A 5-year follow-up of pulmonary function tests in childhood-onset systemic lupus erythematosus: a single-center retrospective study.

Significance: Pulmonary involvement in childhood-onset systemic lupus erythematosus (cSLE), contributes to significant morbidity and mortality. Manifestations include chronic interstitial pneumonitis, pneumonia, pleuritis, alveolar hemorrhage, and shrinking lung syndrome. However, many patients can be asymptomatic from a respiratory standpoint and still have pulmonary function test (PFT) abnormalities. Our aim is to describe PFT abnormalities in patients with cSLE.

Methods: We completed a retrospective review of 42 patients with cSLE followed at our center. These patients were at least 6 years old (so they could complete PFTs). We collected data from July 2015 to July 2020.

Results: Out of the 42 patients, 10 (23.8%) had abnormal PFTs. These 10 patients had a mean age at diagnosis of 13 ± 2.9 years. Nine were female. One-fifth (20%) self-identified as Hispanic, 20% as Asian, 10% as Black or African American, and the remaining 50% as "Other." Of the 10, 3 had restrictive disease only, 3 with diffusion impairment only, and 4 with both restrictive lung disease and diffusion impairment. Patients with restrictive patterns had a mean total lung capacity (TLC) of 72.5 ± 5.8 throughout the study period. The average diffusing capacity for carbon monoxide corrected for hemoglobin (DsbHb) among patients with diffusion limitation during the study period was 64.8 ± 8.3.

Conclusions: The most common PFT abnormalities seen in patients with cSLE are alterations in diffusing capacity as well as restrictive lung disease.