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: Dysfunction in the renin-angiotensin-aldosterone system (RAAS) has been observed in patients with coronavirus disease 2019 (COVID-19). It is presumed that the effect of reducing interleukin-6 (IL-6) levels by angiotensin II receptor blockers (ARBs) by RAAS modulation. We investigated changes in angiotensin II and IL-6 levels in four COVID-19 patients treated with ARBs. Case Presentation. Cases 1 and 2 were who had not received ARBs before and were newly administered ARBs. Case 3 restarted ARBs after discontinuation for 7 days, and case 4 received an increased dose of ARBs. The mean in angiotensin II levels (607.5 pg/mL, range: 488-850 pg/mL, reference range < 100 pg/mL), C-reactive protein (CRP) (10.58 mg/dL, range 4.45-18.05 mg/dL), and IL-6 (55.78 pg/mL, range: 12.86-144.82 pg/mL, reference range < 7 pg/mL) was observed at the admission in all patients. Upon clinical improvement, the mean decrease in CRP (1.02 mg/dL, range 0.06-3.78 mg/dL) and IL-6 (5.63 pg/mL, range 0.17-20.87 pg/mL) was observed in all patients. Conversely, angiotensin II levels gradually increased. Conclusion: This report supports the potential benefit of ARBs to improve the clinical outcomes of COVID-19 patients by controlling RAAS dysfunction.
["Case Report"]