Cobas e602

For the biochemical analysis, venous blood samples were collected after overnight fasting of at least 10 h. The serum was separated through centrifugation and stored at −80 °C. Fasting blood glucose (FBG), triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and uric acid (UA) were measured using a Hitachi Automatic Biochemical Analyzer 7180 (Hitachi, Ltd., Tokoy, Japan. Fasting insulin (FINS) was measured using a fully automatic electrochemiluminescence analyzer Roche Cobas E602 (Roche Diagnostics, Mannheim, Germany). Insulin sensitivity was assessed by homeostasis model assessment–insulin resistance (HOMA-IR), which was calculated as follows: HOMA-IR = FBG (mmol/L) × FINS (μU/mL)/22.5.
Circulating markers of inflammation include C-reactive protein concentration (CRP), tumor necrosis factor α (TNF-α), and free fatty acids (FFA). CRP was determined using an automatic electrochemiluminescence analyzer Roche Cobas C702 (Roche Diagnostics, Mannheim, Germany). TNF-α and FFA were determined using the multifunctional enzyme marker Tecan sunrise (Tecan, Mannedorf, Switzerland).

Two milliliters of peripheral venous blood was collected from all hospitalized children before treatment and centrifuged for 10 min (3,000 r/min, centrifugal radius 70 mm), and the serum was cryopreserved in an ultra-low temperature freezer at −80 °C for future testing. Levels of antimicrobial peptide LL-37 were measured by ELISA, and human antimicrobial peptide ELISA kit was purchased from Shanghai Keshun Biotechnology Co., Ltd. Serum 25(OH)D levels were measured by the Roche electrochemical method, and relevant results were obtained from the clinical laboratory of the hospital, the analyzer is Roche Cobas E602 (Roche Diagnostics Gmbh, Germany, Manufactured 2014).

Liver biochemical parameters were determined by a biochemistry analyzer (7600 Series; Hitachi, Tokyo, Japan). Platelet was measured by Sysmex XN-2000 (Kobe, Japan). Serum HBsAg, anti-HBs, hepatitis B e antigen (HBeAg), hepatitis B e antibody (anti-HBe), and hepatitis B core antibody (anti-HBc) were detected using an enzyme-linked immunosorbent assay kit (ARCHITECT i2000 SR; Abbott Architect, USA). Serum HBsAg were retested (Roche Cobas e602; Roche, Switzerland) when it exceeded the upper linearity limit (250 IU/mL). HBV DNA was quantified by using a real-time PCR assay (DAAN Diagnostics, Guangzhou, China). Detection limits of HBsAg, anti-HBs, HBeAg, anti-HBe, anti-HBc, and HBV DNA were 0.05 IU/mL, 10 IU/L, 1 S/CO, 1 S/CO, 1 S/CO, 500 IU/mL, respectively. The upper limit of normal (ULN) of ALT has been defined as 40 U/L for women and 50 U/L for men. The ULN of bilirubin has been defined as 21 μmol/L for women and 26 μmol/L for men. The normal range of albumin was 40-55 g/L. In addition, hepatitis B core-related antigen (HBcrAg) was not detected due to the lack of serum samples.

Laboratory values were collected including complete blood count, high-sensitivity cardiac troponin I (hs-cTNI), NT-proBNP, biochemical tests, d-dimer, and procalcitonin (PCT). Complete blood count was measured with a Sysmex XN-9000 (Sysmex, Kobe, Japan) automatic hematology analyzer. Coagulation parameters, such as d-dimer, were measured with a Stago STA-R automatic blood coagulation analyzer (Stago, Paris, France). Biochemical tests, namely, alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, albumin, blood urea nitrogen (BUN), and creatinine were performed using Roche Cobas 8000 automatic biochemical analyzer (Roche, Rotkreuz, Switzerland). Hs-cTNI was measured with an Abbott ARCHITECT i2000SR chemiluminescence immunoanalyzer (Abbott Laboratories, Illinois, United States). Elevated hs-cTNI was defined as plasma levels of hs-cTNI above the 99th-percentile upper reference limit. NT-proBNP was analyzed with a Roche Cobas e602 electrochemical luminescence analyzer (Roche, Germany).

Glucose was measured using Cobas 6000 (Roche Diagnostics) or with a spectrophotometric method using Radiometer ABL 800 flex Blood Gas Analyzer which uses the hexokinase method on serum. Hemoglobin (Hb) was measured with a spectrophotometry method using Radiometer ABL 800 flex Blood Gas Analyzer or using the Sysmex XN-10, using a spectrophotometric method on hemolyzed blood. Creatinine was analyzed using Cobas 6000 (Roche Diagnostics) or with a spectrophotometric method using Radiometer ABL 800 flex Blood Gas Analyzer. Details on analytical and reference ranges for these analyses can be found in the Additional file 1.
Samples of hs-cTnT were collected in lithium heparin tubes and analyzed with the Roche Cobas e602 (Roche Diagnostics). This assay has a limit of detection of 5 ng/L and a limit of blank of 3 ng/L. Coefficient of variation is < 10% at 13 ng/L and the 99^th percentile cut-off point is at 14 ng/L [21 (link)].