OP0173 EROSIVE HAND OSTEOARTHRITIS ASSOCIATES WITH LOW OCCURRENCE OF KNEE OSTEOARTHRITIS
Authors: Natividad Oreiro, Ignacio Rego-Perez, Sara Relaño-Fernandez, Maria Teresa Silva, Paula Ramos-Louro, Alejandro Durán-Sotuela, Sonia Pertega, Francisco J. Blanco
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Erosive hand osteoarthritis (OA) is considered a more severe form of hand OA that includes pain and inflammation (1,2). However, more data are needed regarding the different hand OA phenotypes, especially erosive and non-erosive, to conclude if they represent two different subsets of hand OA or even different degrees of affectation of the same disease (1,3,4) <h3>Objectives</h3> To compare the clinical pattern of patients with erosive hand OA with those that do not show this phenotype <h3>Methods</h3> The study was conducted in the Prospective Cohort of Osteoarthritis A Coruna (PROCOAC). This cohort consists of 1107 subjects, of which 747 suffered from radiographic hand OA. We split the cohort into patients with and without erosive hand OA, and analyzed both clinical and demographic data within each group, together with the assessment of the AUStralian CANadian Osteoarthritis Hand (AUSCAN) index. The study consisted in a univariate analysis comparing different variables between both groups, followed by a stepwise logistic regression analysis taking into account the significant confounder variables analyzed in the Univariate approach <h3>Results</h3> The mean age of the cohort was 63.23±8.85 years and consisted of 627 females and 120 males. Of the 747 OA patients, 179 had erosive hand OA and 568 did not. The univariate analysis revealed that patients with erosive hand OA were younger (60.25±8.10 vs 64.16±8.88;p&lt;0.001), smokers (p=0.005), with lower body mass index (p=0.005), increased inflammatory episodes (p&lt;0.001), with family history or suffering from psoriasis (p=0.021) and less number of damaged joints (p&lt;0.001). In addition, metabolic syndrome (MetS) was not associated with erosive hand OA and, despite the higher number of females suffering from hand OA, no significant differences between erosive and non-erosive phenotypes in terms of gender were detected. The regression model confirmed the strong association of age (OR=0.9734; 95% CI=0.947-0.999; p=0.044), inflammation (OR=5.096; 95% CI=2.868-9.058; p&lt;0.001), number of damaged joints (OR=0.490; 95% CI=0.307-0.782; p=0.003) and, interestingly, showed MetS as a risk factor too (OR=2.146; 95% CI=1.250-3.682; p=0.006). Regarding the number of damaged joints, a lower frequency of both knee and hip OA was detected in patients with erosive hand OA compared with non-erosive patients (24.4% vs 54.7% for knee OA prevalence and 11.6% vs 16.7% for hip OA prevalence); however, only knee OA occurred at a significant lower frequency (OR=0.267; 95% CI=0.182-0.393; p&lt;0.001). In addition, the three subscales of the AUSCAN score showed significantly higher mean values in patients with the erosive phenotype: pain (57.67±29.30 vs 43.86±31.45; p&lt;0.001), function (55.61±27.68 vs 40.53±29.48; p&lt;0.001) and stiffness (55.40±32.26 vs 40.95±36.23;p=0.001) <h3>Conclusion</h3> The erosive hand OA phenotype is associated with more inflammation in younger patients, and worst AUSCAN score. Contrarily to the non-erosive phenotype, the presence of erosions associates with a lower occurrence of other forms of OA, specially knee OA. In our cohort, erosive hand OA seems to be more localized in the hand and it also seems to be associated with psoriasis. This different profile could serve the clinicians to provide personalized prevention strategies, and the researchers to investigate the pathogenesis of this specific phenotype <h3>References</h3> [1] Haugen, et al. Osteoarthritis Cartilage2016;24:647-654 [2] Marshall, et al. Ann Rheum Dis2015;74:136-141 [3] Dolzani, et al. Clin Exp Rheumatol2011;29:1006-1009 [4] Punzi, et al. Ann Rheum Dis2005;64:955-957 <h3>Disclosure of Interests</h3> Natividad Oreiro: None declared, Ignacio Rego-Perez: None declared, Sara Relaño-Fernandez: None declared, Maria Teresa Silva: None declared, Paula Ramos-Louro: None declared, Alejandro Durán-Sotuela: None declared, Sonia Pertega: None declared, Francisco J. Blanco Consultant for: AbbVie, Bioiberica, BMS, GSK, Grünenthal, Janssen, Lilly, Pfizer, Regeneron, Roche, Sanofi, TRB Chemedica, and UCB