Cobas 8000 modular analyzer series

All RA patients were subjected to a routine medical examination. Both the patient’s and care provider’s global assessments of disease activity were based on a 100-mm visual analog scale (VAS). Disease activity was calculated by means of 28-joint Disease Activity Score (DAS28), DAS28-C-reactive protein (CRP) [30 (link)], and Simplified Disease Activity Index (SDAI) [31 (link)] scores, and the medications used were logged from the medical files and by asking the patient during examination. Blood samples were tested for plasma RF and CRP, using an immunoturbidimetric assay (Roche/cobas® 8000 Modular Analyzer Series, Roche Diagnostics, USA), and for ACPA (anti-CCP-2) by Immunoscan CCPlus®. Euro Diagnostica with a positive value established as that exceeding 25 U/mL in both serological tests, and 3 mg/L in the CRP test. Anti-CCP antibody levels were stratified as low (between 25 and 75 U/mL), moderate (76–300 U/mL), or high (> 300 U/mL).

At baseline, a 10-ml spot urine sample was collected for urinalysis which detects proteinuria by using Sysmex UF-1000i analyzer (TOA Medical Electronics, Kobe, Japan). Fasting blood samples were drawn for laboratory examination.
Serum creatinine and cystatin C were determined using Roche Cobas 8000 modular analyzer Series (Roche, Inc., Mannheim, Germany) with the enzymatic assay creatinine Plus Ver.2 (Roche, Mannheim, Germany) and a particle-enhanced immunonephelometric assay (Roche, Tina-quant Cystatin C, Mannheim, Germany) on cobas c702 and cobas c501 platforms, respectively.
We calculated GFR by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. We chose the combined creatinine–cystatin C equation of CKD-EPI which performed better than only creatinine or only cystatin C equation as the primary GFR_crcys estimation method [13 (link)].

Serum concentrations of PG I, PG II, G-17, and anti-Hp IgG antibody were tested by commercial ELISA kits (PGI, PGII, G-17, and Helicobacter pylori antibody ELISA kits; Biohit, Helsinki, Finland). Carcinoembryonic antigen (CEA) and carbohydrate antigen 199 (CA199) were tested by electrochemiluminescence immunoassay. The detection instrument is Roche cobas 8,000 modular analyzer series (Mannheim, Germany). CEA and CA199 were divided into negative ( ≤ 5 ng/ml) or positive (>5 ng/ml) and negative ( ≤ 37 U/ml) or positive (>37 U/ml), respectively. The test was conducted by the unified training personnel of all qualified laboratories in every hospital. The definition of seropositivity for each indicator was determined by the manufacturer's protocol.

The serum levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), albumin, triglycerides (TG), cholesterol, and high-density lipoprotein (HDL) were determined using standard kit methods using a fully automated COBAS^® 8000 modular analyzer series in the King Fahad Armed Forces Hospital, Jeddah, Saudi Arabia. The levels of LDL and VLDL were assessed according to Friedewald’s equation [107 (link)]:

Three types of CMRFs were considered in this study, including hypertension, diabetes and dyslipidemia. A lower number of CMRFs implied better cardiometabolic health.
Three blood pressure measurements on participants were performed using a standardized electronic sphygmomanometer, recording systolic blood pressure (SBP) and diastolic blood pressure (DBP). Hypertension was defined as SBP ≥140 mmHg or DBP≥90 mmHg or the use of any antihypertensive medication (18 (link)).
After fasting for more than 10 h, blood samples were collected from all participants. Cobas8000^® modular analyzer series (Basel, Switzerland) was used to measure the fasting blood glucose (FPG), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDLC), and low-density lipoprotein cholesterol (LDLC) by standard methods. Type 2 diabetes mellitus (T2DM) was defined by the American Diabetes Association guidelines (19 (link)) as FPG ≥ 7.0 mmol/L or the use of any glucose-lowering medication. Dyslipidemia was defined as TG ≥ 2.3 mmol/L, TC ≥ 6.2 mmol/L, LDL-C ≥ 4.1 mmol /L, HDL-C < 1.0 mmol/L, or the use of any hypolipidemic drugs based on Chinese guidelines for the management of dyslipidemia in adults dyslipidemia (20 (link)).

Renal function was assessed by BUN concentration (26 (link), 27 (link)). Blood samples were obtained via lateral tail vein sampling in micro tubes with clotting activator (Micro tube 1.3 ml Z, Clotting Activator/Serum, Sarstedt, Nümbrecht, Germany). Preparation of clotted blood samples was conducted using a precooled tabletop centrifuge (Eppendorf centrifuge 5427R, Eppendorf AG, Hamburg, Germany). To receive designated serum, probes were centrifugated at 2,000 × g for 10 min at 5°C. Measurement of BUN concentration was performed using cobas 8000 modular analyzer (cobas 8000 modular analyzer series, Roche, Basel) by the central laboratories of the University Medical Center, Freiburg. To avoid invalidation, samples that showed macroscopic levels of hemolysis were excluded.