Successful treatment of positive-sense RNA virus coinfection with autoimmune hepatitis using double filtration plasmapheresis.

Double filtration plasmapheresis (DFPP) is an apheretic technique that selectively removes high molecular weight substances using a plasma component filter. DFPP has been used to treat positive-sense RNA virus infections, mainly chronic hepatitis C virus (HCV) infection, because of its ability to directly eliminate viral particles from blood plasma from 2008 to about 2015, before direct-acting antiviral agents was marketed. This effect has been termed virus removal and eradication by DFPP. HCV is a positive-sense RNA virus similar to West Nile virus, dengue virus and the SARS and Middle East respiratory syndrome coronaviruses. SARS-CoV-2 is classified same viral species. These viruses are all classified in Family Flaviviridae which are family of single-stranded plus-stranded RNA viruses. Viral particles are 40-60 nm in diameter, enveloped and spherical in shape. We present a rare case of HCV removal where an RNA virus infection that copresented with virus-associated autoimmune hepatitis was eliminated using DFPP. Our results indicate that DFPP may facilitate prompt viraemia reduction and may have novel treatment applications for SARS-CoV-2, that is, use of therapeutic plasma exchange for fulminant COVID-19.