OA phenotypes, rather than disease stage, drive structural progression – identification of structural progressors from 2 phase III randomized clinical studies with symptomatic knee OA

SummaryBackground/PurposeThe aim of this study was to identify key characteristics of disease progression through investigation of the association of radiographic progression over two years with baseline Joint Space Width (JSW), Kellgren–Lawrence (KL) grade, Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain, Joint Space Narrowing (JSN), and BMI.MethodsData from 2206 subjects (4390 knees) were combined for this post-hoc analysis of two randomized, double-blind, multi-center, placebo-controlled phase III trials (NCT00486434 and NCT00704847) that evaluated the efficacy and safety of 2-years treatment with oral salmon calcitonin of subjects with painful knee osteoarthritis (OA).ResultsThere was a clear positive and significant correlation between KL grade and WOMAC pain and total WOMAC, albeit the variance in pain measures was from min-to-max for all KL categories, emphasizing the heterogeneity of this patient population and pain perception. 32% of target knees did not progress, and only 51% had changes over minimum significant change (MSC). BMI, KL-Score and WOMAC pain was diagnostic, but only KL-score and pain had prognostic value, albeit pain in a non-linear manner.ConclusionThese data clearly describe significant associations between KL grade, JSW, pain and BMI in patients with symptomatic knee OA. KL grade, BMI and WOMAC pain were diagnostically associated with OA based on JSW but only KL-score and pain in a non-linier fashion was prognostic. 50% of patients did not progress more than MSC, highlighting the importance for identification of structural progressors and the phenotypes associated with these. These results suggest that disease phenotypes, rather than disease status, are responsible for disease progression

Association between biomarkers of tissue inflammation and progression of osteoarthritis: evidence from the Rotterdam study cohort

__Background:__ We aimed to investigate the prognostic value of two biomarkers of tissue inflammation, matrix metalloproteinase-dependent degradation of C-reactive protein (CRPM) and connective tissue type I collagen turnover (C1M), on the incidence and progression of radiographic osteoarthritis (OA) in the Rotterdam Study, a prospective cohort. Moreover, the independent effect of these biomarkers with respect to the established biomarkers of OA progression, like urinary type II collagen degradation (uCTX-II) and serum cartilage oligomeric protein (COMP), was evaluated. __Methods:__ Serum levels of C1M, CRPM, COMP and CRP of 1335 participants aged >55 years were measured in fasting serum using ELISA. The commercial ELISA detecting CTX-II was used in urine. Radiographs at baseline and 5-year follow-up were scored for OA stage by Kellgren-Lawrence grade. The associations between progression and incidence of OA and the baseline biomarkers were examined using logistic regression and generalized estimating equations adjusted for age, sex, BMI, and possible other confounders. __Results:__ The uCTX-II, COMP, and CRP concentrations were associated with the incidence and progression of OA. Moreover, OA progression was positively associated with CRPM (OR = 1.3, p = 0.01) and CRP (OR = 1.3, p = 0.01) levels with similar effect size as uCTX-II (OR = 1.3, p = 0.01) and COMP (OR = 1.2, p = 0.02). CRPM had prognostic value for progression of OA independent from the uCTX-II and COMP. __Conclusions:__ Our study confirmed the associations between uCTX-II and COMP concentrations and OA progression. Importantly, we showed for the first time that CRPM predicts the risk of OA progression independent of the established biomarkers uCTX-II and COMP

Serum biomarkers in prednisolone-treated hand osteoarthritis patients

Objectives To investigate whether biomarkers are modulated by prednisolone treatment in patients with hand OA and whether they can predict response to prednisolone. Methods Biomarkers reflecting tissue turnover and inflammation [aggrecanase-derived neoepitope of arggecan (ARGS), MMP-derived neoepitope of type I collagen (C1M), MMP-derived neoepitope of type III collagen (C3M), marker of true type V collagen formation (PROC5), MMP-derived neoepitope of CRP (CRPM), citrullinated vimentin fragment (VICM), high-sensitivity (hsCRP)] were measured in sera from 78 patients with painful inflammatory hand OA, who were randomized between prednisolone or placebo treatment. Association of baseline biomarker levels with disease characteristics [visual analogue scale (VAS) pain, synovial thickening ultrasonography sum score and erosive OA] and OMERACT-Osteoarthritis Research Society International (OARSI) response after 6 weeks were analysed with linear or logistic regression and adjusted for age, BMI and sex. Change in biomarker levels after 6 weeks was assessed with linear regression adjusted for baseline biomarker levels, age, BMI and sex. Results For all patients (mean age 64 years, 79% female), there were no associations between biomarker levels and VAS finger pain or synovial thickening score at baseline. Patients with erosive hand OA had higher levels of C1M and hsCRP [adjusted geometric mean ratio 1.24 (95% CI 1.03, 1.49) and 1.91 (1.19, 3.06), respectively]. Biomarker levels did not decrease over time. There was no association between baseline biomarkers levels and OARSI response, except for CRPM [geometric mean ratio of 0.88 (0.77, 1.00)]. Conclusion Erosive disease was associated with higher levels of C1M and hsCRP. Biomarker levels were not influenced by treatment with prednisolone. Current biomarkers were not associated with response to prednisolone in hand OA.Pathophysiology and treatment of rheumatic disease