Telomere-related lung fibrosis is diagnostically heterogeneous but uniformly progressive

Late-onset telomere biology disorders in adults: clinical insights and treatment outcomes from a retrospective registry cohort

ABSTRACT

Pathogenic germ line variants affecting proper telomere maintenance result in premature telomere shortening and cause telomere biology disorders (TBDs). Although classical dyskeratosis congenita in children is rather well defined, late-onset ("cryptic") TBDs remain underrecognized, resulting in underdiagnosis and inadequate treatment in affected adults. Here, we present a series of adult TBD cases collected through the German TBD reference center between 2014 and 2024. Patients aged ≥18 years with an age-matched telomere length (TL) <10th percentile in lymphocytes, a detection of either a variant of uncertain significance, a pathogenic, or a likely pathogenic variant in TBD-associated genes, and available clinical data were included in this analysis. Based on this, a novel point-based algorithm for categorization into proven, probable, and suspected-only TBD cases was developed. Of 1537 TL analyses, 42 patients with proven (n = 29) or probable (n = 13) TBD were identified. The median age at first clinical manifestation and at diagnosis was 20.0 and 34.1 years, respectively. Bone marrow failure (BMF) was the most frequent manifestation observed in our cohort (73.8%), followed by liver or interstitial lung diseases (50.0% and 41.5%, respectively). Immunosuppressive therapy was administered in 6 patients with BMF, but none of them responded. In comparison, 8 of 8 evaluable patients treated with androgen derivatives showed hematologic response. Our data provide novel real-world insights into the clinical manifestation spectrum, diagnosis, clinical course, and treatment of TBD in adult, late-onset cases of this hereditary disease.

Idiopathic pleuroparenchymal fibroelastosis: diagnosis and management

INTRODUCTION

Idiopathic pleuroparenchymal fibroelastosis (iPPFE) is a rare progressive interstitial lung disease characterized by upper-lobe fibrosis, severe restrictive impairment, and poor prognosis. Unlike idiopathic pulmonary fibrosis, in which acute exacerbations, chronic respiratory failure, and lung cancer are the major causes of death, iPPFE primarily leads to progressive respiratory failure, often complicated by malnutrition and recurrent pneumothorax. Despite growing recognition, its pathogenesis remains unclear and no effective treatments exist.

AREAS COVERED

This review summarizes the epidemiological, clinical, radiological, and pathological features of iPPFE, as well as diagnostic and prognostic advancements. Key prognostic factors include weight loss, reduced forced vital capacity, hypercapnia, and lower-lobe interstitial pneumonia. Serum biomarkers (e.g. latent transforming growth factor-beta binding protein-4) are being explored for early detection and prognostic purposes. Although antifibrotic agents show limited efficacy, supportive care - pulmonary rehabilitation, nutritional management, and pneumothorax prevention - remains essential. Research on the fibroelastotic pathways may inform the development of future therapies.

EXPERT OPINION

IPPFE remains a challenging disease. Therefore, early diagnosis and comprehensive management of this condition are crucial. Future research should refine prognostic models and explore novel therapeutic approaches for treating fibroelastosis. Lung transplantation may be an option for select patients. Further studies are required to optimize these outcomes.

Rare variants and survival of patients with idiopathic pulmonary fibrosis: analysis of a multicentre, observational cohort study with independent validation

BACKGROUND

Rare pathogenic variants in telomere-related genes are associated with poorer clinical outcomes in idiopathic pulmonary fibrosis (IPF). We aimed to assess whether rare qualifying variants in monogenic adult-onset pulmonary fibrosis genes are associated with IPF survival. Using polygenic risk scores (PRS), we also evaluated the influence of common IPF risk variants in patients carrying the qualifying variants.

METHODS

We identified qualifying variants in telomere and non-telomere genes using whole-genome sequences from individuals clinically diagnosed with IPF and enrolled in the Pulmonary Fibrosis Foundation Patient Registry (PFFPR), a large multicentre, observational cohort study (March 29, 2016 to June 15, 2018, n=888). We also derived a PRS for IPF (PRS-IPF) from known common sentinel IPF variants. The primary outcome was the association between qualifying variants and survival. The secondary outcome was the association between qualifying variants and PRS-IPF. We used logistic regression models adjusted for sex, age at diagnosis, and principal components of genetic heterogeneity to examine the mutual relationship of qualifying variants and PRS-IPF. The association between qualifying variants and PRS-IPF with survival was tested using Cox proportional hazard models adjusted for baseline confounders. Validation of the results was sought in data from an independent multicentre, prospective, observational cohort study of IPF in the UK (PROFILE, May 17, 2010 to Sept 5, 2017, n=472), and results were meta-analysed under a fixed-effects model.

FINDINGS

We included 888 patients from PFFPR and 472 from PROFILE, totalling 1360 participants. In the PFFPR, carriers of qualifying variants in monogenic adult-onset pulmonary fibrosis genes were associated with lower PRS-IPF (odds ratio 1·79 [95% CI 1·15-2·81]; p=0·010) and shorter survival (hazard ratio 1·53 [1·12-2·10]; p=7·33 × 10-3). Individuals with the lowest PRS-IPF also had worse survival (1·61 [1·25-2·07]; p=1·87 × 10-4). These findings were validated in PROFILE and the meta-analysis of the results showed a consistent direction of effect across both cohorts.

INTERPRETATION

We found non-additive effects between qualifying variants and common risk variants in IPF survival, suggesting distinct disease subtypes and raising the possibility of using PRS to guide sequencing prioritisation. Assessing the carrier status for qualifying variants and modelling PRS-IPF promises to further contribute to predicting disease progression among patients with IPF.

FUNDING

Instituto de Salud Carlos III; Instituto Tecnológico y de Eenergías Renovables; Cabildo Insular de Tenerife; Fundación DISA; National Heart, Lung, and Blood Institute of the US National Institutes of Health; and UK Medical Research Council.

Familial pulmonary fibrosis with dyskeratosis congenita associated with a rare RTEL1 gene mutation

A subset of idiopathic pulmonary fibrosis cases has a familial component. Telomeric mutations, such as those in the Regulator of Telomere Elongation Helicase 1 (RTEL1) gene, have been associated with lung fibrosis and a minority of dyskeratosis congenita (DC) cases.We present the case of a A male in his 50s with pulmonary fibrosis, cryptogenic hepatic cirrhosis, chronic anaemia and thrombocytopenia, lacy skin hyperpigmentation, dystrophic nails and canities. Family history included pulmonary fibrosis in two brothers. Genetic testing identified a RTEL1 mutation (c.3730T>C, p.Cys1244Arg) in heterozygosity, linked to a few cases of pulmonary fibrosis and DC. This mutation was confirmed in one brother and two sons. The patient was started on pirfenidone and referred for respiratory rehabilitation, haematological and transplant evaluations.Recognising family history and extrapulmonary manifestations in familial pulmonary fibrosis can expedite diagnosis, treatment and genetic counselling. Early detection of DC allows timely management of bone marrow failure and malignancy screening.

MUC5B Genotype and Other Common Variants Are Associated with Computational Imaging Features of Usual Interstitial Pneumonia

Rationale: Idiopathic pulmonary fibrosis (IPF) is a complex and heterogeneous disease. Given this, we reasoned that differences in genetic profiles may be associated with unique clinical and radiologic features. Computational image analysis, sometimes referred to as radiomics, provides objective, quantitative assessments of radiologic features in subjects with pulmonary fibrosis. Objectives: To determine if the genetic risk profile of patients with IPF identifies unique computational imaging phenotypes. Methods: Participants with IPF were included in this study if they had genotype data and computed tomography (CT) scans of the chest available for computational image analysis. The extent of lung fibrosis and the likelihood of a usual interstitial pneumonia (UIP) pattern were scored automatically using two separate, previously validated deep learning techniques for CT analysis. UIP pattern was also classified visually by radiologists according to established criteria. Results: Among 329 participants with IPF, MUC5B and ZKSCAN1 were independently associated with the deep learning-based UIP score. None of the common variants were associated with fibrosis extent by computational imaging. We did not find an association between MUC5B or ZKSCAN1 and visually assessed UIP pattern. Conclusions: Select genetic variants are associated with computer-based classification of UIP on CT in this IPF cohort. Analysis of radiologic features using deep learning may enhance our ability to identify important genotype-phenotype associations in fibrotic lung diseases.

A non-resolving cough in a 41-year-old woman: a case of familial pulmonary fibrosis

Identification of cases of familial pulmonary fibrosis is important with the risk of a monogenic cause. Patients appear to be younger and may have a more progressive disease. Consideration for antifibrotics and early transplant referral should be made. https://bit.ly/42jJ3aO.

The Dawn of Precision Medicine in Fibrotic Interstitial Lung Disease

TOPIC IMPORTANCE

Interstitial lung diseases (ILDs) represent a broad group of heterogeneous parenchymal lung diseases. Some ILDs progress, causing architectural distortion and pulmonary fibrosis, and thus are called fibrotic ILDs. Recent studies have shown a beneficial effect of antifibrotic therapy in fibrotic ILDs other than idiopathic pulmonary fibrosis (IPF) that manifest progressive pulmonary fibrosis (PPF). However, it remains challenging to predict which patients with fibrotic ILDs will demonstrate PPF. Precision medicine approaches could identify patients at risk for progression and guide treatment in patients with IPF or PPF.

REVIEW FINDINGS

Multiple biomarkers able to highlight disease susceptibility risk, to provide an accurate diagnosis, and to prognosticate or assess treatment response have been identified. Advances in precision medicine led to the identification of endotypes that could discriminate patients with different fibrotic ILDs or patients with different disease courses. Importantly, recent studies have shown that particular compounds were efficacious only in particular endotypes. The aforementioned findings are promising. However, implementation in clinical practice remains an unmet need.

SUMMARY

Substantial progress has been observed in the context of precision medicine approaches in fibrotic ILDs in recent years. Nonetheless, infrastructure, financial, regulatory, and ethical challenges remain before precision medicine can be implemented in clinical practice. Overcoming such barriers and moving from a one-size-fits-all approach to patient-centered care could improve patient quality of life and survival substantially.

Viewpoint: Pre- and post-lung transplant considerations for patients with ultra-short telomere length

Lung transplantation remains the only life-extending procedure for patients with idiopathic pulmonary fibrosis (IPF) and related progressive interstitial lung disease (ILD). Discoveries from recent decades have shown that mutations in telomerase and other telomere maintenance genes are their most common inherited risk factor, identifiable in up to 30–35% of families with pulmonary fibrosis [1]. Mutations in nine telomerase and telomere maintenance genes are confirmed to predispose to adult-onset pulmonary fibrosis by co-segregation in large families and functional studies (table 1) [2–13]. They compromise telomerase abundance, recruitment and function [1, 14].

Patients with ultra-short telomere length develop recurrent complications after lung transplantation; therefore, pre-transplant assessment and individualised post-transplant management may improve outcome in carefully defined high risk patient subsets https://bit.ly/3WvfLC1

Rapid dynamics allow the low-abundance RTEL1 helicase to promote telomere replication

Regulator of telomere length 1 (RTEL1) helicase facilitates telomere replication by disassembling DNA secondary structures, such as G-quadruplexes and telomeric loops (t-loops), at the ends of the chromosomes. The recruitment of RTEL1 to telomeres occurs during the S-phase of the cell cycle, but the dynamics of the process has not been studied. Here, we utilized CRISPR genome editing and single-molecule imaging to monitor RTEL1 movement within human cell nuclei. RTEL1 utilizes rapid three-dimensional diffusion to search for telomeres and other nuclear targets. Only 5% of the chromatin-bound RTEL1 is associated with telomeres at any time in the S-phase, but the telomere-bound RTEL1 has much more extended associations. This binding is enhanced by the interaction between RTEL1 and the telomeric protein TRF2 but is largely independent of RTEL1 ATPase activity. The absence of RTEL1 catalytic activity leads to severe defects in cell proliferation, slow progression out of S-phase, and chromosome end-to-end fusion events. We propose that the rapid diffusion of RTEL1 allows this low-abundance protein to explore the nucleus, bind TRF2, and be recruited to telomeres.

Telomeropathies in Interstitial Lung Disease and Lung Transplant Recipients

Telomeropathies, or telomere biology disorders (TBDs), are syndromes that can cause a number of medical conditions, including interstitial lung disease (ILD), bone marrow failure, liver fibrosis, and other diseases. They occur due to genetic mutations to the telomerase complex enzymes that result in premature shortening of telomeres, the caps on the ends of cellular DNA that protect chromosome length during cell division, leading to early cell senescence and death. Idiopathic pulmonary fibrosis (IPF) is the most common manifestation of the telomere biology disorders, although it has been described in other interstitial lung diseases as well, such as rheumatoid arthritis-associated ILD and chronic hypersensitivity pneumonitis. Telomere-related mutations can be inherited or can occur sporadically. Identifying these patients and offering genetic counseling is important because telomerapathies have been associated with poorer outcomes including death, lung transplantation, hospitalization, and FVC decline. Additionally, treatment with immunosuppressants has been shown to be associated with worse outcomes. Currently, there is no specific treatment for TBD except to transplant the organ that is failing, although there are a number of promising treatment strategies currently under investigation. Shortened telomere length is routinely discovered in patients undergoing lung transplantation for IPF. Testing to detect early TBD in patients with suggestive signs or symptoms can allow for more comprehensive treatment and multidisciplinary care pre- and post-transplant. Patients with TBD undergoing lung transplantation have been reported to have both pulmonary and extrapulmonary complications at a higher frequency than other lung transplant recipients, such as graft-specific complications, increased infections, and complications related to immunosuppressive therapy.

Diagnosis, screening, and follow-up of patients with familial interstitial lung disease: Results from an international survey

BACKGROUND

Advances in the field of genetics of interstitial lung diseases (ILDs) have led to the recent consensus statements made by expert groups. International standards for genetic testing in ILD have not yet been established. We aimed to examine current real-world strategies employed by pulmonologists working with familial ILD.

METHODS

A panel of pulmonologists with expertise in ILD developed an international survey aimed at clinicians working with ILD. The survey consisted of 74 questions divided into eight topics: characteristics of respondents, diagnosis, screening of first-degree relatives, screening tools, genetic testing methods, lung transplantation, ethical concerns, and future needs.

RESULTS

Overall, 237 pulmonologists from 50 countries participated. A family history of ILD was asked for by 91% of respondents while fewer asked for symptoms related to telomere disorders. Respondents stated that 59% had access to genetic testing, and 30% to a genetic multidisciplinary team (MDT). Many respondents were unaware of specific genetic testing methods. Pathogenic genetic variants were seen as a potential contraindication for lung transplantation in 6-8% of respondents. Genetic screening of relatives was supported by 80% of respondents who indicated insufficient evidence and a lack of formal guidelines for genetics and ILD. Only 16% had a standardized program.

CONCLUSION

Most pulmonologists ask for a family history of ILD and recommend genetic testing for ILD and screening in relatives but have limited knowledge of specific tests and access to genetic MDT. Evidence-based guidelines to inform patients, relatives, and physicians are still warranted.

Idiopathic pleuroparenchymal fibroelastosis: A review of the previous literature and current knowledge

Idiopathic pleuroparenchymal fibroelastosis (iPPFE) is characterized by upper lobe-dominant fibrosis involving the pleura and subpleural lung parenchyma. Pathologically, it is characterized by parenchymal intra-alveolar fibrosis with marked deposition of elastic fibers and dense thickening of the visceral pleura. Since iPPFE was categorized as a rare idiopathic interstitial pneumonia (IIP) by the America Thoracic Society/European Respiratory Society, several studies have been conducted, revealing an overall picture of iPPFE in terms of epidemiology, clinical manifestations, and mortality, in addition to its radiological and histological characteristics. Subsequently, several clinical diagnostic criteria that were not necessary for pathological analyses were proposed. Further, the underlying diseases responsible for secondary PPFE and PPFE-like lesions and their clinical implications were delineated. Typically, patients with iPPFE exhibit lean body stature together with platythorax, as well as relatively severe impairment of pulmonary function. In addition to upper-lobe PPFE lesions, lower-lobe interstitial lung disease (ILD) is commonly observed in patients with iPPFE, with the usual interstitial pneumonia pattern being most frequent. These distinct features of iPPFE were mostly associated with mortality, resulting in a poor prognosis relative to fibrotic ILD. Despite increased knowledge regarding the clinical characteristics of iPPFE, no effective therapy has been established other than lung transplantation. The efficacy of antifibrotic therapy, nutrition intervention, and pulmonary rehabilitation has not been determined. This article reviews previous studies and discusses the etiology, clinical manifestations, mortality risk, and treatment of iPPFE.

Investigational gene expression inhibitors for the treatment of idiopathic pulmonary fibrosis

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrosing interstitial lung disease of unknown cause that occurs primarily in older adults and is associated with poor quality of life and substantial healthcare utilization. IPF has a dismal prognosis. Indeed, first-line therapy, which includes nintedanib and pirfenidone, does not stop disease progression and is often associated with tolerability issues. Therefore, there remains a high medical need for more efficacious and better tolerated treatments.

AREAS COVERED

Gene therapy is a relatively unexplored field of research in IPF that has the potential to mitigate a range of profibrotic pathways by introducing genetic material into cells. Here, we summarize and critically discuss publications that have explored the safety and efficacy of gene therapy in experimentally-induced pulmonary fibrosis in animals, as clinical studies in humans have not been published yet.

EXPERT OPINION

The application of gene therapy in pulmonary fibrosis requires further investigation to address several technical and biological hurdles, improve vectors' design, drug delivery, and target selection, mitigate off-target effects and develop markers of gene penetration into target cells. Long-term clinical data are needed to bring gene therapy in IPF one step closer to practice.

Diagnostic and prognostic implications of family history of fibrotic interstitial lung diseases

BACKGROUND

Patients with familial fibrotic interstitial lung disease (ILD) experience worse survival than patients with sporadic disease. Current guidelines do not consider family aggregation or genetic information in the diagnostic algorithm for idiopathic pulmonary fibrosis or other fibrotic ILDs. Better characterizing familial cases could help in diagnostic and treatment decision-making.

METHODS

This retrospective cohort study included 222 patients with fibrotic ILD (104 familial and 118 sporadic) from Bellvitge University Hospital. Clinical, radiological, pulmonary functional tests (PFT), and histological evaluations were performed at diagnosis and follow-up. Telomere shortening and disease-associated variants (DAVs) in telomerase-related genes were analysed in familial patients and sporadic patients with telomeric clinical signs. Primary outcomes were the presence of a UIP histological pattern and disease progression.

RESULTS

Patients with idiopathic pulmonary fibrosis (IPF) (52%), fibrotic hypersensitivity pneumonitis (23%), and other fibrotic ILDs (25%) were included. 42% of patients underwent lung biopsy. Patients with family aggregation were younger and less frequently associated comorbidities, male sex, and smoking history. However, usual interstitial pneumonia (UIP) was more frequent on pathology (p = 0.005; OR 3.37), especially in patients with indeterminate or non-UIP radiological patterns. Despite similar PFT results at diagnosis, familial patients were more likely to present with progressive disease (p = 0.001; OR 3.75). Carrying a DAV increased the risk of fibrotic progression in familial and sporadic patients (p = 0.029, OR 5.01).

DISCUSSION

Familial patients diagnosed with different fibrotic ILDs were more likely to exhibit a histological UIP pattern and disease progression than sporadic patients, independent of radiological findings and pulmonary function at diagnosis.

CONCLUSION

Considering the diagnostic likelihood of the histological UIP pattern and disease outcome, the presence of family aggregation would be useful in the decision making of multidisciplinary committees.

Progressive Early Interstitial Lung Abnormalities in Persons at Risk for Familial Pulmonary Fibrosis: A Prospective Cohort Study

Rationale: Relatives of patients with familial pulmonary fibrosis (FPF) are at increased risk to develop FPF. Interstitial lung abnormalities (ILAs) are a radiologic biomarker of subclinical disease, but the implications of very mild abnormalities remain unclear. Objectives: To quantify the progression risk among FPF relatives with abnormalities below the threshold for ILAs as described by the Fleischner Society and to describe the characteristics of participants with new or progressive ILAs during observation. Methods: Asymptomatic FPF relatives undergo serial screening high-resolution chest computed tomography. For this analysis, early ILAs (no minimum threshold of lung involvement) were subclassified as mild (all interstitial abnormalities involve <5% of a lung zone) or moderate (any abnormality involves >5%). Identification of new or progressive ILAs on high-resolution chest computed tomography and the development of pulmonologist-diagnosed clinical FPF were defined as progression. Covariate-adjusted logistic regression identified progression-associated characteristics. Measurements and Main Results: From 2008 to 2023, 273 participants in follow-up procedures were 53.2 ± 9.4 years of age at enrollment, 95 (35%) were men, and 73 of 268 (27%) were ever-smokers. During a mean follow-up period of 6.2 ± 3.0 years, progression occurred among 31 of 211 (15%) of those with absence of ILAs at enrollment, 32 of 49 (65%) of those with mild ILAs, and 10 of 13 (77%) of those with moderate ILAs. Subjects with mild ILAs had 9.15 (95% confidence interval, 4.40-19.00; P < 0.0001) times and those with moderate ILAs had 17.14 (95% confidence interval, 4.42-66.49; P < 0.0001) times the odds of progression as subjects without ILAs. Conclusions: In persons at risk for FPF, minor interstitial abnormalities, including reticulation that is unilateral or involves <5% of a lung zone, frequently represent subclinical disease.

[Diagnosis and Treatment of Hypersensitivity Pneumonitis - S2k Guideline of the German Respiratory Society and the German Society for Allergology and Clinical Immunology]

Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease (ILD) in sensitized individuals caused by a large variety of inhaled antigens. The clinical form of acute HP is often misdiagnosed, while the chronic form, especially the chronic fibrotic HP, is difficult to differentiate from other fibrotic ILDs. The present guideline for the diagnosis and treatment of HP replaces the former German recommendations for the diagnosis of HP from 2007 and is amended explicitly by the issue of the chronic fibrotic form, as well as by treatment recommendations for the first time. The evidence was discussed by a multidisciplinary committee of experts. Then, recommendations were formulated for twelve questions on important issues of diagnosis and treatment strategies. Recently published national and international guidelines for ILDs and HP were considered. Detailed background information on HP is useful for a deeper insight into HP and the handling of the guideline.

Diagnosis and Management of Pulmonary Manifestations of Telomere Biology Disorders

PURPOSE OF REVIEW

Telomere biology disorders (TBD) are a group of genetic disorders characterized by premature shortening of telomeres, resulting in accelerated aging of somatic cells. This often leads to major multisystem organ dysfunction, and TBDs have become increasingly recognized as a significant contributor to numerous disease processes within the past 10-15 years. Both research and clinical practice in this field are rapidly evolving.

RECENT FINDINGS

A subset of patients with TBD suffers from interstitial lung disease, most commonly pulmonary fibrosis. Often, the clinical presentation is indistinguishable from other forms of lung fibrosis. There are no pathognomonic radiographic or histological features, and a high level of suspicion is therefore required. Telomere evaluation is thus crucial to establishing the diagnosis. This review details the clinical presentation, objective evaluation, indicated genetic testing, and recommended management strategies for patients affected by interstitial lung disease associated with TBDs. Our goal is to empower pulmonologists and other healthcare professionals who care for these patients to provide appropriate and personalized care for this population.

Pulmonary, Hepatic, and Allogeneic Hematopoietic Stem Cell Transplantation in Patients with Telomere Biology Disorders

PURPOSE OF THE REVIEW

This study aimed to summarize evidence and provide consensus-based guidelines for management of transplantation in patients with telomere biology disorders (TBD). Specifically, this review focuses on clinical management of lung, liver, and bone marrow transplantation in TBD patients.

RECENT FINDINGS

TBD patients have specific unique biological vulnerabilities such as T cell immunodeficiency, susceptibility to infections, hypersensitivity to chemotherapy and radiation, and cytopenias. Furthermore, multiple organ involvement at diagnosis makes clinical management especially challenging due to higher degree of organ damage, and stress-induced telomeric crisis. Sequential and combined organ transplants, development of novel radiation and alkylator-free conditioning regimen, and use of novel drugs for graft-versus-host disease prophylaxis are some of the recent updates in the field. Multidisciplinary management is essential to optimize transplant outcomes in patients with TBD. In this review, we provide consensus-based transplant management guidelines for clinical management of transplant in TBD.

Noncoding RNA network crosstalk in organ fibrosis

Fibrosis is a process involving excessive accumulation of extracellular matrix components, the severity of which interferes with the function of the organ in question. With the advances in RNA sequencing and in-depth molecular studies, a large number of current studies have pointed out the irreplaceable role of non-coding RNAs (ncRNAs) in the pathophysiological development of organ fibrosis. Here, by summarizing the results of a large number of studies on the interactions between ncRNAs, some studies have found that long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), among others, are able to act as sponges or decoy decoys for microRNAs (miRNAs), act as competing endogenous RNAs (ceRNAs) to regulate the expression of miRNAs, and subsequently act on different mRNA targets, playing a role in the development of fibrosis in a wide variety of organs, including the heart, liver, kidneys, and spleen. parenchymal organs, including heart, liver, kidney, and spleen, play important roles in the development of fibrosis. These findings elucidate the intricate involvement of the lncRNA/circRNA-miRNA-mRNA axis in the pathophysiological processes underpinning organ fibrosis, thereby enhancing our comprehension of the onset and progression of this condition. Furthermore, they introduce novel potential therapeutic targets within the realm of ncRNA-based therapeutics, offering avenues for the development of innovative drugs aimed at mitigating or reversing the effects of organ fibrosis.

Genetic Risk Factors in Idiopathic and Non-Idiopathic Interstitial Lung Disease: Similarities and Differences

Recent advances in genetics and epigenetics have provided critical insights into the pathogenesis of both idiopathic and non-idiopathic interstitial lung diseases (ILDs). Mutations in telomere-related genes and surfactant proteins have been linked to familial pulmonary fibrosis, while variants in MUC5B and TOLLIP increase the risk of ILD, including idiopathic pulmonary fibrosis and rheumatoid arthritis-associated ILD. Epigenetic mechanisms, such as DNA methylation, histone modifications, and non-coding RNAs such as miR-21 and miR-29, regulate fibrotic pathways, influencing disease onset and progression. Although no standardized genetic panel for ILD exists, understanding the interplay of genetic mutations and epigenetic alterations could aid in the development of personalized therapeutic approaches. This review highlights the genetic and epigenetic factors driving ILD, emphasizing their potential for refining diagnosis and treatment.

Clinical predictors of physiologic change after treatment with immunosuppression in hypersensitivity pneumonitis

INTRODUCTION

Treatment of hypersensitivity pneumonitis involves removal of the antigen and may include the use of immunosuppression or antifibrotic therapy. It remains unclear whether antifibrotic or immunosuppressive therapy is more beneficial in fibrotic hypersensitivity pneumonitis or if clinical markers can predict a patient's response to therapy.

METHODS

We evaluated a retrospective cohort in order to determine if certain clinical characteristics can predict physiologic improvement with immunosuppressive treatment in patients with chronic hypersensitivity pneumonitis. Patients with a diagnosis of hypersensitivity pneumonitis with a moderate, high, or definite confidence according to the American Thoracic Society criteria were included in the study.

RESULTS

Overall immunosuppression did not lead to improvement in % predicted forced vital capacity (FVC%) and % predicted diffusion capacity (DLCO%). Patients with fibrotic hypersensitivity pneumonitis and those with familial interstitial lung disease demonstrated a decline in FVC% predicted as well as DLCO% predicted over one year and the use of immunosuppression does not modify that risk. In contrast, patients with extensive ground glass demonstrated improvement in DLCO% predicted but not FVC% predicted over one year with or without the use of immunosuppression.

CONCLUSION

Our study demonstrates that certain radiographic variables trend toward a significant impact on FVC% predicted as well as DLCO% predicted and suggests that antifibrotic therapy may be a better initial choice of therapy in patients with fibrotic hypersensitivity pneumonitis as decline occurred with or without the use of immunosuppression.

Clinical Impact of Telomere Length Testing for Interstitial Lung Disease

BACKGROUND

Shortened telomere length (TL) is a genomic risk factor for fibrotic interstitial lung disease (ILD), but its role in clinical management is unknown.

RESEARCH QUESTION

What is the clinical impact of TL testing on the management of ILD?

STUDY DESIGN AND METHODS

Patients were evaluated in the Columbia University ILD clinic and underwent Clinical Laboratory Improvement Amendments-certified TL testing by flow cytometry and fluorescence in situ hybridization (FlowFISH) as part of clinical treatment. Short TL was defined as below the 10th age-adjusted percentile for either granulocytes or lymphocytes by FlowFISH. Patients were offered genetic counseling and testing if they had short TL or a family history of ILD. FlowFISH TL was compared with research quantitative polymerase chain reaction (qPCR) TL measurement.

RESULTS

A total of 108 patients underwent TL testing, including those with clinical features of short telomere syndrome such as familial pulmonary fibrosis (50%) or extrapulmonary manifestations in the patient (25%) or a relative (41%). The overall prevalence of short TL was 46% and was similar across clinical ILD diagnoses. The number of short telomere clinical features was independently associated with detecting short TL (OR, 2.00; 95% CI, 1.27-3.32). TL testing led to clinical treatment changes for 35 patients (32%), most commonly resulting in reduction or avoidance of immunosuppression. Of the patients who underwent genetic testing (n = 34), a positive or candidate diagnostic finding in telomere-related genes was identified in 10 patients (29%). Inclusion of TL testing below the 1st percentile helped reclassify eight of nine variants of uncertain significance into actionable findings. The quantitative polymerase chain reaction test correlated with FlowFISH, but age-adjusted percentile cutoffs may not be equivalent between the two assays.

INTERPRETATION

Incorporating TL testing in ILD impacted clinical management and led to the discovery of new actionable genetic variants.

Neutrophils and Lymphocytes: Yin and Yang of Lung Fibrosis and Patient Outcome in Diffuse Interstitial Lung Diseases

Objective: Antifibrotics can improve the outcome of patients with idiopathic pulmonary fibrosis (IPF) and other fibrosing interstitial lung diseases (F-ILDs), but predictive biomarkers at diagnosis are needed to guide the use of immunomodulating and antifibrotic therapies. Methods: Flow cytometry quantification of lymphocytes and neutrophils in bronchoalveolar lavage (BAL) of 145 IPFs, 561 non-IPF-ILDs (125 F-ILDs), and 112 BAL controls were retrospectively correlated with the incidence of fibrosis and third-quartile overall survival (Q3-OS). Results: The incidence of IPF was directly proportional (9.6%, 22.2%, and 42.6%, p < 0.001) to BAL neutrophil counts (<5%, 5-15%, and >15%), but inversely proportional (34.1%, 18.6%, and 8.8%, p < 0.001) to BAL lymphocyte counts (<7%, 7-20%, and >20%). Elevated neutrophils (>5%) with low lymphocytes (<7%) were associated with an increasingly higher incidence of IPF (10.0-56.3%, p < 0.001) in patients aged 40 to 80, compared to the rest of patients (13.0-17.1%). Lymphocytes >20% compared to lymphocytes <7% strongly protected patients with neutrophils >15% (59.7% vs. 20.7%, p < 0.001) from IPF. In contrast, the incidence of F-ILD was not clearly related to BAL lymphocyte/neutrophil counts. Although, IPF and F-ILD showed a shorter Q3-OS (1.8 ± 0.3 and 4.6 ± 0.8 years; p < 0.001) than non-fibrotic-ILDs (11.1 ± 1.3 years), lymphocyte and neutrophil counts were associated with a longer and shorter Q3-OS of non-fibrotic-ILDs (p < 0.03) and F-ILDs (p < 0.04), respectively, but not with a Q3-OS of IPF patients (p < 0.708). Corticosteroids in patients with fibrosis showed a shorter Q3-OS than other immunomodulators (2.4 ± 0.3 vs. 4.0 ± 1.8 years, p = 0.011). Conclusions: Accurate counting of BAL lymphocytes and neutrophils by flow cytometry in ILD patients at diagnosis could help guide immunomodulatory and antifibrotic therapies.

Rare variants and survival of patients with idiopathic pulmonary fibrosis

Background

The clinical course of idiopathic pulmonary fibrosis (IPF) is highly variable and unpredictable, with multiple genetic variants influencing IPF outcomes. Notably, rare pathogenic variants in telomere-related genes are associated with poorer clinical outcomes in these patients. Here we assessed whether rare qualifying variants (QVs) in monogenic adult-onset pulmonary fibrosis (PF) genes are associated with IPF survival. Using polygenic risk scores (PRS), we also evaluated the influence of common IPF risk variants in individuals carrying these QVs.

Methods

We identified QVs in telomere and non-telomere genes linked to monogenic PF forms using whole-genome sequences (WGS) from 888 Pulmonary Fibrosis Foundation Patient Registry (PFFPR) individuals. We also derived a PRS for IPF (PRS-IPF) from 19 previously published common sentinel IPF variants. Using regression models, we then examined the mutual relationships of QVs and PRS-IPF and their association with survival. Validation of results was sought in WGS from an independent IPF study (PROFILE, n=472), and results from the two cohorts were meta-analyzed.

Results

Carriers of QVs in monogenic adult-onset PF genes, representing nearly 1 out of 6 IPF patients, were associated with lower PRS-IPF (Odds Ratio [OR]: 1.79; 95% Confidence Interval [CI]: 1.15-2.81; p=0.010) and shorter survival (Hazard Ratio [HR]: 1.53; 95% CI: 1.12-2.10; p=7.3×10-3). Notably, carriers of pathogenic variants at telomere genes showed the strongest association with survival (HR: 1.76; 95% CI: 1.13-2.76; p=0.013). The meta-analysis of the results showed a consistent direction of effect across both cohorts.

Conclusions

We revealed the opposite effects of QVs and PRS-IPF on IPF survival. Thus, a distinct IPF molecular subtype might be defined by QVs in monogenic adult-onset PF genes. Assessing the carrier status for QVs and modelling PRS-IPF promises to further contribute to predicting disease progression among IPF patients.

Inherited Telomere Biology Disorders: Pathophysiology, Clinical Presentation, Diagnostics, and Treatment

Background

Telomeres are the end-capping structures of all eukaryotic chromosomes thereby protecting the genome from damage and degradation. During the aging process, telomeres shorten continuously with each cell division until critically short telomeres prevent further proliferation whereby cells undergo terminal differentiation, senescence, or apoptosis. Premature aging due to critically short telomere length (TL) can also result from pathogenic germline variants in the telomerase complex or related genes that typically counteract replicative telomere shortening in germline and certain somatic cell populations, e.g., hematopoetic stem cells. Inherited diseases that result in altered telomere maintenance are summarized under the term telomere biology disorder (TBD).

Summary

Since TL both reflects but more importantly restricts the replicative capacity of various human tissues, a sufficient telomere reserve is particularly important in cells with high proliferative activity (e.g., hematopoiesis, immune cells, intestinal cells, liver, lung, and skin). Consequently, altered telomere maintenance as observed in TBDs typically results in premature replicative cellular exhaustion in the respective organ systems eventually leading to life-threatening complications such as bone marrow failure (BMF), pulmonary fibrosis, and liver cirrhosis.

Key Messages

The recognition of a potential congenital origin in approximately 10% of adult patients with clinical BMF is of utmost importance for the proper diagnosis, appropriate patient and family counseling, to prevent the use of inefficient treatment and to avoid therapy-related toxicities including appropriate donor selection when patients have to undergo stem cell transplantation from related donors. This review summarizes the current state of knowledge about TBDs with particular focus on the clinical manifestation patterns in children (termed early onset TBD) compared to adults (late-onset TBD) including typical treatment- and disease course-related complications as well as their prognosis and adequate therapy. Thereby, it aims to raise awareness for a disease group that is currently still highly underdiagnosed particularly when it first manifests itself in adulthood.

Rare genetic interstitial lung diseases: a pictorial essay

The main monogenic causes of pulmonary fibrosis in adults are mutations in telomere-related genes. These mutations may be associated with extrapulmonary signs (hepatic, haematological and dermatological) and typically present radiologically as usual interstitial pneumonia or unclassifiable fibrosis. In children, the monogenic causes of pulmonary fibrosis are dominated by mutations in surfactant-related genes. These mutations are not associated with extrapulmonary signs and often manifest radiologically as unclassifiable fibrosis with cysts that can lead to chest wall deformities in adults. This review discusses these mutations, along with most of the monogenic causes of interstitial lung disease, including interferon-related genes, mutations in genes causing cystic lung disease, Hermansky-Pudlak syndrome, pulmonary alveolar proteinosis, lysinuric protein intolerance and lysosomal storage disorders, and their pulmonary and extrapulmonary manifestations.

Rare interstitial lung diseases: a narrative review

Background and Objective

Interstitial lung diseases (ILDs) encompass over 200 entities. Among them, fibrosing lung diseases, have recently generated special interest due to the emerging therapies for their management. However, it is important to deepen our knowledge of other less prevalent ILD, since many of them are associated with a poor prognosis. This narrative review aims to provide a practical and up-to-date description of some poorly recognized ILD. It covers rare idiopathic interstitial pneumonias and their histologic patterns, genetic disorders with interstitial lung involvement (Hermansky-Pudlak syndrome), and ILD associated with benign proliferation of pulmonary lymphoid tissue, namely follicular bronchiolitis and granulomatous-lymphocytic interstitial lung disease.

Methods

Electronic searches of PubMed and Google Scholar using specific keywords were conducted. Articles underwent screening for relevance, covering review articles, meta-analyses, systematic reviews, case series, prospective studies, society guidelines, editorials in peer-reviewed journals; scientific books on the subject. The data included was limited to English and Spanish publications.

Key Content and Findings

Despite the low prevalence of these diseases, the increased recognition of radiological patterns, pathological features, and diagnostic procedures, have permitted their better characterization. This review highlights epidemiology, clinical presentation, diagnosis, natural history, and treatment.

Conclusions

Lesser-studied ILD represent a diagnostic and therapeutic challenge and can be frequently misdiagnosed. Also, due to the lack of randomized controlled trials, there are no well-established therapeutic options. Further studies or registries are needed to improve accurate diagnosis and management.

Syndromic genetic causes of pulmonary fibrosis

PURPOSE OF REVIEW

The identification of extra-pulmonary symptoms plays a crucial role in diagnosing interstitial lung disease (ILD). These symptoms not only indicate autoimmune diseases but also hint at potential genetic disorders, suggesting a potential overlap between genetic and autoimmune origins.

RECENT FINDINGS

Genetic factors contributing to ILD are predominantly associated with telomere (TRG) and surfactant-related genes. While surfactant-related gene mutations typically manifest with pulmonary involvement alone, TRG mutations were initially linked to syndromic forms of pulmonary fibrosis, known as telomeropathies, which may involve hematological and hepatic manifestations with variable penetrance. Recognizing extra-pulmonary signs indicative of telomeropathy should prompt the analysis of TRG mutations, the most common genetic cause of familial pulmonary fibrosis. Additionally, various genetic diseases causing ILD, such as alveolar proteinosis, alveolar hemorrhage, or unclassifiable pulmonary fibrosis, often present as part of syndromes that include hepatic, hematological, or skin disorders.

SUMMARY

This review explores the main genetic conditions identified over the past two decades.

Genetics and Genomics of Pulmonary Fibrosis: Charting the Molecular Landscape and Shaping Precision Medicine

Recent genetic and genomic advancements have elucidated the complex etiology of idiopathic pulmonary fibrosis (IPF) and other progressive fibrotic interstitial lung diseases (ILDs), emphasizing the contribution of heritable factors. This state-of-the-art review synthesizes evidence on significant genetic contributors to pulmonary fibrosis (PF), including rare genetic variants and common SNPs. The MUC5B promoter variant is unusual, a common SNP that markedly elevates the risk of early and established PF. We address the utility of genetic variation in enhancing understanding of disease pathogenesis and clinical phenotypes, improving disease definitions, and informing prognosis and treatment response. Critical research gaps are highlighted, particularly the underrepresentation of non-European ancestries in PF genetic studies and the exploration of PF phenotypes beyond usual interstitial pneumonia/IPF. We discuss the role of telomere length, often critically short in PF, and its link to progression and mortality, underscoring the genetic complexity involving telomere biology genes (TERT, TERC) and others like SFTPC and MUC5B. In addition, we address the potential of gene-by-environment interactions to modulate disease manifestation, advocating for precision medicine in PF. Insights from gene expression profiling studies and multiomic analyses highlight the promise for understanding disease pathogenesis and offer new approaches to clinical care, therapeutic drug development, and biomarker discovery. Finally, we discuss the ethical, legal, and social implications of genomic research and therapies in PF, stressing the need for sound practices and informed clinical genetic discussions. Looking forward, we advocate for comprehensive genetic testing panels and polygenic risk scores to improve the management of PF and related ILDs across diverse populations.

Interstitial Lung Diseases and Non-Small Cell Lung Cancer: Particularities in Pathogenesis and Expression of Driver Mutations

INTRODUCTION

Interstitial lung diseases are a varied group of diseases associated with chronic inflammation and fibrosis. With the emerging and current treatment options, survival rates have vastly improved. Having in mind that the most common type is idiopathic pulmonary fibrosis and that a significant proportion of these patients will develop lung cancer as the disease progresses, prompt diagnosis and personalized treatment of these patients are fundamental.

SCOPE AND METHODS

The scope of this review is to identify and characterize molecular and pathogenetic pathways that can interconnect Interstitial Lung Diseases and lung cancer, especially driver mutations in patients with NSCLC, and to highlight new and emerging treatment options in that view.

RESULTS

Common pathogenetic pathways have been identified in sites of chronic inflammation in patients with interstitial lung diseases and lung cancer. Of note, the expression of driver mutations in EGFR, BRAF, and KRAS G12C in patients with NSCLC with concurrent interstitial lung disease is vastly different compared to those patients with NSCLC without Interstitial Lung Disease.

CONCLUSIONS

NSCLC in patients with Interstitial Lung Disease is a challenging diagnostic and clinical entity, and a personalized medicine approach is fundamental to improving survival and quality of life. Newer anti-fibrotic medications have improved survival in IPF/ILD patients; thus, the incidence of lung cancer is going to vastly increase in the next 5-10 years.

Clinical, radiological and histopathological features of patients with familial pulmonary fibrosis

BACKGROUND

In familial pulmonary fibrosis (FPF) at least two biological relatives are affected. Patients with FPF have diverse clinical features.

RESEARCH QUESTION

We aimed to characterize demographic and clinical features, re-evaluate high-resolution computed tomography (HRCT) scans and histopathology of surgical lung biopsies, assess survival and investigate the suitability of risk prediction models for FPF patients.

STUDY DESIGN

A retrospective cohort study.

METHODS

FPF data (n = 68) were collected from the medical records of Oulu University Hospital (OUH) and Oulaskangas District Hospital between 1 Jan 2000 and 11 Jan 2023. The inclusion criterion was pulmonary fibrosis (PF) (ICD 10-code J84.X) and at least one self-reported relative with PF. Clinical information was gathered from hospital medical records. HRCT scans and histology were re-evaluated.

RESULTS

Thirty-seven (54.4%) of the patients were men, and 31 (45.6%) were women. The mean ages of the women and men were 68.6 and 61.7 years, respectively (p = 0.003). Thirty-seven (54.4%) patients were nonsmokers. The most common radiological patterns were usual interstitial pneumonia (UIP) (51/75.0%), unclassifiable (8/11.8%) and nonspecific interstitial pneumonia (NSIP) (3/4.4%). Pleuroparenchymal fibroelastosis (PPFE) was observed as a single or combined pattern in 13.2% of the patients. According to the 2022 guidelines for idiopathic pulmonary fibrosis (IPF), the patients were categorized as UIP (31/45.6%), probable UIP (20/29.4%), indeterminate for UIP (7/10.3%) or alternative diagnosis (10/14.7%). The histopathological patterns were UIP (7/41.2%), probable UIP (1/5.9%), indeterminate for UIP (8/47.2%) and alternative diagnosis (1/5.9%). Rare genetic variants were found in 9 patients; these included telomerase reverse transcriptase (TERT, n = 6), telomerase RNA component (TERC, n = 2) and regulator of telomere elongation helicase 1 (RTEL1, n = 1). Half of the patients died (n = 29) or underwent lung transplantation (n = 5), with a median survival of 39.9 months. The risk prediction models composite physiology index (CPI), hazard ratio (HR) 1.07 (95.0% CI 1.04-1.10), and gender-age-physiology index (GAP) stage I predicted survival statistically significantly (p<0.001) compared to combined stages II and III.

CONCLUSIONS

This study confirmed the results of earlier studies showing that FPF patients' radiological and histopathological patterns are diverse. Moreover, radiological and histological features revealed unusual patterns and their combinations.

Innate and adaptive effector immune drivers of cytomegalovirus disease in lung transplantation: a double-edged sword

Up to 90% of the global population has been infected with cytomegalovirus (CMV), a herpesvirus that remains latent for the lifetime of the host and drives immune dysregulation. CMV is a critical risk factor for poor outcomes after solid organ transplant, though lung transplant recipients (LTR) carry the highest risk of CMV infection, and CMV-associated comorbidities compared to recipients of other solid organ transplants. Despite potent antivirals, CMV remains a significant driver of chronic lung allograft dysfunction (CLAD), re-transplantation, and death. Moreover, the extended utilization of CMV antiviral prophylaxis is not without adverse effects, often necessitating treatment discontinuation. Thus, there is a critical need to understand the immune response to CMV after lung transplantation. This review identifies key elements of each arm of the CMV immune response and highlights implications for lung allograft tolerance and injury. Specific attention is paid to cellular subsets of adaptive and innate immune cells that are important in the lung during CMV infection and reactivation. The concept of heterologous immune responses is reviewed in depth, including how they form and how they may drive tissue- and allograft-specific immunity. Other important objectives of this review are to detail the emerging role of NK cells in CMV-related outcomes, in addition to discussing perturbations in CMV immune function stemming from pre-existing lung disease. Finally, this review identifies potential mechanisms whereby CMV-directed treatments may alter the cellular immune response within the allograft.

Genetic evidence reveals a causal relationship between rheumatoid arthritis and interstitial lung disease

Background/purpose: Previous epidemiological studies have associated interstitial lung disease (ILD) with rheumatoid arthritis (RA), yet the causality of this relationship remains uncertain. This study aimed to investigate the genetic causal link between ILD and RA. Methods: Genome-wide association study (GWAS) statistics for ILD and RA were collected from public datasets. Relevant single-nucleotide polymorphisms (SNPs) were selected by executing quality control steps from the GWAS summary results. A two-sample bidirectional Mendelian randomization (MR) analysis was performed to assess the causal relationship between the two conditions. The MR analysis primarily used the inverse variance weighting (IVW), weighted median (WM), and MR-Egger regression methods. Sensitivity analyses, including MR-Egger, leave-one-out, and MR Pleiotropy RESidual Sum and Outlier (MR-PRESSO), were conducted to evaluate the heterogeneity and pleiotropy. Replication analyses using Asian datasets were also conducted to enhance the robustness of our findings. Results: In the European population, RA was found to increase the risk of ILD by 9.6% (OR: 1.096, 95% CI: 1.023-1.174, p = 0.009). Conversely, ILD was associated with a 12.8% increased risk of RA (OR: 1.128, 95% CI: 1.013-1.256, p = 0.029). Replication analyses from Asian GWAS further supported these findings, particularly the increased risk of ILD attributable to RA (OR: 1.33, 95% CI: 1.18-1.49, p-value <0.001). Conclusion: Our findings underscore the clinical importance of screening for ILD in RA patients and suggest that effective management of RA could significantly benefit ILD patients. The potential applicability of novel RA treatments to ILD warrants further exploration. Additionally, racial disparities in the manifestation of these diseases should not be overlooked, as they may offer new perspectives for targeted therapies in diverse populations.

Exploration of the potential causative genes for inflammatory bowel disease: Transcriptome-wide association analysis, Mendelian randomization analysis and Bayesian colocalisation

Background

Inflammatory bowel disease (IBD) poses a complex challenge due to its intricate underlying mechanisms, and curative treatments remain elusive. Consequently, there is an urgent need to identify genes causally associated with IBD.

Methods

We extracted blood eQTL data from the GTExv8.ALL.Whole_Blood database, genome-wide association studies (GWAS) summary statistics of IBD from the IEU GWAS database, and performed a three-fold analysis protocol, including transcriptome-wide association analysis, Mendelian randomisation analysis, Bayesian colocalisation, and subsequent potential therapeutic agents identification.

Results

We identified four pathogenic genes, namely CARD9, RTEL1, STMN3 and ARFRP1, that promote the development of IBD, encompassing both ulcerative colitis (UC) and Crohn's disease (CD). Notably, ARFRP1 exhibited the ability to suppress IBD (encompassing UC and CD) development. Regarding drug prediction, cyclophosphamide emerged as a promising novel therapeutic option for IBD, encompassing UC and CD.

Conclusion

We identified several potential genes related to IBD (UC and CD), including CARD9, RTEL1, STMN3 and ARFRP1, warranting further investigation in functional studies to elucidate underlying disease mechanisms. Additionally, clinical studies exploring the potential of cyclophosphamide as a treatment avenue for IBD are warranted.

Familial pulmonary fibrosis: Defining inherited fibrotic lung disease in the era of clinical genetic testing

See related article

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.

Prediction of progressive fibrosing interstitial lung disease in patients with systemic sclerosis: insight from the CRDC cohort study

BACKGROUND

This study aims to establish a reliable prediction model of progressive fibrosing interstitial lung disease (PF-ILD) in patients with systemic sclerosis (SSc)-ILD, to achieve early risk stratification and to help better in preventing disease progression.

METHODS

304 SSc-ILD patients with no less than three pulmonary function tests within 6-24 months were included. We collected data at baseline and compared differences between SSc patients with and without PF-ILD. Least absolute shrinkage and selection operator regularisation regression and multivariable Cox regression were used to construct the prediction model, which were presented as nomogram and forest plot.

RESULTS

Among the 304 patients with SSc-ILD included, 92.1% were women, with a baseline average age of 46.7 years. Based on the 28 variables preselected by comparison between SSc patients without PF-ILD group (n=150) and patients with SSc PF-ILD group (n=154), a 9-variable prediction model was constructed, including age≥50 years (HR 1.8221, p=0.001), hyperlipidemia (HR 4.0516, p<0.001), smoking history (HR 3.8130, p<0.001), diffused cutaneous SSc subtype (HR 1.9753, p<0.001), arthritis (HR 2.0008, p<0.001), shortness of breath (HR 2.0487, p=0.012), decreased serum immunoglobulin A level (HR 2.3900, p=0.002), positive anti-Scl-70 antibody (HR 1.9573, p=0.016) and usage of cyclophosphamide/mycophenolate mofetil (HR 0.4267, p<0.001). The concordance index after enhanced bootstrap resampling adjustment was 0.874, while the optimism-corrected Brier Score was 0.144 in internal validation.

CONCLUSION

This study developed the first prediction model for PF-ILD in patients with SSc-ILD, and internal validation showed favourable accuracy and stability of the model.

Treatment of idiopathic pulmonary fibrosis and progressive pulmonary fibrosis: A position statement from the Thoracic Society of Australia and New Zealand 2023 revision

Idiopathic pulmonary fibrosis (IPF) is a progressive disease leading to significant morbidity and mortality. In 2017 the Thoracic Society of Australia and New Zealand (TSANZ) and Lung Foundation Australia (LFA) published a position statement on the treatment of IPF. Since that time, subsidized anti-fibrotic therapy in the form of pirfenidone and nintedanib is now available in both Australia and New Zealand. More recently, evidence has been published in support of nintedanib for non-IPF progressive pulmonary fibrosis (PPF). Additionally, there have been numerous publications relating to the non-pharmacologic management of IPF and PPF. This 2023 update to the position statement for treatment of IPF summarizes developments since 2017 and reaffirms the importance of a multi-faceted approach to the management of IPF and progressive pulmonary fibrosis.

The many faces of the helicase RTEL1 at telomeres and beyond

Regulator of telomere elongation 1 (RTEL1) is known as a DNA helicase that is important for telomeres and genome integrity. However, the diverse phenotypes of RTEL1 dysfunction, the wide spectrum of symptoms caused by germline RTEL1 mutations, and the association of RTEL1 mutations with cancers suggest that RTEL1 is a complex machine that interacts with DNA, RNA, and proteins, and functions in diverse cellular pathways. We summarize the proposed functions of RTEL1 and discuss their implications for telomere maintenance. Studying RTEL1 is crucial for understanding the complex interplay between telomere maintenance and other nuclear pathways, and how compromising these pathways causes telomere biology diseases, various aging-associated pathologies, and cancer.

Outcomes of lung transplantation in patients with telomere-related forms of progressive fibrosing interstitial lung disease pulmonary fibrosis: A systematic review

Background

Lung transplantation (LTX) is the last life-extending option for patients with progressive fibrosing interstitial lung diseases (fILD). Between 12% and 71% of patients with fILD are patients with underlying telomere-dysfunction (trILD) related to pathogenic telomere-related gene (TRG) variants and/or short telomere length. TrILD patients tend to have earlier disease onset, faster progression, and worse prognosis causing them to be referred for LTX more often. Regarding LTX outcomes in trILD, there are contradictory reports on patient and graft survival, as well as numerous other outcomes. There is no consensus on whether trILD is associated with poorer outcomes after LTX and what considerations regarding candidacy are appropriate.

Methods

We aimed to systematically review LTX outcomes of patients with trILD in comparison to those with non-trILD.

Results

A systematic literature search yielded 13 studies that met the inclusion criteria including 933 LTX, 281 in trILD, and 652 in non-trILD. Despite large heterogeneity in the methodological study quality and reported outcomes among the studies, patient and graft survival after LTX in trILD did not evidently seem inferior to LTX in non-trILD. However, there may be increased risk of specific complications, such as cytopenias, airway complications, and cytomegalovirus-reactivation.

Conclusions

In summary, due to large heterogeneity in methodological study quality and reported outcomes, no firm conclusions can be drawn. Patient and graft survival do not seem unequivocally inferior in patients with trILD deemed eligible for LTX. On top of limited available high-quality data, specific patient selection and post-transplant management strategies may affect the currently acquired results. As such, differences may exist regarding transplant-related outcomes, which could require special attention and consideration. Further high-quality comparative studies on LTX outcomes in trILD are needed to draw final conclusions and provide recommendations regarding patient selection and post-transplantation management.

Thin-Section CT in the Categorization and Management of Pulmonary Fibrosis including Recently Defined Progressive Pulmonary Fibrosis

While idiopathic pulmonary fibrosis (IPF) is the most common type of fibrotic lung disease, there are numerous other causes of pulmonary fibrosis that are often characterized by lung injury and inflammation. Although often gradually progressive and responsive to immune modulation, some cases may progress rapidly with reduced survival rates (similar to IPF) and with imaging features that overlap with IPF, including usual interstitial pneumonia (UIP)-pattern disease characterized by peripheral and basilar predominant reticulation, honeycombing, and traction bronchiectasis or bronchiolectasis. Recently, the term progressive pulmonary fibrosis has been used to describe non-IPF lung disease that over the course of a year demonstrates clinical, physiologic, and/or radiologic progression and may be treated with antifibrotic therapy. As such, appropriate categorization of the patient with fibrosis has implications for therapy and prognosis and may be facilitated by considering the following categories: (a) radiologic UIP pattern and IPF diagnosis, (b) radiologic UIP pattern and non-IPF diagnosis, and (c) radiologic non-UIP pattern and non-IPF diagnosis. By noting increasing fibrosis, the radiologist contributes to the selection of patients in which therapy with antifibrotics can improve survival. As the radiologist may be first to identify developing fibrosis and overall progression, this article reviews imaging features of pulmonary fibrosis and their significance in non-IPF-pattern fibrosis, progressive pulmonary fibrosis, and implications for therapy. Keywords: Idiopathic Pulmonary Fibrosis, Progressive Pulmonary Fibrosis, Thin-Section CT, Usual Interstitial Pneumonia © RSNA, 2024.

Genetic Underpinnings of Pulmonary Fibrosis: An Overview

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive disorder, in which genetic and environmental factors are involved in disease onset. Although, by definition, the disease is considered idiopathic in nature, evidence-based studies have indicated familial cases of pulmonary fibrosis, in which genetic factors contribute to IPF pathogenesis.

METHODS

Both common as well as rare genetic variants are associated with sporadic as well as familial forms of IPF. Although clinical inferences of the genetic association have still not been explored properly, observation-based studies have found a genotypic influence on disease development and outcome.

RESULTS

Based on genetic studies, individuals with a risk of IPF can be easily identified and can be classified more precisely. Identification of genetic variants also helps to develop more effective therapeutic approaches.

CONCLUSION

Further comprehensive research is needed to get a blueprint of IPF pathogenesis. The rapidly evolving field of genetic engineering and molecular biology, along with the bioinformatics approach, will possibly explore a new horizon very soon to achieve this goal.

A new variant in the ZCCHC8 gene: diverse clinical phenotypes and expression in the lung

Introduction

Pulmonary fibrosis is a severe disease which can be familial. A genetic cause can only be found in ∼40% of families. Searching for shared novel genetic variants may aid the discovery of new genetic causes of disease.

Methods

Whole-exome sequencing was performed in 152 unrelated patients with a suspected genetic cause of pulmonary fibrosis from the St Antonius interstitial lung disease biobank. Variants of interest were selected by filtering for novel, potentially deleterious variants that were present in at least three unrelated pulmonary fibrosis patients.

Results

The novel c.586G>A p.(E196K) variant in the ZCCHC8 gene was observed in three unrelated patients: two familial patients and one sporadic patient, who was later genealogically linked to one of the families. The variant was identified in nine additional relatives with pulmonary fibrosis and other telomere-related phenotypes, such as pulmonary arterial venous malformations, emphysema, myelodysplastic syndrome, acute myeloid leukaemia and dyskeratosis congenita. One family showed incomplete segregation, with absence of the variant in one pulmonary fibrosis patient who carried a PARN variant. The majority of ZCCHC8 variant carriers showed short telomeres in blood. ZCCHC8 protein was located in different lung cell types, including alveolar type 2 (AT2) pneumocytes, the culprit cells in pulmonary fibrosis. AT2 cells showed telomere shortening and increased DNA damage, which was comparable to patients with sporadic pulmonary fibrosis and those with pulmonary fibrosis carrying a telomere-related gene variant, respectively.

Discussion

The ZCCHC8 c.586G>A variant confirms the involvement of ZCCHC8 in pulmonary fibrosis and short-telomere syndromes and underlines the importance of including the ZCCHC8 gene in diagnostic gene panels for these diseases.

Diagnosis of interstitial lung diseases: from Averill A. Liebow to artificial intelligence

Histopathologic criteria of usual interstitial pneumonia (UIP)/idiopathic pulmonary fibrosis (IPF) were defined over the years and endorsed by leading organizations decades after Dr. Averill A. Liebow first coined the term UIP in the 1960s as a distinct pathologic pattern of fibrotic interstitial lung disease. Novel technology and recent research on interstitial lung diseases with genetic component shed light on molecular pathogenesis of UIP/IPF. Two antifibrotic agents introduced in the mid-2010s opened a new era of therapeutic approaches to UIP/IPF, albeit contentious issues regarding their efficacy, side effects, and costs. Recently, the concept of progressive pulmonary fibrosis was introduced to acknowledge additional types of progressive fibrosing interstitial lung diseases with the clinical and pathologic phenotypes comparable to those of UIP/IPF. Likewise, some authors have proposed a paradigm shift by considering UIP as a stand-alone diagnostic entity to encompass other fibrosing interstitial lung diseases that manifest a relentless progression as in IPF. These trends signal a pendulum moving toward the tendency of lumping diagnoses, which poses a risk of obscuring potentially important information crucial to both clinical and research purposes. Recent advances in whole slide imaging for digital pathology and artificial intelligence technology could offer an unprecedented opportunity to enhance histopathologic evaluation of interstitial lung diseases. However, current clinical practice trends of moving away from surgical lung biopsies in interstitial lung disease patients may become a limiting factor in this endeavor as it would be difficult to build a large histopathologic database with correlative clinical data required for artificial intelligence models.

Role of Telomere Length in Survival of Patients with Idiopathic Pulmonary Fibrosis and Other Interstitial Lung Diseases

Interstitial lung diseases (ILDs) constitute a group of more than 200 disorders, with idiopathic pulmonary fibrosis (IPF) being one of the most frequent. Telomere length (TL) shortening causes loss of function of the lung parenchyma. However, little is known about its role as a prognostic factor in ILD patients. With the aim of investigating the role of TL and telomerase activity in the prognosis of patients affected by ILDs, we analysed lung tissue samples from 61 patients. We measured relative TL and telomerase activity by conventional procedures. Both clinical and molecular parameters were associated with overall survival by the Kaplan-Meier method. Patients with IPF had poorer prognosis than patients with other ILDs (p = 0.034). When patients were classified according to TL, those with shortened telomeres reported lower overall survival (p = 0.085); differences reached statistical significance after excluding ILD patients who developed cancer (p = 0.021). In a Cox regression analysis, TL behaved as a risk-modifying variable for death associated with rheumatic disease (RD) co-occurrence (p = 0.029). Also, in patients without cancer, ferritin was significantly increased in cases with RD and IPF co-occurrence (p = 0.032). In relation to telomerase activity, no significant differences were detected. In conclusion, TL in lung tissue emerges as a prognostic factor in ILD patients. Specifically, in cases with RD and IPF co-occurrence, TL can be considered as a risk-modifying variable for death.

Clinical manifestations of telomere biology disorders in adults

Telomere biology disorders (TBDs) are a spectrum of inherited bone marrow failure syndromes caused by impaired telomere function due to pathogenic germline variants in genes involved in telomere maintenance. TBDs can affect many organ systems and are often thought of as diseases of childhood. However, TBDs may present in mid- or even late adulthood with features similar to but not always the same as the childhood-onset TBDs. Adult-onset TBDs are often cryptic with isolated pulmonary, liver, or hematologic disease, or cancer, and may lack the classic disease-defining triad of abnormal skin pigmentation, nail dysplasia, and oral leukoplakia. Diagnostics include detection of very short leukocyte telomeres and germline genetic testing. Notably, adult-onset TBDs may show telomeres in the 1st to 10th percentile for age, and some cases may not have an identifiable genetic cause. TBD genetic etiology includes all modes of inheritance, with autosomal dominant the most frequent in adult-onset disease. Variable symptom onset due to incomplete penetrance, variable expressivity, and genetic anticipation add to the diagnostic challenges. Adult-onset TBDs are likely underrecognized, but their correct identification is of utmost importance, since affected patients are faced with numerous clinical complications, including but not limited to an increased risk of malignancies requiring close surveillance for early detection. Currently lung, liver, or hematopoietic cell transplants are the only curative therapeutic approaches but can be complicated by comorbidities, despite improved medical care. This review highlights the challenges of identifying adult-onset TBDs and addresses currently recommended clinical screening measures and therapy options.

Genetic Counseling and Family Screening Recommendations in Patients with Telomere Biology Disorders

PURPOSE OF REVIEW

Telomere biology disorders (TBDs) encompass a spectrum of genetic diseases with a common pathogenesis of defects in telomerase function and telomere maintenance causing extremely short telomere lengths. Here, we review the current literature surrounding genetic testing strategies, cascade testing, reproductive implications, and the role of genetic counseling.

RECENT FINDINGS

The understanding of the genetic causes and clinical symptoms of TBDs continues to expand while genetic testing and telomere length testing are nuanced tools utilized in the diagnosis of this condition. Access to genetic counseling is becoming more abundant and is valuable in supporting patients and their families in making informed decisions. Patient resources and support groups are valuable to this community. Defining which populations should be offered genetic counseling and testing is imperative to provide proper diagnoses and medical management for not only the primary patient, but also their biological relatives.