An official European Respiratory Society/American Thoracic Society research statement: interstitial pneumonia with autoimmune features

Abstract

Many patients with an idiopathic interstitial pneumonia (IIP) have clinical features that suggest an underlying autoimmune process but do not meet established criteria for a connective tissue disease (CTD). Researchers have proposed differing criteria and terms to describe these patients, and lack of consensus over nomenclature and classification limits the ability to conduct prospective studies of a uniform cohort.The "European Respiratory Society/American Thoracic Society Task Force on Undifferentiated Forms of Connective Tissue Disease-associated Interstitial Lung Disease" was formed to create consensus regarding the nomenclature and classification criteria for patients with IIP and features of autoimmunity.The task force proposes the term "interstitial pneumonia with autoimmune features" (IPAF) and offers classification criteria organised around the presence of a combination of features from three domains: a clinical domain consisting of specific extra-thoracic features, a serologic domain consisting of specific autoantibodies, and a morphologic domain consisting of specific chest imaging, histopathologic or pulmonary physiologic features.A designation of IPAF should be used to identify individuals with IIP and features suggestive of, but not definitive for, a CTD. With IPAF, a sound platform has been provided from which to launch the requisite future research investigations of a more uniform cohort. @ERSpublications ERS/ATS task force provides nomenclature and classification criteria for patients with IIP and autoimmune features

Is It Idiopathic Pulmonary Fibrosis or Not?

“…Many patients present with an underlying autoimmune feature but do not meet established criteria for a CTD; therefore, ERS/ATS recently proposed the term, "interstitial pneumonia with autoimmune features" (IPAF) and offered its diagnostic criteria. 27 This new guideline suggests a pos- sible underlying autoimmune etiology in patients with NSIP despite a lack of definitive CTD diagnosis. Moreover, since CHP and NSIP have many overlapping findings on radiography and histopathologic examination, a comprehensive environmental, occupational, and avocational history is also a critical step.…”

Evaluation of patients with fibrotic interstitial lung disease: A Canadian Thoracic Society position statement

“…29 Conversely, referral to a rheumatologist should be considered in patients with suggestive clinical features, specific autoantibodies, or high titre ANA ( 1:320) and/or RF ( 60 IU/mL). 18,19 Similarly, a rheumatology referral should be considered in patients that meet criteria for IPAF (see Reference 19 for IPAF criteria). 19 Some Canadian centres offer combined pulmonary-rheumatology ILD clinics for coordinated multidisciplinary evaluation of patients with suspected CTD-ILD.…”

“…18,19 Similarly, a rheumatology referral should be considered in patients that meet criteria for IPAF (see Reference 19 for IPAF criteria). 19 Some Canadian centres offer combined pulmonary-rheumatology ILD clinics for coordinated multidisciplinary evaluation of patients with suspected CTD-ILD.…”

“…17,18 Consensus criteria have recently been proposed for interstitial pneumonia with autoimmune features (IPAF), defined as patients with ILD who have autoimmune features that do not meet criteria for a defined CTD. 19 Key Messages: High Resolution Computed Tomography All patients being evaluated for fibrotic ILD should undergo high-resolution computed tomography (HRCT) imaging of the chest, unless contraindicated. Expiratory and prone HRCT imaging may provide valuable diagnostic information.…”

Idiopathic pulmonary fibrosis: another step in understanding the burden of this disease

“…Although clinicians can be guided by excellent international consensus statements [18,19], there will always be variation when there is no pathological "yes or no" answer to clinch a diagnosis, rather a mix of terms such as "probable" and "possible" put forward by variably experienced members of multidisciplinary teams. When a specific imaging pattern can mean IPF (and potential exciting new medications) or asbestosis (if the appropriate detailed history is elicited) or even connective tissue disease-related interstitial lung disease or interstitial pneumonia with autoimmune features (if the hospital has the appropriate panel of new autoimmune tests available) [20] then the reliability of diagnostic labels may clearly vary between centres, let alone countries. It is clear that radiologists may disagree with regards to identifying a usual interstitial pneumonia pattern on imaging [21]; an interesting proposal would be to share sample case histories and radiology between different specialist centres and assess the degree of diagnostic concordance that arises.…”