Ayodeji Adegunsoye, Justin M. Oldham, Eleanor Valenzi, Cathryn Lee, Leah J. Witt, Lena Chen, Steven Montner, Jonathan H. Chung, Imre Noth, Rekha Vij, Mary E. Strek, and Aliya N. Husain (2017) Interstitial Pneumonia With Autoimmune Features: Value of Histopathology. Archives of Pathology & Laboratory Medicine: July 2017, Vol. 141, No. 7, pp. 960-969.

ORIGINAL ARTICLES

Interstitial Pneumonia With Autoimmune Features: Value of Histopathology

Ayodeji Adegunsoye, MD, MS; Justin M. Oldham, MD, MS; Eleanor Valenzi, MD; Cathryn Lee, MD; Leah J. Witt, MD; Lena Chen, BS;Steven Montner, MD; Jonathan H. Chung, MD; Imre Noth, MD; Rekha Vij, MD; Mary E. Strek, MD; Aliya N. Husain, MD

From the Section of Pulmonary and Critical Care Medicine, Department of Medicine (Drs Adegunsoye, Witt, Noth, Vij, and Strek and Ms Chen) and the Departments of Medicine (Drs Valenzi and Lee), Radiology (Drs Montner and Chung), and Pathology (Dr Husain), University of Chicago, Chicago, Illinois; and the Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, Davis (Dr Oldham). Drs Adegunsoye and Oldham contributed equally to this article.

Reprints: Ayodeji Adegunsoye, MD, Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, 5841 S Maryland Ave, MC6076, Chicago, IL 60637 (email: deji@uchicago.edu).

The authors have no relevant financial interest in the products or companies described in this article.

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.