Hepatitis E virus and transfusion transmitted infection in Scotland

Background: Hepatitis E (HEV) is an increasingly recognised cause of severe acute liver injury in developed countries. In addition, HEV is now well accepted as a cause of chronic hepatitis in immune-compromised patients such as post-transplant patients and HIV infected patients. There have also been several cases of HEV infection via blood transfusion and one reported case via liver transplantation. Here we assess the incidence of HEV in the post-transplant population in Scotland.
Methods: Patients attending the Scottish Liver Transplant Unit for routine post-transplant checkup were asked to provide a sample for HEV screening. Patients were asked to complete a questionnaire regarding exposure to known HEV risk factors (such as dietary factors, travel history and occupational exposure). Samples were screened for anti-HEV IgM and IgG antibodies by ELISA (Wantai, Beijing, China) and for HEV RNA by qRT-PCR. The patient demographic (n = 317) ranged from 18 to 85years (× 56.4 s13.6) with a male to female ratio of 1:1.07. The time post-transplant ranged up to 20 years (× 5.0 s5.3).
Results: The IgG seroprevalence within the cohort was 13.0%, and three IgM positive patients were identified (0.9%). Among the IgG seropositive patients there was no significant correlation with known HEV risk factors. A 46 year old male, was identified as HEV viraemic with a viral load of 1.6 × 106 IU/ml, despite being anti-HEV IgM and IgG seronegative. Prior to transplant this patient had suffered from primary sclerosing cholangitis, resulting in the development of chloangiocarcinoma. During this routine clinic appointment it was suspected that the patient had recurrent metastatic disease. The patient was admitted to hospital and died 14 days later (82 days post-transplant). Sequencing of the vRNA isolated from the patient's serum showed the patient was infected with genotype HEV3C. Retrospective screening of an archived serum sample from this patient (3 months prior to transplant) tested HEV RNA negative and antibody negative. The patient received a transfusion from a pool of fresh frozen plasma which also tested positive for HEV RNA. Sequence analysis confirmed the identity of the two samples to be 99.8%.
Conclusion: This is the first incidence of a potentially transfusion transmitted HEV infection in the Scotland. Overall, the HEV IgG seroprevalence in this cohort was considerably higher than the reported IgG seroprevalence of the Scottish blood donor population (4.7%). The fact that a patient with high viraemia and no antibody response emphasizes the need for molecular screening of HEV in transplant patients.