High-resolution computed tomography and rheumatoid arthritis: semi-quantitative evaluation of lung damage and its correlation with clinical and functional abnormalities.

BACKGROUND: We aimed to establish risk factors for radiological lung damage associated with rheumatoid arthritis (RA) and determine whether clinical findings and pulmonary function test were correlated with Warrick score calculated on the basis of high-resolution computed tomography or not.

METHODS: One hundred thirty RA patients who were followed at rheumatology outpatient clinic were included through retrospective screening. To evaluate radiological involvement, the semi-quantitative evaluation proposed by Warrick was used to assign a score for each lesion based on the severity and extent of the pulmonary damage. In addition to the total score, indices for alveolitis and fibrosis were created. The correlations between each score and clinical and functional parameters were tested for all patients.

RESULTS: We showed that age was an independent explanatory variable of radiological lung damage. Percentage of predicted lung diffusion capacity for carbon monoxide (DLco) below 75 % and presence of respiratory symptoms were found to contribute more to radiological lung damage. Warrick score was positively correlated with age at study onset (r = 0.43, p < 0.001). In addition, a negative correlation was found between Warrick score and DLco % predicted (r = -0.357, p = 0.001). Alveolitis index was negatively correlated with DLco % predicted (r = -0.321, p = 0.003).

CONCLUSIONS: It is considered that this semi-quantitative method may have added value in early diagnosis, appropriate treatment decisions and follow-up when taken into account together with risk factors associated with pulmonary damage in RA.