A 54-year old man presented to the emergency department of Erfan Niyayesh Hospital, Tehran, Iran, with complains of high-grade fever, cough, and dyspnea for five days. At admission time, he had fever up to 38 °C. Peripheral oxygen saturation was 90% with a face mask. No abnormality was seen in laboratory results except positive C-reactive protein, lymphopenia with 570 cells/µL, and severe respiratory acidosis. The chest X-ray imaging revealed bilateral infiltration in both upper and lower lobs (Figure 1a) (Figure 1c) . Also, the inflammatory cytokines were measured 48 hours following the last session of hemoperfusion and showed a remarkable decrease. IL-1, and IL-6 were decreased from 523.3 pg/mL to 38.25 pg/mL, and 226.35 pg/mL to 210.18 pg/mL, respectively. The measurements also showed the decrease in IL-8 from 886.5 pg/mL to 482.4 pg/mL. Tumor necrosis factor alpha level decreased from 49.5 pg/mL to 47.3 pg/mL at the end of 3 sessions of hemoperfusion. The patient was finally transferred to the ward with an acceptable clinical condition.
The "cytokine cascade" in patients with new coronavirus (COVID-19) is a leading cause of death in critically ill patients [1] . A variety of blood purification technology treatment methods such as CRRT plus hemoperfusion seem to be effective in certain cases. Cytokine release storm is the probable Phenomenon in severe COVID-19 cases [2] . Extracorporeal organ support can not only support vital organ functions such as the heart, lungs, kidneys, and liver but also avoid organ damage by removing excess inflammatory mediators [3] . Extracorporeal blood J o u r n a l P r e -p r o o f purification technology has been proven to effectively eliminate inflammatory cytokines such as CRP, IL-1, IL-6, etc. [4] . Here, we reported a successful case to represent our experience of extracorporeal blood purification in a patient with confirmed COVID-19 pneumonia. In this case, IL-6 was high and Tocilizumab, as an IL-6 antagonist, was another potential agent.
However, Tocilizumab therapy may be associated with adverse effects and the access to Tocilizumab is limited in Iran. Also, tocilizumab is effective only on IL-6 regarding its mechanism. Hemoperfusion can have impact on more than one cytokine and may be more effective. This case responded to hemoperfusion and CRRT without remarkable complication.
Hence, hemoperfusion with a disposable cartridge may be a promising option to decrease the inflammatory cytokines in COVID-19 induced ARDS. However, it is necessary to conduct clinical trials to find the efficacy and safety of this strategy. 