Unclassifiable Interstitial Lung Disease Research Articles

Relative incidence of interstitial lung diseases in Brazil.

To assess the relative frequency of incident cases of interstitial lung diseases (ILDs) in Brazil. This was a retrospective survey of new cases of ILD in six referral centers between January of 2013 and January of 2020. The diagnosis of ILD followed the criteria suggested by international bodies or was made through multidisciplinary discussion (MDD). The condition was characterized as unclassifiable ILD when there was no specific final diagnosis following MDD or when there was disagreement between clinical, radiological, or histological data. The sample comprised 1,406 patients (mean age = 61 ± 14 years), and 764 (54%) were female. Of the 747 cases exposed to hypersensitivity pneumonitis (HP)-related antigens, 327 (44%) had a final diagnosis of HP. A family history of ILD was reported in 8% of cases. HRCT findings were indicative of fibrosis in 74% of cases, including honeycombing, in 21%. Relevant autoantibodies were detected in 33% of cases. Transbronchial biopsy was performed in 23% of patients, and surgical lung biopsy, in 17%. The final diagnoses were: connective tissue disease-associated ILD (in 27%), HP (in 23%), idiopathic pulmonary fibrosis (in 14%), unclassifiable ILD (in 10%), and sarcoidosis (in 6%). Diagnoses varied significantly among centers (c2 = 312.4; p < 0.001). Our findings show that connective tissue disease-associated ILD is the most common ILD in Brazil, followed by HP. These results highlight the need for close collaboration between pulmonologists and rheumatologists, the importance of detailed questioning of patients in regard with potential exposure to antigens, and the need for public health campaigns to stress the importance of avoiding such exposure.

Low bleeding rates following transbronchial lung cryobiopsy in unclassifiable interstitial lung disease.

Bronchoscopic transbronchial lung cryobiopsy (TBLC) is a guideline-endorsed alternative to surgical lung biopsy for tissue diagnosis in unclassifiable interstitial lung disease (ILD). The reported incidence of post-procedural bleeding has varied widely. We aimed to characterize the incidence, severity and risk factors for clinically significant bleeding following TBLC using an expert-consensus airway bleeding scale, in addition to other complications and diagnostic yield. A retrospective cohort study of consecutive adult outpatients with unclassifiable ILD who underwent TBLC following multidisciplinary discussion at a single centre in the UK between July 2016 and December 2021. TBLC was performed under general anaesthesia with fluoroscopic guidance and a prophylactic endobronchial balloon. One hundred twenty-six patients underwent TBLC (68.3% male; mean age 62.7 years; FVC 86.2%; DLCO 54.5%). Significant bleeding requiring balloon blocker reinflation for >20 min, admission to ICU, packed red blood cell transfusion, bronchial artery embolization, resuscitation or procedural abandonment, occurred in 10 cases (7.9%). Significant bleeding was associated with traction bronchiectasis on HRCT (OR 7.1, CI 1.1-59.1, p = 0.042), a TBLC histological pattern of UIP (OR 4.0, CI 1.1-14, p = 0.046) and the presence of medium-large vessels on histology (OR 37.3, CI 6.5-212, p < 0.001). BMI ≥30 (p = 0.017) and traction bronchiectasis on HRCT (p = 0.025) were significant multivariate predictors of longer total bleeding time (p = 0.017). Pneumothorax occurred in nine cases (7.1%) and the 30-day mortality was 0%. Diagnostic yield was 80.6%. TBLC has an acceptable safety profile in experienced hands. Radiological traction bronchiectasis and obesity increase the risk of significant bleeding following TBLC.

ILD-GAP combined with the monocyte ratio could be a better prognostic prediction model than ILD-GAP in patients with interstitial lung diseases

BackgroundThe ILD-GAP scoring system is known to be useful in predicting prognosis in patients with interstitial lung disease (ILD). An elevated monocyte count was associated with increased risks of IPF poor prognosis. We examined whether the ILD-GAP scoring system combined with the monocyte ratio (ILD-GAPM) is superior to the conventional ILD-GAP model in predicting ILD prognosis.MethodsIn patients with ILD treated between April 2013 and April 2017, we were retrospectively assessed the relationships between baseline clinical parameters, including age, sex, Charlson Comorbidity Index score (CCIS), ILD diagnosis, blood biomarkers, pulmonary function test results, and disease outcomes. In ILD patients were included idiopathic pulmonary fibrosis (IPF), idiopathic nonspecific interstitial pneumonia (iNSIP), collagen vascular disease-related interstitial pneumonia (CVD-IP), chronic hypersensitivity pneumonitis (CHP), and unclassifiable ILD (UC-ILD). We also assessed the ability to predict prognosis was compared between the ILD-GAP and ILD-GAPM models.ResultsA total of 179 patients (mean age, 73 years) were assessed. All of them were taken pulmonary function test, including percentage predicted diffusion capacity for carbon monoxide. ILD patients included 56 IPF cases, 112 iNSIP and CVD-IP cases, 6 CHP cases and 5 UC-ILD cases. ILD-GAPM provided a greater area under the receiver-operating characteristic curve (0.747) than ILD-GAP (0.710) for predicting 3-year ILD-related events. Furthermore, the log-rank test showed that the Kaplan-Meier curves in ILD-GAPM were significantly different by stage (P = 0.015), but not by stage in ILD-GAP (P = 0.074).ConclusionsThe ILD-GAPM model may be a more accurate predictor of prognosis for ILD patients than the ILD-GAP model.

Hospitalisation patterns in interstitial lung diseases: data from the EXCITING-ILD registry

BackgroundInterstitial lung diseases (ILD) comprise a heterogeneous group of mainly chronic lung diseases with more than 200 entities and relevant differences in disease course and prognosis. Little data is available on hospitalisation patterns in ILD.MethodsThe EXCITING-ILD (Exploring Clinical and Epidemiological Characteristics of Interstitial Lung Diseases) registry was analysed for hospitalisations. Reasons for hospitalisation were classified as all cause, ILD-related and respiratory hospitalisations, and patients were analysed for frequency of hospitalisations, time to first non-elective hospitalisation, mortality and progression-free survival. Additionally, the risk for hospitalisation according to GAP index and ILD subtype was calculated by Cox proportional-hazard models as well as influencing factors on prediction of hospitalisation by logistic regression with forward selection.ResultsIn total, 601 patients were included. 1210 hospitalisations were recorded during the 6 months prior to registry inclusion until the last study visit. 800 (66.1%) were ILD-related, 59.3% of admissions were registered in the first year after inclusion. Mortality was associated with all cause, ILD-related and respiratory-related hospitalisation. Risk factors for hospitalisation were advanced disease (GAP Index stages II and III) and CTD (connective tissue disease)-ILDs. All cause hospitalisations were associated with pulmonary hypertension (OR 2.53, p = 0.005). ILD-related hospitalisations were associated with unclassifiable ILD and concomitant emphysema (OR = 2.133, p = 0.001) as well as with other granulomatous ILDs and a positive smoking status (OR = 3.082, p = 0.005).ConclusionOur results represent a crucial contribution in understanding predisposing factors for hospitalisation in ILD and its major impact on mortality. Further studies to characterize the most vulnerable patient group as well as approaches to prevent hospitalisations are warranted.

Real-world experience of nintedanib for progressive fibrosing interstitial lung disease in the UK.

Nintedanib slows progression of lung function decline in patients with progressive fibrosing (PF) interstitial lung disease (ILD) and was recommended for this indication within the United Kingdom (UK) National Health Service in Scotland in June 2021 and in England, Wales and Northern Ireland in November 2021. To date, there has been no national evaluation of the use of nintedanib for PF-ILD in a real-world setting. 26 UK centres were invited to take part in a national service evaluation between 17 November 2021 and 30 September 2022. Summary data regarding underlying diagnosis, pulmonary function tests, diagnostic criteria, radiological appearance, concurrent immunosuppressive therapy and drug tolerability were collected via electronic survey. 24 UK prescribing centres responded to the service evaluation invitation. Between 17 November 2021 and 30 September 2022, 1120 patients received a multidisciplinary team recommendation to commence nintedanib for PF-ILD. The most common underlying diagnoses were hypersensitivity pneumonitis (298 out of 1120, 26.6%), connective tissue disease associated ILD (197 out of 1120, 17.6%), rheumatoid arthritis associated ILD (180 out of 1120, 16.0%), idiopathic nonspecific interstitial pneumonia (125 out of 1120, 11.1%) and unclassifiable ILD (100 out of 1120, 8.9%). Of these, 54.4% (609 out of 1120) were receiving concomitant corticosteroids, 355 (31.7%) out of 1120 were receiving concomitant mycophenolate mofetil and 340 (30.3%) out of 1120 were receiving another immunosuppressive/modulatory therapy. Radiological progression of ILD combined with worsening respiratory symptoms was the most common reason for the diagnosis of PF-ILD. We have demonstrated the use of nintedanib for the treatment of PF-ILD across a broad range of underlying conditions. Nintedanib is frequently co-prescribed alongside immunosuppressive and immunomodulatory therapy. The use of nintedanib for the treatment of PF-ILD has demonstrated acceptable tolerability in a real-world setting.

Clinical and Functional Characteristics of Interstitial Lung Disease in Algeria: A Single-Center Prospective Study

Introduction: There are a limited number of epidemiological studies describing the global burden of chronic diffuse interstitial lung diseases (ILD) and their subtypes’ heterogeneity worldwide. Our main is to characterize new-onset ILDs in Algeria and compare our results with data from other populations. Materials and Methods: Newly diagnosed ILDs were prospectively collected in a single-center observational cohort study including all patients diagnosed as ILDs in the pulmonology, phthisiology, and allergology departments between 2015 and 2019. Detailed anamnestic and clinical data were collected at the time of diagnosis. The results of high-resolution computed tomography (HRCT), serological tests, biology data, and respiratory functional exploration were systematically performed and collected. Results: A total of 455 cases were included. The mean age was 59.4 ± 13.2 years. There was a slight predominance of females (300; 65.9%). The most common disease was ILD secondary to connective tissue disease (CTD) or ILD-CTD (48.1%), followed by idiopathic interstitial pneumonias (IIPs) (23.5%), sarcoidosis (16.9%), interstitial pneumonia with autoimmune features (IPAF) (12.1%), and hypersensitivity pneumonitis (HP) (2.4%). Idiopathic pulmonary fibrosis (IPF) was present in 8.6% and unclassifiable ILD in 4.6% of the total ILD cases. Conclusions: ILD-CTD, IIP, and sarcoidosis were the most frequently observed ILDs in this Algerian population. Similarities and many differences were found compared to previous data from other countries.

Characteristics and risk factors of interstitial pneumonia with autoimmune features

BackgroundInterstitial pneumonia with autoimmune features (IPAF) has features of connective tissue disease-associated interstitial lung disease (CTD-ILD), but without meeting criteria for a specific CTD. We compared baseline characteristics, survival, and response to treatment of IPAF to both CTD-ILD and unclassifiable ILD. MethodsMeasurements were extracted from a prospective registry. Baseline features and survival were compared in IPAF against both CTD-ILD and unclassifiable ILD. Linear trajectory of lung function decline (%-predicted forced vital capacity [FVC%] and diffusion capacity of the lung for carbon monoxide [DLCO%]) before and after initiation of mycophenolate or azathioprine were compared in IPAF against both CTD-ILD and unclassifiable ILD using linear mixed models. ResultsCompared to CTD-ILD (n = 1240), patients with IPAF (n = 128) were older, more frequently male, and had greater smoking history. Compared to unclassifiable ILD (n = 665), patients with IPAF were younger, more frequently female, and had worse baseline lung function. IPAF had higher mortality compared to CTD-ILD and similar risk of mortality compared to unclassifiable ILD. Mycophenolate initiation was associated with stabilization of FVC% and DLCO% in all ILD subtypes except for FVC% in patients with IPAF, and azathioprine initiation with stabilization of FVC% and DLCO% in all ILD subtypes except for FVC% decline in IPAF and DLCO% decline in CTD-ILD. ConclusionPatients with IPAF had worse survival compared to those with CTD-ILD and similar mortality to unclassifiable ILD, with treatment being associated with stabilization in lung function in all three ILDs. It is uncertain whether IPAF should be considered a distinct ILD diagnostic subgroup.

Chinese expert consensus on multidisciplinary discussion of interstitial lung disease

Interstitial lung disease (ILD) is a group of heterogeneous diseases characterized by interstitial lung inflammation and fibrosis. Its causes are diverse, symptoms can be non-specific, and the associated imaging and pathologic patterns can vary widely. The diagnosis and management of these conditions often require input from multiple medical disciplines. Over the past few decades, the importance of multidisciplinary discussion (MDD) in the management of ILD has grown internationally, and MDD has gradually become a part of the gold standard for ILD diagnosis and an essential reference for disease management. Recognizing this, the Chinese Medical Association-Chinese Thoracic Society and the Chinese Association of Chest Physicians have collaborated with experts to standardize the ILD-MDD process in China.Key recommendations:1. Formation of teams: ILD centers should establish multidisciplinary teams (MDT) and integrate MDD into the ILD patient care process. (strong recommendation)2. Patient preparation: Prior to ILD-MDD, patients should undergo as thorough an ILD assessment as possible, including medical history, diagnostic tests, and functional evaluations. (strong recommendation)3. MDD frequency & logistics:(1) The frequency, duration and number of cases to be discussed in ILD-MDD should be based on the clinical needs of each center, but should be held at least monthly. (2) Consistent timing and location of ILD-MDD is recommended to improve attendance. (medium recommendation)4. Team composition: The MDT should include experts from a range of disciplines with experience of ILD. These should include specialists in Pulmonary and Critical Care Medicine, Radiology, and Pathology. Where appropriate, experts in Rheumatology, Hematology, Thoracic Surgery, and Respiratory Care and Rehabilitation should also be involved. (strong recommendation)5. Case presentation & goals:(1) The physician in charge should present clinical information, preferably using standardized slides. Real-time imaging and pathology data are encouraged. (2) The primary goals of ILD-MDD discussions should be disease diagnosis and management. (strong recommendation)6. Operational leadership: Assign a dedicated professional to manage the ILD-MDD operations and maintain the information discussed. (strong recommendation)7. Specific conditions:(1) Suspected idiopathic pulmonary fibrosis should be diagnosed by a standardized MDD process. (2) Suspected idiopathic interstitial pneumonia (IIP) should be classified by MDD. If IIP is indicated by imaging or pathology, prioritize identifying potential underlying causes such as connective tissue diseases (CTDs), certain medications, or aspiration.(3) Suspected hypersensitivity pneumonitis should also be diagnosed by MDD. (4) If an ILD patient shows signs suggestive of CTDs, the diagnosis should be made by ILD-MDD with the involvement of rheumatologists. (strong recommendation)8. Unclassifiable ILD: For ILD patients who cannot be clearly classified, create a tailored management plan based on the patient's specific disease features. (strong recommendation)9. Progressive pulmonary fibrosis: Use ILD-MDD to determine whether an ILD patient meets the criteria for progressive pulmonary fibrosis and to discuss a personalized care plan. (strong recommendation).

Unclassifiable interstitial lung disease and autoimmunity: Towards IPAF in children?

Interstitial pneumonia with autoimmune features (IPAF) has been defined for adults with interstitial lung disease (ILD) and autoimmunity who do not meet the criteria for a specific connective tissue disease (CTD). We aimed to determine whether IPAF criteria could apply to children. We retrospectively studied patients with ILD and autoimmunity followed at Necker Hospital between 2008 and 2019. Children were classified according to specific CTD and IPAF criteria. The epidemiology and course of the disease were studied according to the final diagnosis. Among 27 patients, 6 fulfilled the criteria for IPAF and represented 4.5% of all patients with ILD during the study period. Other diagnoses included juvenile dermatomyositis (30%), overlap syndromes (19%), systemic lupus erythematosus (15%), systemic sclerosis (7%), mixed CTD (4%), and rheumatoid arthritis (4%). IPAF patients were more frequently boys versus CTD-ILD patients (67% vs. 14%, p = .02). Two patients had severe respiratory distress that led to death for one of them. The course was favorable for the others, with a good response to steroids. The course tended to be more favorable for IPAF patients than for those with CTD-ILD (0% lung fibrosis in the IPAF group vs. 43% in the CTD-ILD group, p = .07). We confirmed the existence of IPAF in children. Its prevalence was lower than in adults but comparable to that found for other pediatric series. Boys were more highly represented than in CTD-ILD. The course was favorable for most cases. Larger and more prospective studies are needed to confirm these results.

Telomere length and immunosuppression in non-idiopathic pulmonary fibrosis interstitial lung disease.

Studies suggest a harmful pharmacogenomic interaction exists between short leukocyte telomere length (LTL) and immunosuppressants in idiopathic pulmonary fibrosis (IPF). It remains unknown if a similar interaction exists in non-IPF interstitial lung disease (ILD). A retrospective, multicentre cohort analysis was performed in fibrotic hypersensitivity pneumonitis (fHP), unclassifiable ILD (uILD) and connective tissue disease (CTD)-ILD patients from five centres. LTL was measured by quantitative PCR for discovery and replication cohorts and expressed as age-adjusted percentiles of normal. Inverse probability of treatment weights based on propensity scores were used to assess the association between mycophenolate or azathioprine exposure and age-adjusted LTL on 2-year transplant-free survival using weighted Cox proportional hazards regression incorporating time-dependent immunosuppressant exposure. The discovery and replication cohorts included 613 and 325 patients, respectively. In total, 40% of patients were exposed to immunosuppression and 22% had LTL <10th percentile of normal. fHP and uILD patients with LTL <10th percentile experienced reduced survival when exposed to either mycophenolate or azathioprine in the discovery cohort (mortality hazard ratio (HR) 4.97, 95% CI 2.26-10.92; p<0.001) and replication cohort (mortality HR 4.90, 95% CI 1.74-13.77; p=0.003). Immunosuppressant exposure was not associated with differential survival in patients with LTL ≥10th percentile. There was a significant interaction between LTL <10th percentile and immunosuppressant exposure (discovery pinteraction=0.013; replication pinteraction=0.011). Low event rate and prevalence of LTL <10th percentile precluded subgroup analyses for CTD-ILD. Similar to IPF, fHP and uILD patients with age-adjusted LTL <10th percentile may experience reduced survival when exposed to immunosuppression.

Integration and Application of Radiologic Patterns From Clinical Practice Guidelines on Idiopathic Pulmonary Fibrosis and Fibrotic Hypersensitivity Pneumonitis

Clinical practice guidelines separately describe radiologic patterns of usual interstitial pneumonia (UIP) and fibrotic hypersensitivity pneumonitis (fHP), without direction on whether or how to apply these approaches concurrently within a single patient. How can we integrate guideline-defined radiologic patterns to diagnose interstitial lung disease (ILD) and what are the pitfalls associated with described patterns that require reassessment in future guidelines? Patients from the Canadian Registry for Pulmonary Fibrosis underwent detailed reevaluation in standardized multidisciplinary discussion. CT scan features were quantified by chest radiologists masked to clinical data, and guideline-defined patterns were assigned. Clinical data then were provided to the radiologist and an ILD clinician, who jointly determined the leading diagnosis. Clinical-radiologic diagnosis in 1,593 patients was idiopathic pulmonary fibrosis (IPF) in 26%, fHP in 12%, connective tissue disease-associated ILD (CTD-ILD) in 34%, idiopathic pneumonia with autoimmune features in 12%, and unclassifiable ILD in 10%. Typical and probable UIP patterns corresponded to a diagnosis of IPF in 66%and 57%of patients, respectively. Typical fHP pattern corresponded to an fHP clinical diagnosis in 65%of patients, whereas compatible fHP was nonspecific and associated with CTD-ILD or IPAF in 48%of patients. No pattern ruled out CTD-ILD. Gas trapping affecting > 5%of lung parenchyma on expiratory imaging was an important feature broadly separating compatible and typical fHP from other patterns (sensitivity, 0.77; specificity, 0.91). An integrated approach to guideline-defined UIP and fHP patterns is feasible and supports > 5%gas trapping as an important branch point. Typical or probable UIP and typical fHP patterns have moderate predictive values for a corresponding diagnosis of IPF and fHP, although occasionally confounded by CTD-ILD; compatible fHP is nonspecific.

Role of Transbronchial Lung Cryobiopsy in the Diagnosis of Interstitial Lung Disease: A Meta-analysis of 68 Studies and 6300 Patients.

Diagnosis of interstitial lung disease (ILD) is based on multidisciplinary team discussion (MDD) with the incorporation of clinical, radiographical, and histopathologic information if available. We aim to evaluate the diagnostic yield and safety outcomes of transbronchial lung cryobiopsy (TBLC) in the diagnosis of ILD. We conducted a meta-analysis by comprehensive literature search to include all studies that evaluated the diagnostic yields and/or adverse events with TBLC in patients with ILD. We calculated the pooled event rates and their 95% confidence intervals (CIs) for the diagnostic yield by MDD, histopathologic diagnostic yield, and various clinical adverse events. We included 68 articles (44 full texts and 24 abstracts) totaling 6386 patients with a mean age of 60.7±14.1 years and 56% men. The overall diagnostic yield of TBLC to achieve a definite or high-confidence diagnosis based on MDD was 82.3% (95% CI: 78.9%-85.2%) and histopathologic diagnosis of 72.5% (95% CI: 67.7%-76.9%). The overall rate of pneumothorax was 9.6% (95% CI: 7.9%-11%), while the rate of pneumothorax requiring drainage by a thoracostomy tube was 5.3% (95% CI: 4.1%-6.9%). The rate of moderate bleeding was 11.7% (95% CI: 9.1%-14.9%), while the rate of severe bleeding was 1.9% (95% CI: 1.4%-2.6%). The risk of mortality attributed to the procedure was 0.9% (95% CI: 0.7%-1.3%). Among patients with undiagnosed or unclassified ILD requiring tissue biopsy for diagnosis, transbronchial cryobiopsy represents a reliable alternative to surgical lung biopsy with decreased incidence of various clinical adverse events.

ILD-GAP Combined with the Charlson Comorbidity Index Score (ILD-GAPC) as a Prognostic Prediction Model in Patients with Interstitial Lung Disease.

The ILD-GAP scoring system has been widely used to predict the prognosis of patients with interstitial lung disease (ILD). The ability of the ILD-GAP scoring system combined with the Charlson Comorbidity Index score (CCIS) (ILD-GAPC) to predict ILD prognosis was investigated. In ILD patients, including idiopathic pulmonary fibrosis (IPF), idiopathic nonspecific interstitial pneumonia (iNSIP), collagen vascular disease-related interstitial pneumonia (CVD-IP), chronic hypersensitivity pneumonitis (CHP), and unclassifiable ILD (UC-ILD), treated between April 2013 and April 2017, the relationships between baseline clinical parameters, including age, sex, CCIS, ILD diagnosis, pulmonary function test results, and disease outcomes, were retrospectively assessed, and the ability to predict prognosis was compared between the ILD-GAP and ILD-GAPC models, respectively. A total of 185 patients (mean age, 71.9 years), all of whom underwent pulmonary function testing, including percentage predicted diffusion capacity for carbon monoxide, were assessed. ILD diagnosis consisted of IPF in 57 cases, iNSIP and CVD-IP in 117 cases, CHP in 6 cases, and UC-ILD in 5 cases. The ILD-GAPC provided a greater area under the receiver operating characteristic curve (0.758) for predicting 3-year ILD-related events than the ILD-GAP (0.721). In addition, log-rank tests showed that the Kaplan-Meier curves differed significantly among low, middle, and high ILD-GAPC scores (P < 0.001), unlike ILD-GAP scores (P = 0.083). The ILD-GAPC model could provide more accurate information for predicting prognosis in patients with ILD than the ILD-GAP model.

Patterns of Interstitial Lung Disease and Prognosis in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

Background: Interstitial lung disease (ILD) is a common pulmonary manifestation of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Objectives: We aimed to clarify the clinical predictors of mortality in a cohort of patients with AAV-related ILD (AAV-ILD). Method: We retrospectively identified AAV-ILD patients seen at Peking University First Hospital from January 2010 to June 2020 and manually screened for study inclusion. Baseline computed tomography (CT) images were further classified as nonspecific interstitial pneumonia (NSIP), usual interstitial pneumonia (UIP), organizing pneumonia (OP), and unclassified ILD. Disease characteristics and other pulmonary findings including pulmonary function test and bronchoalveolar lavage (BAL) were also evaluated. Multivariable Cox regression analysis was performed to identify clinical predictors of mortality. Results: The cohort included 204 patients with AAV-ILD, 152 had UIP on CT (AAV-UIP), 39 had NSIP on CT (AAV-NSIP), 3 had OP, and 10 had unclassified ILD. Microscopic polyangiitis was more prevalent in patients with UIP, while granulomatosis with polyangiitis was more common in the NSIP and OP groups, and eosinophilic granulomatosis with polyangiitis was more frequent in patients with unclassified ILD. ILD diagnosis before AAV was more common in patients with either UIP or NSIP patterns. During the median follow-up of 40 months, 44 (21.6%) patients died. One- and 5-year overall survival rates were 88.2% (95% CI, 83.7–92.7%) and 81.0% (95% CI, 74.9–87.1%) for the entire cohort. Patients with UIP patterns had the worst prognosis, while those with NSIP patterns had the best long-term outcome. Specifically, patients with UIP patterns had an approximately 5-fold risk of death compared to those with NSIP. After controlling for potential confounding factors, we observed that each 10% increase in the BAL fluid neutrophil percentage was associated with nearly a 20% increased risk of death (HR 1.195, 95% CI 1.018–1.404). Conclusions: Clinical characteristics and survival differ between subgroups defined by CT patterns. BAL fluid neutrophilia is an independent predictor of mortality among AAV-ILD patients, and therefore, the clinical utility of BAL at the time of AAV diagnosis should be considered.

Immunomodulatory treatment in unclassifiable interstitial lung disease: A retrospective study of treatment response.

The optimal management of unclassifiable Interstitial lung disease (ILD) remains a challenge. The aim of this study was to describe pulmonary function trajectories for patients treated with immunomodulatory therapy and for untreated patients. Clinical information and treatment data were obtained retrospectively at two ILD centres. Pulmonary function data were analysed using (1) mixed effects linear regression models with and without clinical covariates and (2) propensity score matching using gender, age, physiology (GAP) stage, smoking and presence of ground glass opacities. Sixty-five percent of the 249 patients included received corticosteroids and/or other immunomodulators. Treated patients had lower forced vital capacity (FVC) (72% vs. 83% predicted) and diffusing capacity for carbon monoxide (DLco) (44% vs. 60% predicted). In mixed effects linear regression, the adjusted change in FVC was -0.22%, [-0.34; -0.11], and -0.15% [-0.28;-0.012] for DLco. The difference in pulmonary function decline between treated and untreated patients was insignificant, -0.082% per month, [-0.28; 0.11], p= 0.10 for FVC and -0.14% per month, [-0.36; 0.079], p= 0.15, for DLco. In propensity score matched analysis, the difference in change in FVC was 0.039% per month, p= 0.12, and for DLco, 0.0085% per month, p= 0.7. The pulmonary function trajectories for treated and untreated patients were parallel, despite treated patients having more severe disease at baseline. The persisting differences between the groups suggest no overall effect, although improvement or stabilization may be seen in some patients. Prospective studies are needed to define subsets of patients with unclassifiable interstitial lung disease and their optimal management.

A review of the challenges, learnings and future directions of home handheld spirometry in interstitial lung disease

BackgroundPatients with interstitial lung disease (ILD) require regular physician visits and referral to specialist ILD clinics. Difficulties or delays in accessing care can limit opportunities to monitor disease trajectory and response to treatment, and the COVID-19 pandemic has added to these challenges. Therefore, home monitoring technologies, such as home handheld spirometry, have gained increased attention as they may help to improve access to care for patients with ILD. However, while several studies have shown that home handheld spirometry in ILD is acceptable for most patients, data from clinical trials are not sufficiently robust to support its use as a primary endpoint. This review discusses the challenges that were encountered with handheld spirometry across three recent ILD studies, which included home spirometry as a primary endpoint, and highlights where further optimisation and research into home handheld spirometry in ILD is required. bodyRate of decline in forced vital capacity (FVC) as measured by daily home handheld spirometry versus site spirometry was of primary interest in three recently completed studies: STARLINER (NCT03261037), STARMAP and a Phase II study of pirfenidone in progressive fibrosing unclassifiable ILD (NCT03099187). Unanticipated practical and technical issues led to problems with estimating FVC decline. In all three studies, cross-sectional correlations for home handheld versus site spirometry were strong/moderate at baseline and later timepoints, but longitudinal correlations were weak. Other issues observed with the home handheld spirometry data included: high within-patient variability in home handheld FVC measurements; implausible longitudinal patterns in the home handheld spirometry data that were not reflected in site spirometry; and extreme estimated rates of FVC change.ConclusionsHome handheld spirometry in ILD requires further optimisation and research to ensure accurate and reliable FVC measurements before it can be used as an endpoint in clinical trials. Refresher training, automated alerts of problems and FVC changes, and patient support could help to overcome some practical issues. Despite the challenges, there is value in incorporating home handheld spirometry into clinical practice, and the COVID-19 pandemic has highlighted the potential for home monitoring technologies to help improve access to care for patients with ILD.

Efficacy of Pirfenidone vs. Placebo in Unclassifiable Interstitial Lung Disease, by Surgical Lung Biopsy Status: Data From a post-hoc Analysis

Approximately 12–13% of patients with interstitial lung disease (ILD) are diagnosed with unclassifiable ILD (uILD), often despite thorough evaluation. A recent Phase 2 study (NCT03099187) described a significant effect of pirfenidone vs. placebo on forced vital capacity (FVC) measured by site spirometry in patients with progressive fibrosing uILD (hereafter referred to as the pirfenidone in uILD study). Here, we present the results from a post-hoc analysis of this study to assess patient baseline characteristics and the efficacy of pirfenidone vs. placebo analyzed by surgical lung biopsy (SLB) status. Mean FVC (mL) change over 24 weeks was included as a post-hoc efficacy outcome. Of 253 randomized patients, 88 (34.8%) had a SLB and 165 (65.2%) did not. Baseline characteristics were generally similar between SLB subgroups; however, patients who had a SLB were slightly younger and had a higher 6-min walk distance than those without a SLB. Mean FVC change over 24 weeks for pirfenidone vs. placebo was −90.9 vs. −146.3 mL, respectively, in patients who had a SLB, and 8.2 vs. −85.3 mL, respectively, in patients without a SLB. Overall, the results from the post-hoc analysis identified that pirfenidone may be an effective treatment in progressive fibrosing uILD over 24 weeks, irrespective of SLB status; however, caution should be taken when interpreting these data due to several limitations. There are differences in the treatment effect of pirfenidone between the subgroups that require further pathological and radiological investigation. In this manuscript, we also descriptively compared baseline characteristics from the overall pirfenidone in uILD study population with other uILD populations reported in the literature, with the aim of understanding if there are any similarities or differences within these cohorts. Most baseline characteristics for patients in the pirfenidone in uILD study were within the ranges reported in the literature; however, ranges were wide, highlighting the heterogeneity of uILD populations.Clinical Trial RegistrationClinicalTrials.gov, identifier: NCT03099187.

Clinical relevance of rheumatoid factor and anti-citrullinated peptides in fibrotic interstitial lung disease.

Rheumatoid arthritis (RA) is a frequent cause of interstitial lung disease (ILD); however, the impact of rheumatoid factor and anti-citrullinated peptide antibody seropositivity in ILD without connective tissue disease (CTD) is unclear. We examined the association of seropositivity with ILD progression, mortality and response to immunosuppression in non-CTD ILD. A total of 1570 non-CTD patients (with idiopathic pulmonary fibrosis, hypersensitivity pneumonitis, interstitial pneumonia with autoimmune features or unclassifiable ILD) and 181 RA-ILD patients were included from a prospective registry. Longitudinal forced vital capacity (FVC), transplant-free survival and incidence of progressive fibrosing-ILD (PF-ILD) were compared between seronegative non-CTD ILD (reference group), seropositive non-CTD ILD and RA-ILD using linear mixed-effect and Cox proportional hazards models adjusted for age, sex, smoking pack-years and baseline FVC. Interaction between seropositivity and immunosuppression on FVC decline was assessed in patients with ≥6months of follow-up before and after the treatment. Two hundred and seventeen (13.8%) patients with seropositive non-CTD ILD had similar rates of FVC decline and transplant-free survival compared to seronegative non-CTD ILD, but more frequently met the criteria for PF-ILD (hazard ratio [HR]=1.35, p= 0.004). RA-ILD had slower FVC decline (p= 0.03), less PF-ILD (HR=0.75, p= 0.03) and lower likelihood of lung transplant or death (HR=0.66, p= 0.01) compared to seronegative non-CTD ILD. No interaction was found between seropositivity and treatment on FVC decline in non-CTD ILD. Seropositivity in non-CTD ILD was not associated with improved outcomes or treatment response, highlighting the importance of other disease features in determining prognosis and predicting response to immunosuppression.

Care patterns of patients with chronic fibrosing interstitial lung disease (ILD) with a progressive phenotype

BackgroundInterstitial lung diseases (ILDs) include a variety of parenchymal lung diseases. The most common types of ILDs are idiopathic pulmonary fibrosis (IPF), autoimmune ILDs and hypersensitivity pneumonitis (HP). There is limited real world data on care patterns of patients with chronic fibrosing ILDs with a progressive phenotype other than IPF. Therefore, the aim of this study is to describe care patterns in these patients.MethodsThis retrospective cohort study used claims data from 2015 to 2019 from the Optum Research Database. The study population included adults (≥ 18 years old) with at least two diagnosis codes for fibrosing ILD during the identification period (1OCT2016 to 31DEC2018). A claim-based algorithm for disease progression was used to identify patients likely to have a progressive fibrotic phenotype using progression proxies during the identification period. Index date was the first day of progression proxy identification after fibrosing ILD diagnosis. Patients were required to have continuous enrollment for 12 months before (baseline) and after (follow-up) index date. Patients with an IPF diagnosis were excluded. Descriptive statistics were used to describe the patient population and care patterns.Results11,204 patients were included in the study. Mean age of the patient population was 72.7 years, and 54.5% were female. Unclassified ILDs (48.0%), HP (25.2%) and autoimmune ILDs (16.0%) were the most common ILD types. Other respiratory conditions were prevalent among patients including chronic obstructive pulmonary disease (COPD) (58.9%), obstructive sleep apnea (OSA) (25.0%) and pulmonary hypertension (9.8%). During baseline, 65.3% of all patients had at least one pulmonology visit, this proportion was higher during follow-up, at 70.6%. Baseline and follow-up use for HRCT were 39.9% and 48.8%, and for pulmonary function tests were 43.7% and 48.5% respectively. Use of adrenal corticosteroids was higher during follow-up than during baseline (62.5% vs. 58.0%). Anti-inflammatory and immunosuppressive medication classes were filled by a higher percentage of patients during follow-up than during baseline.ConclusionsComprehensive testing is essential for diagnosis of a progressive phenotype condition, but diagnostic tests were underutilized. Patients with this condition frequently were prescribed anti-inflammatory and immunosuppressive medications.

Comorbidities in unclassifiable interstitial lung disease

BackgroundComorbidities are common in interstitial lung diseases (ILD) and have an important association with survival, but the frequency and prognostic impact of comorbidities in unclassifiable interstitial lung disease (uILD) remains elusive. We aimed to describe the prevalence of comorbidities and assess the impact on survival in patients with uILD. Furthermore, we aimed to identify and characterize potential phenotypes based on clusters of comorbidities and examine their association with disease progression and survival.MethodsIncident patients diagnosed with uILD were identified at two ILD referral centers in Denmark and Germany from 2003 to 2018. The diagnosis uILD was based on multidisciplinary team meetings. Clinical characteristics and comorbidities were extracted from ILD registries and patient case files. Survival analyses were performed using Cox regression analyses, disease progression was analyzed by linear mixed effects models, and clusters of comorbidities were analyzed using self-organizing maps.ResultsA total of 249 patients with uILD were identified. The cohort was dominated by males (60%), former (49%) or current (15%) smokers, median age was 70 years, mean FVC was 75.9% predicted, and mean DLCO was 49.9% predicted. One-year survival was 89% and three-year survival was 73%. Eighty-five percent of the patients had ≥ 1 comorbidities, 33% had ≥ 3 comorbidities and 9% had ≥ 5 comorbidities. The only comorbidity associated with excess mortality was dyslipidemia. No association between survival and number of comorbidities or the Charlson comorbidity index was observed. Three clusters with different comorbidities profiles and clinical characteristics were identified. A significant annual decline in FVC and DLCO % predicted was observed in cluster 1 and 2, but not in cluster 3. No difference in mortality was observed between the clusters.ConclusionsThe comorbidity burden in uILD is lower than reported in other types of ILD and the impact of comorbidities on mortality needs further clarification. Three clusters with distinct comorbidity profiles were identified and could represent specific phenotypes. No difference in mortality was observed between clusters, but slower disease progression was observed in cluster 3. Better understanding of disease behavior and mortality will require further studies of subgroups of uILD with longer observation time.