Insight into the distinctive paradigm of Human Cytomegalovirus associated intrahepatic and extrahepatic cholestasis in neonates

Human Cytomegalovirus has been implicated as a probable cause for the development of hepatic cholestasis among neonates. Our study tried to ascertain the exact demographic, biochemical and immunological markers to differentially diagnose patients with HCMV associated intrahepatic and extrahepatic cholestasis and also decipher the phylogenetic variability among the viral strains infecting the two groups. A total of 110 neonates collected over a span of 2 years were selected for the study classified into four different groups based on the presence of hepatic cholestasis and active HCMV infection. Our analysis predicted that total Cholesterol, GGT, ALP and TNFα were the only significant biological markers with exact cut-off scores, capable of distinguishing between HCMV associated intrahepatic and extrahepatic cholestasis. We confirmed that in patients belonging to both of these groups, the inflammasome is activated and the extent of this activation is more or less same except for the initial activators NLRP3 and AIM2 respectively. When we performed two separate phylogenetic analyses with HCMV gM and gN gene sequences, we found that in both cases the sequences from the IHC and EHC groups formed almost separate phylogenetic clusters. Our study has shown that the HCMV clinical strains infecting at intrahepatic and extrahepatic sites are phylogenetically segregated as distinct clusters. These two separate groups show different physiological as well as immunological modulations while infecting a similar host.