Role of CAMK2D in neurodevelopment and associated conditions.

The calcium/calmodulin-dependent protein kinase type 2 (CAMK2) family consists of four different isozymes, encoded by four different genes-CAMK2A, CAMK2B, CAMK2G, and CAMK2D-of which the first three have been associated recently with neurodevelopmental disorders. CAMK2D is one of the major CAMK2 proteins expressed in the heart and has been associated with cardiac anomalies. Although this CAMK2 isoform is also known to be one of the major CAMK2 subtypes expressed during early brain development, it has never been linked with neurodevelopmental disorders until now. Here we show that CAMK2D plays an important role in neurodevelopment not only in mice but also in humans. We identified eight individuals harboring heterozygous variants in CAMK2D who display symptoms of intellectual disability, delayed speech, behavioral problems, and dilated cardiomyopathy. The majority of the variants tested lead to a gain of function (GoF), which appears to cause both neurological problems and dilated cardiomyopathy. In contrast, loss-of-function (LoF) variants appear to induce only neurological symptoms. Together, we describe a cohort of individuals with neurodevelopmental disorders and cardiac anomalies, harboring pathogenic variants in CAMK2D, confirming an important role for the CAMK2D isozyme in both heart and brain function.

Bexotegrast in Patients with Idiopathic Pulmonary Fibrosis: The INTEGRIS-IPF Study.

RATIONALE: Idiopathic pulmonary fibrosis (IPF) is a rare and progressive disease, which causes progressive cough, exertional dyspnea, impaired quality of life and death. OBJECTIVES: Bexotegrast (PLN 74809) is an oral, once-daily, investigational drug in development for the treatment of IPF. METHODS: This Phase 2a, multicenter, clinical trial, randomized participants with IPF to receive oral, once daily bexotegrast 40 mg, 80 mg, 160 mg, 320 mg, or placebo, with or without background IPF therapy (pirfenidone or nintedanib), in an approximately 3:1 ratio in each bexotegrast dose cohort, for at least 12 weeks. The primary endpoint was incidence of treatment-emergent adverse events (TEAEs). Exploratory efficacy endpoints included change from baseline in forced vital capacity (FVC); quantitative lung fibrosis (QLF) extent (%) and changes from baseline in fibrosis-related biomarkers. MEASUREMENTS AND MAIN RESULTS: Bexotegrast was well tolerated with similar rates of TEAEs in the pooled bexotegrast and placebo groups (62/89 [69.7%] and 21/31 [67.7%], respectively). Diarrhea was the most common TEAE; most participants with diarrhea also received nintedanib. Bexotegrast treated participants experienced a reduction in FVC decline over 12 weeks vs. placebo, with or without background therapy. A dose-dependent antifibrotic effect of bexotegrast was observed with QLF imaging and a decrease in fibrosis-associated biomarkers was observed with bexotegrast vs. placebo. CONCLUSIONS: Bexotegrast demonstrated a favorable safety and tolerability profile, up to 12 weeks for the doses studied. Exploratory analyses suggest an antifibrotic effect according to FVC, QLF imaging, and circulating levels of fibrosis biomarkers. Clinical trial registration available at www. CLINICALTRIALS: gov, ID: NCT04396756. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Increased expression of CXCL6 in secretory cells drives fibroblast collagen synthesis and is associated with increased mortality in idiopathic pulmonary fibrosis.

RATIONALE: Recent data suggest that the localisation of airway epithelial cells in the distal lung in idiopathic pulmonary fibrosis (IPF) may drive pathology. We set out to discover whether chemokines expressed in these ectopic airway epithelial cells may contribute to the pathogenesis of IPF. METHODS: We analysed whole lung and single-cell transcriptomic data obtained from patients with IPF. In addition, we measured chemokine levels in blood, bronchoalveolar lavage (BAL) of IPF patients and air-liquid interface cultures. We employed ex vivo donor and IPF lung fibroblasts and an animal model of pulmonary fibrosis to test the effects of chemokine signalling on fibroblast function. RESULTS: By analysis of whole-lung transcriptomics, protein and BAL, we discovered that CXCL6 (a member of the interleukin-8 family) was increased in patients with IPF. Elevated CXCL6 levels in the BAL of two cohorts of patients with IPF were associated with poor survival (hazard ratio of death or progression 1.89, 95% CI 1.16-3.08; n=179, p=0.01). By immunostaining and single-cell RNA sequencing, CXCL6 was detected in secretory cells. Administration of mCXCL5 (LIX, murine CXCL6 homologue) to mice increased collagen synthesis with and without bleomycin. CXCL6 increased collagen I levels in donor and IPF fibroblasts 4.4-fold and 1.7-fold, respectively. Both silencing of and chemical inhibition of CXCR1/2 blocked the effects of CXCL6 on collagen, while overexpression of CXCR2 increased collagen I levels 4.5-fold in IPF fibroblasts. CONCLUSIONS: CXCL6 is expressed in ectopic airway epithelial cells. Elevated levels of CXCL6 are associated with IPF mortality. CXCL6-driven collagen synthesis represents a functional consequence of ectopic localisation of airway epithelial cells in IPF.

Sfrp1 inhibits lung fibroblast invasion during transition to injury-induced myofibroblasts.

BACKGROUND: Fibroblast-to-myofibroblast conversion is a major driver of tissue remodelling in organ fibrosis. Distinct lineages of fibroblasts support homeostatic tissue niche functions, yet their specific activation states and phenotypic trajectories during injury and repair have remained unclear. METHODS: We combined spatial transcriptomics, multiplexed immunostainings, longitudinal single-cell RNA-sequencing and genetic lineage tracing to study fibroblast fates during mouse lung regeneration. Our findings were validated in idiopathic pulmonary fibrosis patient tissues in situ as well as in cell differentiation and invasion assays using patient lung fibroblasts. Cell differentiation and invasion assays established a function of SFRP1 in regulating human lung fibroblast invasion in response to transforming growth factor (TGF)ß1. MEASUREMENTS AND MAIN RESULTS: We discovered a transitional fibroblast state characterised by high Sfrp1 expression, derived from both Tcf21-Cre lineage positive and negative cells. Sfrp1 + cells appeared early after injury in peribronchiolar, adventitial and alveolar locations and preceded the emergence of myofibroblasts. We identified lineage-specific paracrine signals and inferred converging transcriptional trajectories towards Sfrp1 + transitional fibroblasts and Cthrc1 + myofibroblasts. TGFß1 downregulated SFRP1 in noninvasive transitional cells and induced their switch to an invasive CTHRC1+ myofibroblast identity. Finally, using loss-of-function studies we showed that SFRP1 modulates TGFß1-induced fibroblast invasion and RHOA pathway activity. CONCLUSIONS: Our study reveals the convergence of spatially and transcriptionally distinct fibroblast lineages into transcriptionally uniform myofibroblasts and identifies SFRP1 as a modulator of TGFß1-driven fibroblast phenotypes in fibrogenesis. These findings are relevant in the context of therapeutic interventions that aim at limiting or reversing fibroblast foci formation.

Mortality surrogates in combined pulmonary fibrosis and emphysema.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) with coexistent emphysema, termed combined pulmonary fibrosis and emphysema (CPFE) may associate with reduced forced vital capacity (FVC) declines compared to non-CPFE IPF patients. We examined associations between mortality and functional measures of disease progression in two IPF cohorts. METHODS: Visual emphysema presence (>0% emphysema) scored on computed tomography identified CPFE patients (CPFE/non-CPFE: derivation cohort n=317/n=183, replication cohort n=358/n=152), who were subgrouped using 10% or 15% visual emphysema thresholds, and an unsupervised machine-learning model considering emphysema and interstitial lung disease extents. Baseline characteristics, 1-year relative FVC and diffusing capacity of the lung for carbon monoxide (D LCO) decline (linear mixed-effects models), and their associations with mortality (multivariable Cox regression models) were compared across non-CPFE and CPFE subgroups. RESULTS: In both IPF cohorts, CPFE patients with ≥10% emphysema had a greater smoking history and lower baseline D LCO compared to CPFE patients with <10% emphysema. Using multivariable Cox regression analyses in patients with ≥10% emphysema, 1-year D LCO decline showed stronger mortality associations than 1-year FVC decline. Results were maintained in patients suitable for therapeutic IPF trials and in subjects subgrouped by ≥15% emphysema and using unsupervised machine learning. Importantly, the unsupervised machine-learning approach identified CPFE patients in whom FVC decline did not associate strongly with mortality. In non-CPFE IPF patients, 1-year FVC declines ≥5% and ≥10% showed strong mortality associations. CONCLUSION: When assessing disease progression in IPF, D LCO decline should be considered in patients with ≥10% emphysema and a ≥5% 1-year relative FVC decline threshold considered in non-CPFE IPF patients.

varAmpliCNV: analyzing variance of amplicons to detect CNVs in targeted NGS data.

MOTIVATION: Computational identification of copy number variants (CNVs) in sequencing data is a challenging task. Existing CNV-detection methods account for various sources of variation and perform different normalization strategies. However, their applicability and predictions are restricted to specific enrichment protocols. Here, we introduce a novel tool named varAmpliCNV, specifically designed for CNV-detection in amplicon-based targeted resequencing data (Haloplex™ enrichment protocol) in the absence of matched controls. VarAmpliCNV utilizes principal component analysis (PCA) and/or metric dimensional scaling (MDS) to control variances of amplicon associated read counts enabling effective detection of CNV signals. RESULTS: Performance of VarAmpliCNV was compared against three existing methods (ConVaDING, ONCOCNV and DECoN) on data of 167 samples run with an aortic aneurysm gene panel (n = 30), including 9 positive control samples. Additionally, we validated the performance on a large deafness gene panel (n = 145) run on 138 samples, containing 4 positive controls. VarAmpliCNV achieved higher sensitivity (100%) and specificity (99.78%) in comparison to competing methods. In addition, unsupervised clustering of CNV segments and visualization plots of amplicons spanning these regions are included as a downstream strategy to filter out false positives. AVAILABILITY AND IMPLEMENTATION: The tool is freely available through galaxy toolshed and at: https://hub.docker.com/r/cmgantwerpen/varamplicnv. Supplementary Data File S1: https://tinyurl.com/2yzswyhh; Supplementary Data File S2: https://tinyurl.com/ycyf2fb4. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

RUNX2-related metaphyseal dysplasia with maxillary hypoplasia: A rare skeletal disorder resembling SFRP4-related Pyle disease.

Metaphyseal dysplasia with maxillary hypoplasia with or without brachydactyly (MDMHB) is an ultra-rare skeletal dysplasia caused by heterozygous intragenic RUNX2 duplications, comprising either exons 3 to 5 or exons 3 to 6 of RUNX2. In this study, we describe a 14-year-old Belgian boy with metaphyseal dysplasia with maxillary hypoplasia but without brachydactyly. Clinical and radiographic examination revealed mild facial dysmorphism, dental anomalies, enlarged clavicles, genua valga and metaphyseal flaring and thin cortices with an osteoporotic skeletal appearance. Exome sequencing led to the identification of a de novo heterozygous tandem duplication within RUNX2, encompassing exons 3 to 7. This duplication is larger than the ones previously reported in MDMHB cases since it extends into the C-terminal activation domain of RUNX2. We review previously reported cases with MDMHB and highlight the resemblance of this disorder with Pyle disease, which may be explained by intersecting molecular pathways between RUNX2 and sFRP4. This study expands our knowledge on the genotypic and phenotypic characteristics of MDMHB and the role of RUNX2 in rare bone disorders.

Clinical course of suspected familial and sporadic idiopathic pulmonary fibrosis: Data from the PROOF-Next registry.

BACKGROUND AND OBJECTIVE: Real-life data on suspected familial fibrosis, defined as the occurrence of the disease in a patient younger than 50 and/or having at least one relative affected by pulmonary fibrosis remain scarce. METHODS: The Belgian and Luxembourg IPF registry (PROOF-Next) is a multicentric prospective longitudinal and observational study set in Belgium and Luxembourg. We compared characteristics and clinical course of patients with suspected familial pulmonary fibrosis (FPF) and sporadic IPF. RESULTS: We included 618 patients in the analysis, of whom 76 (12%) fulfilled criteria for FPF. They were significantly younger than sIPF (median age (range) 65 (43-87), vs. 72 (51-98), p = 0.0001). Male gender proportion and smoking status did not differ between groups, but the number of pack-year among current and former smokers was lower in FPF (20 vs. 25, p = 0.02). Besides, 87% of FPF and 76% of sIPF were treated with antifibrotic (p = 0.047). Baseline pulmonary function tests were similar in both groups, as well as median time before progression and transplant-free survival. Finally, genetic testing, performed in a minority, led to the identification of 10 telomerase-related gene variants. CONCLUSION: Although younger and exposed to less tobacco, patients with FPF show an equally aggressive progression as observed in sporadic IPF patients. These results warrant early referral of FPF patients to expert centres for optimal management.

Heterozygous pathogenic variants involving CBFB cause a new skeletal disorder resembling cleidocranial dysplasia.

BACKGROUND: Cleidocranial dysplasia (CCD) is a rare skeletal dysplasia with significant clinical variability. Patients with CCD typically present with delayed closure of fontanels and cranial sutures, dental anomalies, clavicular hypoplasia or aplasia and short stature. Runt-related transcription factor 2 (RUNX2) is currently the only known disease-causing gene for CCD, but several studies have suggested locus heterogeneity. METHODS: The cohort consists of eight subjects from five unrelated families partially identified through GeneMatcher. Exome or genome sequencing was applied and in two subjects the effect of the variant was investigated at RNA level. RESULTS: In each subject a heterozygous pathogenic variant in CBFB was detected, whereas no genomic alteration involving RUNX2 was found. Three CBFB variants (one splice site alteration, one nonsense variant, one 2 bp duplication) were shown to result in a premature stop codon. A large intragenic deletion was found to delete exon 4, without affecting CBFB expression. The effect of a second splice site variant could not be determined but most likely results in a shortened or absent protein. Affected individuals showed similarities with RUNX2-related CCD, including dental and clavicular abnormalities. Normal stature and neurocognitive problems were however distinguishing features. CBFB encodes the core-binding factor ß subunit, which can interact with all RUNX proteins (RUNX1, RUNX2, RUNX3) to form heterodimeric transcription factors. This may explain the phenotypic differences between CBFB-related and RUNX2-related CCD. CONCLUSION: We confirm the previously suggested locus heterogeneity for CCD by identifying five pathogenic variants in CBFB in a cohort of eight individuals with clinical and radiographic features reminiscent of CCD.

Physical activity coaching in patients with interstitial lung diseases: A randomized controlled trial.

OBJECTIVES: Physical activity is reduced in patients with interstitial lung disease (ILD) and physical inactivity is related to poor health outcomes. We investigated the effect of a telecoaching intervention to improve physical activity in patients with ILD. METHODS: Eighty patients with ILD were randomized into the intervention or control group. Patients in the intervention group received a 12-week telecoaching program including a step counter, a patient-tailored smartphone application, and coaching calls. Patients in the control group received usual care. Physical activity (primary outcome), physical fitness and quality of life were measured at baseline and 12 weeks later with an accelerometer, 6-min walking test and quadriceps muscle force and the King's Brief Interstitial Lung Disease questionnaire (K-BILD). RESULTS: Participation in telecoaching did not improve physical activity: between-group differences for step count: 386 ± 590 steps/day, p = .52; sedentary time: 4 ± 18 min/day, p = .81; movement intensity: 0.04 ± 0.05 m/s2, p = .45). Between-group differences for the 6-min walking test, quadriceps muscle force and K-BILD were 14 ± 10 m, p = .16; 2 ± 3% predicted, p = .61; 0.8 ± 1.7 points, p = .62 respectively. CONCLUSIONS: Twelve weeks of telecoaching did not improve physical activity, physical fitness or quality of life in patients with ILD. Future physical or behavioural interventions are needed for these patients to improve physical activity.

Radiologic and Histologic Correlates of Early Interstitial Lung Changes in Explanted Lungs.

Background Interstitial lung abnormalities (ILAs) reflect imaging features on lung CT scans that are compatible with (early) interstitial lung disease. Despite accumulating evidence regarding the incidence, risk factors, and prognosis of ILAs, the histopathologic correlates of ILAs remain elusive. Purpose To determine the correlation between radiologic and histopathologic findings in CT-defined ILAs in human lung explants. Materials and Methods Explanted lungs or lobes from participants with radiologically documented ILAs were prospectively collected from 2010 to 2021. These specimens were air-inflated, frozen, and scanned with CT and micro-CT (spatial resolution of 0.7 mm and 90 µm, respectively). Subsequently, the lungs were cut and sampled with core biopsies. At least five samples per lung underwent micro-CT and subsequent histopathologic assessment with semiquantitative remodeling scorings. Based on area-specific radiologic scoring, the association between radiologic and histopathologic findings was assessed. Results Eight lung explants from six donors (median age at explantation, 71 years [range, 60-83 years]; four men) were included (unused donor lungs, n = 4; pre-emptive lobectomy for oncologic indications, n = 2). Ex vivo CT demonstrated ground-glass opacification, reticulation, and bronchiectasis. Micro-CT and histopathologic examination demonstrated that lung abnormalities were frequently paraseptal and associated with fibrosis and lymphocytic inflammation. The histopathologic results showed varying degrees of fibrosis in areas that appeared normal on CT scans. Regions of reticulation on CT scans generally had greater fibrosis at histopathologic analysis. Vasculopathy and bronchiectasis were also often present at histopathologic examination of lungs with ILAs. Fully developed fibroblastic foci were rarely observed. Conclusion This study demonstrated direct histologic correlates of CT-defined interstitial lung abnormalities. © RSNA, 2022 Supplemental material is available for this article. See also the editorial by Jeudy in this issue.

Occupational interstitial lung diseases.

Millions of workers are exposed to substances known to cause occupational interstitial lung diseases (ILDs), particularly in developing countries. However, the burden of the disease is likely to be underestimated due to under-recognition, under-reporting or both. The diagnosis of occupational ILD requires a high level of suspicion and a thorough occupational history, as occupational and non-occupational ILDs may be clinically, functionally and radiologically indistinguishable, leading to delayed diagnosis and inappropriate management. A potential occupational aetiology should always be considered in the differential diagnosis of ILD, as removal from the workplace exposure, with or without treatment, is a key therapeutic intervention and may lead to significant improvement. In this article, we provide an overview of the 'traditional' inorganic dust-related ILDs but also address idiopathic pulmonary fibrosis and the immunologically mediated chronic beryllium disease, sarcoidosis and hypersensitivity pneumonitis, with emphasis on the importance of surveillance and prevention for reducing the burden of these conditions. To this end, health-care professionals should be specifically trained about the importance of occupational exposures as a potential cause of ILD.

Mass spectrometry-based identification of new anti-Ly and known antisynthetase autoantibodies.

OBJECTIVES: To discover new and detect known antisynthetase autoantibodies (ASAs) through protein immunoprecipitation combined with gel-free liquid chromatography-tandem mass spectrometry (IP-MS). METHODS: IP-MS was performed using sera of individuals showing features of antisynthetase syndrome (ASyS) without (n=5) and with (n=12) previously detected ASAs, and healthy controls (n=4). New candidate aminoacyl-tRNA-synthetase (ARS) autoantigens identified through unbiased IP-MS were confirmed by IP-western blot. A targeted IP-MS assay for various ASA specificities was developed and validated with sera of patients with known ASAs (n=16), disease controls (n=20) and healthy controls (n=25). The targeted IP-MS assay was applied in an additional cohort of patients with multiple ASyS features or isolated myositis without previously detected ASAs (n=26). RESULTS: Autoantibodies to cytoplasmic cysteinyl-tRNA-synthetase (CARS1) were identified by IP-MS and confirmed by western blot as a new ASA specificity, named anti-Ly, in the serum of a patient with ASyS features. Rare ASAs, such as anti-OJ, anti-Zo and anti-KS, and common ASAs could also be identified by IP-MS. A targeted IP-MS approach for ASA detection was developed and validated. Application of this method in an additional cohort identified an additional patient with anti-OJ autoantibodies that were missed by line and dot immunoassays. DISCUSSION: CARS1 is the dominant cognate ARS autoantigen of the newly discovered anti-Ly ASA specificity. Rare and common ASA specificities could be detected by both unbiased and targeted IP-MS. Unbiased and targeted IP-MS are promising methods for discovery and detection of autoantibodies, especially autoantibodies that target complex autoantigens.

Autoantibodies against the NineTeen complex and U5 RNP in systemic sclerosis.

ObjectiveMultiple spliceosome components are known autoantigens in systemic sclerosis (SSc). Here we aim to identify new and characterize rare anti-spliceosomal autoantibodies in patients with SSc without known autoantibody specificity. MethodsSera that precipitated spliceosome subcomplexes, as detected by immunoprecipitation-mass spectrometry (IP-MS), were identified from a database of 106 patients with SSc without known autoantibody specificity. New autoantibody specificities were confirmed with immunoprecipitation-western blot. The IP-MS pattern of new anti-spliceosomal autoantibodies was compared with anti-U1 RNP-positive sera of patients with different systemic autoimmune rheumatic diseases and anti-SmD-positive sera of patients with systemic lupus erythematosus (n = 24). ResultsThe NineTeen Complex (NTC) was identified and confirmed as new spliceosomal autoantigen in one patient with SSc. U5 RNP, as well as additional splicing factors, were precipitated by the serum of another patient with SSc. The IP-MS patterns of anti-NTC and anti-U5 RNP autoantibodies were distinct from those of anti-U1 RNP- and anti-SmD-positive sera. Furthermore, there was no difference in IP-MS patterns between a limited number of anti-U1 RNP-positive sera of patients with different systemic autoimmune rheumatic diseases. ConclusionAnti-NTC autoantibodies are a new anti-spliceosomal autoantibody specificity, here first identified in a patient with SSc. Anti-U5 RNP autoantibodies are a distinct but rare anti-spliceosomal autoantibody specificity. All major spliceosomal subcomplexes have now been described as target of autoantibodies in systemic autoimmune diseases.

Identification of new telomere- and telomerase-associated autoantigens in systemic sclerosis.

PURPOSE: In up to 20% of patients with systemic sclerosis (SSc) no known autoantibody specificity can be identified. Recently discovered autoantigens, such as telomeric repeat binding factor 1 (TERF1), as well as established autoantigens, like RuvBL1/2, are associated with telomere and telomerase biology. We aimed to identify new telomere- and telomerase-associated autoantigens in patients with SSc without known autoantibody specificity. METHODS: Unlabelled protein immunoprecipitation combined with gel-free liquid chromatography-tandem mass spectrometry (IP-MS) was performed with sera of 106 patients with SSc from two tertiary referral centres that had a nuclear pattern on HEp-2 indirect immunofluorescence without previously identified autoantibody. Telomere- or telomerase-associated proteins or protein complexes precipitated by individual sera were identified. Candidate autoantigens were confirmed through immunoprecipitation-western blot (IP-WB). A custom Luminex xMAP assay for 5 proteins was evaluated with sera from persons with SSc (n = 467), other systemic autoimmune rheumatic diseases (n = 923), non-rheumatic disease controls (n = 187) and healthy controls (n = 199). RESULTS: Eight telomere- and telomerase-associated autoantigens were identified in a total of 11 index patients, including the THO complex (n = 3, all with interstitial lung disease and two with cardiac involvement), telomeric repeat-binding factor 2 (TERF2, n = 1), homeobox-containing protein 1 (HMBOX1, n = 2), regulator of chromosome condensation 1 (RCC1, n = 1), nucleolar and coiled-body phosphoprotein 1 (NOLC1, n = 1), dyskerin (DKC1, n = 1), probable 28S rRNA (cytosine(4447)-C(5))-methyltransferase (NOP2, n = 1) and nuclear valosin-containing protein-like (NVL, n = 2). A Luminex xMAP assay for THO complex subunit 1 (THOC1), TERF2, NOLC1, NOP2 and NVL revealed high reactivity in all index patients, but also in other patients with SSc and disease controls. However, the reactivity by xMAP assay in these other patients was not confirmed by IP-WB. CONCLUSION: IP-MS revealed key telomere- and telomerase-associated proteins and protein complexes as autoantigens in patients with SSc.

MUC5B rs35705950 minor allele associates with older age and better survival in idiopathic pulmonary fibrosis.

BACKGROUND AND OBJECTIVE: The minor T-allele of the MUC5B promoter polymorphism rs35705950 is strongly associated with idiopathic pulmonary fibrosis (IPF). However, conflicting results have been reported on the relationship between the MUC5B minor allele and survival and it is unknown whether a specific subgroup of IPF patients might benefit from MUC5B minor allele carriage. We investigated the association between MUC5B rs35705950, survival and patient characteristics in a real-world population of European IPF patients. METHODS: In this retrospective study, 1751 patients with IPF from 8 European centres were included. MUC5B rs35705950 genotype, demographics, clinical characteristics at diagnosis and survival data were analysed. RESULTS: In a multi-variate Cox proportional hazard model the MUC5B minor allele was a significant independent predictor of survival when adjusted for age, sex, high resolution computed tomography pattern, smoking behaviour and pulmonary function tests in IPF. MUC5B minor allele carriers were significantly older at diagnosis (p = 0.001). The percentage of MUC5B minor allele carriers increased significantly with age from 44% in patients aged <56 year, to 63% in patients aged >75. In IPF patients aged <56, the MUC5B minor allele was not associated with survival. In IPF patients aged ≥56, survival was significantly better for MUC5B minor allele carriers (45 months [CI: 42-49]) compared to non-carriers (29 months [CI: 26-33]; p = 4 × 10-12 ). CONCLUSION: MUC5B minor allele carriage associates with a better median transplant-free survival of 16 months in the European IPF population aged over 56 years. MUC5B genotype status might aid disease prognostication in clinical management of IPF patients.

Lung cancer in patients with idiopathic pulmonary fibrosis: A retrospective multicentre study in Europe.

BACKGROUND AND OBJECTIVE: There remains a paucity of large databases for patients with idiopathic pulmonary fibrosis (IPF) and lung cancer. We aimed to create a European registry. METHODS: This was a multicentre, retrospective study across seven European countries between 1 January 2010 and 18 May 2021. RESULTS: We identified 324 patients with lung cancer among 3178 patients with IPF (prevalence = 10.2%). By the end of the 10 year-period following IPF diagnosis, 26.6% of alive patients with IPF had been diagnosed with lung cancer. Patients with IPF and lung cancer experienced increased risk of all-cause mortality than IPF patients without lung cancer (HR: 1.51, [95% CI: 1.22-1.86], p < 0.0001). All-cause mortality was significantly lower for patients with IPF and lung cancer with a monocyte count of either <0.60 or 0.60-<0.95 K/µl than patients with monocyte count ≥0.95 K/µl (HR [<0.60 vs. ≥0.95 K/µl]: 0.35, [95% CI: 0.17-0.72], HR [0.60-<0.95 vs. ≥0.95 K/µl]: 0.42, [95% CI: 0.21-0.82], p = 0.003). Patients with IPF and lung cancer that received antifibrotics presented with decreased all cause-mortality compared to those who did not receive antifibrotics (HR: 0.61, [95% CI: 0.42-0.87], p = 0.006). In the adjusted model, a significantly lower proportion of surgically treated patients with IPF and otherwise technically operable lung cancer experienced all-cause mortality compared to non-surgically treated patients (HR: 0.30 [95% CI: 0.11-0.86], p = 0.02). CONCLUSION: Lung cancer exerts a dramatic impact on patients with IPF. A consensus statement for the management of patients with IPF and lung cancer is sorely needed.

Phase 2B Study of Inhaled RVT-1601 for Chronic Cough in Idiopathic Pulmonary Fibrosis: A Multicenter, Randomized, Placebo-controlled Study (SCENIC Trial).

Rationale: Chronic cough remains a major and often debilitating symptom for patients with idiopathic pulmonary fibrosis (IPF). In a phase 2A study, inhaled RVT-1601 (cromolyn sodium) reduced daytime cough and 24-hour average cough counts in patients with IPF. Objectives: To determine the efficacy, safety, and optimal dose of inhaled RVT-1601 for the treatment of chronic cough in patients with IPF. Methods: In this multicenter, randomized, placebo-controlled phase 2B study, patients with IPF and chronic cough for ⩾8 weeks were randomized (1:1:1:1) to receive 10, 40, and 80 mg RVT-1601 three times daily or placebo for 12 weeks. The primary endpoint was change from baseline to end of treatment in log-transformed 24-hour cough count. Key secondary endpoints were change from baseline in cough severity and cough-specific quality of life. Safety was monitored throughout the study. Measurements and Main Results: The study was prematurely terminated owing to the impact of the coronavirus disease (COVID-19) pandemic. Overall, 108 patients (mean age 71.0 years, 62.9% males) received RVT-1601 10 mg (n = 29), 40 mg (n = 25), 80 mg (n = 27), or matching placebo (n = 27); 61.1% (n = 66) completed double-blind treatment. No statistically significant difference was observed in the least-square mean change from baseline in log-transformed 24-hour average cough count, cough severity, and cough-specific quality of life score between the RVT-1601 groups and the placebo group. The mean percentage change from baseline in 24-hour average cough count was 27.7% in the placebo group. Treatment was generally well tolerated. Conclusions: Treatment with inhaled RVT-1601 (10, 40, and 80 mg three times a day) did not provide benefit over placebo for the treatment of chronic cough in patients with IPF.

Lung Microenvironments and Disease Progression in Fibrotic Hypersensitivity Pneumonitis.

Rationale: Fibrotic hypersensitivity pneumonitis (fHP) is an interstitial lung disease caused by sensitization to an inhaled allergen. Objectives: To identify the molecular determinants associated with progression of fibrosis. Methods: Nine fHP explant lungs and six unused donor lungs (as controls) were systematically sampled (4 samples/lung). According to microcomputed tomography measures, fHP cores were clustered into mild, moderate, and severe fibrosis groups. Gene expression profiles were assessed using weighted gene co-expression network analysis, xCell, gene ontology, and structure enrichment analysis. Gene expression of the prevailing molecular traits was also compared with idiopathic pulmonary fibrosis (IPF). The explant lung findings were evaluated in separate clinical fHP cohorts using tissue, BAL samples, and computed tomography scans. Measurements and Main Results: We found six molecular traits that associated with differential lung involvement. In fHP, extracellular matrix and antigen presentation/sensitization transcriptomic signatures characterized lung zones with only mild structural and histological changes, whereas signatures involved in honeycombing and B cells dominated the transcriptome in the most severely affected lung zones. With increasing disease severity, endothelial function was progressively lost, and progressive disruption in normal cellular homeostatic processes emerged. All six were also found in IPF, with largely similar associations with disease microenvironments. The molecular traits correlated with in vivo disease behavior in a separate clinical fHP cohort. Conclusions: We identified six molecular traits that characterize the morphological progression of fHP and associate with in vivo clinical behavior. Comparing IPF with fHP, the transcriptome landscape was determined considerably by local disease extent rather than by diagnosis alone.

Integrating Clinical Probability into the Diagnostic Approach to Idiopathic Pulmonary Fibrosis: An International Working Group Perspective.

Background: When considering the diagnosis of idiopathic pulmonary fibrosis (IPF), experienced clinicians integrate clinical features that help to differentiate IPF from other fibrosing interstitial lung diseases, thus generating a "pre-test" probability of IPF. The aim of this international working group perspective was to summarize these features using a tabulated approach similar to chest HRCT and histopathologic patterns reported in the international guidelines for the diagnosis of IPF, and to help formally incorporate these clinical likelihoods into diagnostic reasoning to facilitate the diagnosis of IPF. Methods: The committee group identified factors that influence the clinical likelihood of a diagnosis of IPF, which was categorized as a pre-test clinical probability of IPF into "high" (70-100%), "intermediate" (30-70%), or "low" (0-30%). After integration of radiological and histopathological features, the post-test probability of diagnosis was categorized into "definite" (90-100%), "high confidence" (70-89%), "low confidence" (51-69%), or "low" (0-50%) probability of IPF. Findings: A conceptual Bayesian framework was created, integrating the clinical likelihood of IPF ("pre-test probability of IPF") with the HRCT pattern, the histopathology pattern when available, and/or the pattern of observed disease behavior, into a "post-test probability of IPF." The diagnostic probability of IPF was expressed using an adapted diagnostic ontology for fibrotic interstitial lung diseases. Interpretation: The present approach will help incorporate the clinical judgment into the diagnosis of IPF, thus facilitating the application of IPF diagnostic guidelines and, ultimately improving diagnostic confidence and reducing the need for invasive diagnostic techniques.