Dade thrombin reagent

Blood specimens were collected during the week before surgery. Plasma fibrinogen and serum albumin were measured immediately after blood sample collection. Plasma fibrinogen was assayed using Dade Thrombin Reagent (Siemens, Germany) and a CA7000 analyser (Sysmex Corporation), and the cumulative coefficient of variation (CV) was 7.3%. Serum albumin was measured using the bromocresol green (BCG) dye method and a biochemical analyser (7600-210, Hitachi, Japan), and the CV was 4.4% in the Clinical Laboratory of the First Hospital of Jilin University. Time-dependent receiver operating characteristic (ROC) analysis was performed to determine the optimal cut-off values of fibrinogen and albumin. Values above the optimal cut-off value were considered to be elevated, and those below the optimal cut-off value were considered to be decreased.
To reflect the effects of the two factors and the combined impact on GC prognosis, a scoring system of 2, 1, or 0 was chosen. Fib-Alb scoring was performed as follows: patients with elevated fibrinogen and decreased albumin levels were assigned a Fib-Alb score of 2; those with only one of these abnormalities were assigned a Fib-Alb score of 1; and those with neither of these abnormalities were assigned a Fib-Alb score of 0.

Prothrombin time (PT), international normalized ratio (INR) and fibrinogen concentration were measured in platelet free citrated plasma. All assays were performed using standard coagulometric methods on a Sysmex CS2000i coagulation analyzer (Sysmex Corporation, Kobe, Japan). Briefly, the PT was determined by mixing patient plasma and Innovin reagent (Dade Behring Inc., United States) in a 1:2 ratio, and the time taken for clot formation was measured in seconds. The INR was then automatically derived from the PT according to standard formula. For the fibrinogen assay patient plasma was diluted 1:10 in Owrens Veronal Buffer before being mixed in a 2:1 ratio with Dade Thrombin Reagent (Siemens Healthcare Diagnostic Inc., United States) and time to clot formation was measured in seconds. Fibrinogen concentration was then determined using a standard curve of serially diluted standard human plasma in g/L. The normal range for fibrinogen was defined as 2 to 4 g/L.

Complete blood count (leukocyte count, platelet count, hemoglobin, and hematocrit) was performed on a Sysmex XN-9000 analyzer (Sysmex Corporation, Kobe, Hyogo, Japan) using EDTA blood. PT (Dade Innovin; Siemens, Marburg, Germany), aPTT (Dade Actin FSL; Siemens), fibrinogen concentration (Clauss method, Dade Thrombin Reagent; Siemens), D-dimer concentration (Innovance; Siemens), and Anti-Xa activity (Biophen Heparin LRT; Hyphen Biomed, Neuville-Sur-Oise, France) were measured on a Sysmex CS2100i (Sysmex Corporation) in 3.2% citrated blood. For the anti-Xa measurement, COVID-19 patient samples (18 μl) were three times diluted with reference pooled plasma (36 μl). Anti-Xa activity was determined using an LMWH calibration line (aXa-LMWH; Hyphen Biomed). UFH activity was subsequently calculated with a previously determined formula: UFH anti-Xa = 1.55 ^* LMWH anti-Xa (26 (link)). Bilirubin (Bilirubin Total, third-generation; Roche Diagnostics, Basel, Switzerland) and creatinine (Enzymatic Reagent; Roche Diagnostics) were determined in serum on a COBAS® 8000 (Roche Diagnostics).