THU0009 Role of the Mtdna Haplogroups on the Radiographic Progression of Knee Osteoarthritis in Patients of the Check Cohort: A Replication Study of the OAI Data
Authors: A. Soto-Hermida, M. Fernández-Moreno, M.E. Vázquez-Mosquera, E. Cortés-Pereira, S. Relaño-Fernández, J. Fernández-Tajes, N. Oreiro-Villar, C. Fernández-Lόpez, F.J. Blanco, I. Rego-Pérez
Journal: Annals of the Rheumatic Diseases (2015)

<h3>Background</h3> Significant influence of the mtDNA haplogroups on radiographic progression of knee OA (KOA) has been reported; however, further validation in other well-defined prospective cohorts is necessary <h3>Objectives</h3> To validate, in patients from the CHECK cohort, the results obtained in patients from the OAI by which the mtDNA haplogroups influence the radiographic progression of knee Osteoarthritis. The CHECK cohort is a running 10-year prospective multi-center cohort of subjects, with pain and/or stiffness of one and/or both knees <h3>Methods</h3> We assigned the mtDNA haplogroups to the entire CHECK cohort (n=1002 subjects). In accordance with the early-stage OA in CHECK subjects (van Spil et al 2012), we selected subjects that did show radiographic KOA at baseline (K&amp;L grade=1 for the left and/or right knee), reaching a total of n=417 subjects. Progression in these subjects was defined as an increase of ≥1 K&amp;L grade for the left and/or right knee during 5 years follow-up period.Appropriate statistical analyses, including Receiver Operating Curves (ROC) with their respective Area Under the Curve (AUC), were carried out using SPSS software (v.19) <h3>Results</h3> The 417 subjects that met the eligibility criteria to study radiographic progression included 81.1% females and 18.9% males, they were older than 45 years (mean age: 56.24±5.07 years; range: 45-66) and had a mean BMI of 26.80 kg/m<sup>2</sup> (range: 15.43-48.85). Chi-square analysis revealed that the mtDNA haplogroup T significantly associated with lower risk of radiographic progression (OR=0.467; CI=0.250-0.874; p=0.015); analysing by mtDNA clusters, the cluster TJ significantly associated with lower risk of progression too (OR=0.586; CI=0.366-0.939; p=0.025). By comparing each of the mtDNA haplogroups with the most common haplogroup H in the regression model, we detected that carriers of the mtDNA haplogroup T were at lower risk for K&amp;L grade progression (31.4% progressors) than carriers of the most common mtDNA haplogroup H (50.6% progressors) (OR=0.414; CI=0.204-0.844; p=0.015); in terms of mtDNA clusters, subjects in cluster TJ were at lower risk of progression than subjects in the cluster HV (OR=0.551; CI=0.317-0.955; p=0.034). Additionally, either including mtDNA haplogroups or mtDNA clusters in the regression model, both BMI (OR=1.064; CI=1.010-1.120; p=0.020) and bilateral KL=1 at baseline (OR=3.595; CI=2.345-5.510; p&lt;0.001) were also significantly associated with an increased risk of radiographic progression of KOA attending to K&amp;L grade. The AUC of this regression model was 0.723 and 0.722 after including either haplogroups or clusters respectively. <h3>Conclusions</h3> As noted in KOA patients of the OAI cohort, the early identification and classification of patients with haplogroup T and the most common haplogroup H would permit to identify those patients more prone to a rapid radiographic progression of the disease <h3>References</h3> Van Spil WE, et al. Cros-sectional and predictive associations between plasma adipokines and radiographic signs of early-stage knee osteoarthritis: data from CHECK. Osteoarthritis Cartilage 2012;20:1278-1285 <h3>Acknowledgements</h3> We would like to thank the participants, principal investigators, coinvestigators and staff of the CHECK study. <h3>Disclosure of Interest</h3> None declared