Associations of local bone involvement with disease activity, damage and functional disability in Sjogren's disease: A cross-sectional study.

BACKGROUND: Sjogren's disease (SjD) arthritis is non-erosive, but joint involvement in this disease remains unclear. This study investigated the association between bone erosions and clinical parameters using high-resolution peripheral quantitative computed tomography (HR-pQCT) in patients with SjD. METHODS: In this cross-sectional study at a quaternary hospital in Brazil, 106 female patients with SjD, aged 18-65 years, who met ACR/EULAR 2016 criteria were evaluated. Exclusion criteria were the use of osteoporosis medication and other bone or autoimmune diseases. Disease activity, damage, functional disability, and laboratory tests were assessed. HR-pQCT was used to identify bone erosions and osteophytes in the 2nd and 3rd metacarpophalangeal and proximal interphalangeal joints, and functional impairment was measured by the handgrip test. Associations between bone erosions, osteophytes, and clinical indices were analysed using logistic regression and generalised linear models. FINDINGS: Between July 2022 and October 2023, 368 patients were screened, and 106 were included. Bone erosions were present in 56.7 % of patients, predominantly in the 3rd metacarpal head, with a mean volume of 5.71 mm(3). Osteophytes were identified in 7.2 % of cases. Erosion volume was significantly higher in older and postmenopausal women, in those with greater damage and in those with osteophytes. Erosion volume increased by 7 % per year of age, and postmenopausal women had a 3.54-fold increase in erosion volume compared to premenopausal women. No significant associations were observed between erosions and disease indices or clinical outcomes. INTERPRETATION: This study shows a higher prevalence of bone erosions in SjD than previously described, particularly in older, postmenopausal women. These findings highlight the potential of HR-pQCT as a sensitive tool to detect joint damage in SjD, challenging its non-erosive classification.