Occult hepatitis B is defined by the presence of hepatitis B virus (HBV) DNA in a serum or liver in the absence of hepatitis B surface antigen (HBsAg).
The prevalence and clinical correlates of occult hepatitis B remain undefined.
In this study, doctors from Baltimore, Maryland, determined the prevalence of occult hepatitis B in a high-risk cohort of 188 injection drug users.
All individuals had chronic hepatitis C viral infections confirmed by RNA detection and liver biopsy.
|Occult hepatitis B was detected in 45%.|
The team performed serologic assays for HBsAg and core antibody (HBcAb).
In addition, serum HBV DNA was detected using the COBAS HBV AMPLICOR monitor assay and a semi-nested PCR assay.
The doctors found that although 96% of patients were anti-HBC positive, only 4% were HBsAg positive.
However, occult hepatitis B was detected in 45% of patients using semi-nested PCR.
They found that overall, liver disease was mild, with a median serum alanine aminotransferase (ALT) of 38 IU/L, median activity grade of 3/18, and median fibrosis stage of 1/6.
There was no association detected between the serum AST (aspartate aminotransferase), activity grade, or stage of liver disease and the presence of occult hepatitis B.
The doctors found that serum ALT levels were slightly higher in patients without occult hepatitis B (46 versus 35 IU/L).
They also found that median length of time since first injection drug use was longer in those without occult hepatitis B (24 versus 20 years).
Dr Michael Torbenson's team concluded, "Although further research is needed to assess its clinical significance, there is a high prevalence of occult HBV infection in this cohort of HCV-infected injection drug users".