Soluble lectin-like oxidized low-density lipoprotein receptor-1 levels in synovial fluid are correlated with disease severity of knee osteoarthritis

High-Density Lipoprotein Cholesterol and Apolipoprotein A1 in Synovial Fluid: Potential Predictors of Disease Severity of Primary Knee Osteoarthritis

OBJECTIVES

The aim of this study was to detect levels of common lipid species in serum and synovial fluid (SF) of primary knee osteoarthritis (OA) patients and investigate their correlations with disease severity.

MATERIALS AND METHODS

The study enrolled 184 OA patients receiving arthroscopic debridement or total knee arthroplasty and 180 healthy controls between April 2012 and March 2018. Total triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (ApoA1), and apolipoprotein B (ApoB) levels were analyzed in serum and SF of OA patients, and in serum of healthy individuals. The Noyes rating criteria, Kellgren-Lawrence (KL) grading system, and Western Ontario McMaster University Osteoarthritis Index (WOMAC) scores were, respectively, used to assess cartilage damage, radiographic severity, and symptomatic severity of OA.

RESULTS

No significant differences were found in serum TG and ApoB levels between the 2 groups, while OA patients had higher TC and LDL-C levels and lower HDL-C and ApoA1 levels (P < 0.05). Pearson correlation analysis revealed SF HDL-C and ApoA1 levels were negatively correlated with cartilage damage scores, KL grades as well as WOMAC scores (P < 0.05), which were still significant after adjusting for confounding factors (P < 0.05). Receiver operating characteristic curve analysis revealed SF HDL-C (area under the curve [AUC]: 0.816) and ApoA1 (AUC: 0.793) were also good predictors of advanced-stage OA (P < 0.001).

CONCLUSION

SF HDL-C and ApoA1 levels were negatively correlated with cartilage damage, radiographic severity, and symptomatic severity of primary knee OA, emerging as potential biomarkers for radiographic advanced-stage OA, which may serve as predictors of disease severity.

Systemic and Local Adipose Tissue in Knee Osteoarthritis

Osteoarthritis is a common chronic joint disorder affecting older people. The knee is the major joint affected. The symptoms of osteoarthritis include limited range of motion, joint swelling, and pain causing disability. There are no disease modifying drugs available, and treatments are mainly focused on pain management. Total knee replacement performed at the end stage of the disease is considered the only cure available. It has been found that obese people have an increased risk to develop not only knee but also hand osteoarthritis. This supports the concept that adipose tissue might be related to osteoarthritis not only through overloading. As matter of fact, obesity induces a low grade systemic inflammatory state characterized by the production and secretion of several adipocytokines that may have a role in osteoarthritis development. Furthermore, hypertension, impaired glucose, and lipid metabolism, which are comorbidities associated with obesity, have been shown to alter the joint tissue homeostasis. Moreover, infrapatellar fat pad in the knee has been demonstrated to be a local source of adipocytokines and potentially contribute to osteoarthritis pathogenesis. Here, we discuss the role of systemic and local adipose tissue in knee osteoarthritis. J. Cell. Physiol. 232: 1971-1978, 2017. © 2016 Wiley Periodicals, Inc.

Neopterin concentrations in synovial fluid may reflect disease severity in patients with osteoarthritis

We aimed to detect neopterin concentrations in serum and synovial fluid (SF) of knee osteoarthritis (OA) patients and to clarify their relationship with clinical severity of the disease. We cross-sectionally enrolled 176 knee OA patients and 63 age- and sex-matched controls. We measured neopterin concentrations by enzyme-linked immunosorbent assay (ELISA) and investigated the correlation between serum/SF neopterin concentrations and Kellgren-Lawrence (KL) grades as well as Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores in OA patients. Our results demonstrated that increased SF neopterin concentrations were independently correlated with greater symptomatic and radiographic severity in OA patients. These results suggested a crucial role of neopterin activation in the development and progression of knee OA. Assessment of neopterin levels in SF is a potential biomarker to evaluate disease severity in OA patients.

Decreased synovial fluid omentin-1 concentrations reflect symptomatic severity in patients with knee osteoarthritis

The aim of this study was to measure omentin-1 concentrations in serum and synovial fluid (SF) of knee osteoarthritis (OA) patients and to investigate their correlation with patient-reported symptomatic severity. We enrolled 263 knee OA patients and 62 healthy controls. We collected Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores from OA patients and measured omentin-1 concentrations in serum and SF by enzyme-linked immunosorbent assay (ELISA). Our results demonstrated that omentin-1 concentrations in SF but not serum were independently and negatively correlated with self-reported greater pain and physical disability in OA patients. Omentin-1 in SF might serve as a potential biomarker for reflecting the symptomatic severity of OA.

Association of MIF in serum and synovial fluid with severity of knee osteoarthritis

OBJECTIVE

Recent evidences suggest that inflammation contributes to the development and progression of osteoarthritis (OA). This study aims to determine macrophage migration inhibitory factor (MIF) levels in serum and synovial fluid (SF) of patients with knee OA and to analyze the association of MIF levels with the radiographic severity of OA.

DESIGN AND METHODS

224 patients with knee OA and 186 healthy controls were enrolled in this study.

RESULTS

Higher levels of serum MIF were found in knee OA patients compared with healthy controls. Knee OA patients with Kellgren and Lawrence (KL) grade 4 showed significantly elevated MIF levels in serum and SF compared with those with KL grade 2 and 3. MIF levels in serum and SF of knee OA patients were significantly related to disease severity evaluated by KL grading criteria.

CONCLUSION

MIF levels in serum and SF were closely related to the radiographic severity of OA.