ABSTRACT
OBJECTIVE: The Disease Activity Score based on 28 joints (DAS28) has been widely used in clinical practice and research studies of rheumatoid arthritis (RA). The objective of this study was to evaluate the discordance in the DAS28 based on the erythrocyte sedimentation rate (ESR) versus C-reactive protein (CRP) levels in Korean patients with RA. METHODS: From August to December 2011, 540 patients with RA who visited two rheumatology clinics affiliated with Hallym University (Korea) and had at least one DAS28 evaluation were examined. RESULTS: The mean age of the included patients was 53 years, and 82% were female. The mean duration of disease was 32.9 ± 41.2 months. The mean DAS28-ESR was higher than the DAS28-CRP (3.65 vs. 3.44; P < 0.001). In the DAS28-ESR group, 126 patients (23.3%) satisfied the criteria for remission versus 134 (24.8%) in the DAS28-CRP group. High disease activity was determined in 80 (14.8%) patients in the DAS28-ESR group and in 43 (8.0%) in the DAS28-CRP group. A comparison of the two groups with respect to four DAS28 disease activity categories showed agreement in 344 patients (63.7%; κ = 0.45). In classifying patients as European League Against Rheumatism (EULAR) responders, agreement between the two methods was shown in 56 patients (71.8%; κ = 0.76). When disagreements between the two scores occurred, more patients had a better EULAR response based on the DAS28-ESR than on the DAS28-CRP (19.2% vs. 8.9%, respectively). CONCLUSION: The discordance between the ESR-based and CRP-based DAS28 could affect clinical treatment decisions for patients with RA.
Subject(s)
Arthritis, Rheumatoid/blood , Arthritis, Rheumatoid/diagnosis , Blood Sedimentation , C-Reactive Protein/analysis , Disability Evaluation , Joints/physiopathology , Adult , Aged , Ambulatory Care Facilities , Arthritis, Rheumatoid/physiopathology , Arthritis, Rheumatoid/therapy , Biomarkers/blood , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Prognosis , Reproducibility of Results , Republic of Korea , Severity of Illness IndexABSTRACT
Monosodium urate (MSU) crystals, which are highly precipitated in the joint cartilage, increase the production of cartilage-degrading enzymes and pro-inflammatory mediators in cartilage, thereby leading to gouty inflammation and joint damage. In this study, we investigated the effect of MSU crystals on the viability of human articular chondrocytes and the mechanism of MSU crystal-induced chondrocyte death. MSU crystals significantly decreased the viability of primary chondrocytes in a time- and dose-dependent manner. DNA fragmentation was observed in a culture medium of MSU crystal-treated chondrocytes, but not in cell lysates. MSU crystals did not activate caspase-3, a marker of apoptosis, compared with actinomycin D and TNF-α-treated cells. MSU crystals did not directly affect the expression of endoplasmic reticulum (ER) stress markers at the mRNA and protein levels. However, MSU crystals significantly increased the LC3-II level in a time-dependent manner, indicating autophagy activation. Moreover, MSU crystal-induced autophagy and subsequent chondrocyte death were significantly inhibited by 3-methyladenine, a blocker of autophagosomes formation. MSU crystals activated autophagy via inhibition of phosporylation of the Akt/mTOR signaling pathway. These results demonstrate that MSU crystals may cause the death of chondrocytes through the activation of the autophagic process rather than apoptosis or ER stress.
