[Occult hepatitis B virus infection and hepatocellular carcinoma]

Occult Hepatitis B virus (HBV) infection and challenges for hepatitis elimination: A literature review

Occult hepatitis B infection (OBI) is characterized by the detection of hepatitis B virus (HBV) DNA in serum or liver but negativity for hepatitis B surface antigen. OBI, which is thought to be maintained by host, immunological, viral and/or epigenetic factors, is one of the most challenging clinical features in the study of viral hepatitis. Currently, there is no validated detection test for OBI. It is believed that OBI is widely distributed throughout the world, with a higher prevalence in populations at high-risk HBV, but the detailed worldwide prevalence patterns are unknown. We conducted a survey of recently published studies on OBI rates across all continents. High prevalence rates of OBI are observed in some specific groups, including patients with hepatitis C virus, human immunodeficiency virus co-infection or hepatocellular carcinoma. In 2016, the World Health Organization adopted strategies to eliminate viral hepatitis by 2030, but the difficulties in detecting and treating OBI currently challenge this goal. Subjects with OBI can transmit HBV, and episodes of reactivation can occur. Further studies to understanding the mechanisms that drive the development of OBI are needed and can contribute to efforts at eliminating viral hepatitis.

Potential etiology, prevalence of cirrhosis, and mode of detection among patients with non-B non-C hepatocellular carcinoma in Korea

BACKGROUND/AIMS

We systematically evaluated the clinical characteristics, prevalence of cirrhosis, and mode of detection in virus-unrelated (non-B non-C, NBNC) hepatocellular carcinoma (HCC) patients in Korea.

METHODS

A total of 447 consecutive treatment-naïve NBNC-HCC adult patients who were registered at the Samsung Medical Center HCC registry in Korea from 2010 to 2013 were analyzed. NBNC was defined as negative hepatitis B surface antigen and negative anti-hepatitis C virus antibody. Presence of cirrhosis was determined based on histological, radiological, endoscopic, and serologic results. Mode of detection was classified as either under surveillance, incidental, or symptomatic.

RESULTS

Heavy alcohol use was the most common potential etiology in NBNCHCC (NBNC-A, alcohol) (59.7%). Ten patients had other identifiable causes (NBNC-O, other identifiable cause) such as autoimmune hepatitis. The rest (38.0%) had no-identifiable cause (NBNC-NA-NO, non-alcohol, no-other identifiable cause). In NBNC-NA-NO group, 83.5% (96/115) of patients with available hepatitis B core immunoglobulin G antibody (HBcIgG) showed HBcIgG positivity, and 80.6% (137/170) had metabolic risk factors (diabetes, obesity, hypertension, and/ or dyslipidemia). Cirrhosis was present in 90.0%, 70.4%, and 60.0% of NBNC-O, NBNC-A, and NBNC-NA-NO patients, respectively. The proportion of patients diagnosed under surveillance was 25.5% across all patients, with specific proportions being 80.0%, 27.7%, and 18.8% for NBNC-O, NBNC-A, and NBNC-NA-NO, respectively.

CONCLUSION

Among NBNC-HCC patients, heavy alcohol use or any other identifiable cause was not found in 38.0%. These NBNC-NA-NO HCC patients showed a high prevalence of HBcIgG positivity and metabolic risk factors, suggesting that prior hepatitis B virus infection and metabolic risk factors may be major contributing factors in the hepatocarcinogenesis in NBNC-NA-NO patients.

[Clinical features of non-alcoholic fatty liver disease in cryptogenic hepatocellular carcinoma]

BACKGROUND/AIMS

Nonalcoholic fatty liver disease (NAFLD) may be one of the important causes of cryptogenic hepatocellular carcinoma (HCC). The aim of this study was to evaluate whether patients with cryptogenic HCC share clinical features similar to that of NAFLD.

METHODS

Cryptogenic HCC was defined as HCC that occurs in patients with the following conditions: HBsAg(-), anti-HCV(-), and alcohol ingestion of less than 20 g/day. All patients diagnosed with cryptogenic HCC from 2005 to 2012 (cryptogenic HCC group), and all patients diagnosed with HBV associated HCC between 2008 and 2012 (HBV-HCC group) were enrolled in the present study. Clinical features, BMI, lipid profiles, presence of diabetes mellitus, hypertension, and metabolic syndrome were compared between the two groups.

RESULTS

Cryptogenic HCC group was composed of 35 patients (19 males and 16 females) with a mean age of 70 ± 11 years. HBV-HCC group was composed of 406 patients (318 males and 88 females) with a mean age of 56 ± 7 years. Patients in the cryptogenic HCC group were older (p=0.001) and female dominant (p=0.042) than those in the HBV-HCC group. There were no differences in the laboratory test results including lipid profiles and Child-Turcotte-Pugh class between the two groups. Patients in the cryptogenic HCC group had higher prevalence of diabetes (37% vs. 17%, p=0.015), hypertension (49% vs.27%, p=0.051), metabolic syndrome (37% vs. 16%, p=0.001), and higher BMI (25.3 kg/m(2) vs. 24.1 kg/m(2), p=0.042) than those in the HBV- HCC group. The tumor stage was more advanced (stage III and IV) at diagnosis in the cryptogenic HCC group than in the HBV-HCC group (60% vs. 37%, p=0.007).

CONCLUSIONS

Cryptogenic HCC has clinical features similar to that of NAFLD and is diagnosed at a more advanced tumor stage.