https://www.selleckchem.com/products/wnk-in-11.html Serologic testing for CTD was positive in 19 patients (43%) and most commonly included antinuclear antibody, rheumatoid factor, and anti-cyclic citrullinated antibodies. Seven of these patients with positive serologic results were eventually diagnosed to have CTD. Connective tissue diseases included rheumatoid arthritis in 4 patients, Sjögren syndrome in 2, and undifferentiated CTD in 1 patient. CONCLUSIONS Nearly one-half of patients with cryptogenic CB manifest positive CTD serology, and some of these patients have CTD not previously diagnosed. These results suggest that CB can be the presenting manifestation of a CTD.BACKGROUND Rheumatoid arthritis (RA) is a systemic autoimmune disease that increased bone resorption. Periodontal disease (PD) is an associated risk factor of RA. Studies suggest an association between bone markers such as the dickkopf-related protein 1 (DKK-1) and progression of radiological damage. We aimed to evaluate the marker DKK-1, its polymorphisms in patients with early rheumatoid arthritis (eRA), and its association with rheumatic, radiological, and periodontal variables. METHODS This article is a cross-sectional study. Samples were obtained from 63 patients with eRA. Radiographs of hands and feet were evaluated by Sharp-van der Heijde score (SHS) and Simple Erosion Narrowing Score (SENS). Serum DKK-1 levels and high-resolution fusion analysis was used for polymorphisms (rs1896368, rs1896367, rs1528873). Bivariate analyses were performed. RESULTS Individuals heterozygous for rs1896367 had more frequent erosions (p = 0.026) and joint space narrowing (p = 0.005) in the feet, higher SHS (p = 0.016), and higher SENS (p ≤ 0.001). Patients homozygous for rs1896368 had less frequent joint space narrowing in hands and feet as assessed by SHS and less presence of erosions by SENS (odds ratio, 0.04; 95% confidence interval, 0.00-0.93; p less then 0.05). The presence of PD was associated with the hom