THU0081 ELEVATED SERUM TREM-1 LEVELS ARE ASSOCIATED WITH DAS28 AND PERIODONTITIS IN RHEUMATOID ARTHRITIS
Authors: Nevsun Inanc, Gonca Mumcu, Meryem Can, Haner Direskeneli, Nagihan Bostancı
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> The Triggering Receptor Expressed on Myeloid cells 1 (TREM-1) along with its putative ligand peptidoglycan recognition protein 1 (PGLYRP1) are involved in the propagation of the inflammatory response to microbial exposure(1). Periodontal disease (PD) has been suggested as an environmental risk factor for rheumatoid arthritis (RA), yet further studies are required to dissect the mechanisms underlying the association between the two(2). <h3>Objectives</h3> The present study aimed to investigate whether serum levels of TREM–1 and PGLYRP1 in patients with RA correlate with the presence and severity of PD, as well as bacterial load in saliva. <h3>Methods</h3> Serum and saliva samples were collected from 65 individuals with RA (F/M: 48/17), under sDMARD treatment for more than 6 months and never used biologic treatment), with Behcet syndrome (BS, n= 45, F/M: 31/12) and with systemic health (HC, n= 59, F/M: 40/19). RA disease activity was assessed by using 28-joint disease activity score (DAS-28). Oral health was evaluated by dental and periodontal indices. TREM-1 and PGLYRP1 were measured by ELISA, while total oral bacteria in saliva was assessed by quantitative real-time polymerase chain reaction and normalized against tooth number. For statistical analysis, non-parametric Kruskal Wallis, Mann-Whitney U and Spearman correlation tests were used. <h3>Results</h3> Patients with RA presented with a smaller number of teeth than the BS and HC groups (18.67±8.45; 24.02±3.7; 25.36±3.83, respectively) (p&lt;0.001). Prevalence of severe periodontitis was higher in the RA group (33,8%) compared to BS (20,9%) and HC (5,1%). Total bacterial load was significantly higher in saliva of RA than HC (p&lt;0.05). Serum TREM-1 and PGLYRP1 levels were significantly higher in RA (167,1±95,0 pg/ml; 157,5±228,8 pg/ml) than BS (102,8±44,4 pg/ml; 52,4±26,01pg/ml) and HC (90,7±56,5 pg/ml; 68,8±37,7 pg/ml) (p&lt;0.05). Correlation analysis showed a significant positive correlations between TREM-1 and and DAS-28 scores (p&lt;0.05). In the RA group, while TREM-1 levels (127,9±61,7 pg/ml vs 198,4±105,7 pg/ml) were significantly reduced by methotrexate intake, but presence of severe periodontitis resulted in higher TREM-1 and PGLYRP1 (p&lt;0.05). <h3>Conclusion</h3> The present study demonstrated that there is an increased levels of TREM-1 and PGLYRP1 in serum of patients with RA which is further potentiated by periodontitis. Moreover, TREM-1 correlates with clinical disease activity. MTX therapy of patients with RA is accompanied by reduced TREM-1 levels in serum. <h3>References</h3> [1] Cheng Z, Meade J, Mankia K, Emery P, Devine DA. Periodontal disease and periodontal bacteria as triggers for rheumatoid arthritis. Best Pract Res Clin Rheumatol. 2017 Feb;31(1):19-30 [2] Tammaro A, Derive M, Gibot S, Leemans JC, Florquin S, Dessing MC. REM-1 and its potential ligands in non-infectious diseases: from biology to clinical perspectives. Pharmacol Ther. 2017 Sep;177:81-95. <h3>Disclosure of Interests</h3> None declared