Interstitial pneumonia with autoimmune features and undifferentiated connective tissue disease: Our interdisciplinary rheumatology-pneumology experience, and review of the literature.

Interstitial lung diseases (ILDs) are a heterogeneous group of disorders characterized by inflammation and/or fibrosis of the lungs, varying from idiopathic interstitial pneumonias to secondary variants, including the ILDs associated to connective tissue diseases (CTDs). In addition, a number of patients are recognized as unclassifiable ILD (U-ILD), because of the inability to reach a definite diagnosis; some of them show autoimmune manifestations not fulfilling the classification criteria of a given CTD. The term interstitial pneumonia with autoimmune features (IPAF) has been recently proposed for this particular ILD subset. Here, we report our experience resulting from the integrated - pneumology/rheumatology - approach to patients with suspected ILDs or CTDs referred to our university-based Center for the Rare Pulmonary Diseases and Rheumatology Unit, from January 2009 to June 2015, with particular attention to the above-mentioned U-ILD, IPAF, and undifferentiated connective tissue disease (UCTD). The comparative analysis of these clinical variants was carried out; moreover, the observed findings were compared with the results of the updated review of the literature. After the first clinical assessment, the U-ILD were identified in 50 patients; afterwards, on the basis of clinico-serological and radiological findings U-ILD group was subdivided into 2 subgroups, namely U-ILD without any clinical extra-thoracic manifestations and/or immunological alterations (15 pts) and IPAF according to the above-mentioned classification criteria (35 pts). Patients with either IPAF or U-ILD were compared with a series of 52 stable UCTD (disease duration ≥3 years), followed at our Rheumatology Unit. Some important differences were evidenced among the 3 series of U-ILD, IPAF, and UCTD: firstly, female gender was more frequent in patients with UCTD (86%) or IPAF (69%) compared with U-ILD (60%) or idiopathic pulmonary fibrosis (24%; p=0.001). In addition, UCTD patients were younger and showed longer disease duration. More interestingly, both UCTD and IPAF series show a comparable prevalence of various clinical manifestations, with the exception of the interstitial lung involvement detectable in a very small percentage of UCTD patients. Concordantly, the review of the literature evidenced two main subsets of U-ILD, one is characterized by isolated unclassifiable interstitial pneumonia and another one composed by subjects with clinically prevalent lung involvement in the setting of not definite CTD, the recently proposed IPAF. We hypothesize that IPAF and UCTD might represent two clinical variants of the same systemic autoimmune disorders. The marked difference regarding the prevalence of ILD, which is the clinical hallmark of IPAF but very rare in UCTD, may at least in part reflect a selection bias of patients generally referred to different specialist centers, i.e. pneumology or rheumatology, according to the presence/absence of clinically dominant ILD, respectively. Well-integrated, interdisciplinary teams are recommended for the assessment and management of these patients in the clinical practice. Finally, the cooperation between multidisciplinary groups with different experiences may be advisable for a validation study of the proposed nomenclature and classification criteria of these indefinable ILD/CTD variants.

Ferri C ，Manfredi A ，Sebastiani M ，Colaci M ，Giuggioli D ，Vacchi C ，Della Casa G ，Cerri S ，Torricelli P ，Luppi F ... -  《-》

Overlap of interstitial pneumonia with autoimmune features with undifferentiated connective tissue disease and contribution of UIP to mortality.

Criteria for interstitial pneumonia with autoimmune features (IPAF) were recently established for research purposes in a joint statement from the European Respiratory Society (ERS) and American Thoracic Society (ATS). We reviewed the utility of these criteria in patients previously diagnosed as broadly defined undifferentiated connective tissue disease (UCTD) and noted overlapping IPAF findings. Additional review was given to IPAF patients with usual interstitial pneumonia (UIP) on histopathology or radiology in terms of survival and outcome. Patients with prior UCTD-interstitial lung disease (ILD) were screened by ERS/ATS criteria for IPAF. Clinical data along with all-cause mortality were collated and compared with selected idiopathic pulmonary fibrosis (IPF) patients from the same study period. Survival was compared between IPAF subgroups with and without UIP features. One hundred and one UCTD-ILD subjects (91%) evaluated from 2005 to 2012 also met strict criteria for IPAF. Frequent clinical findings included Raynaud's phenomenon, positive anti-nuclear antibody (ANA) and non-specific interstitial pneumonia (NSIP) pattern on chest computed tomography (CT). Nineteen had features of UIP either on histopathology or CT imaging. As compared with IPF, IPAF patients had overall better survival except in those with UIP features. Current IPAF criteria encompassed the majority of broadly defined UCTD-ILD and included those with UIP findings. Survival compared with IPF in those with UIP was similar. Further studies are necessary to refine IPAF definitions for clinical use and guide directed management strategies.

Kelly BT ，Moua T 《-》

Non-specific interstitial pneumonia and features of connective tissue disease: What are the consequences of a different point of view?

Biffi A ，Dei G ，De Giacomi F ，Stainer A ，Parma LO ，Pozzi MR ，Faverio P ，Pesci A ... -  《-》

Idiopathic Interstitial Pneumonia Associated With Autoantibodies: A Large Case Series Followed Over 1 Year.

Some patients with autoimmune characteristics and idiopathic interstitial pneumonia, particularly usual interstitial pneumonia (UIP), do not fit neatly into the category of connective tissue disease-associated interstitial lung disease (CTD-ILD), idiopathic pulmonary fibrosis (IPF), or recently proposed yet to be validated criteria for interstitial pneumonia with autoimmune features (IPAF). Outcomes of these patients are unknown. This was a retrospective single-center study. Analyses of variance compared differences in mean change in FVC and diffusion capacity (Dlco) over 1 year among 124 well-defined patients (20 patients with positive autoantibodies with or without symptoms of connective tissue disease [AI-ILD], 15 patients with IPAF, 36 patients with CTD-ILD, and 53 patients with IPF with negative CTD serologies [Lone-IPF]). Of the patients, 75% with AI-ILD, 33% with IPAF, and 33% with CTD-ILD had UIP. Initial FVC and Dlco were similarly moderately reduced across groups. Mean change in FVC over 12 months was as follows: -60 mL (IPAF), -110 mL (AI-ILD), -10 mL (CTD-ILD), and -90 mL (Lone-IPF) (P = .52). Mean change in Dlco was as follows: 2.39 mL/mm Hg/min (IPAF), -1.15 mL/mm Hg/min (AI-ILD), -0.27 mL/mm Hg/min (CTD-ILD), and -1.05 mL/mm Hg/min (Lone-IPF) (P < .001). By pattern of disease, the mean change in FVC was as follows: -140 mL (UIP), 10 mL (nonspecific interstitial pneumonia), and 12 mL (unclassifiable/other) (P = .001). No clinically significant differences in pulmonary function to distinguish between patients with AI-ILD, IPAF, CTD-ILD, and Lone-IPF were observed after 1 year. Longer periods of follow-up are needed to understand the outcomes of these patients. It is not yet clear whether AI-ILD is a distinct phenotype or a variant of the newly proposed entity IPAF.

Collins BF ，Spiekerman CF ，Shaw MA ，Ho LA ，Hayes J ，Spada CA ，Stamato CM ，Raghu G ... -  《-》

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.

Bozzao F ，Tomietto P ，Baratella E ，Kodric M ，Cifaldi R ，Della Porta R ，Prearo I ，Pirronello SMG ，Confalonieri P ，Ruaro B ，Fischetti F ，Fabris B ... -  《-》