Findings and feasibility of major salivary gland ultrasound in childhood-onset systemic lupus erythematosus: a pilot study

BACKGROUND: Childhood-onset systemic lupus erythematosus (cSLE) is a complex autoimmune disorder with multi-organ manifestations and can be associated with other rheumatic diseases including Sjögren’s syndrome (SS). Salivary gland ultrasound (SGUS) represents a noninvasive tool to screen for salivary gland disease in rheumatic disease patients. The aims of this cross-sectional study were to determine feasibility of major SGUS in a clinic setting and to identify characteristics in a cohort of cSLE patients (without confirmed SS) that may be associated with salivary gland abnormalities consistent with secondary SS. METHODS: Patients with SLE onset prior to age 18 were recruited. Patients completed questionnaires rating symptoms and underwent major SGUS examination. Disease and demographic differences were compared between cSLE patients with abnormal SGUS vs. cSLE patients with normal SGUS using t-tests and Fisher’s exact tests. RESULTS: Thirty-one cSLE patients were recruited, 84% were female, 55% were Caucasian. The average disease duration among all patients was 5 years. Average time to complete the SGUS examination and scoring protocol was 7 min. 35% of SGUS scores were abnormal and significantly associated with IgG level at diagnosis, and anti-Ro and anti-La antibodies. CONCLUSIONS: This is one of the first studies to our knowledge that assesses major SGUS in a cohort of patients with cSLE without prior diagnoses of SS. The SGUS protocol was feasible to perform by rheumatologists in a clinic setting. Although the sample size was small, SGUS abnormalities were identified in one-third of patients. IgG level at diagnosis and anti-Ro and anti-La antibodies may be associated with SGUS abnormalities.