Clinical utility of two-step hepatitis E virus IgM antibody testing in a low-prevalence setting: A 10-year retrospective multicenter study.

BACKGROUND

Diagnostic uncertainty caused by the low positive predictive value of HEV-specific IgM antibody (Ab) testing in a low-prevalence setting. We investigated the utility of a two-step HEV IgM Ab testing approach for diagnosing HEV infection.

METHODS

We retrospectively reviewed all adults who underwent HEV IgM Ab and/or HEV RNA testing from July 2013 through June 2023 at Mayo Clinic. Two-step HEV IgM testing involved initial testing using recomWell HEV IgM ELISA (Mikrogen, Neuried, Germany), with reflex to recomLine HEV IgM Strip (Mikrogen, Neuried, Germany) on all recomWell HEV IgM-reactive or IgM-equivocal specimens, as recomLine HEV IgM has higher specificity than recomWell HEV IgM but is more labor-intensive.

RESULTS

A total of 1640 patients had HEV IgM Ab or HEV RNA testing, including 1293 (79%) with only HEV IgM Ab testing, 213 (13%) with only HEV RNA testing, and 134 (8%) with both HEV IgM Ab and HEV RNA testing. Eighteen HEV infections were diagnosed with acute (N=16) and chronic (N=2) infections. Two-step IgM Ab testing did not identify 2 solid organ transplant recipients with chronic HEV infection. In acute HEV infection with HEV viremia, 3 out of 4 patients (2 solid organ transplant recipients and 1 patient with Guillain-Barre syndrome) were treated with ribavirin.

CONCLUSIONS

A two-step HEV IgM Ab test may accurately diagnose acute HEV infection in immunocompetent persons. However, this approach fails to identify chronic HEV infection in immunocompromised individuals who need HEV RNA testing to establish the diagnosis.