Clinical spectrum time course of interstitial pneumonia with autoimmune features in patients positive for antisynthetase antibodies

Interstitial Pneumonia with Autoimmune Features: Aiming to Define, Refine, and Treat

Interstitial pneumonia with autoimmune features (IPAF) was defined for research purposes as interstitial lung disease (ILD) associated with features of autoimmunity without diagnosed rheumatic disease. Since publication of the IPAF criteria in 2015, there have been multiple studies of IPAF. However, much remains unknown regarding pathogenesis, prognosis, and treatment in IPAF. This narrative review details the history and classification of IPAF, lists challenges associated with classifying patients as IPAF, and explores the prevalence, epidemiology and presentation of IPAF. We also examine prognosis and important features determining IPAF clinical course, outline pathogenesis, and review treatment strategies.

Characteristics of Interstitial Pneumonia With Autoimmune Features (IPAF): Protocol for a Multicenter Prospective Study

BACKGROUND

"Interstitial lung disease" (ILD) is a broad term encompassing diseases of different backgrounds. "Interstitial pneumonia with autoimmune features" (IPAF) is a recent term that implies the presence of autoimmunity.

OBJECTIVE

This study aims to determine the characteristics of Polish patients with IPAF, compare them with patients with other interstitial pneumonias, and search for the prognostic and diagnostic biomarkers of IPAF in serum and bronchoalveolar lavage fluid (BALF).

METHODS

This multicenter prospective study plans to recruit 240 participants divided into 1 study group and 2 control groups. Biological fluid samples will be collected according to Polish Respiratory Society management guidelines and stored at -80°C for further tests. Prospective 5-year observations of 60 newly diagnosed individuals are planned. The study will be divided into subsections. First, we plan to characterize Polish patients with IPAF (study group) against their peers with other ILDs (2 control groups). Control group 1 will comprise patients with idiopathic ILDs, including mainly idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia. Control group 2 will comprise patients with connective tissue disease-associated interstitial lung diseases, such as rheumatoid arthritis, systemic sclerosis, polymyositis, dermatomyositis, Sjögren's syndrome, mixed connective tissue disease, and systemic lupus erythematosus. Radiological and functional parameters will be analyzed. Patients will be compared in terms of high-resolution computed tomography results, the 6-minute walking test performance, and pulmonary function test parameters. The diagnosis of IPAF will be reassessed on a regular basis through multidisciplinary discussion in order to determine its clinical stability. In the laboratory arm, inflammation and fibrosis pathways will be assessed. Cytokine levels (interleukin 8, transforming growth factor beta 1, chemokine C-C motif ligand [CXCL]18, CXCL1, surfactant protein [SP]-A, SP-D, Krebs von den Lungen-6 protein, and chitinase 1) will be measured in serum and BALF. A comparative analysis of serum and BALF cytokine levels will be performed in order to establish potential differences between systemic and local inflammatory pathways. In the quality of life (QoL) arm of the study, dyspnea and cough and their impact on various aspects of the QoL will be assessed. Depression and anxiety will be measured with the Hospital Anxiety and Depression Modified Scale and the 9-item Patient Health Questionnaire, and potential correlations with symptom prevalence will be assessed.

RESULTS

This study will start recruiting patients to phase 1 in October 2023. The final results will be available in 2028. We plan to publish preliminary results after 2-3 years from the start of phase 1.

CONCLUSIONS

This study will be a step toward a better understanding of IPAF etiopathogenesis and outcomes.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/44802.

Clinical Characterization and Predictive Factors for Progression in a Cohort of Patients with Interstitial Lung Disease and Features of Autoimmunity: The Need for a Revision of IPAF Classification Criteria

Background and Objectives: The "interstitial pneumonia with autoimmune features" (IPAF) criteria have been criticized because of the exclusion of usual interstitial pneumonia (UIP) patients with a single clinical or serological feature. To classify these patients, the term UIPAF was proposed. This study aims to describe clinical characteristics and predictive factors for progression of a cohort of interstitial lung disease (ILD) patients with at least one feature of autoimmunity, applying criteria for IPAF, specific connective tissue diseases (CTD), and a definition of UIPAF when possible. Methods: We retrospectively evaluated data on 133 consecutive patients with ILD at onset associated with at least one feature of autoimmunity, referred by pulmonologists to rheumatologists from March 2009 to March 2020. Patients received 33 (16.5-69.5) months of follow-up. Results: Among the 101 ILD patients included, 37 were diagnosed with IPAF, 53 with ILD-onset CTD, and 11 with UIPAF. IPAF patients had a lower prevalence of UIP pattern compared to CTD-ILD and UIPAF patients (10.8% vs. 32.1% vs. 100%, p < 0.01). During the follow-up, 4 IPAF (10.8%) and 2 UIPAF (18.2%) patients evolved into CTD-ILD. IPAF patients presented features not included in IPAF criteria, such as sicca syndrome (8.1%), and were more frequently affected by systemic hypertension (p < 0.01). Over one year, ILD progression (greater extent of fibrosis on HRCT and/or decline in PFTs) was less frequent in the IPAF group compared to CTD-ILD and UIPAF (32.3% vs. 58.8% vs. 72.7, p = 0.02). A UIP pattern and an IPAF predicted a faster (OR: 3.80, p = 0.01) and a slower (OR: 0.28, p = 0.02) ILD progression, respectively. Conclusions: IPAF criteria help identify patients who might develop a CTD-ILD, even though a single clinical or serological feature is respected. Future revisions of IPAF criteria should include sicca syndrome and separate UIP-pattern into a different definition (UIPAF), given its association with a different prognosis, independently from ILD classification.

Fine-tuning characterization of patients with interstitial pneumonia and an underlying autoimmune disease in real-world practice: We get closer with Nailfold videocapillaroscopy

Objectives

To assess performance of interstitial pneumonia (IP) with autoimmune features (IPAF) criteria in clinical practice and describe the utility of additional workup in identifying patients with underlying connective tissue diseases (CTD).

Methods

We set a retrospective study of our patients with autoimmune IP, who were allocated to CTD-IP, IPAF or undifferentiated autoimmune IP (uAIP) subgroups according to the updated classification criteria. Presence of the process-related variables comprising IPAF defining domains was scrutinized in all patients, and, when available, the results of nailfold videocapillaroscopy (NVC) were recorded.

Results

Thirty nine out of 118 patients, accounting for 71% of former undifferentiated cases, fulfilled IPAF criteria. Arthritis and Raynaud's phenomenon were prevalent in this subgroup. While systemic sclerosis-specific autoantibodies were restricted to CTD-IP patients, anti-tRNA synthetase antibodies were also present in IPAF. In contrast, rheumatoid factor, anti-Ro antibodies and ANA nucleolar patterns could be found in all subgroups. Usual interstitial pneumonia (UIP) / possible UIP were the most frequently observed radiographic patterns Therefore, the presence of thoracic multicompartimental findings as also performance of open lung biopsies were useful in characterizing as IPAF those UIP cases lacking a clinical domain. Interestingly, we could observe NVC abnormalities in 54% of IPAF and 36% of uAIP tested patients, even though many of them did not report Raynaud's phenomenon.

Conclusion

Besides application of IPAF criteria, distribution of IPAF defining variables along with NVC exams help identify more homogeneous phenotypic subgroups of autoimmune IP of potential relevance beyond clinical diagnosis.

Identification and Prognosis of Patients With Interstitial Pneumonia With Autoimmune Features

BACKGROUND/OBJECTIVE

Patients classified as interstitial pneumonia with autoimmune features (IPAF) have interstitial lung disease (ILD) and features of autoimmunity but do not fulfill criteria for connective tissue diseases (CTDs). Our goal was to identify patients classifiable as IPAF, CTD-ILD, and idiopathic pulmonary fibrosis (IPF) from a preexisting pulmonary cohort and evaluate the prognosis of patients with IPAF.

METHODS

We reviewed the medical records of 456 patients from a single-center pulmonary ILD cohort whose diagnoses were previously established by a multidisciplinary panel that did not include rheumatologists. We reclassified patients as IPAF, CTD-ILD, or IPF. We compared transplant-free survival using Kaplan-Meier methods and identified prognostic factors using Cox models.

RESULTS

We identified 60 patients with IPAF, 113 with CTD-ILD, and 126 with IPF. Transplant-free survival of IPAF was not statistically significantly different from that of CTD-ILD or IPF. Among IPAF patients, male sex (hazard ratio, 4.58 [1.77-11.87]) was independently associated with worse transplant-free survival. During follow-up, only 10% of IPAF patients were diagnosed with CTD-ILD, most commonly antisynthetase syndrome.

CONCLUSION

Despite similar clinical characteristics, most patients with IPAF did not progress to CTD-ILD; those who did often developed antisynthetase syndrome, highlighting the critical importance of comprehensive myositis autoantibody testing in this population. As in other types of ILD, male sex may portend a worse prognosis in IPAF. The routine engagement of rheumatologists in the multidisciplinary evaluation of ILD will help ensure the accurate classification of these patients and help clarify prognostic factors.

Phenotypic clusters and survival analyses in interstitial pneumonia with myositis-specific autoantibodies

Background:

Idiopathic inflammatory myopathy (IIM) is highly combined with interstitial pneumonia (IP), often as the initial or solo presentation with positive myositis-specific autoantibodies (MSAs) but does not fulfill the diagnostic criteria.

Objectives:

We aimed to explore the phenotypic clusters and prognosis of the patients with IP and positive MSA, which is called MSA-IP in the present study.

Methods:

A total of 178 patients with MSA-IP were prospectively enrolled for analysis. Serum MSAs were detected using Western blotting. Radiological patterns of IP were determined according to the classification of idiopathic IPs. Clusters of patients with MSA-IP were identified using cluster analysis. Predictors for acute/subacute onset, therapeutic response, IP progression and survival were also analyzed.

Results:

Patients with MSA-IP were classified into four distinct clusters. Cluster 1 were the elderly with chronic onset, nearly normal oxygenation and good survival. Cluster 2 had dyspnea on exertion and nonspecific IP pattern, with moderate survival. Patients in cluster 3 had chronic onset and were prone to IP progression (OR 2.885). Cluster 4 had multi-systemic involvements, positive anti-melanoma differentiation associated gene 5 antibody, and were prone to acute/subacute onset (OR 3.538) and IP progression (OR 5.472), with poor survival. Corticosteroids combined immunosuppressants showed therapeutic response in MSA-IP (OR 4.303) and had a protective effect on IP progression (OR 0.136).

Conclusions:

Four clusters of the patients with MSA-IP suggested the distinct clinical, radiological and prognostic features.

Myositis Antibodies and Interstitial Lung Disease

BACKGROUND

Interstitial lung disease (ILD) comprises a heterogeneous group of inflammatory and fibrotic conditions, often resulting in progressive lung function decline and increased mortality. Connective tissue disease (CTD) should be considered in all patients with ILD, as distinguishing between CTD-ILD and other forms of fibrotic lung disease has important therapeutic and prognostic implications. The idiopathic inflammatory myopathies (IIM) represent a CTD subtype of growing interest to ILD experts. The expansion and availability of myositis-specific and myositis-associated antibody testing has allowed for improved disease detection and characterization.

CONTENT

In this review, we highlight the relationship between myositis antibodies and ILD. Select forms of IIM, such as the antisynthetase syndrome and clinically amyopathic dermatomyositis can present with rapidly progressive ILD, warranting timely disease diagnosis and management. Disease phenotypes, prevalence, laboratory testing, prognosis, and management strategies are described according to select myositis antibodies.

SUMMARY

Myositis antibodies provide valuable information for clinicians managing patients with ILD. This review aims to increase awareness of their role in disease detection, pathophysiology, and possibly therapeutics.

Real world utilization of the myositis autoantibody panel

OBJECTIVE

Myositis autoantibody panel results can offer diagnostic and prognostic information in patients with concern for idiopathic inflammatory myopathy (IIM). However, there has been widespread utilization of myositis autoantibody testing clinically, often in situations where concern for an IIM is unclear. We sought to determine ordering practices and factors predicting positive results on ordered myositis antibody panels.

METHODS

We included all patients in the Duke University Health System who had a "myositis antibody panel" ordered from October 2014 through December 2016. Retrospective chart review was performed evaluating antibody positivity, provider specialty, ordering location, demographics, medical history, review of systems (ROS), physical examination (PE), and laboratory values. Fisher's exact and t test tests and backward multivariable regression analysis were performed for statistical analysis.

RESULTS

There were 642 unique tests obtained with 114 positive autoantibodies (17.7%) over the 26-month period. Myositis-specific autoantibodies (MSAs) were the most common and anti-Mi-2 was the most frequent (40% of MSAs). Pulmonology providers ordered the majority of tests (383; 59.6%). Adult Rheumatology had the highest antibody positivity rate (34.3%, p=0.0001) among specialties with at least 10 panels ordered. In backward multivariable regression analysis, factors independently associated with a positive myositis antibody panel were chronic corticosteroid use (OR: 2.10, 95% CI: 1.30-3.38) and sclerodermoid skin changes (OR: 6.89; 95% CI: 2.02-23.47).

CONCLUSION

The positivity rate of myositis antibody panel testing in this real-world clinical setting was 18%. Anti-Mi-2 antibody was the most frequent autoantibody present. Specific factors associated with positive results can be utilized to identify patients at higher risk for IIM.

KEY POINTS

• Only eighteen percent of all myositis antibody panel tests ordered returned positive. • Anti-Mi-2 antibody was the most frequent autoantibody in our cohort. • Specific factors associated with positive results can help identify patients at higher risk for IIM, particularly for non-rheumatologists.

Single Nucleotide Polymorphism in the IL17A Gene Is Associated with Interstitial Lung Disease Positive to Anti-Jo1 Antisynthetase Autoantibodies

Antisynthetase syndrome (ASSD) is a rare multisystemic connective tissue disease affecting the skin, joints, muscles, and lungs, characterized by anti-aminoacyl transfer-RNA-synthetases (anti-tRNA) autoantibodies production, being anti-Jo1 the most frequent. We included one-hundred twenty-one ASSD patients and 340 healthy subjects (HS), and also, we divided the case group into anti-Jo1 and non-anti-Jo1. Two single nucleotide polymorphisms (SNPs) in the IL17A gene were evaluated. Anti-Jo1 was the most common anti-tRNA antibody in our cohort, and the most frequent tomographic pattern was non-specific interstitial pneumonia (NSIP). Anti-Jo1 ASSD patients had higher levels of creatine phosphokinase than the non-anti-Jo1 group. Significant differences in genotype frequencies with rs8193036/CC between anti-Jo1 vs. non-anti-Jo1 ASSD patients (p < 0.001), maintaining the association after Bonferroni correction (p = 0.002). Additionally, in the anti-Jo1 group vs. HS comparison, we found a statistically significant difference with the same SNP (p = 0.018, OR = 2.91, 95% CI = 1.15-7.35), maintaining the association after Bonferroni correction (p = 0.036). The rs8193036/CC genotype in IL17A is associated with ASSD patients with anti-Jo1. Also, anti-Jo1 and non-anti-Jo1 patients display differences in genotype frequencies.

Antisynthetase syndrome: A distinct disease spectrum

The discovery of novel autoantibodies related to idiopathic inflammatory myopathies (collectively referred to as myositis) has not only advanced our understanding of the clinical, serological, and pathological correlation in the disease spectrum but also played a role in guiding management and prognosis. One group of the myositis-specific autoantibodies is anti-aminoacyl-tRNA synthetase (anti-ARS or anti-synthetase) which defines a syndrome with predominant interstitial lung disease, arthritis, and myositis. Autoantibodies to eight aminoacyl-tRNA synthetases have been identified with anti-Jo1 the most common in all of idiopathic inflammatory myopathies. Disease presentation and prognosis vary depending on which anti-aminoacyl-tRNA synthetase antibody is present. In this review, we will discuss the clinical characteristics, overlap features with other autoimmune diseases, prognostic factors, and management of the antisynthetase syndrome.

Risk of progression of interstitial pneumonia with autoimmune features to a systemic autoimmune rheumatic disease

OBJECTIVE

The aim of this study was to determine the risk of developing a systemic autoimmune rheumatic disease (ARD) after an initial diagnosis of interstitial pneumonia with autoimmune features (IPAF).

METHODS

We performed a retrospective cohort study of patients with interstitial lung disease (ILD) who were evaluated at Columbia University Irving Medical Center from 2009 to 2017. We divided patients with idiopathic ILD into two groups: those who met IPAF criteria and those who did not meet IPAF criteria at initial ILD diagnosis. We examined the association between IPAF and diagnosis of ARD during the follow-up period using a multivariable-adjusted logistic regression model.

RESULTS

Of the 697 patients with ILD who were screened, 174 met inclusion criteria (50 met IPAF criteria and 124 did not). During a median follow-up period of 5.2 years, 16% (8/50) of subjects with IPAF were diagnosed with an ARD compared with 1.6% (2/124) of subjects without IPAF (P = 0.001). Adjusting for age, sex, smoking status and use of immunosuppressive therapy, the odds of progressing to an ARD were 14 times higher in subjects with IPAF than in those without IPAF (odds ratio 14.18, 95% CI 1.44-138.95, P = 0.02).

CONCLUSION

The presence of IPAF confers an increased risk of developing an ARD. Patients with IPAF should therefore be followed closely for the development of an ARD.

Myositis-specific Antibodies Identify A Distinct Interstitial Pneumonia with Autoimmune Features Phenotype

Interstitial pneumonia with autoimmune features (IPAF) characterises individuals with interstitial lung disease (ILD) and features of connective tissue disease (CTD) who fail to satisfy CTD criteria. Inclusion of myositis-specific antibodies (MSAs) in the IPAF criteria has generated controversy, as these patients also meet proposed criteria for an anti-synthetase syndrome. Whether MSAs and myositis associated antibodies (MAA) identify phenotypically distinct IPAF subgroups remains unclear.A multi-center, retrospective investigation was conducted to assess clinical features and outcomes in patients meeting IPAF criteria stratified by the presence of MSAs and MAAs. IPAF subgroups were compared to cohorts of patients with idiopathic inflammatory myopathy-ILD (IIM-ILD), idiopathic pulmonary fibrosis (IPF) and non-IIM CTD-ILDs. The primary endpoint assessed was three-year transplant-free survival. Two hundred sixty-nine patients met IPAF criteria, including 35 (13%) with MSAs and 65 (24.2%) with MAAs. Survival was highest among patients with IPAF-MSA and closely approximated those with IIM-ILD. Survival did not differ between IPAF-MAA and IPAF without MSA/MAA cohorts. Usual interstitial pneumonia (UIP) morphology was associated with differential outcome risk, with IPAF patients with non-UIP morphology approximating survival observed in non-IIM CTD-ILDs. MSAs, but not MAAs identified a unique IPAF phenotype characterised by clinical features and outcomes similar to IIM-ILD. UIP morphology was a strong predictor of outcome in others meeting IPAF criteria. Because IPAF is a research classification without clear treatment approach, these findings suggest MSAs should be removed from the IPAF criteria and such patients should be managed as an IIM-ILD.

The Spectrum of Interstitial Lung Disease Associated with Autoimmune Diseases: Data of a 3.6-Year Prospective Study from a Referral Center of Interstitial Lung Disease and Lung Transplantation

Interstitial lung disease (ILD) may occur in patients with a rheumatic autoimmune disease (AD), increasing their risk of morbidity and mortality. However, little is known about the prevalence of AD in patients diagnosed with an ILD. In this prospective study, we determined the spectrum of ILD associated with AD (AD-ILD) among patients sent for assessment to a single clinic of ILD and lung transplantation from a referral center between May 2016 and December 2019. ILD diagnosis was made by pneumologists based on clinical and radiological findings and pulmonary function test abnormalities. All patients with ILD were also assessed by experienced rheumatologists. During the period of assessment, 338 patients were diagnosed with ILD. Among them, 32.8% fulfilled definitions for an AD. Most cases with AD-ILD had a diagnosis of rheumatoid arthritis (27.0%), systemic sclerosis (26.1%) or anti-synthetase syndrome (17.1%). Interestingly, 18% of the patients with AD-ILD were diagnosed as having an interstitial pneumonia with autoimmune features. Antinuclear antibodies and non-specific interstitial pneumonia were the most frequent positive autoantibodies and radiological pattern found in AD-ILD patients, respectively. In conclusion, our study indicates that a high number of ILD patients have a related AD. Consequently, close collaboration among rheumatologists and pneumologists is needed.

Impact of a systematic evaluation of connective tissue disease on diagnosis approach in patients with interstitial lung diseases

To date, there is no clear agreement regarding which is the best method to detect a connective tissue disease (CTD) during the initial diagnosis of interstitial lung diseases (ILD). The aim of our study was to explore the impact of a systematic diagnostic strategy to detect CTD-associated ILD (CTD-ILD) in clinical practice, and to clarify the significance of interstitial pneumonia with autoimmune features (IPAF) diagnosis in ILD patients.Consecutive patients evaluated in an ILD Diagnostic Program were divided in 3 groups: IPAF, CTD-ILD, and other ILD forms. Clinical characteristics, exhaustive serologic testing, high resolution computed tomography (HRCT) images, lung biopsy specimens, and follow-up were prospectively collected and analyzed.Among 139 patients with ILD, CTD was present in 21 (15.1%), 24 (17.3%) fulfilled IPAF criteria, and 94 (67.6%) were classified as other ILD forms. Specific systemic autoimmune symptoms such as Raynaud phenomenon (19%), inflammatory arthropathy (66.7%), and skin manifestations (38.1%) were more frequent in CTD-ILD patients than in the other groups (all P < .001). Among autoantibodies, antinuclear antibody was the most frequently found in IPAF (42%), and CTD-ILD (40%) (P = .04). Nonspecific interstitial pneumonia, detected by HRCT scan, was the most frequently seen pattern in patients with IPAF (63.5%), or CTD-ILD (57.1%) (P < .001). In multivariate analysis, a suggestive radiological pattern by HRCT scan (odds ratio [OR] 15.1, 95% confidence interval [CI] 4.7-48.3, P < .001) was the strongest independent predictor of CTD-ILD or IPAF, followed by the presence of clinical features (OR 14.6, 95% CI 4.3-49.5, P < .001), and serological features (OR 12.4, 95% CI 3.5-44.0, P < .001).This systematic diagnostic strategy was useful in discriminating an underlying CTD in patients with ILD. The defined criteria for IPAF are fulfilled by a considerable proportion of patients referred for ILD.

Influence of Antisynthetase Antibodies Specificities on Antisynthetase Syndrome Clinical Spectrum Time Course

Antisynthetase syndrome (ASSD) is a rare clinical condition that is characterized by the occurrence of a classic clinical triad, encompassing myositis, arthritis, and interstitial lung disease (ILD), along with specific autoantibodies that are addressed to different aminoacyl tRNA synthetases (ARS). Until now, it has been unknown whether the presence of a different ARS might affect the clinical presentation, evolution, and outcome of ASSD. In this study, we retrospectively recorded the time of onset, characteristics, clustering of triad findings, and survival of 828 ASSD patients (593 anti-Jo1, 95 anti-PL7, 84 anti-PL12, 38 anti-EJ, and 18 anti-OJ), referring to AENEAS (American and European NEtwork of Antisynthetase Syndrome) collaborative group’s cohort. Comparisons were performed first between all ARS cases and then, in the case of significance, while using anti-Jo1 positive patients as the reference group. The characteristics of triad findings were similar and the onset mainly began with a single triad finding in all groups despite some differences in overall prevalence. The “ex-novo” occurrence of triad findings was only reduced in the anti-PL12-positive cohort, however, it occurred in a clinically relevant percentage of patients (30%). Moreover, survival was not influenced by the underlying anti-aminoacyl tRNA synthetase antibodies’ positivity, which confirmed that antisynthetase syndrome is a heterogeneous condition and that antibody specificity only partially influences the clinical presentation and evolution of this condition.

Evolution of Pulmonary Function in a Cohort of Patients with Interstitial Lung Disease and Positive for Antisynthetase Antibodies

Objective.

To describe the evolution of the pulmonary function in patients with interstitial lung disease (ILD) who are positive for at least 1 of the antisynthetase antibodies (ASAB) after medical treatment, and to compare whether the evolution of pulmonary function is associated with the type of ASAB.

Methods.

Patients with ILD and positive for at least 1 of the ASAB (anti-Jo1, anti-PL7, anti-PL12, anti-EJ, or anti-OJ) were included. The clinical evolution, time until death or censoring, and improvement of lung disease were registered.

Results.

The study included 118 patients. Most of the patients had a high extent of ground glass opacities in high-resolution computed tomography (HRCT) and low extent of fibrosis. In the final evaluation of pulmonary function (median 749.5 days of followup), 67% of the patients had lung disease improvement. The improvement occurred within the first 6 months after initiating medical treatment; thereafter, pulmonary function remained stable in most of the patients. A decrease of the extent of ground glass opacities was demonstrated in HRCT at followup in those patients with pulmonary improvement. No differences were observed in the percentage of patients who achieved improvement between the ASAB groups, or in survival.

Conclusion.

Improvement of pulmonary function was observed in 67% of the patients. Improvement was observed in all ASAB groups and occurred within 6 months after initiating medical treatment.

Idiopathic inflammatory myopathies: state of the art on clinical practice guidelines [corrected]

Idiopathic inflammatory myopathies (IIMs) encompass a heterogeneous group of rare autoimmune diseases characterised by muscle weakness and inflammation, but in antisynthetase syndrome arthritis and interstitial lung disease are more frequent and often inaugurate the disease. Clinical practice guidelines (CPGs) have been proposed for IIMs, but they are sparse and heterogeneous. This work aimed at identifying: i) current available CPGs for IIMs, ii) patients ' and clinicians' unmet needs not covered by CPGs. It has been performed in the framework of the European Reference Network on rare and complex connective tissue and musculoskeletal diseases (ReCONNET), a network of centre of expertise and patients funded by the European Union's Health Programme. Fourteen original CPGs were identified, notably recommending that: i) extra-muscular involvements should be assessed; ii) corticosteroids and methotrexate or azathioprine are first-line therapies of IIMs. ii) IVIG is a treatment of resistant-DM that may be also used in other resistant-IIMs; iii) physical therapy and sun protection (in DM patients) are part of the treatment; v) tumour screening for patients with DM include imaging of chest, abdomen, pelvis and breast (in woman) along with colonoscopy (in patients over 50 years); vi) disease activity and damages should be monitor using standardised and validated tools. Yet, only half of these CPGs were evidence-based. Crucial unmet needs were identified both by patients and clinicians. In particular, there was a lack of large multidisciplinary working group and of patients ' preferences. The following fields were not or inappropriately targeted: diagnosis; management of extra-muscular involvements other than skin; co-morbidities and severe manifestations.

Interstitial Lung Disease in patients with Polymyalgia Rheumatica: A case series

INTRODUCTION

Severe morning stiffness with painful involvement of the girdles are often referred by patients with Interstitial Lung Disease (ILD), but the association between ILD and Polymyalgia Rheumatica (PMR) is rarely reported. The purpose of the work is to describe a series of patients classified as having PMR with ILD.

MATERIAL AND METHODS

We retrospectively enrolled patients with a diagnosis of PMR referred to our center during the previous year for respiratory symptoms. Data concerning clinical and serological manifestations suggesting Connective Tissue Disease (CTD), High-Resolution Chest Tomography (HRCT), and Pulmonary Function Tests (PFTs) were systematically collected in order to verify the diagnosis.

RESULTS

Fifteen out of seventeen PMR patients had ILD. Ten patients had a confirmed diagnosis of PMR, while in five patients a CTD was discovered. Seven patients showed a severe restrictive pattern at PFTs requiring oxygen supplementation (five with PMR and two with CTD). In thirteen patients pulmonary symptoms started before or together with muscular symptoms. Regarding HRCT patterns, patients showed a Nonspecific Interstitial Pneumonia in nine cases, Usual Interstitial Pneumonia (UIP) and possible UIP in two and three cases, and a single case of Organizing Pneumonia and Combined Pulmonary Fibrosis and Emphysema Syndrome.

CONCLUSIONS

Lung involvement should be evaluated in PMR patients, especially if asthenia is poorly responsive to low doses of steroids. In these cases, the diagnosis should be re-evaluated in depth, looking for a seronegative Rheumatoid Arthritis, a clinically amyopathic myositis or Interstitial Pneumonia with Autoimmune features.

Interstitial Pneumonia With Autoimmune Features: An Emerging Challenge at the Intersection of Rheumatology and Pulmonology

Interstitial lung disease (ILD) remains a cause of significant morbidity and mortality in patients with connective tissue disease (CTD)-associated ILD. While some patients meet clear classification criteria for a systemic rheumatic disease, a subset of patients do not meet classification criteria but still benefit from immunosuppressive therapy. In 2015, the American Thoracic Society and European Respiratory Society described classification criteria for interstitial pneumonia with autoimmune features (IPAF) to identify patients with lung-predominant CTD who lack sufficient features of a systemic rheumatic disease to meet classification criteria. Although these criteria are imperfect, they are an important attempt to classify the patient with undifferentiated disease for future study. Rheumatologists play a key role in the evaluation of potential IPAF in patients, especially as many patients with a myositis-spectrum disease (e.g., non-Jo-1 antisynthetase syndrome, anti-melanoma differentiation-associated protein 5 antibody inflammatory myositis, or anti-PM/Scl antibody-associated inflammatory myositis) would be classified under IPAF using the currently available criteria for inflammatory myositis, and would therefore benefit from rheumatologic comanagement. The aim of this review was to describe the historical context that led to the development of these criteria and to discuss the limitations of the current criteria, diagnostic challenges, treatment options, and strategies for disease monitoring.

Effect of Genetic and Laboratory Findings on Clinical Course of Antisynthetase Syndrome in a Hungarian Cohort

The aim of this study was to determine the clinical, serological, and genetic features of anti-Jo-1 positive antisynthetase patients followed by a Hungarian single centre to identify prognostic markers, which can predict disease phenotypes and disease progression. It was a retrospective study using clinical database of 49 anti-Jo-1 positive patients. 100% of patients exhibited myositis, 73% interstitial lung disease, 88% arthritis, 65% Raynaud's phenomenon, 43% fever, 33% mechanic's hand, and 12% dysphagia. We could detect significant correlation between anti-Jo-1 titer and the CK and CRP levels at disease onset and during disease course. HLA DRB1⁎03 positivity was present in 68.96% of patients, where the CK level at diagnosis was significantly lower compared to the HLA DRB1⁎03 negative patients. HLA DQA1⁎0501-DQB1⁎0201 haplotype was found in 58.62% of patients, but no significant correlation was found regarding any clinical or laboratory features. Higher CRP, ESR level, RF positivity, and the presence of fever or vasculitic skin lesions at the time of diagnosis indicated a higher steroid demand and the administration of higher number of immunosuppressants during the follow-up within anti-Jo-1 positive patients. The organ involvement of the disease was not different in HLA-DRB1⁎0301 positive or negative patients who were positive to the anti-Jo-1 antibody; however, initial CK level was lower in HLA-DRB1⁎0301 positive patients. Distinct laboratory and clinical parameters at diagnosis could be considered as prognostic markers.

Interstitial pneumonia with autoimmune features: a new classification still on the move

In the past decade, the attention has been focused on the relationship between interstitial lung disease (ILD) and connective tissue diseases (CTDs). The clinical impact, as well as the therapeutic approach, classification and diagnosis have been addressed. These two latter items represent an area of great interest because the underlying conditions leading to ILD and the most appropriate treatment still needs to be defined. Recently, the European Respiratory Society/American Thoracic Society proposed the interstitial pneumonia with autoimmune features (IPAF) criteria which represents the effort of pulmonologists to classify patients that may remain clinically undefined [1]. The analysis of these criteria shows that IPAF, similarly to pulmonary arterial hypertension classification [2], may cluster conditions referring to a wide spectrum of rheumatic conditions such as systemic sclerosis, myositis, rheumatoid arthritis and overlap syndromes. These diseases are characterised by highly different characteristics, evolution and therapeutic approaches. Furthermore, IPAF criteria have an intrinsically changing structure, related to the regular update of existing CTD classification criteria and to the even more common identification of new biomarkers in CTDs. By far the most important effect of these criteria is the identification of a grey zone of not well-defined rheumatology conditions, e.g. anti-synthetase syndrome (ASSD) [3]. In this issue of the European Respiratory Review, Sambataroet al. [4] address the need to identify specific clinical characteristics and potential areas of improvement in IPAF patients. The starting point of the review is interesting because of the exclusion of papers that included patients diagnosed with ASSD, because no ASSD established classification criteria still exist. The authors' choice is related to the unique characteristics of ASSD, in which it is not unusual to observe the occurrence during follow-up of findings lacking at disease onset. [5]. However, as reported previously [6], in the case of anti-synthetase antibody positivity, the diagnostic scenario may vary with the same patient diagnosed with ASSD if referred to a rheumatologist, or IPAF if referred to a pulmonologist. In fact, a high prevalence of anti-synthetase antibody positivity is reported in the majority of papers evaluated by Sambataroet al. [4], thus confirming the fact that despite the presence of this antibody (identifying ASSD) patients may frequently end up being classified as having IPAF. However, some IPAF patients could not be tested for the entire spectrum of antibodies, probably due to the local unavailability of these tests, or because initial anti-Ro antibody positivity might have prompted the clinicians to evaluate further non-anti-Jo-1 myositis specific auto-antibodies. In fact, it is established that anti-Ro antibodies and anti-synthetase antibodies may co-occur in about 50% of cases, even when patients could be classified as IPAF [7]. Furthermore, we should also consider that if eight anti-synthetase antibodies have been identified to date, at least another 12 aminoacyl-tRNA synthetase enzymes exist, and that the entire spectrum of anti-synthetase antibodies is not covered by any of the existing commercially available tests. All these points clearly indicate the risk that anti-synthetase antibody positivity could be underestimated and that it could be clustered in IPAF. This evidence clearly suggests that well-established and clinically based ASSD classification criteria are needed to reduce the risk of stratifying patients across specialties, in areas that may contribute to real-time incorrectly diagnosed primary disease. Recently, the CLASS (classification criteria of anti-synthetase syndrome) project has been funded by the American College of Rheumatology and the European League against Rheumatism. The aim of the project is to define clinically based criteria of ASSD involving a large number of rheumatology, pulmonology, dermatology, immunology and internal medicine centres expert in the management of rheumatoid arthritis, systemic sclerosis, Sjogren's syndrome and other lung fibrosing conditions. From a scientific point of view, by putting together different specialists we hope to solve the daily discussions about “anti-synthetase antibody positive patient classification” that may delay the correct approach and treatment of affected patients.

IPAF classification criteria include several autoimmune conditions with different evolution. The progression into established CTD is common and a continuous up-to-date process of classification criteria of both IPAF and CTD is mandatory.http://ow.ly/pXNW30knUzl

Clinical spectrum of anti-Jo-1-associated disease

PURPOSE OF REVIEW

To provide the most recent evidence on anti-Jo-1 syndrome.

RECENT FINDINGS

Several new evidences on anti-Jo-1 syndrome have recently emerged. It has been clearly established that, at disease onset, the classic clinical triad (arthritis, myositis and interstitial lung disease - ILD) is only rarely observed. Indeed, disease onset with an isolated arthritis is common. Patients presenting with an isolated manifestation are at high risk for the subsequent occurrence of initially lacking triad findings. Moreover, the ex-novo occurrence of accompanying features such as Raynaud's phenomenon, mechanic's hands and fever during follow-up is a strong risk factor for the occurrence of overt antisynthetase syndrome (ASSD) with further triad manifestations. Several contributions on ILD involvement and prognosis have been published, as well as the distinctive muscle MRI characteristics compared with healthy controls, and a novel definition of a rare skin manifestation (hiker's feet).

SUMMARY

Recent evidence has shed a light on the need for a better understanding of the clinical course, imaging modalities and prognosis of anti-Jo-1 syndrome, providing some relevant elements to allow early diagnosis of this often unrecognized disease.

State of the art in interstitial pneumonia with autoimmune features: a systematic review on retrospective studies and suggestions for further advances

The term interstitial pneumonia with autoimmune features (IPAF) has been proposed to define patients with interstitial lung disease (ILD) associated with autoimmune signs not classifiable for connective tissue diseases (CTDs). This new definition overcomes previous nomenclatures and provides a uniform structure for prospective studies through specific classification criteria.This work evaluates the characteristics of IPAF patients reported in the literature, to highlight potential limits through a comparative analysis and to suggest better performing classification criteria.Four retrospective studies on the IPAF population have been considered. The study subjects differed in age, sex, smoking habit, ILD pattern and outcomes. Another important difference lies in the diverse items considered in the classification criteria. The retrospective design of the studies and the absence from some of them of a rheumatologist clearly involved in the diagnosis may have influenced the data, but current IPAF criteria seem to include a rather heterogeneous population. To overcome these discrepancies, this review suggests a limitation in the use of single items and the exclusion of extremely specific CTD criteria. This should avoid the definition of IPAF for those diseases at different stages or at early onset. The investigation of a functional or morphological cut-off of pulmonary involvement would be useful.

Bench to bedside review of myositis autoantibodies

Idiopathic inflammatory myopathies represent a heterogeneous group of autoimmune diseases with systemic involvement. Even though numerous specific autoantibodies have been recognized, they have not been included, with the only exception of anti-Jo-1, into the 2017 Classification Criteria, thus perpetuating a clinical-serologic gap. The lack of homogeneous grouping based on the antibody profile deeply impacts the diagnostic approach, therapeutic choices and prognostic stratification of these patients. This review is intended to highlight the comprehensive scenario regarding myositis-related autoantibodies, from the molecular characterization and biological significance to target antigens, from the detection tools, with a special focus on immunofluorescence patterns on HEp-2 cells, to their relative prevalence and ethnic diversity, from the clinical presentation to prognosis. If, on the one hand, a notable body of literature is present, on the other data are fragmented, retrospectively based and collected from small case series, so that they do not sufficiently support the decision-making process (i.e. therapeutic approach) into the clinics.

Clinical characteristics of patients with anti-aminoacyl-tRNA synthetase antibody positive idiopathic interstitial pneumonia

BACKGROUND

Anti-aminoacyl-tRNA synthetase (ARS) antibodies have been detected in patients with polymyositis/dermatomyositis (PM/DM) and are especially correlated with interstitial lung disease (ILD). The aim of this study was to clarify the clinical features of patients with anti-ARS antibody positive idiopathic interstitial pneumonias (IIPs).

METHODS

Patients were classified into three groups: 1) IIP with anti-ARS antibodies (ARS(+)IIP), 2) IIP without anti-ARS antibodies (ARS(-)IIP), and 3) PM/DM-associated ILD with anti-ARS antibodies (ARS(+)PM/DM-ILD). Clinical characteristics were compared retrospectively between the ARS(+)IIP group and the ARS(-)IIP group or ARS(+)PM/DM-ILD group.

RESULTS

Eighteen ARS(+)IIP, 284 ARS(-)IIP, and 20 ARS(+)PM/DM-ILD patients were enrolled. The ARS(+)IIP group was significantly older and the male sex was predominant, had a lower prevalence of signs of connective tissue disease, differences in HRCT findings and patterns, and higher KL-6 levels compared to the ARS(+)PM/DM-ILD group. The findings in the bronchoalveolar lavage fluid (BALF) showing lymphocytosis and a lower CD4/CD8 ratio were similar between the two groups. However, the ARS(+)IIP group had significantly lower percentage of sputum, higher prevalence of mechanic's hand, higher KL-6 levels, lower percentage of vital capacity in the pulmonary function test, and lower CD4/CD8 ratio in BALF, compared to the ARS(-)IIP group.

CONCLUSIONS

The present study demonstrated that features of pulmonary involvement were similar to those in the ARS(+)PM/DM-ILD group; however, some differences including HRCT findings and higher KL-6 levels suggest that ARS(+)IIP has severe ILD compared with ARS(+)PM/DM-ILD. Further prospective studies with a larger number of patients will elucidate the exact role of anti-ARS antibodies in IIPs.