Characterization of a subset of patients with primary Sjögren's syndrome initially presenting with C3 or C4 hypocomplementemia.

OBJECTIVE: This study aimed to determine the association of C3 and C4 hypocomplementemia at the diagnosis of primary Sjögren's syndrome (pSS) with clinical manifestations, disease activity, and disease damage. METHODS: A cross-sectional study was conducted in 94 Puerto Ricans with pSS. Patients were aged ≥21 years and met the 2012 American College of Rheumatology Classification Criteria for pSS. Demographic characteristics, health-related features, cumulative extraglandular manifestations, serologic tests at pSS diagnosis, comorbidities, disease activity (per European League Against Rheumatism Sjögren's Syndrome Disease Activity Index [ESSDAI]), disease damage (per Sjögren's Syndrome Disease Damage Index [SSDDI]), and pharmacologic therapy were determined. Serum C3 and C4 levels were measured at pSS diagnosis by immunoturbidimetry. Patients with and without hypocomplementemia were analyzed using bivariate and multivariate logistic regression analyses adjusted for age, sex, and disease duration. RESULTS: The mean age and disease duration of the study population were 52.4±12.4 years and 5.9±4.8 years, respectively; of the total study population, 94% were female. C3 and C4 hypocomplementemia were observed in 9.6% and 13.8% of the patients, respectively. In the multivariate analysis, C3 hypocomplementemia was associated with leukocytoclastic vasculitis, interstitial lung disease, higher SSDDI score, and exposure to rituximab. C4 hypocomplementemia was associated with leukocytoclastic vasculitis, interstitial lung disease, and higher ESSDAI and SSDDI scores. CONCLUSION: In this population of patients with pSS, low C3 and C4 levels at diagnosis were associated with extraglandular manifestations such as vasculitis and interstitial lung disease, as well as disease activity and damage accrual. These results suggest that complements C3 and C4 have clinical and prognostic value in patients with pSS.

Factors Associated With Disease Damage in Puerto Ricans With Primary Sjögren Syndrome.

OBJECTIVE: The aim of this study was to determine the association of demographic parameters, clinical manifestations, disease activity, and pharmacologic therapy with disease damage in a group of Puerto Ricans with primary Sjögren syndrome (pSS). METHODS: A cross-sectional study was conducted in 100 Hispanics of Puerto Rico with pSS. Patients were 21 years or older and fulfilled the 2012 American College of Rheumatology classification criteria for pSS. Demographic factors, lifestyle behaviors, extraglandular manifestations, serologic tests, comorbidities, pharmacologic therapy, disease activity (per European League Against Rheumatism Sjögren Syndrome Disease Activity Index), and disease damage (per Sjögren Syndrome Disease Damage Index [SSDDI]) were assessed. Patients with disease damage (SSDDI ≥1) and without damage (SSDDI = 0) were compared using bivariate analysis and multivariate regression analysis adjusted for age, sex, and disease duration. RESULTS: The mean age of patients was 52.8 years; 94% were women. The mean disease duration was 5.9 years. Thirty-nine patients had disease damage. Disease damage was mainly attributed to pulmonary fibrosis and peripheral neuropathy. In the bivariate analysis, disease damage was associated with low C3 and C4, coronary artery disease, infections, and higher activity index and was more frequently treated corticosteroids and azathioprine. In the multivariate analysis, low C3, disease activity, and corticosteroid exposure retained significance. CONCLUSIONS: In this population of Puerto Ricans with pSS, C3 and C4 hypocomplementemia, coronary artery disease, infections, and exposure to corticosteroids and azathioprine were associated with damage accrual. Clinicians should be aware of these factors to identify those who may require close follow-up and early therapeutic intervention.