Pulmonary manifestations in systemic lupus erythematosus: association with disease activity

Background and objective: Although systemic lupus erythematosus (SLE) is the most common connective tissue disease affecting the lung, few studies have assessed risk factors that predict pulmonary manifestations. The objectives of the present study were to determine the prevalence of lung manifestations in SLE patients from Western Saudi Arabia by analysing results from high-resolution computed tomography (HRCT) scans and to identify independent risk factors for lung involvement.

Methods: This was a 10-year retrospective study involving 184 SLE patients. We examined all HRCT lung abnormalities and determined whether findings were associated with the presence of lupus nephritis (LN), SLE disease activity (as defined by SLE Disease Activity Index 2000 item scores ≥ 4 for any and all items) or levels of complement and anti-double-stranded DNA (anti-dsDNA).

Results: We identified 61 patients (33%) with pulmonary involvement, and 52 (85%) of these subjects showed HRCT abnormalities. The most common HRCT findings were pleural effusion, consolidation and atelectasis (58%, 42% and 42%, respectively). There was a significant association between abnormal HRCT results and hypocomplementemia, high levels of anti-dsDNA and disease activity (P < 0.05), particularly with regard to pleuropericardial effusion and consolidation. Pulmonary abnormalities were significantly higher within the first five years after SLE diagnosis (P < 0.001). However, neither disease duration nor LN was associated with increased risk.

Conclusions: Lung manifestations were frequent in SLE patients from Saudi Arabia, with pleural effusion, consolidation and atelectasis being the most common. Low complement levels, high anti-dsDNA levels and disease activity were significantly associated with abnormal HRCT findings (all P < 0.001).