Association of Dickkopf-1 Polymorphisms With Radiological Damage and Periodontal Disease in Patients With Early Rheumatoid Arthritis

Gene variants for the WNT pathway are associated with severity in periodontal disease

OBJECTIVE

Studies of Wnt variants-related to bone resorption in periodontitis are limited. The aim of this study was to establish the genotype and allele frequency of gene variants associated with the Wnt pathway in systemically healthy individuals with and without periodontitis (PD).

MATERIALS AND METHODS

One hundred fifty-seven systemically healthy individuals were evaluated, 90 with PD and 67 without PD. Periodontal clinical indexes, serological and clinical indices of inflammation, and the following variants associated with the Wnt pathway: DKK, SOST, LRP5, and KREMEN were analyzed by high resolution melting and confirmed by Sanger sequencing.

RESULTS

In the PD-free group, 67.2% of the individuals presented the variant for DKKrs1896367 (p = 0.008) and 82.6% had the variant for KREMEN rs132274 (p = 0.016). The heterozygous variant for the DKK rs1896367 polymorphism was associated with the absence of PD and lower severity OR: 0.33 (CI95% 0.15-0.70) and OR: 0.24 (CI95% 0.11-0.53), respectively. Similarly, KREMEN rs132274 was the homozygous variant associated with the absence of PD (OR: 0.33 (CI95% 0.13-0.88)). On the contrary, 85.6% of individuals with PD presented a variant for DKK rs1896368 (p = 0.042), all suffering severe forms of periodontitis.

CONCLUSION

The presence of DKKrs1896367 and KREMENrs132274 variants in individuals without PD suggests that these single nucleotide polymorphisms could be protective factors for bone loss in PD. A very interesting finding is that the DKKrs1896368 variant was found in a high percentage of severe cases, suggesting that the presence of this variant may be related to the severe bone loss observed in PD.

Association of Serum and Crevicular Fluid Dickkopf-1 Levels with Disease Activity and Periodontitis in Patients with Early Rheumatoid Arthritis

BACKGROUND

The aim of this study was to assess DKK-1 levels, in Gingival Crevicular Fluid (GCF) and serum, as a biomarker for bone loss and disease activity in periodontitis and early RA (eRA).

METHODS

In this cross-sectional study, we obtained serum and GCF from 10 interproximal sites (Distal Buccal I/S, Mesio Buccal I/S, Distal Palatal/Lingual, Mesio Palatal/Lingual) according to the highest degree of inflammation by a patient for 240 sites from eRA patients. Patients received a periodontal assessment, a radiographic evaluation, tomography of interproximal sites, and DKK1 levels were determined by ELISA. Comparisons were performed by the Mann-Whitney U test and analysis by Chi2 test, and a logistic regression model was applied.

RESULTS

The mean age was 46.33 ± 12.0 years, the Disease Activity Score (DAS-28-ESR) was 4.08 ± 1.4. Periodontitis was present in 65.2% of the patients, and 59.6% of these patients had bone loss in interproximal sites. Higher GCF-DKK1 levels were associated with serum-DKK1 (OR:2.41 IC95% 1.14-5.09, p=0.021) and were related with DAS28-ESR (p=0.001), Routine Assessment of Patient Index Data 3 (RAPID 3) (p=0.001), and tender joints (p=0.040). Foot bone erosion and juxta-articular osteopenia were associated with high levels of serum-DKK1 (p=0.009 and 0.001, respectively). Serum-DKK1 were associated with SDAI (OR: 2.38 IC95% 1.03-5.52, p=0.043), RAPID 3 (p=0.001), and rheumatoid factor (p=0.018). The GCF-DKK1 levels were associated with periodontal bone loss (p=0.011), periodontitis (p=0.070) and its severity (OR: 2.58 IC95% 2.28-7.28, p=0.001). Bone loss was more frequent in buccal sites (73.5%) and was associated with increased levels of DKK1 (p=0.033).

CONCLUSION

In the early stages of the eRA disease, serum and GCF-DKK1 could be a biomarker for clinical disease activity and periodontal and articular bone erosion.