Pulmonary function and high-resolution CT findings five years after disease onset in patients with Wegener's granulomatosis

Abstract

Objective: Although pulmonary involvement is common in Wegener's granulomatosis (WG), little is known about the pulmonary outcome. We evaluated the relationship between clinical disease characteristics and pulmonary function and high-resolution computed tomography (HRCT) findings after disease duration of 5 years.

Methods: A pulmonary function test (PFT) and pulmonary HRCT were performed in 41 patients from a population-based register of WG. Clinical predictors for abnormal PFT and HRCT were tested by logistic regression.

Results: Previous WG-related lung involvement (PLI) had occurred in 80% of patients, but only 24% of patients still reported pulmonary symptoms at the research visit. One-third of patients had abnormal PFT findings, with reduced alveolar diffusion by KCO (transfer coefficient) being most common (24%). The number of PLI episodes was associated with reduced KCO and reduced FEV1% (forced expiratory volume in 1 s as a percentage of forced vital capacity) (overall presence 10%). Reduced KCO was also associated with disease duration. Reduced total lung capacity (TLC) (overall presence 8%) was only related to prior WG-related lung nodules. Pulmonary HRCT was abnormal in 80%, but with more severe abnormalities in only 30%. Pleural thickening and parenchymal bands were associated with PLI. None of the treatment variables was associated with the PFT or HRCT findings.

Conclusion: Five years after disease onset a quarter of the WG patients reported pulmonary symptoms, had severe abnormalities on HRCT, and abnormal PFT. The correlation between these abnormalities was poor, but the number of pulmonary involvements was a risk factor for reduced gas diffusion, obstructive lung disease, parenchymal bands, and pleural thickening. Treatment variables had no discernible negative pulmonary effects.