IRCT20080901001165N58 IRCT 2020-05-27 Bagheiat-allah University of Medical Sciences Investigating the efficacy and safety of Plasmapheresis in patients with Moderate to severe COVID-19 Investigating the efficacy and safety of Plasmapheresis in patients with Moderate to severe COVID-19 2020-04-29 anticipated 100 Complete https://irct.ir/trial/48394 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Treatment, Randomization description: Block Randomization method is used to randomized the patients. In this method, the number of people assigned to each group is usually almost equal. Blocks are formed based on the considered variables and within each block, half of the people are involved and half are considered as witnesses. The main goal in this method is to balance the number of participants in each group. N/A COVID-19. Intervention 1: Intervention group: Plasmapheresis 3-5 session (based on clinical improvement), In addition to Amp. Methylprednisolone (500 mg day1, 250 mg day 2 and day3, IV) and routine treatment according to the latest national guideline for the treatment of new corona-virus. Intervention 2: Control group: Amp. Methylprednisolone (500 mg day1, 250 mg day 2 and day3, IV) and routine treatment according to the latest national guideline for the treatment of new corona-virusfor the treatment of new corona-virus. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is The release schedule is not clear yet.