Familial Pulmonary Fibrosis: Genetic Features and Clinical Implications

Updates in Diagnostic Tools for ILD

Interstitial lung disease (ILD) is a group of diffuse parenchymal disorders, which are diagnosed in many cases by multidisciplinary discussion (MDD). In some cases, diagnosis can be challenging, and the addition of histopathology can increase diagnostic confidence. The tools to obtain a histopathological sample to diagnose ILD are expanding. In this review, we will discuss the various modalities, their sensitivities and specificities, and procedural complication rates. In this review, we conducted a comprehensive review of literature focusing on emerging and established diagnostic tools for ILD. A systematic search of peer-reviewed publications was performed using PubMed with a focus on clinical trials, retrospective and prospective cohort studies, and systematic reviews. The key diagnostic modalities in focus were genomic classifier (GC), transbronchial cryobiopsy (TBLC), surgical lung biopsy (SLB), endobronchial ultrasound cryobiopsy (EBUS-C), genetic testing, and speckled transthoracic echocardiography (STE). Data extracted from these studies focused on diagnostic yield, specificity, sensitivity, and procedural complication rate. Genomic classifier, a gene-based molecular diagnostic tool, has a high specificity for histological usual interstitial pneumonia (UIP). However, in cases of a negative result, it often results in a need for further invasive sampling by TBLC or SLB. TBLC results in a larger histological sample, which can increase diagnostic yield and increase diagnostic confidence at MDD. Recent prospective trials have compared this modality with SLB and found 63-77% interobserver agreement between pathologists. SLB remains the gold standard with diagnostic yields reported to be more than 90%. EBUS-C has shown promising results increasing diagnostic yield in patients with suspected sarcoidosis or lymphoma. All diagnostic modalities have procedural complications with most common being pneumothorax, bleeding and, rarely, death. Advancements in diagnostic tools for interstitial lung disease (ILD) have significantly improved accuracy. Even though surgical lung biopsy remains the gold standard, the alternative modalities are promising and provide a promising yield with a lower procedural risk.

Deciphering the cellular and molecular landscape of pulmonary fibrosis through single-cell sequencing and machine learning

Pulmonary fibrosis is characterized by progressive lung scarring, leading to a decline in lung function and an increase in morbidity and mortality. This study leverages single-cell sequencing and machine learning to unravel the complex cellular and molecular mechanisms underlying pulmonary fibrosis, aiming to improve diagnostic accuracy and uncover potential therapeutic targets. By analyzing lung tissue samples from pulmonary fibrosis patients, we identified distinct cellular phenotypes and gene expression patterns that contribute to the fibrotic process. Notably, our findings revealed a significant enrichment of activated B cells, CD4 T cells, macrophages, and specific fibroblast subpopulations in fibrotic versus normal lung tissue. Machine learning analysis further refined these observations, resulting in the development of a diagnostic model with enhanced precision, based on key gene signatures including TMEM52B, PHACTR1, and BLVRB. Comparative analysis with existing diagnostic models demonstrates the superior accuracy and specificity of our approach. Through In vitro experiments involving the knockdown of PHACTR1, TMEM52B, and BLVRB genes demonstrated that these genes play crucial roles in inhibiting the expression of α-SMA and collagen in lung fibroblasts induced by TGF-β. Additionally, knockout of the PHACTR1 gene reduced inflammation and collagen deposition in a bleomycin-induced mouse model of pulmonary fibrosis in vivo. Additionally, our study highlights novel gene signatures and immune cell profiles associated with pulmonary fibrosis, offering insights into potential therapeutic targets. This research underscores the importance of integrating advanced technologies like single-cell sequencing and machine learning to deepen our understanding of pulmonary fibrosis and pave the way for personalized therapeutic strategies.

Pathology of idiopathic pulmonary fibrosis with particular focus on vascular endothelium and epithelial injury and their therapeutic potential

Idiopathic pulmonary fibrosis (IPF) remains a challenging disease with no drugs available to change the trajectory. It is a condition associated with excessive and highly progressive scarring of the lungs with remodelling and extracellular matrix deposition. It is a highly "destructive" disease of the lungs. The diagnosis of IPF is challenging due to continuous evolution of the disease, which also makes early interventions very difficult. The role of vascular endothelial cells has not been explored in IPF in great detail. We do not know much about their contribution to arterial or vascular remodelling, extracellular matrix changes and contribution to pulmonary hypertension and lung fibrosis in general. Endothelial to mesenchymal transition appears to be central to such changes in IPF. Similarly, for epithelial changes, the process of epithelial to mesenchymal transition seem to be the key both for airway epithelial cells and type-2 pneumocytes. We focus here on endothelial and epithelial cell changes and its contributions to IPF. In this review we revisit the pathology of IPF, mechanistic signalling pathways, clinical definition, update on diagnosis and new advances made in treatment of this disease. We discuss ongoing clinical trials with mode of action. A multidisciplinary collaborative approach is needed to understand this treacherous disease for new therapeutic targets.

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.

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.

The management of Familial Pulmonary Fibrosis in different medical settings: Where does that leave us? An Italian nationwide survey

BACKGROUND AND AIM

Familial Pulmonary Fibrosis (FPF) is an emerging group of interstitial lung diseases (ILDs) caused by mutations mainly involving "telomere-related genes" and "surfactant-related genes". Although, in 2023, European Respiratory Society proposed a statement for FPFs management, these still remain a burden. Our work aimed to evaluate the management and impact of FPF in three Italian different medical settings: University Hospitals (UHs), non-University Hospitals (N-UHs) and outpatient clinics.

METHODS

This survey was created by ILDs Study Group Società Italiana di Pneumologia/ Italian Respiratory Society (SIP-IRS) and diffused via email to all SIP-IRS members. The descriptive statistical analysis was conducted through GraphPad Prism software (version 8.0).  Results: Twenty participants replied to the survey, of which 65% (13/20) worked at UH while the remaining 25% (6/20) and 5% (1/20) worked at N-UH and outpatient clinics, respectively. Centers with, at least, 150 ILD patients visits/year followed a higher number of FPF patients, regardless of University affiliation (p=0.0046). Despite significant discrepancies in genetic testing and availability of counselling were registered, no statistically significant differences in patients' anamnesis assessment were observed between UHs and N-UHs (p=0.4192 and p=0.6525). However, there were relevant differences in the number of FPF patients undergoing genetic assessment in the Centers with Genetics Lab or Unit inside the Hospital (p=0.0253). There was no consensus regarding the impact of FPF diagnosis on lung transplantation and screening of asymptomatic relatives. Similarly, no differences were reported in antifibrotic prescriptions between UHs and N-UHs. Although the typical UIP pattern was the most common radiological pattern observed in FPF patients, there were no differences in the prevalence of histopathological patterns between UH and N-UH.

CONCLUSIONS

Improving pulmonologists' knowledge of the approach, diagnosis and management of FPF is a global medical topic. Scientific societies can provide significant support in raising physicians' awareness of this issue.

Transcriptomic analysis reveals PC4's participation in thermotolerance of scallop Argopecten irradians irradians by regulating myocardial bioelectric activity

Rising ocean temperatures due to global warming pose a significant threat to the bay scallop aquaculture industry. Understanding the mechanisms of thermotolerance in bay scallops is crucial for developing thermotolerant breeds. Our prior research identified Arg0230340.1, part of the positive cofactor 4 (PC4) family, as a key gene associated with the thermotolerance index Arrhenius break temperature (ABT) in bay scallops. Further validation through RNA interference (RNAi) reinforced PC4's role in thermotolerance, offering a solid basis for investigating thermal response mechanisms in these scallops. In this study, we performed a comparative transcriptomic analysis on the temperature-sensitive hearts of bay scallops after siRNA-mediated RNAi targeting Arg0230340.1, to delve into the detailed molecular mechanism of PC4's participation in thermotolerance regulation. The analysis revealed that silencing Arg0230340.1 significantly reduced the expression of mitochondrial tRNA and rRNA, potentially affecting mitochondrial function and the heart's blood supply capacity. Conversely, the up-regulation of genes involved in energy metabolism, RNA polymerase II (RNAPII)-mediated basal transcription, and aminoacyl-tRNA synthesis pathways points to an intrinsic protective response, providing energy and substrates for damage repair and maintenance of essential functions under stress. GO and KEGG enrichment analyses indicated that the up-regulated genes were primarily associated with energy metabolism and spliceosome pathways, likely contributing to myocardial remodeling post-Arg0230340.1 knockdown. Down-regulated genes were enriched in ion channel pathways, particularly those for Na+, K+, and Ca2+ channels, whose dysfunction could disrupt normal myocardial bioelectric activity. The impaired cardiac performance resulting from RNAi targeting Arg0230340.1 reduced the cardiac workload in scallop hearts, thus affecting myocardial oxygen consumption and thermotolerance. We propose a hypothetical mechanism where PC4 down-regulation impairs cardiac bioelectric activity, leading to decreased thermotolerance in bay scallops, providing theoretical guidance for breeding thermotolerant scallop varieties and developing strategies for sustainable aquaculture in the face of long-term environmental changes.

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.

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

See related article

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.

Recent advances in the genetics of idiopathic pulmonary fibrosis

PURPOSE OF REVIEW

Genetics contributes substantially to the susceptibility to idiopathic pulmonary fibrosis (IPF). Genetic studies in sporadic and familial disease have identified several IPF-associated variants, mainly in telomere-related and surfactant protein genes.Here, we review the most recent literature on genetics of IPF and discuss how it may contribute to disease pathogenesis.

RECENT FINDINGS

Recent studies implicate genes involved in telomere maintenance, host defence, cell growth, mammalian target of rapamycin signalling, cell-cell adhesion, regulation of TGF-β signalling and spindle assembly as biological processes involved in the pathogenesis of IPF. Both common and rare genetic variants contribute to the overall risk of IPF; however, while common variants (i.e. polymorphisms) account for most of the heritability of sporadic disease, rare variants (i.e. mutations), mainly in telomere-related genes, are the main contributors to the heritability of familial disease. Genetic factors are likely to also influence disease behaviour and prognosis. Finally, recent data suggest that IPF shares genetic associations - and probably some pathogenetic mechanisms - with other fibrotic lung diseases.

SUMMARY

Common and rare genetic variants are associated with susceptibility and prognosis of IPF. However, many of the reported variants fall in noncoding regions of the genome and their relevance to disease pathobiology remains to be elucidated.

Analysis of influencing factors and a predictive model of small airway dysfunction in adults

BACKGROUND

Small airway dysfunction (SAD) is a widespread but less typical clinical manifestation of respiratory dysfunction. In lung diseases, SAD can have a higher-than-expected impact on lung function. The aim of this study was to explore risk factors for SAD and to establish a predictive model.

METHODS

We included 1233 patients in the pulmonary function room of TangDu Hospital from June 2021 to December 2021. We divided the subjects into a small airway disorder group and a non-small airway disorder group, and all participants completed a questionnaire. We performed univariate and multivariate analyses to identify the risk factors for SAD. Multivariate logistic regression was performed to construct the nomogram. The performance of the nomogram was assessed and validated by the Area under roc curve (AUC), calibration curves, and Decision curve analysis (DCA).

RESULTS

One. The risk factors for small airway disorder were advanced age (OR = 7.772,95% CI 2.284-26.443), female sex (OR = 1.545,95% CI 1.103-2.164), family history of respiratory disease (OR = 1.508,95% CI 1.069-2.126), history of occupational dust exposure (OR = 1.723,95% CI 1.177-2.521), history of smoking (OR = 1.732,95% CI 1.231-2.436), history of pet exposure (OR = 1.499,95% CI 1.065-2.110), exposure to O₃ (OR = 1.008,95% CI 1.003-1.013), chronic bronchitis (OR = 1.947,95% CI 1.376-2.753), emphysema (OR = 2.190,95% CI 1.355-3.539) and asthma (OR = 7.287,95% CI 3.546-14.973). 2. The AUCs of the nomogram were 0.691 in the training set and 0.716 in the validation set. Both nomograms demonstrated favourable clinical consistency. 3.There was a dose‒response relationship between cigarette smoking and SAD; however, quitting smoking did not reduce the risk of SAD.

CONCLUSION

Small airway disorders are associated with age, sex, family history of respiratory disease, occupational dust exposure, smoking history, history of pet exposure, exposure to O₃, chronic bronchitis, emphysema, and asthma. The nomogram based on the above results can effectively used in the preliminary risk prediction.

Challenges in the diagnosis of idiopathic pulmonary fibrosis: the importance of a multidisciplinary approach

INTRODUCTION

The diagnosis of Idiopathic pulmonary fibrosis (IPF) requires the careful exclusion of secondary causes of interstitial lung disease (ILD), and the collaboration among different specialists is considered paramount to establish a diagnosis with high diagnostic confidence. The multidisciplinary discussion (MDD) has assumed an increasing importance over the years in the different phases of the IPF diagnostic work-up.

AREAS COVERED

The role of MDD in the diagnosis and management of IPF will be described. Practical insights will be provided into how and when to perform MDD based on the available scientific evidence. Current limitations and future perspectives will be discussed.

EXPERT OPINION

In the absence of high diagnostic confidence, agreement between different specialists during MDD is recognized as a surrogate indicator of diagnostic accuracy. Often, despite a lengthy evaluation, the diagnosis remains unclassifiable in a significant percentage of patients. MDD therefore appears to be pivotal in attaining an accurate diagnosis of ILDs. The discussion among different specialists can also include other specialists, such as rheumatologists and thoracic surgeons, in addition to the core group of pulmonologists, radiologists, and pathologists. Such discussions can allow greater diagnostic accuracy and have important effects on management, pharmacologic therapies, and prognosis.

The world of rare interstitial lung diseases

The world of rare interstitial lung diseases (ILDs) is diverse and complex. Diagnosis and therapy usually pose challenges. This review describes a selection of rare and ultrarare ILDs including pulmonary alveolar proteinosis, pulmonary alveolar microlithiasis and pleuroparenchymal fibroelastosis. In addition, monogenic ILDs or ILDs in congenital syndromes and various multiple cystic lung diseases will be discussed. All these conditions are part of the scope of the European Reference Network on rare respiratory diseases (ERN-LUNG). Epidemiology, pathogenesis, diagnostics and treatment of each disease are presented.

Idiopathic Pulmonary Fibrosis and Progressive Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF), a common interstitial lung disease (ILD), is a chronic, progressive fibrosing interstitial pneumonia, with an unknown cause. IPF has been linked to several genetic and environmental risk factors. Disease progression is common and associated with worse outcomes. Management often encompasses pharmacotherapy, supportive interventions, addressing comorbidities when present, and treating hypoxia with ambulatory O2. Consideration for antifibrotic therapy and lung transplantation evaluation should occur early. Patients with ILD other than IPF, and who have radiological evidence of pulmonary fibrosis, may have progressive pulmonary fibrosis.

Novel diagnostic techniques in interstitial lung disease

Research into novel diagnostic techniques and targeted therapeutics in interstitial lung disease (ILD) is moving the field toward increased precision and improved patient outcomes. An array of molecular techniques, machine learning approaches and other innovative methods including electronic nose technology and endobronchial optical coherence tomography are promising tools with potential to increase diagnostic accuracy. This review provides a comprehensive overview of the current evidence regarding evolving diagnostic methods in ILD and to consider their future role in routine clinical care.

The Genetic and Epigenetic Footprint in Idiopathic Pulmonary Fibrosis and Familial Pulmonary Fibrosis: A State-of-the-Art Review

Idiopathic pulmonary fibrosis (IPF) is a rare disease of the lung with a largely unknown etiology and a poor prognosis. Intriguingly, forms of familial pulmonary fibrosis (FPF) have long been known and linked to specific genetic mutations. There is little evidence of the possible role of genetics in the etiology of sporadic IPF. We carried out a non-systematic, narrative literature review aimed at describing the main known genetic and epigenetic mechanisms that are involved in the pathogenesis and prognosis of IPF and FPF. In this review, we highlighted the mutations in classical genes associated with FPF, including those encoding for telomerases (TERT, TERC, PARN, RTEL1), which are also found in about 10-20% of cases of sporadic IPF. In addition to the Mendelian forms, mutations in the genes encoding for the surfactant proteins (SFTPC, SFTPA1, SFTPA2, ABCA3) and polymorphisms of genes for the mucin MUC5B and the Toll-interacting protein TOLLIP are other pathways favoring the fibrogenesis that have been thoroughly explored. Moreover, great attention has been paid to the main epigenetic alterations (DNA methylation, histone modification and non-coding RNA gene silencing) that are emerging to play a role in fibrogenesis. Finally, a gaze on the shared mechanisms between cancer and fibrogenesis, and future perspectives on the genetics of pulmonary fibrosis have been analyzed.

Genetics in Idiopathic Pulmonary Fibrosis: A Clinical Perspective

BACKGROUND

Unraveling the genetic background in a significant proportion of patients with both sporadic and familial IPF provided new insights into the pathogenic pathways of pulmonary fibrosis.

AIM

The aim of the present study is to overview the clinical significance of genetics in IPF.

PERSPECTIVE

It is fascinating to realize the so-far underestimated but dynamically increasing impact that genetics has on aspects related to the pathophysiology, accurate and early diagnosis, and treatment and prevention of this devastating disease. Genetics in IPF have contributed as no other in unchaining the disease from the dogma of a "a sporadic entity of the elderly, limited to the lungs" and allowed all scientists, but mostly clinicians, all over the world to consider its many aspects and "faces" in all age groups, including its co-existence with several extra pulmonary conditions from cutaneous albinism to bone-marrow and liver failure.

CONCLUSION

By providing additional evidence for unsuspected characteristics such as immunodeficiency, impaired mucus, and surfactant and telomere maintenance that very often co-exist through the interaction of common and rare genetic variants in the same patient, genetics have created a generous and pluralistic yet unifying platform that could lead to the understanding of the injurious and pro-fibrotic effects of many seemingly unrelated extrinsic and intrinsic offending factors. The same platform constantly instructs us about our limitations as well as about the heritability, the knowledge and the wisdom that is still missing.

Idiopathic Pulmonary Fibrosis and Telomeres

Idiopathic pulmonary fibrosis is an interstitial lung disease of unknown etiology with a highly compromised prognosis and a significant mortality rate within a few years of diagnosis. Despite being idiopathic, it has been shown that telomeric shortening could play an important role in its etiopathogenesis. Mutations in telomere-related genes have been identified, but they are not always present despite telomere shortening. On the other hand, this telomeric shortening has been linked to a worse prognosis of the disease independently of other clinical factors, implying it may serve as a biomarker.

Diagnosing interstitial lung disease by multidisciplinary discussion: A review

The multidisciplinary meeting (MDM) has been endorsed in current international consensus guidelines as the gold standard method for diagnosis of interstitial lung disease (ILD). In the absence of an accurate and reliable diagnostic test, the agreement between multidisciplinary meetings has been used as a surrogate marker for diagnostic accuracy. Although the ILD MDM has been shown to improve inter-clinician agreement on ILD diagnosis, result in a change in diagnosis in a significant proportion of patients and reduce unclassifiable diagnoses, the ideal form for an ILD MDM remains unclear, with constitution and processes of ILD MDMs varying greatly around the world. It is likely that this variation of practice contributes to the lack of agreement seen between MDMs, as well as suboptimal diagnostic accuracy. A recent Delphi study has confirmed the essential components required for the operation of an ILD MDM. The ILD MDM is a changing entity, as it incorporates new diagnostic tests and genetic markers, while also adapting in its form in response to the obstacles of the COVID-19 pandemic. The aim of this review was to evaluate the current evidence regarding ILD MDM and their role in the diagnosis of ILD, the practice of ILD MDM around the world, approaches to ILD MDM standardization and future directions to improve diagnostic accuracy in ILD.

Idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis is defined as a chronic progressive fibrosing interstitial pneumonia of unknown etiology. There are intrinsic and extrinsic risk factors that could favor the development of the disease in individuals with a genetic predisposition. The diagnosis is made by characteristic radiological and/or histological findings on high-resolution computed tomography and lung biopsy, respectively, in the absence of a specific identifiable cause. The median survival of the disease for patients without treatment is 3-5years from the onset of symptoms, although its natural history is variable and unpredictable. Currently, there are two antifibrotic drugs that reduce disease progression. The multidisciplinary approach will consider the nutritional and emotional status, physical conditioning, and treatment of comorbidities, as well as lung transplantation and palliative care in advanced stages. The following article reviews the fundamental aspects for the diagnosis and treatment of idiopathic pulmonary fibrosis.