PLoS ONE (Jan 2017)

Cynomolgus monkeys are successfully and persistently infected with hepatitis E virus genotype 3 (HEV-3) after long-term immunosuppressive therapy.

  • Noemi Rovaris Gardinali,
  • Juliana Rodrigues Guimarães,
  • Juliana Gil Melgaço,
  • Yohan Britto Kevorkian,
  • Fernanda de Oliveira Bottino,
  • Yasmine Rangel Vieira,
  • Aline Campos de Azevedo da Silva,
  • Douglas Pereira Pinto,
  • Laís Bastos da Fonseca,
  • Leandro Schiavo Vilhena,
  • Edilson Uiechi,
  • Maria Cristina Carlan da Silva,
  • Julio Moran,
  • Renato Sérgio Marchevsky,
  • Oswaldo Gonçalves Cruz,
  • Rodrigo Alejandro Arellano Otonel,
  • Amauri Alcindo Alfieri,
  • Jaqueline Mendes de Oliveira,
  • Ana Maria Coimbra Gaspar,
  • Marcelo Alves Pinto

DOI
https://doi.org/10.1371/journal.pone.0174070
Journal volume & issue
Vol. 12, no. 3
p. e0174070

Abstract

Read online

Epidemiological studies found that hepatitis E virus genotype 3 (HEV-3) infection was associated with chronic hepatitis and cirrhosis in immunocompromised patients. Our study aimed to investigate the relationship between the host immunosuppressive status and the occurrence of HEV-related chronic hepatitis. Here we describe a successful experimental study, using cynomolgus monkeys previously treated with tacrolimus, a potent calcineurin inhibitor immunosuppressant, and infected with a Brazilian HEV-3 strain isolated from naturally infected pigs. HEV infected monkeys were followed up during 160 days post infection (dpi) by clinical signs; virological, biochemical and haematological parameters; and liver histopathology. The tacrolimus blood levels were monitored throughout the experiment. Immunosuppression was confirmed by clinical and laboratorial findings, such as: moderate weight loss, alopecia, and herpes virus opportunistic infection. In this study, chronic HEV infection was characterized by the mild increase of liver enzymes serum levels; persistent RNA viremia and viral faecal shedding; and liver histopathology. Three out of four immunosuppressed monkeys showed recurrent HEV RNA detection in liver samples, evident hepatocellular ballooning degeneration, mild to severe macro and microvesicular steatosis (zone 1), scattered hepatocellular apoptosis, and lobular focal inflammation. At 69 dpi, liver biopsies of all infected monkeys revealed evident ballooning degeneration (zone 3), discrete hepatocellular apoptosis, and at most mild portal and intra-acinar focal inflammation. At 160 dpi, the three chronically HEV infected monkeys showed microscopic features (piecemeal necrosis) corresponding to chronic hepatitis in absence of fibrosis and cirrhosis in liver parenchyma. Within 4-months follow up, the tacrolimus-immunosuppressed cynomolgus monkeys infected with a Brazilian swine HEV-3 strain exhibited more severe hepatic lesions progressing to chronic hepatitis without liver fibrosis, similarly as shown in tacrolimus-immunosuppressed solid organ transplant (SOT) recipients. The cause-effect relationship between HEV infection and tacrolimus treatment was confirmed in this experiment.