Serum chemerin in a cohort of Colombian patients with primary osteoarthritis

Osteoarthritis (OA) is considered the most common degenerative joint pathology in the adult population, being an important cause of disability worldwide, and its prevalence is increasingly associated with different factors, including obesity. Obesity together with metabolic syndrome have been associated with a pro-inflammatory state due to the release of cytokines that induce changes in cartilage metabolism. Chemerin is an adipokine secreted mainly by adipocytes and its final action is to increase the production of IL-6, IL-8, IL-1b, TNF-a and metalloproteinases by macrophages, dendritic cells and chondrocytes, which are responsible for damage to the articular cartilage. This is one of the reasons that obesity and inflammation have been linked to OA. The main objective of this study is to determine whether the serum chemerin concentrations of a group of patients with primary OA are higher when compared with control individuals. A further purpose of the study is to determine the relationship between the presence of obesity/overweight with the severity of the disease measured by a radiological scale.

An analytical cross-sectional study was carried out where serum chemerin levels were quantified by enzyme-linked immunoadsorption assay (ELISA), in patients with primary OA of the hip, knee and hand with criteria from the ACR (American College Of Rheumatology) and controls. Radiological studies of patients and controls were analysed to determine the severity of joint involvement using the Kellgren and Lawrence (KL) classification system. The statistical significance of the difference in serum chemerin values between the two groups was verified and the correlation between the variables of body mass index (BMI) with radiological severity, number of joint regions and serum chemerin levels was analysed.

During the period from July 2015 to July 2016, serum samples and radiographs of compromised joints were collected from 40 patients with primary OA who met the inclusion criteria, as well as serum samples from 20 controls. The average concentration of chemerin was higher in the group of patients with OA compared to that of the control group, being 373ng / ml and 175.55ng / ml respectively (p<2.2×10-16). No significant associations were found between the different degrees of disease severity measured by the KL radiological scale, such as the number of involved joint regions and BMI.

In a group of patients with primary OA of the hand, knee or hip, the values of chemerin were higher than those found in controls, without significant association with the severity of the disease established radiologically by K/L scale, the number of involved joint regions, and the BMI.