The use of auto-antibody testing in the evaluation of interstitial lung disease (ILD) – A practical approach for the pulmonologist

The Impact of Autoantibodies on Outcomes in Patients with Idiopathic Pulmonary Fibrosis: Post-Hoc Analyses of the Phase III ASCEND Trial

INTRODUCTION

Clinical practice guidelines recommend autoimmune serological testing in patients newly diagnosed with interstitial lung disease of apparently unknown cause who may have idiopathic pulmonary fibrosis (IPF), in order to exclude connective tissue disease (CTD). Autoantibody positivity has been associated with unique patient profiles and prognosis in patients with IPF who otherwise lack a CTD diagnosis.

METHODS

This post-hoc analysis of patients with IPF from the Phase III ASCEND trial (NCT01366209) evaluated the association of antinuclear antibodies (ANA), rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) status with baseline disease characteristics, disease progression [percent predicted forced vital capacity (%FVC), forced vital capacity (FVC) volume and progression-free survival (PFS)], and treatment outcomes with pirfenidone and placebo (%FVC, FVC and PFS).

RESULTS

Of 555 participants, 244/514 (47.5%) were ANA positive (ANA+), 83/514 (16.1%) had high ANA+ (ANA titre ≥ 1:160 or positive nucleolar- or centromere-staining patterns), 60/555 (10.8%) were RF positive (RF+) and/or anti-CCP positive (anti-CCP+) and 270/514 (52.5%) were autoantibody negative (AAb-). Baseline demographics and characteristics were generally comparable between autoantibody subgroups. Although not statistically significant, more placebo-treated participants with ANA+ or high ANA+ had a decline from baseline to Week 52 of ≥ 10% in %FVC or death (48.7% and 55.9%, respectively) or in FVC volume or death (48.7% and 47.1%, respectively) compared with the AAb- group (%FVC or death: 42.0%; FVC volume or death: 42.0%). The RF+ and/or anti-CCP+ group was similar to AAb-. No differences were observed in PFS. A treatment benefit for pirfenidone versus placebo was observed regardless of autoantibody status [PFS: ANA+ HR (95% CI): 0.56 (0.37 to 0.86), P = 0.007; AAb- HR (95% CI): 0.50 (0.32 to 0.78), P = 0.002].

CONCLUSION

IPF disease course did not differ by autoantibody status in ASCEND. Pirfenidone had a treatment benefit regardless of the presence of ANA.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01366209.

Relative incidence of interstitial lung diseases in Brazil

OBJECTIVE

To assess the relative frequency of incident cases of interstitial lung diseases (ILDs) in Brazil.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Diagnostic Performance of Anti-Topoisomerase-I, Anti-Th/To Antibody and Anti-Fibrillarin Using Immunoblot Method in Systemic Sclerosis Related Interstitial Lung Disease Patients

Purpose

Systemic Sclerosis related Interstitial Lung Disease (SSc-ILD) is the most common clinical manifestation of SSc with a high morbidity and mortality rate. However, the Thorax High-Resolution Computed Tomography (HCRT) as the gold standard diagnostic tool for SSc-ILD is not widely equipped in health-care facilities. Recently, specific autoantibody examination (anti-topoisomerase-1 (ATA), anti-Th/To antibody, and anti-fibrillarin) has been studied and used for SSc-ILD diagnosis. This study aims to evaluate the diagnostic performance of specific autoantibody examination among SSc-ILD.

Patients and Methods

This retrospective study reviews data from local dedicated SSc database (Sclerosis Systemic Register System Development Electronic Medical Record) which were collected between March 2019 and August 2021. Population of this study include adult inpatients and outpatients at Dr. Hasan Sadikin General Hospital, who have been diagnosed with SSc based on ACR/EULAR 2013 criteria, which met inclusion and exclusion criteria. The SSc patients were grouped into SSc-ILD and SSc non-ILD based on HRCT and tested for SSC-ILD specific autoantibody test (ATA, anti-Th/To antibody, and anti-fibrillarin) to obtain the diagnostic performance (sensitivity, specificity, and positive- and negative-predictive value).

Results

A total of 74 subject grouped into 47 SSc-ILD and 27 SSc-non ILD patients. ATA validity test results showed 85.1% sensitivity, 19.2% specificity, 65.6% PPV, and 41.7% NPV. Anti-Th/To antibody obtained 27.7% sensitivity, 88.9% specificity, 81.3% PPV, and 41.4% NPV. The anti-fibrillarin validity test result showed a 12.8% sensitivity, 96.3% specificity, 85.7% PPV, and 38.8% NPV. The combination of the three parameters had 95.7% sensitivity, 18.5% specificity, 67.1% PPV, and 71.4% NPV.

Conclusion

The combination of the SSc-ILD specific autoantibody test and HCRT is expected to detect all affected patients. Based on these results, SSc-ILD autoantibody-specific test can be used as an alternative examination for screening and diagnosis in health-care facilities that are not equipped with HRCT.

Prevalence and clinical associations of myositis antibodies in a large cohort of interstitial lung diseases

Background

Serologic testing for autoantibodies is recommended in interstitial lung diseases (ILDs), as connective tissue diseases (CTDs) are an important secondary cause. Myositis antibodies are associated with CTD-ILD, but clinical associations with other ILDs are unclear. In this study, associations of myositis antibodies in various ILDs were evaluated.

Methods

1463 ILD patients and 116 healthy subjects were screened for myositis antibodies with a line-blot assay on serum available at time of diagnosis. Additionally, bronchoalveolar lavage fluid (BALf) was analysed.

Results

A total of 394 patients demonstrated reactivity to at least one antibody, including anti-Ro52 (36.0%), anti-Mi-2β (17.3%) and anti-Jo-1 (10.9%). Anti-Jo-1 (OR 6.4; p<0.100) and anti-Ro52 (OR 6.0; p<0.001) were associated with CTD-ILD. Interestingly, anti-Mi-2β was associated with idiopathic pulmonary fibrosis (IPF; OR 5.3; p = 0.001) and hypersensitivity pneumonitis (HP; OR 5.9; p<0.001). Furthermore, anti-Mi-2β was strongly associated with a histological usual interstitial pneumonia (UIP) pattern (OR 6.5; p < 0.001). Moreover, anti-Mi-2β reactivity was identified in BALf and correlated with serum anti-Mi-2β (r = 0.64; p = 0.002). No differences were found in survival rates between ILD patients with and without serum Mi-2β reactivity (hazard ratio 0.835; 95% CI 0.442–1.575; p = 0.577).

Conclusion

In conclusion, novel associations of antibody Mi-2β with fibrotic ILD were found. Furthermore, serum anti-Mi-2β was associated with a histological UIP pattern and presence of anti-Mi-2β in BALf. Possibly, anti-Mi-2β could be implemented as a future diagnostic biomarker for fibrotic ILD.

Screening and characterization of myositis-related autoantibodies in COVID-19 patients

An efficient host immune response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) appears to be crucial for controlling and resolving this viral infection. However, many studies have reported autoimmune characteristics in severe COVID-19 patients. Moreover, clinical observations have revealed that COVID-19-associated acute distress respiratory syndrome shares many features in common with inflammatory myopathy including interstitial lung disease (ILD), most particularly rapidly progressive (RP)-ILD. This study explored this phenomenon by seeking to identify and characterize myositis-specific and related autoantibodies in 25 COVID-19 patients with mild or severe symptoms. Line blot analysis with the EUROLINE Myopathies Ag kit identified 9 (36%) patients with COVID-19 with one or more autoantibodies against several myositis-related antigens (Jo-1, Ku, Mi-2β, PL-7, PL-12, PM-Scl 75, PM-Scl 100, Ro-52, and SRP); no anti-MDA5 antibodies were detected. As the presence of antibodies identified by line blots was unrelated to disease severity, we further characterized the autoantibodies by radioimmunoassay, in which [³⁵ S]methionine-labeled K562 cellular antigens were precipitated and visualized by gel electrophoresis. This result was confirmed by an immunoprecipitation assay and immunoblotting; 2 patients exhibited anti-Ku70 and anti-Ku80 antibodies. Our data suggest that it is necessary to use more than one method to characterize and evaluate autoantibodies in people recovered from COVID-19, in order to avoid misinterpreting those autoantibodies as diagnostic markers for autoimmune diseases.

[Diagnostics of Interstitial Lung Diseases - Practical Instructions with a Focus on Rheumatologic Systemic Diseases]

Interstitial lung diseases (ILD) are etiologically heterogeneous with unknown and known causes like rheumatologic systemic diseases differing in their therapeutic and prognostic consequences. In consensus between pulmonologists, rheumatologists, radiologists, and pathologists, we developed practical instructions for ILD diagnosis in rheumatologic systemic diseases, in particular because ILD can present in early stages of rheumatic systemic diseases. ILD diagnosis is based on clinical assessment results including a detailed medical history, physical examination, focused laboratory tests, radiology with a high-resolution computed tomography, lung function, and histopathology also to differentiate it from cardiac and infection associated lung diseases. The ILD diagnosis is made in a multidisciplinary discussion leading to therapeutic and prognostic consequences. The occurrence of acute exacerbations is especially critical. They are often the causes for ILD progression and are associated with considerable mortality.

Utility of anti-neutrophil cytoplasmic antibody screening in idiopathic interstitial lung disease

Background:

Interstitial lung disease (ILD) is an established manifestation of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Autoimmune serologic screening is recommended by international consensus guidelines during the evaluation of idiopathic ILD, but ANCA testing only on a case-by-case basis.

Objective:

We aimed to evaluate the role of ANCA screening in patients with idiopathic ILD.

Methods:

We performed a retrospective review of patients seen between September 2015 and April 2017 in the ILD clinic at Toronto General Hospital. Patients referred with confirmed or suspected connective tissue disease were excluded. Patient demographics, symptoms, chest imaging, and pulmonary function testing was collected. We performed descriptive statistics based on the presence of ANCAs and estimated operating characteristics for ANCA screening.

Results:

In total, 360 patients with idiopathic ILD were reviewed, 159 met study inclusion criteria and 4 (2.5%) tested positive for ANCAs. Two patients (1.2%) had elevated myeloperoxidase-ANCAs (MPO-ANCA) and 2 (1.2%) had elevated proteinase-3-ANCAs (PR3-ANCA). There were no significant associations between patient demographics and ANCAs. One patient (0.6%) with PR3-ANCAs was diagnosed with vasculitis following rheumatologic evaluation. Despite negative ANCA testing, 1 patient (0.6%) was diagnosed with vasculitis following rheumatologic evaluation. The sensitivity and specificity of ANCA screening for vasculitis in patients with ILD was calculated as 50% (95% CI, 1.3%-98.7%) and 98% (95%CI, 4.4-155.5) respectively. Negative and positive likelihood ratios were 0.5 (95%CI 0.1-2.0) and 26.2 (95%CI 4.4-155.5) respectively.

Conclusion:

ANCA screening in patients with idiopathic ILD rarely yields positive results. These results support an individualized approach to ANCA testing as opposed to widespread screening.

Tofacitinib for the Treatment of Severe Interstitial Lung Disease Related to Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disease characterized by chronic symmetrical erosive synovitis and extra-articular manifestations, including interstitial lung disease (ILD), whose treatment is nowadays challenging due to high infectious risk and possible pulmonary iatrogenic toxicity. Janus kinase inhibitors, namely, tofacitinib, baricitinib, and upadacitinib, are the latest drug class for the treatment of RA with a good safety profile. We present the case of a patient with RA-ILD successfully treated with tofacitinib. A 52-year-old man was referred to our multidisciplinary clinic for rheumatic and pulmonary diseases for an active erosive seropositive RA and progressive ILD. Previous treatments were GC, hydroxychloroquine, methotrexate, etanercept, withdrawn after ILD detection, and tocilizumab, discontinued due to relapsing infections. After our evaluation, we proposed rituximab in addition to low-dose GC and hydroxychloroquine, ineffective on joint involvement. Therefore, we proposed tofacitinib which allowed us to control joint involvement, stabilize ILD improving respiratory symptoms, and manage the frequent infectious episodes that occurred initially. The short half-life and rapid-acting of tofacitinib are two helpful characteristics regarding this aspect. Despite limited data from randomized trials and real-life, tofacitinib could represent a safe therapeutic option for RA-ILD patients. Longitudinal studies are required to confirm this encouraging report.

Clinical features and long-term outcomes of interstitial lung disease with anti-neutrophil cytoplasmic antibody

Background

Patients with interstitial lung disease (ILD) are occasionally positive for anti-neutrophil cytoplasmic antibodies (ANCAs). Differences between ILDs secondary to microscopic polyangiitis (MPA) and isolated ANCA-positive idiopathic interstitial pneumonia (IIP) remain unclear. The aim of this study was to explore the differences in clinical features and outcomes between MPA-associated ILDs and isolated ANCA-positive IIPs.

Methods

We reviewed 1338 ILDs patients with available ANCA results and retrospectively analysed 80 patients who were ANCA-positive. MPA-associated ILDs (MPA-ILDs group) and isolated ANCA-positive IIPs (ANCA-IIPs group) were compared.

Results

Among 80 patients with ANCA-positive ILDs, 31 (38.75%) had MPA-ILDs, and 49 (61.25%) had isolated ANCA-positive IIPs. Compared with ANCA-IIPs group, patients in MPA-ILDs group had a higher proportion of fever (p = 0.006) and higher neutrophil count (p = 0.011), erythrocyte sedimentation rate (ESR) (p < 0.001) and C-reactive protein (CRP) (p = 0.005). Multivariable analysis showed that ESR level was an independent risk factor for mortality in all 80 ANCA-positive ILDs patients (HR 1.028, p = 0.001). Survival in MPA-ILDs group was lower than that in ANCA-IIPs group, and further stratified analysis revealed that ANCA-IIPs patients with elevated ESR or CRP had a worse prognosis than those with normal inflammation markers, with 5-year cumulative survival rates of 60.00%, 86.90% and 100.00% in MPA-ILDs and ANCA-IIPs with and without elevated inflammation markers, respectively.

Conclusions

Among patients with ANCA-positive ILDs, the prognoses of ANCA-IIPs with normal inflammation markers, ANCA-IIPs with elevated inflammation markers and MPA-ILDs were sequentially poorer. Therefore, stratified treatment should be considered in the management of ILDs patients positive for ANCAs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01451-4.

Krebs von den Lungen-6 and surfactant protein-A in interstitial pneumonia with autoimmune features

Interstitial pneumonia with autoimmune features (IPAF) is a special subtype of interstitial lung disease that has received worldwide attention. Krebs von den Lungen-6 (KL-6) and surfactant protein-A (SP-A) can be used as an important biomarker of interstitial lung disease, but its exact relationship with IPAF is poorly understood.A total of 65 IPAF patients were included in the study and were followed up for 52 weeks. The KL-6 and SP-A were evaluated by chemiluminescence enzyme immunoassay. The above indicators were tested at 2 time points, baseline (the first admission of patients) and 52 weeks. We also collected the indicators of antinuclear antibodies and rheumatoid factor. Based on high-resolution computed tomography evaluations, patients were divided into: aggravation, stable, and improvement group. At same time, 30 age-matched normal people as normal control were recruited, the same information was collected. Correlations among the groups were compared and analyzed.The KL-6 and SP-A level in IPAF patients were significantly higher than normal controls (fold increase = 11.35 and 1.39, both P < .001) and differed significantly at baseline and 52 weeks in IPAF (difference ratio = 37.7% and 21.3%, P < .05, both). There were significant differences at baseline and 52 weeks (r values of aggravation, improvement, and stable groups for KL-6 were 0.705, 0.770, and 0.344, P = .001, .001, and .163, and for SP-A the r value were 0.672, 0.375, and 0.316, P = .001, .126, and .152). In aggravation group, KL-6 and SP-A were correlated with CT scores (both P < .05). Diffusing capacity of the lung for carbon monoxide (DLCO) and forced vital capacity (FVC), % predicted showed a progressive downward trend, with a significant difference at baseline and 52 weeks in IPAF patients (difference ratio = 23.8% and 20.6%, both P < .05). There was a significant correlation between KL-6 and FVC % predicted and DLCO (both P < .05), SP-A showed negatively correlated with DLCO, but not significantly correlated with FVC % predicted (P < .05 and .47).This study demonstrated that KL-6 and SP-A can reflect disease progression, and both 2 play a key role at reflection of lung epithelial cell injury and fibrosis degree in IPAF.

Why is a paediatric respiratory specialist integral to the paediatric rheumatology clinic?

Systemic connective tissue diseases (CTDs) are characterised by the presence of autoantibodies and multiorgan involvement. Although CTDs are rare in children, they are associated with pulmonary complications, which have a high morbidity and mortality rate. The exact pathophysiology remains unclear. The pleuropulmonary complications in CTD are diverse in their manifestations and are often complex to diagnose and manage. The most common CTDs are discussed. These include juvenile systemic lupus erythematosus, juvenile dermatomyositis, juvenile systemic sclerosis, Sjögren's syndrome and mixed connective tissue disease. We describe the clinical features of the pleuropulmonary complications, focusing on their screening, diagnosis and monitoring. Treatment strategies are also discussed, highlighting the factors and interventions that influence the outcome of lung disease in CTD and pulmonary complications of treatment. Early detection and prompt treatment in a multidisciplinary team setting, including respiratory and rheumatology paediatricians and radiologists, is paramount in achieving the best possible outcomes for these patients.

Detection of Autoantibodies in Bronchoalveolar Lavage in Patients with Diffuse Interstitial Lung Disease

INTRODUCTION

Serum autoantibodies support the diagnosis of interstitial lung disease (ILD) related to systemic autoimmune diseases (SAD-ILD). Nevertheless, their presence in the bronchoalveolar lavage (BAL) has not been explored.

OBJECTIVES

To demonstrate the presence of autoantibodies in the BAL of ILD patients at onset of clinical evaluation, its relation with serum autoantibodies and to analyze clinical features of patients with autoantibodies in BAL.

METHODS

Autoantibodies against extractable nuclear antigens (ENAs) were analyzed by immunoblot in the BAL of 155 patient with suspected diagnosis of ILD and 10 controls.

RESULTS

Seven ENAs were detected in the BAL of 19 patients (Anti-Ro52, Anti-Ro60, CENP-B, Anti-La, Jo-1, Sm/RNP and Anti-SL70). The most frequent ENA was anti-Ro52 (13 patients; 68,4% of positives ones). Seven patients presented more than one ENAs. Fourteen were diagnosed of SAD-ILD, 3 of interstitial pneumonia with autoimmune features, one of non-specific idiopathic pneumonia and other of silicosis. In 10 cases (52%) IgA autoantibodies were also detected. The autoantibodies observed in BAL were also detected in the serum of 17 patients (90%). There were no significant clinical differences with the patients with SAD-ILD or interstitial pneumonia with autoimmune features with patients with negative BAL.

CONCLUSION

The study of ENAs in BAL is feasible and can be a useful tool in the ILD initial algorithm, specifically sustaining the suspected diagnosis of SAD-ILD.

Prevalence of Novel Myositis Autoantibodies in a Large Cohort of Patients with Interstitial Lung Disease

Connective tissue diseases (CTDs) are an important secondary cause of interstitial lung disease (ILD). If a CTD is suspected, clinicians are recommended to perform autoantibody testing, including for myositis autoantibodies. In this study, the prevalence and clinical associations of novel myositis autoantibodies in ILD are presented. A total of 1194 patients with ILD and 116 healthy subjects were tested for antibodies specific for Ks, Ha, Zoα, and cN1A with a line-blot assay on serum available at the time of diagnosis. Autoantibodies were demonstrated in 63 (5.3%) patients and one (0.9%) healthy control (p = 0.035). Autoantibodies were found more frequently in females (p = 0.042) and patients without a histological and/or radiological usual interstitial pneumonia (UIP; p = 0.010) and a trend towards CTD-ILDs (8.4%) was seen compared with other ILDs (4.9%; p = 0.090). The prevalence of antibodies specific for Ks, Ha, Zoα, and cN1A was, respectively, 1.3%, 2.0%, 1.4%, and 0.9% in ILD. Anti-Ha and Anti-Ks were observed in males with unclassifiable idiopathic interstitial pneumonia (unclassifiable IIP), hypersensitivity pneumonitis (HP), and various CTD-ILDs, whereas anti-cN1A was seen in females with antisynthetase syndrome (ASS), HP, and idiopathic pulmonary fibrosis (IPF). Anti-Zoα was associated with CTD-ILD (OR 2.5; 95%CI 1.11-5.61; p = 0.027). In conclusion, a relatively high prevalence of previously unknown myositis autoantibodies was found in a large cohort of various ILDs. Our results contribute to the awareness that circulating autoantibodies can be found in ILDs with or without established CTD. Whether these antibodies have to be added to the standard set of autoantibodies analysed in conventional myositis blot assays for diagnostic purposes in clinical ILD care requires further study.

Current and Emerging Drug Therapies for Connective Tissue Disease-Interstitial Lung Disease (CTD-ILD)

Interstitial lung disease (ILD) can be associated with all connective tissue diseases and is an important cause of morbidity and mortality. The management of connective tissue disease-interstitial lung disease (CTD-ILD) is challenging due substantial heterogeneity in disease behaviour and paucity of controlled clinical trials to guide treating clinicians. Not all patients require treatment, and the decision to treat needs to be individualised based on a patient's observed disease behaviour, baseline and longitudinal lung function measurements, extent of lung involvement on radiology and patient factors including age, co-morbidities and personal preference. If indicated, treatment of the CTD-ILD is largely with immunomodulation, with the aim to prevent progression of the ILD before further irreversible lung injury and disability occurs. Corticosteroids, cyclophosphamide, mycophenolate mofetil and azathioprine are the most common immunosuppressive agents currently used to treat CTD-ILD, demonstrating stability of lung function in case series and a small number of randomised controlled trials in ILD associated with systemic sclerosis. Biological and non-biological disease-modifying anti-rheumatic drugs, and the anti-fibrotics nintedanib and pirfenidone, have revolutionised the treatment of connective tissue diseases and idiopathic ILD, respectively. Furthermore, anti-fibrotics have recently demonstrated safety and efficacy in ILD associated with systemic sclerosis. There remains a critical unmet need to clarify when and in whom to initiate treatment, and which agent(s) to utilise to achieve optimal outcomes for CTD-ILD patients whilst minimising harms through prospective multicentre trials. This review highlights the challenges faced when treating patients with CTD-ILD and summarises available evidence for current, emerging and novel therapies.

Systematic review and meta-analysis of the prognosis and prognostic factors of interstitial pneumonia with autoimmune features

OBJECTIVE

To clarify the prognosis and prognostic factors of interstitial pneumonia with autoimmune features (IPAF) in comparison to idiopathic pulmonary fibrosis (IPF), the most common idiopathic interstitial pneumonia, and connective tissue disease-associated interstitial pneumonia (CTD-IP).

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

Electronic databases such as Medline and Embase were searched from 2015 through 6 September 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Primary studies that comparatively investigated the prognosis or prognostic factors of IPAF were eligible.

DATA EXTRACTION AND ANALYSIS

Two reviewers extracted relevant data and assessed the risk of bias independently. A meta-analysis was conducted using a random-effects model. The quality of presented evidence was assessed by the Grades of Recommendation, Assessment, Development, and Evaluation system.

RESULTS

Out of a total of 656 records retrieved, 12 studies were reviewed. The clinical features of IPAF were diverse between studies, which included a radiological and/or pathological usual interstitial pneumonia (UIP) pattern of between 0% and 73.8%. All studies contained some risk of bias. There was no significant difference of all-cause mortality between IPAF-UIP and IPF in all studies, although the prognosis of IPAF in contrast to IPF or CTD-IP varied between studies depending on the proportion of UIP pattern. Among the potential prognostic factors identified, age was significantly associated with all-cause mortality of IPAF by a pooled analysis of univariate results with a hazard ratio (HR) of 1.06 (95% confidence interval (CI) 1.04 to 1.07). The adjusted effect of age was also significant in all studies. The quality of presented evidence was deemed as very low.

CONCLUSION

There was no significant difference of all-cause mortality between IPAF-UIP and IPF. Age was deemed as a prognostic factor for all-cause mortality of IPAF. The findings should be interpreted cautiously due to the low quality of the presented evidence.

PROSPERO REGISTRATION NUMBER

CRD42018115870.

Systematic review and meta-analysis of clinical significance of autoantibodies for idiopathic pulmonary fibrosis

OBJECTIVE

To clarify clinical significance of the sole presence of autoantibodies for idiopathic pulmonary fibrosis (IPF) without any other symptoms or signs suggestive of autoimmune disease.

DESIGN

Systematic review and meta-analysis DATA SOURCES: Medline, EMBASE, Science Citation Index Expanded and Google Scholar were searched from 1 January 2002 through 12 February 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Primary studies addressing all-cause mortality and the development of a defined autoimmune disease for IPF with autoantibodies were included for the review.

DATA EXTRACTION AND SYNTHESIS

Two reviewers extracted relevant data and assessed risk of bias independently. Meta-analysis was conducted using a random-effects model if three or more studies reported the same outcome for a certain autoantibody. The quality of evidence was assessed by the Grades of Recommendation, Assessment, Development and Evaluation system.

RESULTS

Out of 4603 records retrieved nine studies were included in this review. All studies contained some risk of bias. Based on pooled data myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) was significantly associated with microscopic polyangiitis incidence with risk ratio (RR) of 20.2 (95% CI: 7.22 to 56.4) and antinuclear antibody (ANA) was also significantly associated with the development of connective tissue diseases with RR of 7.11 (p=0.001) (10 cases in 157 patients with ANA) in one study. However, there was no significant association of autoantibodies with all-cause mortality aside from MPO-ANCA and proteinase 3-ANCA in one study each. MPO-ANCA was not demonstrated to be associated with all-cause mortality by meta-analysis. The quality of evidence was deemed as either low or very low.

CONCLUSIONS

The presence of autoantibodies such as MPO-ANCA and ANA was demonstrated to be associated with the development of some autoimmune diseases for patients with IPF although there was no difference of all-cause mortality. However, the results should be interpreted with caution due to low evidence level.

PROSPERO REGISTRATION NUMBER

CRD42017077336.

Association of serum tumor markers with interstitial lung disease in patients with or without connective tissue disease: A cross-sectional study

Background: Serum markers, such as Krebs von den Lungen-6 (KL-6), are reported to reflect the severity, progression and prognosis of idiopathic pulmonary fibrosis (IPF). We aimed to evaluate whether tumor markers could improve the diagnosis of connective tissue diseases (CTDs) and predict CTD-related interstitial lung diseases (ILDs) (CTD–ILD); and whether there was a significant difference between ILD patients with CTD and without CTD (non-CTD–ILD).

Methods: In this study, 146 patients with ILD only, 61 with CTD–ILD, 102 with lung cancer (LC), 111 with COPD, and 46 with CTD were enrolled. Serum levels of several tumor markers were collected.

Results: Compared with COPD, the serum levels of CEA, NSE, CYFRA21-1, CA19-9 and CA125 were higher, but the level of SCC was lower; meanwhile, there were significant differences in NSE, SCC, CYFRA21-1 and CA125 between CTD–ILD and non-CTD–ILD groups.

Conclusions: It appears that tumor-associated antigens may be the predictive factors for CTD–ILD that could be used to identify CTD from ILD before it is detected on autoimmune symptoms or auto-antibodies. However, further studies are needed to validate our findings and determine whether serum tumor markers have prognostic value or predict progressive CTD–ILD.

Utility of autoimmune serology testing in the assessment of uncharacterized interstitial lung disease: a large retrospective cohort review

BACKGROUND

Autoimmune serologies are often obtained in the initial evaluation of uncharacterized interstitial lung disease (ILD). Whether this practice is helpful in delineating connective-tissue disease related ILD (CTD-ILD) is not well known. We assessed the frequency of incident CTD-ILD as detected by autoimmune serology testing and presenting clinical signs and symptoms.

METHODS

Consecutive patients seen at our institution over a four year period with newly diagnosed uncharacterized ILD and autoimmune serologic testing were included. Serologic assessment was performed as a standardized order set of 13 laboratory tests. Presenting demographics and clinical signs or symptoms suggestive of autoimmune disease were correlated with the presence or absence of positive serology studies and final CTD-ILD diagnoses.

RESULTS

Overall prevalence of newly diagnosed CTD-ILD was 6.9% (42 of 605). Positive serology was seen in 35.2% (213 of 605) of screened ILD. CTD-ILD was diagnosed in 19.2% of those with positive serology, and 52.8% of those with both positive serology and suggestive clinical signs or symptoms. Only 1.4% of those with positive serology and negative review of systems were diagnosed with CTD-ILD. CTD-ILD diagnoses were made more frequently in younger patients ≤60 years with no diagnoses made after the age of 80 (P = 0.009). Positive serology in non-CTD-ILD cases did not appear to confer any survival advantage.

CONCLUSIONS

The yield of autoimmune serology testing in uncharacterized ILD appears greatest in those with suggestive clinical signs or symptoms on presentation for CTD-ILD.

Pulmonary manifestations of rheumatologic diseases

PURPOSE OF REVIEW

The present review intends to provide an overview of the diversity and complexity of pulmonary manifestations of rheumatologic diseases and gaps in knowledge to effectively manage them.

RECENT FINDINGS

Diffuse lung disease in children with rheumatologic diseases represents a heterogeneous group of autoimmune disorders. Despite their significant morbidity and mortality, we have limited understanding about their pathogenesis. Here, we provide an overview of the pathophysiology and current management approach of these disorders, highlighting tools which assist with diagnosis, risk stratification and therapy. In this context, we address the need to develop a standardized approach to diagnose at-risk patients with rheumatologic disease and to predict their progression and the need to develop robust studies which evaluate the factors and interventions that influence pulmonary disease outcome.

SUMMARY

Diffuse lung disease in children with rheumatologic diseases represents a heterogeneous group of severe autoimmune disorders. By adopting a collaborative research approach among multicenters to help diagnose, risk stratify, and understand disease progression, effective management decisions can be optimized to improve clinical outcome.

The Diagnosis and Treatment of Antisynthetase Syndrome

Anti-synthetase syndrome is an autoimmune condition, characterized by antibodies directed against an aminoacycl transfer RNA synthetase along with clinical features that can include interstitial lung disease, myositis, Raynaud's phenomenon, and arthritis. There is a higher prevalence and increased severity of interstitial lung disease in patients with anti-synthetase syndrome, as compared to dermatomyositis and polymyositis, inflammatory myopathies with which it may overlap phenotypically. Diagnosis is made by a multidisciplinary approach, synthesizing rheumatology and pulmonary evaluations, along with serologic, radiographic, and occasionally muscle and/or lung biopsy results. Patients with anti-synthetase syndrome often require multi-modality immunosuppressive therapy in order to control the muscle and/or pulmonary manifestations of their disease. The long-term care of these patients mandates careful attention to the adverse effects and complications of chronic immunosuppressive therapy, as well as disease-related sequelae that can include progressive interstitial lung disease necessitating lung transplantation, pulmonary hypertension, malignancy and decreased survival. It is hoped that greater awareness of the clinical features of this syndrome will allow for earlier diagnosis and appropriate treatment to improve outcomes in patients with anti-synthetase syndrome.