Efficacy of baricitinib on periodontal inflammation in patients with rheumatoid arthritis

Impact of treatment of rheumatoid arthritis on periodontal disease: A review

BACKGROUND

Numerous studies support a bidirectional association between rheumatoid arthritis (RA), a chronic autoimmune degenerative inflammatory joint disease, and periodontitis, a chronic inflammatory disease caused by the immune reaction to bacteria organized in biofilms. RA and periodontitis are both multifactorial chronic inflammatory diseases that share common modifiable and non-modifiable risk factors. There is no cure for RA; treatment is based on lifestyle modifications and a variety of medications: nonsteroidal anti-inflammatory drugs (NSAID), glucocorticoids, and disease-modifying antirheumatic drugs (DMARDs, e.g., conventional synthetic DMARDs [csDMARDs]; biological DMARDs [bDMARD] and targeted synthetic DMARDs). There are molecular pathways of inflammation that are common to both RA and periodontitis. Thus, there is a potential effect of RA treatments on periodontitis. This systematic review aims to assess the impact of antirheumatic agents on periodontal conditions of patients suffering from both RA and periodontitis.

METHODS

PubMed/MEDLINE, Cochrane Library, and Embase online databases were systematically explored, and a manual search was performed to identify relevant studies published until January 2023. This review is registered in the PROSPERO database (CRD42023409006).

RESULTS

A total of 2827 articles were identified, and 35 fulfilled the inclusion criteria. The included studies generally show a consensus that, at normal dosage, NSAID and corticosteroids have negligible impact on periodontium. Similarly, csDMARD alone or in combination with other csDMARD demonstrated no adverse effect on periodontium. Monotherapy with bDMARD had a positive effect on periodontal pocket depths and gingival inflammation in the longitudinal studies up to 6 months but showed negligible effect on the periodontium in interventional studies with a longer follow-up (9 months and 15.1 months). However, the combination of tumor necrosis factor (TNF)-α inhibitors + methotrexate (MTX) was associated with a rise in gingival inflammation. Due to the considerable heterogeneity of the study designs, a meta-analysis could not reasonably be performed.

CONCLUSION

Within the limitations of the available studies, there is evidence to suggest that bDMARD monotherapy may improve the periodontal condition of RA patients with periodontal disease to a certain extent; the concomitant medication of TNF inhibitor + MTX could worsen gingival inflammation. More data are required to understand the impact of RA therapies on periodontal health.

Periodontitis and rheumatoid arthritis-Global efforts to untangle two complex diseases

Understanding the impact of oral health on rheumatoid arthritis (RA) will inform how best to manage patients with both periodontitis and RA. This review seeks to provide an update on interventional and mechanistic investigations, including a brief summary of European Research programs investigating the link between periodontitis and RA. Recent clinical studies are described that evaluate how the treatment of one disease impacts on the other, as are studies in both humans and animal models that have sought to identify the potential mechanisms linking the two diseases.

The Effects of Periodontal Treatment on Rheumatoid Arthritis and of Anti-Rheumatic Drugs on Periodontitis: A Systematic Review

Rheumatoid arthritis (RA) and periodontitis are chronic inflammatory diseases that widely spread and share the same patterns of pro-inflammatory cytokines. This systematic review aims to evaluate the effects of non-surgical periodontal treatment (NSPT) on RA and, conversely, the impact of disease-modifying anti-rheumatic drugs (DMARDs) on periodontitis. PubMed, Embase, and Web of Science were searched using the MESH terms "periodontitis" and "rheumatoid arthritis" from January 2012 to September 2023. A total of 49 articles was included in the final analysis, 10 of which were randomized controlled trials. A total of 31 records concerns the effect of NSPT on parameters of RA disease activity, including a 28-joint disease activity score, anti-citrullinated protein antibodies, rheumatoid factor, C reactive protein, erythrocyte sedimentation rate, pro-inflammatory cytokines and acute phase proteins in serum, saliva, gingival crevicular fluid, and synovial fluid. A total of 18 articles investigated the effect of DMARDs on periodontal indexes and on specific cytokine levels. A quality assessment and risk-of-bias of the studies were also performed. Despite some conflicting results, there is evidence that RA patients and periodontitis patients benefit from NSPT and DMARDs, respectively. The limitations of the studies examined are the small samples and the short follow-up (usually 6 months). Further research is mandatory to evaluate if screening and treatment of periodontitis should be performed systematically in RA patients, and if the administration of DMARDs is useful in reducing the production of cytokines in the periodontium.

JAK/STAT as a Potential Therapeutic Target for Osteolytic Diseases

Several cytokines with major biological functions in inflammatory diseases exert their functions through the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signal transduction pathway. JAKs phosphorylate the cytoplasmic domain of the receptor, inducing the activation of its substrates, mainly the proteins known as STATs. STATs bind to these phosphorylated tyrosine residues and translocate from the cytoplasm to the nucleus, further regulating the transcription of several genes that regulate the inflammatory response. The JAK/STAT signaling pathway plays a critical role in the pathogenesis of inflammatory diseases. There is also increasing evidence indicating that the persistent activation of the JAK/STAT signaling pathway is related to several inflammatory bone (osteolytic) diseases. However, the specific mechanism remains to be clarified. JAK/STAT signaling pathway inhibitors have gained major scientific interest to explore their potential in the prevention of the destruction of mineralized tissues in osteolytic diseases. Here, our review highlights the importance of the JAK/STAT signaling pathway in inflammation-induced bone resorption and presents the results of clinical studies and experimental models of JAK inhibitors in osteolytic diseases.

Baricitinib alleviates lipopolysaccharide‑induced human periodontal ligament stem cell injury and promotes osteogenic differentiation by inhibiting JAK/STAT signaling

Periodontitis is the chronic inflammation of the periodontal tissue. The present study aimed to investigate the role of baricitinib, a Janus kinase (JAK)1/2 inhibitor, in periodontitis by using a lipopolysaccharide (LPS)-induced human periodontal ligament stem cell (PDLSC) model. The viability of PDLSCs stimulated by LPS was assessed in the presence of baricitinib by Cell Counting Kit-8 assay. The induction of oxidative stress was evaluated by detecting the intracellular reactive oxygen species (ROS) levels, superoxide dismutase (SOD) activity and glutathione (GSH) content. ELISA and reverse transcription-quantitative PCR were used to determine the levels of inflammatory factors TNF-α, IL-1β and IL-6. Alkaline phosphatase (ALP) activity and alizarin red staining were used to assess the osteogenic differentiation of PDLSCs. The expression levels of osteogenic differentiation- and JAK/signal transducer and activator of transcription (STAT) signaling-associated proteins were estimated with western blotting. RO8191, an agonist of the JAK/STAT pathway, was used to treat PDLSCs to investigate the regulatory mechanism of baricitinib. The results indicated that baricitinib elevated the LPS-induced decrease in cell viability. LPS-triggered oxidative stress and inflammation were inhibited by baricitinib, as demonstrated by the decreased levels of ROS, TNF-α, IL-1β, IL-6 and increased levels of SOD and GSH. In addition, baricitinib caused a marked elevation in ALP activity and mineralization ability of PDLSCs, as determined by the upregulated osteocalcin and Runt-related transcription factor 2 expression. Moreover, the expression levels of phosphorylated (p)-JAK1, p-JAK2 and p-STAT3 were downregulated by baricitinib in a dose-dependent manner. Furthermore, addition of RO8191 restored the effect of baricitinib on the induction of oxidative stress, inflammation and osteogenic differentiation of PDLSCs exposed to LPS. Collectively, these findings suggested that baricitinib alleviated oxidative stress and inflammation and promoted osteogenic differentiation of LPS-induced PDLSCs by inhibiting JAK/STAT signaling.

Influence of anti-rheumatic agents on the periodontal condition of patients with rheumatoid arthritis and periodontitis: A systematic review and meta-analysis

OBJECTIVE

To evaluate the influence of diverse anti-rheumatic agents on the periodontal condition and to provide clinical medication guidance for patients with rheumatoid arthritis (RA) and periodontitis.

BACKGROUND

In recent years, the correlation between RA and periodontitis has become a hot research topic, but no medication recommendations for patients with RA and periodontitis are available at present.

METHODS

The protocol of this review was registered in advance with PROSPERO (CRD42021248827). Electronic search and manual searches up to March 20, 2021 were conducted. The inclusion criteria for the studies were as follows: included patients diagnosed with periodontitis and RA submitted to anti-rheumatic agent therapy; with a control group receiving no anti-rheumatic agent therapy; with outcomes including at least one periodontal parameter. Probing depth (PD) and clinical attachment loss (CAL) were pooled using weighted mean difference (WMD) and 95% confidence intervals (CI) while gingival index (GI)/modified gingival index (MGI) was analyzed by standardized mean difference (SMD) and 95% CI.

RESULTS

One thousand four hundred and seventy-eight studies potentially related to the aim of this review were screened, but only 463 patients from 14 studies were included in the qualitative analysis, and 146 patients from 4 studies were included in the meta-analysis. Statistically significant reductions were observed among the subjects who received anti-rheumatic agents for PD [WMD = -0.20; 95% CI (-0.33, -0.07); effect p = .003; I²  = 50%; p = .11], CAL [WMD = -0.4; 95% CI (-0.66, -0.15); effect p = .002; I²  = 57%; p = .07] and GI/MGI [SMD = -0.61;95% CI (-0.94, -0.27; effect p = .0004; I²  = 26%; p = .25]. Consistent with the above results, this systematic review produced promising results that PD, CAL, GI/MGI, and bleeding on probing (BOP) decreased when patients with RA and periodontitis were treated with conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs), anti-B lymphocyte agents, anti-IL-6R agents, or JAK inhibitors. PD and CAL declined after the administration of anti-TNF-α agents; most studies reported decreased GI/MGI and BOP, while 2 studies reported increased GI/MGI and BOP.

CONCLUSIONS

These results revealed that csDMARDs, anti-B lymphocyte agents, anti-IL-6R agents, anti-TNF-α agents, and JAK inhibitors had potential positive effects in improving the periodontal condition of patients with RA and periodontitis. However, future research is needed to elucidate whether anti-TNF-α agents have a side effect of increased gingival inflammation.

Host Modulation and Treatment of Periodontal Disease

Periodontitis is the sixth-most prevalent disease in the world and the first cause for tooth loss in adults. With focus shifted to the inflammatory/immune response in the pathogenesis of periodontitis, there is a critical need to evaluate host modulatory agents. Synthetic and biological disease-modifying antirheumatic drugs are a cornerstone for the treatment of inflammatory diseases. Recent prospective cohort studies showed that synthetic disease-modifying antirheumatic drugs improved periodontal clinical parameters following nonsurgical periodontal treatment in patients with rheumatoid arthritis. Treatment with recombinant humanized monoclonal antibodies against CD20 (rituximab) and IL-6 receptor (tocilizumab), the latter also in clinical trials for the treatment of COVID-19 pneumonia, resulted in decreased periodontal inflammation and improved periodontal status. Studies on the effect of TNF-α inhibitors in patients with periodontitis yielded inconsistent results. Recent data suggest that probiotics provide anti-inflammatory clinical benefit, as do nutritional supplements, such as n-3 fatty acids, when combined with periodontal therapy. Probiotics reduce the production of proinflammatory cytokines/chemokines by suppressing NF-κB pathways and promote the accumulation of T regulatory cells. Statins, like aspirin, have been shown to exhibit anti-inflammatory and bone-preserving actions by upregulating production of Specialized Proresolving Mediators (SPMs). Currently, there is insufficient scientific support for the topical delivery of statins or bisphosphonates as adjuncts to periodontal therapy. Here, we present a critical review of the most recent host modulatory agents applied in humans and the key immune pathways that they target. Emerging evidence from novel drug candidates, including SPMs and complement inhibitors as previously studied in animal models and currently in human clinical trials, suggests future availability of adjunctive therapeutic strategies for the management of periodontitis.

Exploring the Role of Interleukin-6 Receptor Inhibitor Tocilizumab in Patients with Active Rheumatoid Arthritis and Periodontal Disease

BACKGROUND

The aim of our study was to explore the influence of weekly subcutaneous administration of interleukin-6 (IL-6) receptor inhibitor tocilizumab (TCZ) on periodontal status in a local longitudinal study of patients with rheumatoid arthritis (RA) and periodontal disease (PD).

METHODS

We performed a 6-month prospective study in 51 patients with chronic periodontitis and moderate-to-severe RA starting TCZ in accordance with local recommendations. Extensive rheumatologic (clinical activity, inflammatory, serological biomarkers) and periodontal (visible plaque index, gingival index, bleeding on probing, probing pocket depth, clinical attachment loss) assessments were done. Changes in RA activity and periodontal status were reassessed after 3 and 6 months.

RESULTS

We demonstrated significant correlations between periodontal status, disease activity, and serologic biomarkers (p < 0.05). Tocilizumab significantly improved the gingival index scores and decreased the number of sites with bleeding on probing after only 3 months (p < 0.05), while the probing pocket depth significantly decreased after 6 months; overall, clinical attachment loss presented only slight changes without any statistical significance as well as teeth count and plaque levels (p > 0.05).

CONCLUSION

IL-6 inhibition is able to improve periodontal outcomes in patients with RA and concomitant PD, which is essentially related to a dramatic decrease in serum inflammatory mediators.