You are presented with a paragraph from a COVID-19 literature. Classify the topics of this piece of text by choosing from the following categories:

- Epidemic Forecasting: The content relates to predictions about the spread of COVID-19.
- Treatment: The paragraph discusses therapeutic methods or medication for COVID-19.
- Prevention: The content covers measures to prevent the spread of COVID-19.
- Mechanism: The paragraph explains the biological mechanisms of the virus.
- Case Report: The content is a report of a COVID-19 case.
- Transmission: The paragraph discusses how COVID-19 is transmitted.
- Diagnosis: The content is about diagnosing COVID-19 in individuals.

Your classification should be provided as an element within a JSON array. The array should be formatted with topics enclosed in double quotes and separated by commas, following the JSON format, for example: ["Topic1", "Topic2", ...]. Include all applicable topics within the array. Your output should be a valid JSON array, and no additional text should be included in your response.

Article:

INTRODUCTION: We evaluated the Roche Elecsys IL6 assay on the Cobas immunoassay analyser. METHOD: Serum IL6 of 144 controls were compared to 52 samples from patients with COVID-like respiratory symptoms (17 SARS-CoV-2 RT-PCR positive); 25 of these were from the intensive care unit (ICU). We compared the IL6 levels to C-reactive protein (CRP) and procalcitonin (PCT) levels in all cases. RESULTS: The IL6 assay had coefficient-of-variation (CV) of 2.3 % (34.1 pg/mL) and 2.5 % (222.5 pg/mL), a limit of quantitation <1.6 pg/mL, and was linear from 1.6 to 4948 pg/mL. There was a significant difference in IL6 values between patients with COVID-like respiratory symptoms versus controls (p < 0.001). ROC analysis showed that IL6 > 6.4 pg/mL identified symptomatic cases (AUC 0.94, sensitivity 88.2 %, specificity 97.2 %). There was a significant difference between the IL6 of symptomatic ICU/non-ICU cases (median IL6 228 vs 11 pg/mL, p < 0.0001); ROC analysis showed IL6 > 75 pg/mL (sensitivity 76.0 %, specificity 88.9 %) was superior to CRP and PCT in predicting ICU admission (AUC: IL6 0.83, CRP 0.71, PCT 0.82). CONCLUSION: The performance of Elecsys IL6 assay is in keeping with the manufacturer's claims. IL6 > 6.4 pg/mL differentiates healthy from suspected COVID-19 cases and appears to be raised earlier than the other inflammatory markers in some cases. IL6 > 75 pg/mL was a good predictor of ICU admission.
["Diagnosis", "Treatment"]