Predictors of Pulmonary Hypertension and Right Ventricular Dysfunction in Patients with Hypersensitivity Pneumonitis

Background: Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) that occurs in susceptible individuals in response to various inhaled antigens. The fibrotic phenotype of HP is characterized by disease progression and can lead to pulmonary hypertension (PH). The aim of this study was to estimate the prevalence of PH and to identify predictors of PH in patients with chronic HP.

Methods: We conducted an observational longitudinal study that included 85 patients with an established diagnosis of HP. Clinical examination, quality of life questionnaires, high-resolution computed tomography (HRCT) of the chest, arterial blood gases analyses, six-minute walking test (6-MWT), pulmonary function tests, and echocardiography were performed.

Results: Patients were divided into groups with fibrotic (71.8%) and nonfibrotic phenotype (28.2%). PH was detected in 41 (48.2%) patients. Patients with PH had the predominant fibrotic phenotype of HP, were older, more symptomatic, and had a higher FVC/DLco ratio. The most significant predictors of PH were CT signs of fibrosis, finger clubbing, FVC/DLco, decreased distance, and SpO₂ at the end of 6-MWT, as well as the presence of cardiovascular diseases.

Conclusions: PH is a common condition in patients with chronic HP, especially with the fibrotic phenotype. Early detection of the PH predictors is necessary for the timely diagnosis of this complication of HP.