Pulmonary involvement in patients with childhood-onset systemic lupus erythematosus

Pulmonary involvement is a common finding in adults with systemic lupus erythematosus (SLE). The aim of this study was to investigate the frequency of pulmonary abnormalities in patients with childhood-onset SLE, with particular reference to interstitial lung disease (ILD), and to examine any association between pulmonary abnormalities and other disease-related variables.

A cohort of 60 Norwegian patients with childhood-onset SLE was examined in a cross-sectional study by high-resolution computed chest tomography (HRCT) and pulmonary function tests (PFT). Median disease duration was 11.2 years. Disease activity, cumulative organ damage and immunological markers were also assessed.

Five patients (8%) had abnormal HRCT findings, including micronodules in four patients and bronchiectasis in one. None of the patients had radiographic evidence of ILD. PFT results were impaired in 37% of the patients, the most frequent pulmonary dysfunction was reduced carbon monoxide diffusing capacity (26%). HRCT findings, disease activity or serology did not correlate with PFTs. Reduced diffusion capacity was associated with smoking (p-value < 0.05).

Lung function was moderately impaired, while the frequency of pulmonary parenchymal involvement was low. There was no radiographic evidence of ILD, which is an unexpected finding given the high frequencies reported in adult SLE patients assessed with HRCT. The results suggests that PFT values are often abnormal, but these are infrequently associated with development of ILD or other substantial parenchymal alterations in childhood-onset SLE, and do not require further HRCT investigation in asymptomatic patients.