Interstitial Lung Disease in Primary Biliary Cholangitis: A Cohort Prospective Study

Abstract

Interstitial lung disease (ILD) has been recognized as an extrahepatic manifestation ofprimary biliary cholangitis (PBC), althoughlimited data are available on its prevalence and clinical significance. Therefore, we evaluated the occurrence and clinical features of ILD in a cohort of PBC patients. Ninety-three individuals without concomitant rheumatic diseases were enrolled in our prospective cohort study. All patients underwent chest high-resolution computed tomography (HRCT). Liver-related and lung-related survival wereassessed. A lung-related outcome was defined as death from ILD complications; a liver-related outcome was defined as liver transplantation or death from liver cirrhosis complications. HRCT findings suggestive ofILD were detected in 38 patients (40.9%). A sarcoid-like pattern of PBC-associated ILD was the most frequent, followed by subclinical ILD and organizing pneumonia. Patients with ILD were less likely to have liver cirrhosis and liver-related symptoms and presented with higher serum immunoglobulin M(IgM) and M2 subtype antimitochondrial antibodies (AMA-M2) positivity rates. In a multivariate analysis, the absence of liver disease symptoms at the disease presentation (OR 11.509; 95% CI 1.210–109.421; p = 0.033), the presence of hepatic non-necrotizing epithelioid cell granulomas (OR 17.754; 95% CI 1.805–174.631; p = 0.014), higher serum IgM (OR 1.535; 95% CI 1.067–2.208; p = 0.020) and higher blood leukocyte count (OR 2.356; 95% CI 1.170–4.747; p = 0.016) were independent risk factors associated with ILD in PBC. More than a third of patients with ILD showed no respiratory symptoms, and only one ILD-related death occurred during a follow-up of 29.0 months (IQR 11.5; 38.0). Patients with ILD had better liver transplant-free survival.ILD in PBC had a benign course and was associated with a lower liver disease severity. PBC-associated ILD should be included in a list of differential diagnoses of ILD.