Impact of cytomegalovirus infection on biliary disease after liver transplantation-maybe an essential factor

BACKGROUND Cytomegalovirus(CMV)infection is common in liver transplant(LT)_recipients,and biliary complications occur in a large number of patients.It has been reported that CMV-DNA is more detectable in bile than in blood.AIM To investigate the effects of CMV infection on biliary complications by comparing the levels of CMV-DNA in the bile and blood of patients after LT.METHODS We conducted a retrospective analysis of 57 patients who underwent LT,10 of these patients had no biliary complications and 47 patients had biliary complications.We also compared the levels of CMV-DNA in patients’bile and blood,which were sampled concurrently.We used RNAscope technology to identify CMV in paraffin-embedded liver sections.RESULTS CMV-DNA was not detected in bile samples and was detected in 2 blood samples from patients without biliary complications.In the 47 patients with biliary complications,CMV-DNA was detected in 22 bile samples and 8 blood samples,both bile and blood samples were positive for CMV-DNA in 6 patients.The identification rate of CMV-DNA in blood was 17.0%,and was 46.8%in bile.Moreover,tissue samples from 4 patients with biliary complications tested positive using RNAscope technology but were negative with hematoxylin and eosin staining.During the follow-up period,graft failure occurred in 13 patients with biliary complications,8 of whom underwent retransplantation,and 3 died.CMV-DNA in bile was detected in 9 of 13 patients with graft failure.CONCLUSION In patients with biliary complications,the identification rate of CMV-DNA in bile was higher than that in blood.Blood CMV-DNA negative patients with biliary complications should still be monitored for CMV-related biliary tract diseases.Potential occult CMV infection may also be a contributing etiological factor in the development of graft failure.