Characterisation of patients with interstitial pneumonia with autoimmune features

Abstract

Patients with interstitial lung disease (ILD) may have features of connective tissue disease (CTD), but lack findings diagnostic of a specific CTD. A recent European Respiratory Society/American Thoracic Society research statement proposed criteria for patients with interstitial pneumonia with autoimmune features (IPAF). We applied IPAF criteria to patients with idiopathic interstitial pneumonia and undifferentiated CTD-ILD (UCTD). We then characterised the clinical, serological and morphological features of the IPAF cohort, compared outcomes to other ILD cohorts and validated individual IPAF domains using survival as an endpoint. Of 422 patients, 144 met IPAF criteria. Mean age was 63.2 years with a slight female predominance. IPAF cohort survival was marginally better than patients with idiopathic pulmonary fibrosis, but worse than CTD-ILD. A non-usual interstitial pneumonia pattern was associated with improved survival, as was presence of the clinical domain. A modified IPAF cohort of those meeting the clinical domain and a radiographic or histological feature within the morphological domain displayed survival similar to those with CTD-ILD. IPAF is common among patients with idiopathic interstitial pneumonia and UCTD. Specific IPAF features can identify subgroups with differential survival. Further research is needed to replicate these findings and determine whether patients meeting IPAF criteria benefit from immunosuppressive therapy.

Smoke-free legislation and its impact on paediatric respiratory health

“…We read with great interest the study by VARDAVAS et al [1] confirming the independent and interacting roles of tobacco smoke exposure during pregnancy and after birth in the development of respiratory diseases.…”

Interstitial pneumonitis with autoimmune features (IPAF): a work in progress

“…OLDHAM et al [6] retrospectively applied IPAF criteria to a cohort of 422 patients diagnosed with IIP, interstitial pneumonia associated with UCTD or unclassifiable ILD. The finding that approximately one-third of the initial cohort (n=144) met IPAF criteria confirmed earlier reports [4,7,8] that features of CTD are common in patients with IIP.…”

“…Survival mirrored that in CTD-ILD, but this subgroup consisted of 40 of the 46 IPAF patients with non-UIP patterns, who were also characterised by a CTD-ILD-like outcome. Due to major subgroup overlap of this sort and the lack of powering for other outcome analyses, the nuanced prognostic distinctions reported by OLDHAM et al [6] will need to be tested in future cohorts. What can be concluded with confidence is that, within patients meeting IPAF criteria, the distinction between a UIP and a non-UIP pattern, whether on HRCT or biopsy, has major prognostic significance.…”

Diffuse parenchymal lung disease

“…In conclusion, this study by OLDHAM et al [37] is an important first step in evaluating the new IPAF classification criteria, providing useful insights into the characterisations of clinical, morphological and serological features of IPAF in NSIP-OP, IPF, unclassifiable IIPs and UCTD-ILD patients. The strongest message of this study is that the outcome difference in IPAF is primarily linked to the underlying presence of UIP [38], which shows a prognosis similar to IPF, and we believe should be managed accordingly until existing uncertainties are clarified by future studies.…”

“…IPAF was created as a research category, intended to provide a sound platform for the prospective study of these patients. With the aim of characterising the features of IPAF and defining its prognosis in comparison to other DPLDs, OLDHAM et al [37] applied IPAF criteria to a series of 422 patients with IIPs (NSIP, IPF, cryptogenic organising pneumonia (COP) and unclassifiable IIPs) and undifferentiated CTD (UCTD)-associated ILD. A large subgroup of patients (34%, n=144) met the IPAF criteria (30% of NSIP, 60% of COP, 20% of IPF, 25% of unclassifiable IIPs and 91% of UCTD-ILD).…”