023 Jan 31;20(3):329-345. doi: 10.7150/ijms.80358. eCollection 2023.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a severe interstitial lung disease; although the recent introduction of two anti-fibrosis drugs, pirfenidone and Nidanib, have resulted in a significant reduction in lung function decline, IPF is still not curable. Approximately 2-20% of patients with IPF have a family history of the disease, which is considered the strongest risk factor for idiopathic interstitial pneumonia. However, the genetic predispositions of familial IPF (f-IPF), a particular type of IPF, remain largely unknown. Genetics affect the susceptibility and progression of f-IPF. Genomic markers are increasingly being recognized for their contribution to disease prognosis and drug therapy outcomes. Existing data suggest that genomics may help identify individuals at risk for f-IPF, accurately classify patients, elucidate key pathways involved in disease pathogenesis, and ultimately develop more effective targeted therapies. Since several genetic variants associated with the disease have been found in f-IPF, this review systematically summarizes the latest progress in the gene spectrum of the f-IPF population and the underlying mechanisms of f-IPF. The genetic susceptibility variation related to the disease phenotype is also illustrated. This review aims to improve the understanding of the IPF pathogenesis and facilitate his early detection.

PMID:36860670 | PMC:PMC9969503 | DOI:10.7150/ijms.80358

Front Med (Lausanne). 2023 Feb 13;10:1001813. doi: 10.3389/fmed.2023.1001813. eCollection 2023.

ABSTRACT

OBJECTIVE: This study aimed to identify candidate gene biomarkers associated with immune infiltration in idiopathic pulmonary fibrosis (IPF) based on machine learning algorithms.

METHODS: Microarray datasets of IPF were extracted from the Gene Expression Omnibus (GEO) database to screen for differentially expressed genes (DEGs). The DEGs were subjected to enrichment analysis, and two machine learning algorithms were used to identify candidate genes associated with IPF. These genes were verified in a validation cohort from the GEO database. Receiver operating characteristic (ROC) curves were plotted to assess the predictive value of the IPF-associated genes. The cell-type identification by estimating relative subsets of RNA transcripts (CIBERSORT) algorithm was used to evaluate the proportion of immune cells in IPF and normal tissues. Additionally, the correlation between the expression of IPF-associated genes and the infiltration levels of immune cells was examined.

RESULTS: A total of 302 upregulated and 192 downregulated genes were identified. Functional annotation, pathway enrichment, Disease Ontology and gene set enrichment analyses revealed that the DEGs were related to the extracellular matrix and immune responses. COL3A1, CDH3, CEBPD, and GPIHBP1 were identified as candidate biomarkers using machine learning algorithms, and their predictive value was verified in a validation cohort. Additionally, ROC analysis revealed that the four genes had high predictive accuracy. The infiltration levels of plasma cells, M0 macrophages and resting dendritic cells were higher and those of resting natural killer (NK) cells, M1 macrophages and eosinophils were lower in the lung tissues of patients with IPF than in those of healthy individuals. The expression of the abovementioned genes was correlated with the infiltration levels of plasma cells, M0 macrophages and eosinophils.

CONCLUSION: COL3A1, CDH3, CEBPD, and GPIHBP1 are candidate biomarkers of IPF. Plasma cells, M0 macrophages and eosinophils may be involved in the development of IPF and may serve as immunotherapeutic targets in IPF.

PMID:36860337 | PMC:PMC9968813 | DOI:10.3389/fmed.2023.1001813

Front Pharmacol. 2023 Feb 13;14:1130074. doi: 10.3389/fphar.2023.1130074. eCollection 2023.

ABSTRACT

Advances in tissue engineering continue at a rapid pace and have provided novel methodologies and insights into normal cell and tissue homeostasis, disease pathogenesis, and new potential therapeutic strategies. The evolution of new techniques has particularly invigorated the field and span a range from novel organ and organoid technologies to increasingly sophisticated imaging modalities. This is particularly relevant for the field of lung biology and diseases as many lung diseases, including chronic obstructive pulmonary disease (COPD) and idiopathic fibrosis (IPF), among others, remain incurable with significant morbidity and mortality. Advances in lung regenerative medicine and engineering also offer new potential avenues for critical illnesses such as the acute respiratory distress syndrome (ARDS) which also continue to have significant morbidity and mortality. In this review, an overview of lung regenerative medicine with focus on current status of both structural and functional repair will be presented. This will serve as a platform for surveying innovative models and techniques for study, highlighting the need and timeliness for these approaches.

PMID:36860303 | PMC:PMC9968746 | DOI:10.3389/fphar.2023.1130074

Eur Respir J. 2023 Mar 1:2202163. doi: 10.1183/13993003.02163-2022. Online ahead of print.

ABSTRACT

BACKGROUND: Little is known about generalisability of randomised controlled trials (RCTs) for idiopathic pulmonary fibrosis (IPF). We evaluated eligibility criteria for phase III IPF RCTs to determine their representativeness in clinical registries, and calculated forced vital capacity (FVC) changes according to eligibility criteria.

METHODS: Common eligibility criteria used in >60% of IPF RCTs were identified from a literature search and applied to patients with IPF from prospective Australian and Canadian registries. Additional pre-specified criteria of 6-min walk distance (6 MWD) and different measures of preceding disease progression were also evaluated. Joint longitudinal-survival modelling was used to compare FVC decline according to eligibility for individual and composite criteria.

RESULTS: Of 990 patients with IPF, 527 (53%) met all common RCT eligibility criteria at the first clinic visit, including 343 with definite IPF and 184 with radiological probable usual interstitial pneumonia pattern without histological confirmation (i.e., provisional IPF). The percentages of eligible patients for landmark RCTs of nintedanib and pirfenidone were 19-50%. Adding 6 MWD ≥150 m and different measures of preceding disease progression to the composite common criteria reduced the percentages of patients meeting eligibility to 52% (n=516) and 4-18% (n=12-61), respectively. Patients meeting the composite common criteria had less rapid 1-year FVC decline than those who did not (-90 versus -103 ml, p=0.01). Definite IPF generally had more rapid 1-year FVC decline compared to provisional IPF.

CONCLUSIONS: Eligibility criteria of previous IPF RCTs have limited generalisability to clinical IPF populations, with FVC decline differing between eligible and ineligible populations.

PMID:36858445 | DOI:10.1183/13993003.02163-2022

Pneumologie. 2023 Feb;77(2):e1. doi: 10.1055/a-2043-4482. Epub 2023 Mar 1.

NO ABSTRACT

PMID:36858353 | DOI:10.1055/a-2043-4482

Respir Physiol Neurobiol. 2023 Feb 27:104041. doi: 10.1016/j.resp.2023.104041. Online ahead of print.

ABSTRACT

The functional disturbances driving "out-of-proportion" dyspnoea in patients with fibrosing interstitial lung disease (f-ILD) showing only mild restrictive abnormalities remain poorly understood. Eighteen patients (10 with idiopathic pulmonary fibrosis) showing preserved spirometry and mildly reduced total lung capacity (≥70% predicted) and 18 controls underwent an incremental cardiopulmonary exercise test with measurements of operating lung volumes and Borg dyspnoea scores. Patients' lower exercise tolerance was associated with higher ventilation (V̇E)/carbon dioxide (V̇CO2) compared with controls (V̇E/V̇CO2 nadir=35±3 versus 29±2; p<0.001). Patients showed higher tidal volume/inspiratory capacity and lower inspiratory reserve volume at a given exercise intensity, reporting higher dyspnoea scores as a function of both work rate and V̇E. Steeper dyspnoea-work rate slopes were associated with lower lung diffusing capacity, higher V̇E/V̇CO2, and lower peak O2 uptake (p<0.05). Heightened ventilatory demands in the setting of progressively lower capacity for tidal volume expansion on exertion largely explain higher-than-expected dyspnoea in f-ILD patients with largely preserved dynamic and "static" lung volumes at rest.

PMID:36858334 | DOI:10.1016/j.resp.2023.104041

EBioMedicine. 2023 Feb 27;90:104481. doi: 10.1016/j.ebiom.2023.104481. Online ahead of print.

ABSTRACT

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is an age-related, chronic, irreversible fibrotic lung disease. IPF is associated with increased senescent cells burden, which may be alleviated with administration of senescent cell targeting drugs termed 'senolytics'. We previously conducted an open-label single-arm pilot study of the senolytic combination of dasatinib and quercetin (D + Q) in patients with IPF but lack of control group limited interpretation and next-stage trial planning. The primary objective of this confirmatory randomized placebo-controlled pilot trial (RCT; NCT02874989) was to report adverse events with D + Q and inform study feasibility for future efficacy trials.

METHODS: Twelve participants with IPF aged >50 years were blinded and randomized at a 1:1 ratio to either receive three weeks of D + Q (D: 100 mg/d and Q: 1250 mg/d, three consecutive days per week) or matching placebo.

FINDINGS: All participants completed the scheduled drug dosing regimen (108/108 doses) and planned assessments (60/60). While the placebo arm reported fewer overall non-serious AEs (65 vs 22), there were no serious adverse events related to D + Q. Most AEs in the D + Q arm are common in IPF patients or anticipated side effects of D. Sleep disturbances and anxiety were disproportionately represented in the D + Q arm (4/6 vs 0/6). Frailty, pulmonary, or physical function were explored before and after intermittent D + Q; though under-powered to evaluate change, these measures do not appear to differ meaningfully between groups.

INTERPRETATION: Intermittently-dosed D + Q in patients with IPF is feasible and generally well-tolerated. Further prospective studies, such as a larger RCT, are needed to confirm the safety and efficacy of D + Q in patients with IPF.

FUNDING: This work was supported by National Institutes of Health grants R33AG61456 (JLK, TT), Robert and Arlene Kogod (JLK, TT), the Connor Fund (JLK, TT), Robert J. and Theresa W. Ryan (JLK, TT), and the Noaber Foundation (JLK, TT) San Antonio Claude D. Pepper Older Americans Independence Center's (OAIC)Pilot/Exploratory Studies Core (PESC) Grant (AMN, NM); NIHK01 AG059837 (JNJ), P30 AG021332 (SBK, JNJ); NIHR37 AG013925 (JLK), the Connor Group (JLK), Glenn/AFAR BIG Award (JLK), Robert J. and Theresa W. Ryan (JLK), and the Noaber and Ted Nash Long Life Foundations (JLK).

PMID:36857968 | DOI:10.1016/j.ebiom.2023.104481

Ann Am Thorac Soc. 2023 Mar 1. doi: 10.1513/AnnalsATS.202211-935RL. Online ahead of print.

NO ABSTRACT

PMID:36857649 | DOI:10.1513/AnnalsATS.202211-935RL

BMJ Open Respir Res. 2023 Feb;10(1):e001387. doi: 10.1136/bmjresp-2022-001387.

ABSTRACT

BACKGROUND: Interstitial lung disease (ILD) has emerged as the most common indication for lung transplantation globally. However, post-transplant survival varies depending on the underlying disease phenotype and comorbidities. This study aimed to describe the demographics, disease classification, outcomes and factors associated with post-transplant survival in a large single-centre cohort.

METHODS: Data were retrospectively assessed for 284 recipients who underwent lung transplantation for ILD in our centre between 1987 and 2020. Patient characteristics and outcomes were stratified by three eras: 1987-2000, 2001-2010 and 2011-2020.

RESULTS: Median patients' age at time of transplantation was significantly higher in the most recent decade (56 (51-61) years, p<0.0001). Recipients aged over 50 years had worse overall survival compared with younger patients (adjusted HR, aHR 2.36, 95% CI 1.55 to 3.72, p=0.0001). Better survival was seen with bilateral versus single lung transplantation in patients younger than 50 years (log-rank p=0.0195). However, this survival benefit was no longer present in patients aged over 50 years. Reduced survival was observed in fibrotic non-specific interstitial pneumonia compared with idiopathic pulmonary fibrosis, which remained the most common indication throughout (aHR 2.61, 95% CI 1.40 to 4.60, p=0.0015).

CONCLUSION: In patients transplanted for end-stage ILD, older age and fibrotic non-specific interstitial pneumonia were associated with poorer post-transplant survival. The benefit of bilateral over single lung transplantation diminished with increasing age, suggesting that single lung transplantation might still be a feasible option in older candidates.

PMID:36854571 | DOI:10.1136/bmjresp-2022-001387

JCI Insight. 2023 Feb 28:e165609. doi: 10.1172/jci.insight.165609. Online ahead of print.

ABSTRACT

BACKGROUND: Cellular stressors influence the development of clonal hematopoiesis (CH). We hypothesized that aging, environmental, inflammatory, and genotoxic stresses drive the emergence of CH in patients with severe lung disease undergoing lung transplantation.

METHODS: We performed a cross-sectional cohort study of 85 patients with severe lung disease undergoing transplantation to characterize CH prevalence. We evaluated somatic variants using duplex error-corrected sequencing and germline variants using whole exome sequencing. We evaluated CH frequency and burden using chi-square and Poisson regression, associations with clinical and demographic variables using logistic regression, and associations with clinical outcomes using chi-square, logistic, and Cox regression.

RESULTS: CH in DNA damage response (DDR) genes TP53, PPM1D, and ATM was observed at high frequency in transplant recipients compared to a control group of older adults [28% vs. 0%, aOR 12.9 (1.7-100.3), p=0.0002]. Age [OR 1.13 (1.03-1.25), p=0.014] and smoking history [OR 4.25 (1.02-17.82), p=0.048] were associated with CH in DDR genes. Germline variants causing predisposition to idiopathic pulmonary fibrosis, including telomere biology disorders and surfactant-related lung disease were identified but not associated with CH. DDR CH was associated with increased cytomegalovirus viremia compared to patients with no CH [OR 7.23 (1.95-26.8), p=0.009]] or non-DDR CH [OR 7.64 (1.77-32.89, p=0.012)], decreased lymphopenia (aHR 0.49 (0.27 - 0.90), p=0.021) and mycophenolate discontinuation [aOR 3.8 (1.3-12.9), p=0.031].

CONCLUSION: In patients with severe lung disease requiring lung transplantation, CH due to somatic variants in PPM1D, TP53 or ATM is highly prevalent and associated with post-transplant outcomes including cytomegalovirus activation and mycophenolate intolerance.

FUNDING: NIH/NHLBI K01HL155231 (LKT), R25HL105400 (LKT), Foundation for Barnes-Jewish Hospital (LKT), Evans MDS Center at Washington University (KAO, MJW), ASH Scholar Award (KAO), NIH K12CA167540 (KAO), NIH P01AI116501 (AEG, DK), NIH R01HL094601 (AEG), and NIH P01CA101937 (DCL).

PMID:36853803 | DOI:10.1172/jci.insight.165609

JCI Insight. 2023 Feb 28:e166901. doi: 10.1172/jci.insight.166901. Online ahead of print.

ABSTRACT

BACKGROUND: Fibrocytes are bone marrow-derived circulating cells that traffic to the injured lungs and contribute to fibrogenesis. The mTOR inhibitor, sirolimus, inhibits fibrocyte CXCR4 expression, reducing fibrocyte traffic and attenuating lung fibrosis in animal models. We sought to test the hypothesis that short-term treatment with sirolimus reduces the concentration of CXCR4+ circulating fibrocytes in patients with idiopathic pulmonary fibrosis (IPF).

METHODS: We conducted a short-term randomised double-blind placebo-controlled crossoverpilot trial to assess the safety and tolerability of sirolimus in IPF. Subjects were randomly assigned to sirolimus or placebo for approximately 6 weeks, and after a 4 week washout, assigned to the alternate treatment. Toxicity, lung function, and the concentration of circulating fibrocytes were measured before and after each treatment.

RESULTS: In the 28 study subjects, sirolimus resulted in a statistically significant 35% decline in the concentration of total fibrocytes, 34% decline in CXCR4+ fibrocytes, and 42% decline in fibrocytes expressing ɑ-smooth muscle actin, but no significant change in these populations occurred on placebo. Respiratory adverse events occurred more frequently during treatment with placebo than sirolimus; the incidence of adverse events and drug tolerability did not otherwise differ during therapy with drug and placebo. Lung function was unaffected by either treatment with the exception of a small decline in gas transfer during treatment with placebo.

CONCLUSIONS: As compared with placebo, short-term treatment with sirolimus resulted inreduction of circulating fibrocyte concentrations in subjects with IPF with an acceptable safety profile.

CLINICALTRIALS: gov identifier number NCT01462006FUNDING. NIH R01HL098329 and American Heart Association 18TPA34170486.

PMID:36853800 | DOI:10.1172/jci.insight.166901