Clinical, immunological, and radiological characteristics of pulmonary involvement in childhood-onset primary Sjögren's syndrome: a single-center retrospective study.

OBJECTIVE

To describe pulmonary involvement in childhood-onset primary Sjögren's syndrome (cSS).

METHODS

This retrospective study included 17 children with cSS diagnosed at Jiangxi Provincial Children's Hospital between August 2021 and August 2025. Patients were classified by baseline chest high-resolution computed tomography (HRCT)as normal CT (n=8) or abnormal CT (n=9); among patients with abnormal CT, 5 had interstitial lung involvement. Clinical, laboratory, radiological, and outcome data were compared.

RESULTS

Among 17 children, 14 were female (82.4%), and the mean age at onset was 10.83 ± 3.12 years. Abnormal chest CT findings were detected in 9 patients (52.9%). Age at onset was younger in the abnormal CT group than in the normal CT group (9.37 ± 2.67 vs. 12.48 ± 2.88 years, P = 0.036), and was lowest in the interstitial lung involvement subgroup (8.30 ± 2.51 years, P = 0.022). This subgroup had higher total T and CD4+ T lymphocyte proportions and a lower B lymphocyte proportion P = 0.026, 0.027, and 0.023, respectively. Pleural thickening was the most common CT abnormality (77.8%), followed by ground-glass opacities and nodules >3 mm (33.3% each). Among the 5 patients with interstitial lung involvement, 3 met radiological criteria for ILD, comprising 2 with organizing pneumonia and 1 with nonspecific interstitial pneumonia. During follow-up, 3 of 7 patients with longitudinal imaging achieved complete radiological normalization, 2 improved, and 2 remained stable.

CONCLUSION

Pulmonary abnormalities were common in children with cSS. Younger onset and aberrant T/B lymphocyte subsets showed exploratory associations with pulmonary involvement, which appeared mainly inflammatory and demonstrated favorable radiological evolution during follow-up.