Subclinical pulmonary abnormalities in childhood-onset systemic lupus erythematosus patients

The aims of this study were to analyze the pulmonary function of childhood-onset systemic lupus erythematosus (cSLE) patients and to identify possible correlations between the high-resolution computed chest tomography (HRCT) score, disease activity, disease cumulative damage, and the participants' quality of life.

Forty cSLE patients, median age: 14.1 years (range: 7.4-17.9), underwent spirometry and plethysmography. Carbon monoxide diffusing capacity (DLCO), HRCT, disease activity, disease cumulative damage, and quality of life were assessed.

Pulmonary abnormalities were evident in 19/40 (47.5%) cSLE patients according to spirometry/DLCO. Forced expired volume in one second (FEV1%) was the parameter most affected (30%). The HRCT showed some abnormality in 22/30 patients (73%), which were minimal in 43%. Signs of airway affects were found in 50%. Twelve patients were hospitalized due to cSLE-related pulmonary complications before the study began (median discharge: 2.1 years earlier). Total lung capacity (TLC%), vital capacity (VC%), forced vital capacity (FVC%), and FEV1% were significantly lower in the group with hospitalization compared to the group without hospitalization (p = 0.0025, p = 0.0022, p = 0.0032, and p = 0.0004, respectively). Of note, DLCO was positively correlated with disease duration (r = +0.4; p = 0.01). The HRCT-score was negatively correlated with FEV1/VC (r = -0.63; p = 0.0002), FEV1 (r = -0.54; p = 0.018), FEF25%-75% (r = -0.67; p < 0.0001), and HRCT-score was positively correlated with resistance (r = +0.49; p = 0.0056).

Almost half of patients with cSLE had subclinical pulmonary abnormalities, especially airway abnormalities. The cSLE-related pulmonary complications seem to determine long-term functional damage.