Discrepancy between anti-hepatitis E virus immunoglobulin G prevalence assessed by two assays in kidney and liver transplant recipients

Background: Hepatitis E virus (HEV) is an emerging clinical threat in Europe among kidney and liver-transplant recipients. The incidence and prevalence of HEV infection in this special population are poorly known. False-negative results have been observed for anti-HEV IgG detection in severely immunocompromized persons. Moreover, large discrepancies have been reported between rates of anti-HEV IgG detection in blood donors and hepatitis E cases. Objectives: To compare anti-HEV IgG and IgM prevalence using two different commercial microplate enzyme-immuno assays (MEIAs) (Adaltis and Wantai) in 64 kidney-/liver-transplant recipients. Study design: Serum samples tested in our routine clinical practice over the 12/2009-12/2011 period with Adaltis MEIAs were retrospectively tested using Wantai MEIAs. IgG-positive sera were further tested by an immunoblot while those found IgM-positive were further tested with an immunochromatography rapid test and for the presence of HEV RNA. Results: Positive results on anti-HEV IgG testing were obtained for seven (10.9%) compared to 20 (31.3%) serum samples with Adaltis and Wantai assays, respectively (p = 0.005). Then, 6/7 (86%) of the serum samples positive with Adaltis and 16/20 (80%) of those positive with Wantai were positive with the immunoblot. One patient with chronic HEV infection was IgG-negative with both MEIAs. Regarding anti-HEV IgM, Adaltis and Wantai assays were concordant for 97% of the serum samples, prevalence being 8% with both MEIAs. Conclusions: The accuracy of currently available commercial or in-house anti-HEV IgG MEIAs should be tested comparatively on a panel of serum samples collected from solid organ-transplant recipients, including some who experienced PCR-documented HEV infection. (C) 2012 Elsevier B.V. All rights reserved.