Occult HBV infection

Occult hepatitis B virus infection in anti-HBs-positive infants born to HBsAg-positive mothers in China

Objective

To investigate the prevalence of occult HBV infection (OBI) among children and to characterize virology of occult HBV, we conducted an epidemiological survey.

Methods

186 HB-vaccinated infants born to HBsAg-positive mothers were included in the study. Serological tests for HBV markers were performed using commercial ELISA kits. Real-time quantitative PCR and nested PCR were used to detect HBV DNA. PCR products of the C and pre-S/S regions were sequenced and analyzed.

Results

1.61% (3/186) infants were HBsAg positive, and 4.92% (9/183) infants were considered as occult infection. The viral load of mothers was associated with occult infection (P = 0.020). Incomplete three-dose injections of HB vaccine was associated with HBV infection (P = 0.022). Six OBI infants were positive for anti-HBs, but their titers were not greater than 100 mIU/mL. Seven isolated HBV pre-S/S sequences were obtained from nine OBI infants. Three of the sequences were genotype C, and four of the sequences were genotype C/D. Escape mutation S143L was found in the four sequences of genotype C/D. All seven sequences lacked G145R and other escape mutation in S region.

Conclusions

Occult HBV infection was detected in anti-HBs positive infants born to HBsAg-positive mothers in China. Occult infection was associated with absent anti-HBs or with low anti-HBs level, high maternal viral loads and escape mutations in the S gene.

Risk of occult hepatitis B virus infection reactivation in patients with solid tumours undergoing chemotherapy

BACKGROUND

Hepatitis B virus reactivation may occur in occult-infected carriers with haematological malignancies, whereas little data are available in patients undergoing chemotherapy for solid tumours.

AIMS

Evaluation of cancer patients undergoing chemotherapy to investigate occult hepatitis B virus infection and its clinical-virological outcome.

METHODS

Forty-four patients with solid tumours and without liver disease were prospectively enrolled and sampled before starting chemotherapy and between the second and third chemotherapy cycles (time points 1 and 2, respectively); 24 were also sampled 6 months after the end of chemotherapy (time point 3). At each time point, subjects were tested for liver biochemistry, hepatitis B serology and occult infection.

RESULTS

No sample tested positive for virus surface antigen. Twelve subjects (27.3%) were antibody positive to hepatitis B virus. Overall, occult infection was detected in 4 cases (9%), with positive HBV DNA at time points 1 and 2 (one case), at time point 1 only (one case), only at time points 2 and 3 (two cases), respectively. No occult-infected carrier experienced liver biochemistry flares and/or viral surface antigen positivity.

CONCLUSIONS

Occult hepatitis B virus infection may occur in subjects with solid tumours, although the risk of its reactivation under chemotherapy appears to be very low.

Clinical significance of occult hepatitis B infection in progression of liver disease and carcinogenesis

Occult hepatitis B infection (OBI) is defined as long-lasting persistence of hepatitis B virus (HBV) DNA in the liver of patients with hepatitis B surface antigen (HBsAg)-negative status, with or without serological markers of previous exposure (antibodies to HBsAg and/or to hepatitis B core antigen). Over the past two decades, significant progress has been made in understanding OBI and its clinical implications. OBI as a cause of chronic liver disease in patients with HBsAg-negative status is becoming an important disease entity. In conditions of immunocompetence, OBI is inoffensive in itself and detection of HBV DNA in the liver does not always indicate active hepatitis. However, when other factors that cause liver damage, such as hepatitis C virus infection, obesity and alcohol abuse are present, the minimal lesions produced by the immunological response to OBI might worsen the clinical course of the underlying liver disease. Several lines of evidence suggest that OBI is associated with progression of liver fibrosis and the development of hepatocellular carcinoma in patients with chronic liver disease. The major interest in OBI is primarily associated with the growing, widely discussed evidence of its clinical impact. The aim of this review is to highlight recent data for OBI, with a major focus on disease progression or carcinogenesis in patients with chronic liver disease.

Occult hepatitis B: clinical viewpoint and management

Occult HBV infection (OBI) is defined as HBV DNA detection in serum or in the liver by sensitive diagnostic tests in HBsAg-negative patients with or without serologic markers of previous viral exposure. OBI seems to be higher among subjects at high risk for HBV infection and with liver disease. OBI can be both a source of virus contamination in blood and organ donations and the reservoir for full blown hepatitis after reactivation. HBV reactivation depends on viral and host factors but these associations have not been analyzed thoroughly. In OBI, it would be best to prevent HBV reactivation which inhibits the development of hepatitis and subsequent mortality. In diverse cases with insufficient data to recommend routine prophylaxis, early identification of virologic reactivation is essential to start antiviral therapy. For retrieving articles regarding OBI, various databases, including OVID, PubMed, Scopus, and ScienceDirect, were used.

Tuberculosis: a six-month cure

Today the treatment of tuberculosis can be based on a course of chemotherapy that lasts only 6 months, giving patients the best change of cure and affording the health personnel an exceptional opportunity to improve both their patients' compliance with the treatment and the overall efficiency of their own activities.