Interstitial Pneumonia With Autoimmune Features: Value of Histopathology

Abstract

Context Patients with idiopathic interstitial pneumonia may display evidence of autoimmunity, without meeting criteria for a defined connective tissue disease. A recent European Respiratory Society/American Thoracic Society statement proposed research criteria for interstitial pneumonia with autoimmune features (IPAF), which includes findings from the clinical, serologic, and morphologic domains. Objectives To investigate the importance of histopathologic criteria within the morphologic domain and to report our methodology for identifying these features. Design Patients with idiopathic interstitial pneumonia at the University of Chicago, who underwent surgical lung biopsy or lung transplantation were assessed for IPAF histopathologic features, using the initial pathology interpretation in the electronic records. A focused rereview of available slides by a pulmonary pathologist was then performed for patients who failed to meet IPAF criteria on initial pathology assessment. Results Of 422 patients with idiopathic interstitial pneumonia, 176 (41.7%) underwent surgical lung biopsy or lung transplant. Forty-six of those 176 patients (26.1%) met IPAF criteria by initial pathology interpretation and a positive clinical or serologic feature. Of the remaining 130 patients, 73 (56.2%) met either the clinical or serologic domains without meeting the morphologic domain, whereas 36 (27.7%) had slides available for pathology rereview. This rereview demonstrated nonspecific interstitial pneumonia in 8 of 36 patients (22.2%) and lymphoplasmacytic infiltrates in 6 of 36 patients (16.7%), resulting in an additional 7 of 36 patients (19.4%) with idiopathic interstitial pneumonia that met the IPAF criteria. In IPAF, pulmonary vasculopathy was the most prevalent finding (45 of 84; 53.6%) and predicted increased mortality (hazard ratio, 2.5; P = .04). Conclusions Using a methodological approach to identifying IPAF pathology, we demonstrate a significant increase in the number of patients meeting IPAF criteria because of focused pathologic review and highlight the prognostic value of the IPAF pathologic findings.

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

“…Case reports, case series, letters to editors and reviews were not analysed. From three different articles dealing with the same cohort of IPAF patients, only the one with complete data was considered [18][19][20]. Finally, manuscripts considering ASS patients were excluded to avoid any selection bias.…”

Morphologic Aspects of Interstitial Pneumonia With Autoimmune Features

“…15 Intrinsic airways disease was the most common multicompartment finding in IPAF patients observed in the study of Oldham et al, 14 followed by pleural disease and pulmonary vasculopathy. Pulmonary hypertension was present in 10 of 57 IPAF patients (17.5%) studied by Ahmad et al 21 In a study by Adegunsoye et al, 35 pulmonary vasculopathy was also the most prevalent finding in 45 of 84 patients (53.6%) with IPAF. However, the prevalence of pulmonary vasculopathy in IPAF patients was not significantly different from the non-IPAF group (patients meeting criteria for IPF, idiopathic NSIP, cryptogenic organizing pneumonia, or UCTD who had not fulfilled criteria for IPAF).…”

“…However, the prevalence of pulmonary vasculopathy in IPAF patients was not significantly different from the non-IPAF group (patients meeting criteria for IPF, idiopathic NSIP, cryptogenic organizing pneumonia, or UCTD who had not fulfilled criteria for IPAF). 35 In addition, patients with IPAF and pulmonary vasculopathy had worse survival rates compared with the IPAF group without such findings. The same analysis was performed among the non-IPAF patients, and the presence of pulmonary vasculopathy was not associated with worse survival rates in comparison with patients without pulmonary vasculopathy.…”

“…33 The reactive lymphoid hyperplasia can be observed within the fibrotic areas, in subpleural zones, along interlobular septa, and can be associated with bronchial walls. 33,34 A recent study by Adegunsoye et al 35 proposed a new methodologic approach to identify patients with histopathologic characteristics of IPAF. The authors used a quantitative evaluation for interstitial lymphoid aggregates with germinal centers (at least 3 germinal centers in a low-power field) and lymphoplasmacytic infiltration (presence of diffuse infiltrates of lymphocytes and at least 40 plasma cells in a highpower field) to identify patients fulfilling the morphologic criterion of IPAF.…”

“…The same analysis was performed among the non-IPAF patients, and the presence of pulmonary vasculopathy was not associated with worse survival rates in comparison with patients without pulmonary vasculopathy. 35 …”