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:

Some previous studies suggested that the plasma exchange (PE) and hemoperfusion (HP) played a cardinal role in the treatment of severe coronavirus disease 2019 (COVID-19) cases by diminishing the cytokine storm. This study aimed to assess the effects of PE and HP on cytokine storms in patients with severe COVID-19 through a systematic scoping review. Four Electronic databases (Medline [accessed from PubMed], Scopus, Science Direct, and Cochrane library) were searched systematically on February 2, 2021, using MESH terms and related keywords in the English language. Considering the titles and abstracts, unrelated studies were excluded. The full texts of the remained studies were evaluated by authors, independently. Then, their findings were assessed and reported. A total of 755 articles were obtained within the first step of searching, and 518 remained after removing the duplications. Through the title and abstract screening, 438 were removed. Of the rest, 59 papers were excluded. Finally, after reading the full text of the remained articles, 21 were included in data extraction. Most of the previously reported evidence were case reports and case series. Findings were summarized in two categories. The first category encompassed nine studies regarding HP and continuous renal replacement therapy, and the second category included twelve studies about PE. The results revealed that HP and PE within the cytokine storm phase would be beneficial with a high probability in the treatment of severely ill COVID-19 patients. Highlights Some studies showed that plasma exchange (PE) and hemoperfusion (HP) played an important role in the treatment of patients with severe COVID-19 disease. The results of this systematic scoping review revealed that HP and PE within the cytokine storm phase would be beneficial with a high probability in the treatment of severely ill COVID-19 patients.
["Treatment"]