Background and aim: H epatitis E v irus (HEV) infection has
emerged as a c ause o f travel-related a nd autochthonous a cute
hepatitis as well as chronic hepatitis in immunosuppressed patients.
While t ravel-related cases a re c aused primarily b y infections w ith
HEV of g enotype 1 ( HEV-1), autochthonous c ases a nd chronic
cases a re d ue t o genotype 3 (HEV-3), which is s hared between
humans and diverse animal species. The aim of this study was to
establish HEV RNA detection assays f or q uantitative v iral load
testing and genotyping.
Methods: V iral RNA was p urified from plasma or s erum a nd
converted to cDNA prior to (1) multiplex real-time PCR for HEV RNA
quantification and (2) multiplex PCR coupled to DNA sequencing for
HEV genotype determination. Real-time PCR was d esigned to
match a ll known HEV genotypes available i n Genbank while PCR
was designed using conserved primers flanking a variable region of
the HEV RNA.
Results: In a validation panel, the newly developed assays allowed
for the reliable detection and genotyping of HEV-1 or HEV-3. Cases
of t ravel-related and a utochthonous a cute h epatitis E a s well a s
chronic hepatitis E i n immunosuppressed patients have b een
identified using t hese a ssays a nd will be p resented in detail. Anti-
HEV antibodies were n egative i n three well-characterized patients
with chronic hepatitis E after organ transplantation.
Conclusions: We developed and validated a quantitative HEV RNA
detection assay that c an now be o ffered on a r outine basis
(www.chuv.ch/imul/imu-collaborations-viral_hepatitis). Genotyping
can also be offered on selected cases. HEV RNA detection is key in
diagnosing chronic hepatitis E i n immunosuppressed patients with
unexplained transaminase elevations, as serology can be negative
in these patients.