The research protocol consisted of subject allocation, research flow, laboratory examination, method analysis
Subject Allocation
Research subjects who met the inclusion criteria were divided into two groups, namely the mild and severe COVID-19 group
Research Procedures
a. Record the identity of patients/controls who meet the inclusion criteria and provide a complete explanation of what will be done to them, and if they agree, they will fill out and sign an informed consent.
b. Subjects who met the inclusion criteria were taken 3 ml of venous blood samples each in EDTA tubes and plain. The blood in the EDTA tube is checked for complete hematology. Serum was obtained after a tube containing blood formed a clot for 30 minutes at room temperature and was centrifuged for 20 minutes at 3000 rpm. Serum samples were collected until sufficient, and stored at -20°C, while samples were thawed at 25°C before analysis.
Laboratory examination
Interleukin-6 Elecsys System test
Instrument : cobas e 411
a.Sample: Serum
b. Tools and Materials
•Instrument cobas e 411
IL-6 reagent
IL-6 calibrators and controls
•Diluents
Test principle: Sandwich with ECLIA method (electrochemiluminescence)
•Test work, carried out in advance with a series of preparations, including daily calibration and quality control. Sample work is carried out according to the procedures determined by the factory.
Measuring Range: 1.5 – 5000 pg/mL (or 50000 pg/mL if diluted up to 10 times) Reference Value: Up to 7 pg/mL
Analysis Method
The data obtained are grouped according to the purpose and data type, then the appropriate statistical method is selected.
The primary data characteristics are displayed descriptively. The normality test of the data is the Kolmogorov-Smirnov test. Differences in IL-6 levels and NLR values between the two mild and severe COVID-19 groups using Mann Whitney, the IL-6 and NLR cutoffs were determined from the ROC curve, and the correlation of IL-6 and NLR levels with the severity of COVID-19 with the Chi-Square test, Correlation of IL-6 and NLR in COVID-19 with Spearman. The statistical test was stated to be significant if the p-value <0.05