Method Comparison and Bias Estimation of Blood Urea Nitrogen (BUN), Creatinine (Cr), and Uric Acid (UA) Measurements between Two Analytical Methods.

BACKGROUND: A comparison of any two methods is of great importance in a clinical laboratory. In this study, our aim is to compare the assay results of blood urea nitrogen (BUN), creatinine (Cr), and uric acid (UA) obtained through two distinct methods and then assess the analytical agreement of the two methods. METHODS: A test method (Vitros5600 system) measuring BUN, Cr, and UA analytes was compared with a reference method (Hitachi7600 system). The Clinical and Laboratory Standards Institute (CLSI) document EP9-A2 guidelines were followed to evaluate the method comparison and bias using 40 patient samples. RESULTS: A high correlation between the two methods was found for all of the samples (R2 > 0.990). The regression parameters were BUN (R2 = 0.9996, slope = 1.025, intercept = 0.1156), Cr (R2 = 0.9993, slope = 0.9993, intercept = 4.661), and UA (R2 = 0.9971, slope = 1.011, intercept = 1.311). Compared with the Hitachi7600 reference method, the Vitros5600 test method showed that the 95% confidence interval for the predicted bias at medical decision levels was less than the acceptable error. More importantly, Bland-Altman plots indicated that a minimal positive bias (mean ± SD) was observed: BUN (0.352 ± 0.289 mmol/L), Cr (2.702 ± 7.683 µmol/L), UA (5.398 ± 7.086 µmol/L). CONCLUSIONS: The Vitros5600 and Hitachi7600 systems have good correlation and bias for detecting BUN, Cr, and UA analytes. The two systems have a high method agreement.

Tripterygium glycosides inhibit inflammatory mediators in the rat synovial RSC-364 cell line stimulated with interleukin-1ß.

Tripterygium glycosides (TG) are extracted from a traditional Chinese medicinal herb. Using the compound, progress has been made in the treatment of rheumatoid arthritis (RA), but the underlying mechanism of its action is poorly understood. The purpose of the present study was to investigate the role of TG in preventing inflammatory arthritis. An inflammatory cell model was established in the rat synovial RSC-364 cell line via induction with interleukin (IL)-1ß. The expression of IL-32 and matrix metalloproteinases (MMP-1 and MMP-9) was determined using an enzyme-linked immunosorbent assay. Compared with the control group (without IL-1ß), IL-1ß in the treatment group induced the expression of IL-32, MMP-1 and MMP-9 in RSC-364 cells. When a different dose of TG was added to RSC-364 cells stimulated with IL-1ß, TG decreased the expression levels of IL-32, MMP-1 and MMP-9 in a dose-dependent manner. These results indicated that TG suppressed the inflammation response in RSC-364 cells. Taken together, these findings may contribute to a better understanding of the role of TG in the anti-inflammatory therapeutics for RA.

Quantitative Proteomic Analysis of Peripheral Blood Mononuclear Cells in Ankylosing Spondylitis by iTRAQ.

This study was designed to identify and quantify the different proteins expression levels in ankylosing spondylitis (AS) and to explore the pathogenesis of AS. We performed isobaric tags for relative and absolute quantitation (iTRAQ) coupled with multiple chromatographic fractionation and tandem mass spectrometry to detect the proteins profiling in peripheral blood mononuclear cells (PBMCs) from AS patients and healthy controls. Mascot software and the International Protein Index and the Gene Ontology (GO) database were used to conduct the bioinformatics analysis. The differentially expressed proteins were validated by enzyme-linked immunosorbent assay (ELISA). A total of 1,232 proteins were identified by iTRAQ, of which 183 showed differential expression and 18 differentially expressed proteins were acute phase reactants. Upon mapping of the differentially expressed proteins to GO database, we found four differentially expressed proteins involved in the biological process of cell killing, including up-regulated cathepsin G (CTSG), neutrophil defensin3 (DEFA3), protein tyrosine phosphatase receptor type C (PTPRC), and down-regulated peroxiredoxin-1(PRDX1),which were consistent with the verified results of ELISA. Our proteomic analyses suggested that the proteins involved in the biological process of cell killing might play an important role in the pathogenesis of AS.

How does short-term low-dose simvastatin influence serum prohepcidin levels in patients with end-stage renal disease? A pilot study.

Anemia is a common clinical problem in end-stage renal disease (ESRD). Despite adequate erythropoiesis-stimulating agent (ESA) supplementation, some ESRD patients still have suboptimal hemoglobin levels, and iron deficiency and inflammation are recognized as the two most common causes. Hepcidin, a newly discovered key regulator of iron homeostasis, is found to be accumulated in ESRD. As it controls iron uptake and release, better reflecting real-time iron demand and availability, hepcidin might become a target in the management of iron deficiency and ESA resistance in dialysis patients. For their pleiotropic functions apart from lipid-modulation, statins are also used as anti-inflammatory or immune-modulating agents. In this study, we applied simvastatin for the purpose of influencing serum prohepcidin level in a group of maintenance hemodialysis patients. Thirty-three ESRD patients undergoing hemodialysis were enrolled and assigned to experimental and hemodialysis control groups according to their lipid profile. Nineteen healthy adults were chosen as a normal control group. The subjects in the experimental group took 20 mg simvastatin orally per night for eight weeks, and those in the hemodialysis control group took no statins or any other lipid-modulating drugs. Before and after the experiment, the serum prohepcidin concentrations, plasma IL-6, and serum C-reactive protein (CRP), ferritin, hemoglobin, albumin, total cholesterol, glycerinate, and LDL and HDL cholesterol levels were determined. Of the 33 hemodialysis patients, the serum prohepcidin concentration was (175.8 +/- 52.9) ng/mL, significantly higher than that in the normal control group (149.5 +/- 24.2) ng/mL (P = 0.048). In the experimental group, the serum prohepcidin level was (156.7 +/- 51.9) ng/mL before treatment, and (190.6 +/- 49.6) ng/mL after eight weeks (P = 0.127). In the hemodialysis control group, the serum prohepcidin level was (190.6 +/- 49.6) ng/mL at the beginning, and (193.5 +/- 36.0) ng/mL after eight weeks (P = 0.728). In the experimental group, after taking simvastatin for eight weeks the serum total cholesterol and triglyceride levels had lowered by 18.6% (P = 0.004) and 55.1% (P = 0.007), respectively. The plasma IL-6, serum CRP, ferritin, hemoglobin, albumin, and LDL and HDL cholesterol levels in both the hemodialysis group remained unchanged. According to our preliminary study, eight weeks of 20 mg simvastatin did not significantly change the serum prohepcidin, high-sensitive CRP, or IL-6 concentrations in the group of maintenance hemodialysis patients.