YKL-40 and cytokines - a New Diagnostic Constellation in Rheumatoid Arthritis?

BACKGROUND: Rheumatoid arthritis (RA) causes chronic inflammation and alteration of articular tissue and joints. The pathogenesis of the disease remains unclear although it is known that proinflammatory cytokines play a major role in its induction. YKL-40 is a chitinase-like glycoprotein produced by activated macrophages, neutrophils, arthritic chondrocytes and cancer cells. It has been shown that YKL-40 is implicated in tissue remodeling, angiogenesis and inflammation. AIM: to investigate serum and synovial YKL-40 levels in relation to IL-1ß, TNF-α, and IL-6 in RA patients. MATERIALS AND METHODS: Serum and synovial concentrations of YKL-40, TNF-α, IL- 6, and IL-1ß were determined by ELISA in 39 patients (mean age 53.18 ± 16.54 yrs) with active RA. RESULTS: Serum YKL-40 levels were increased in all patients. The highest levels were found in synovial fluid (P<0.01). Our study showed a strong association between serum and synovial levels of YKL-40 and serum TNF-α and IL-1 ß (P<0.05). CONCLUSION: This is the first study finding a significant correlation between serum TNF-α and IL-1ß and YKL-40 in active RA. We suggest that these molecules together might play a dominant role in the pathogenesis and disease activity and could possibly serve as a new diagnostic constellation in rheumatoid arthritis.

Ultrasonographic measurement of carotid artery resistive index and diastolic function of the heart in gout patients.

The aim of the study was to establish the functional disorder in the blood circulation of gout patients with a method that shows early damage of the heart and vascular structures. A total of 117 patients were examined cross-sectionally by a complex multimodal ultrasonography and were divided into four groups: 37 healthy controls, 24 asymptomatic hyperuricemia, 36 gout without tophi and 20 gouty tophi. With pulsed Doppler, common carotid artery resistive index (CCARI) and parameters of the transmitral blood flow were determined: the ratio between maximal early and late flow velocities (E/A ratio) and deceleration time (DT). With tissue Doppler imaging, mitral annular peak velocity (Em) was obtained. In the examined ultrasonographic parameters between healthy controls and the three patient groups, there was a statistically significant difference (p < 0.001). Comparing asymptomatic hyperuricemia and gout without tophi, no significant difference in CCARI (p = 0.656), E/A ratio (p = 0.472), DT (p = 0.990) and Em (p = 0.488) was found. Gouty tophi in comparison with gout without tophi and asymptomatic hyperuricemia had significantly lower Em (mean ± SD 0.07 ± 0.02 vs 0.09 ± 0.03 vs 0.13 ± 0.17) and significantly higher CCARI (mean ± SD 0.74 ± 0.05 vs 0.70 ± 0.05 vs 0.69 ± 0.05). Further multiple logistic regression revealed that tophi increased subject's likelihood of having category of CCARI ≥ 0.7 with an OR = 10.91 (95 % CI 1.80-66.14, p = 0.009), while the category of Em < 0.08 m/s was influenced by renal insufficiency with an OR = 3.07 (95 % CI 1.17-8.02, p = 0.022). Gouty tophi are associated with progression of arteriosclerotic-type vessel changes. Worsening of diastolic dysfunction of the heart is independently associated with renal insufficiency. In terms of CV risk, tophi are an indicator of its increase.