Post-Transfusion Occult Hepatitis B (OBI): A Global Challenge for Blood Recipients and Health Authorities

Prevalence of hepatitis B infection in the Gambian population: A narrative review of recent developments

Hepatitis B is a "silent epidemic", fifty to a hundred (50-100) times more infectious than HIV, a potentially life-threatening liver infection caused by the hepatitis B virus (HBV). HBV can cause acute and chronic infection and subsequently results in a high risk of death from cirrhosis and liver cancer. Despite the availability of a safe and effective vaccine, HBV continues to be a global burden including in The Gambia. This study reviewed the recent trends in the epidemiological characteristics of HBV in the Gambia. The researchers conducted an online literature search for primary studies on HBV prevalence published in the past two decades from Jan 1992 to Feb 2022 inclusive on Google Scholar, PubMed, and Scopus. All retrieved studies were assessed for eligibility according to specific inclusion/exclusion criteria, data completeness, and methodological coherence. We found that HBV infection prevalence is above 8% in The Gambia. Moreover, HBV is the most common cause of hepatocellular carcinoma (HCC) in Gambia. Liver cirrhosis and HCC have the highest mortality contribution among hepatitis patients, with occult HBV carriers as major culprits. Also, vaccination coverage has declined from 91% to 88% according to reports from current literature. To achieve the WHO goal of eliminating HBV by 2030, policies targeting infection transmission control among risk groups, community awareness programs, research, price reduction of drugs, mass vaccinations, and diagnostics should be urgently instituted.

Occult hepatitis B virus infection among hepatitis C virus seropositive and seronegative blood donors in Alexandria, Egypt

BACKGROUND AND AIMS

Occult hepatitis B virus infection (OBI, serum hepatitis B surface antigen negative but hepatitis B virus DNA positive) is an emerging problem in the safety of blood transfusion. The introduction of hepatitis B surface antigen in the screening panel for blood bank donors has substantially reduced, but not entirely eliminated, the risk of hepatitis B virus infection. It has been suggested that infection with hepatitis C virus may inhibit hepatitis B virus replication. Therefore, this study aimed at estimating the prevalence and risk factors for OBI among blood donors and determining its relationship with hepatitis C virus infection.

SUBJECTS AND METHODS

Presence of hepatitis B virus DNA and hepatitis C virus RNA was investigated for among 508 hepatitis B surface antigen-negative blood donors in Alexandria, Egypt. Half of the donors were identified as hepatitis C virus antibody reactive.

RESULTS

OBI was detected in 21 donors (4.1%) from the studied population: eight were among hepatitis C virus antibody positive donors (3.2%), among whom seven (33.3%) had hepatitis C virus RNA in their serum, and 13 (5.1%) were among hepatitis C virus antibody negative donors, with no statistically significant difference. The only significant risk factor for OBI among the studied blood donors was visiting local barbers.

CONCLUSION AND RECOMMENDATIONS

OBI is a considerable risk in blood banks, making screening for hepatitis B virus infection only on the basis of surface antigenemia insufficient.

Occult HBV infection: a faceless enemy in liver cancer development

The hepatitis B virus (HBV) represents a worldwide public health problem; the virus is present in one third of the global population. However, this rate may in fact be higher due to occult hepatitis B virus infection (OBI). This condition is characterized by the presence of the viral genome in the liver of individuals sero-negative for the virus surface antigen (HBsAg). The causes of the absence of HBsAg in serum are unknown, however, mutations have been identified that produce variants not recognized by current immunoassays. Epigenetic and immunological host mechanisms also appear to be involved in HBsAg suppression. Current evidence suggests that OBI maintains its carcinogenic potential, favoring the progression of fibrosis and cirrhosis of the liver. In common with open HBV infection, OBI can contribute to the establishment of hepatocellular carcinoma. Epidemiological data regarding the global prevalence of OBI vary due to the use of detection methods of different sensitivity and specificity. In Latin America, which is considered an area of low prevalence for HBV, diagnostic screening methods using gene amplification tests for confirmation of OBI are not conducted. This prevents determination of the actual prevalence of OBI, highlighting the need for the implementation of cutting edge technology in epidemiological surveillance systems.

Potential roles played by IL-6 in hepatitis B infection

ABSTRACT: 

Hepatitis B is a main disorder of the liver, which is induced by HBV. Hepatitis B can induce liver diseases, such as inflammation, cirrhosis and hepatocellular carcinoma (HCC). Recent studies demonstrated that several patients are unable to eradicate the virus from hepatocytes and develop chronic hepatitis B infections. The main mechanisms responsible for development of chronic hepatitis B and its related cirrhosis as well as HCC are yet to be identified. IL-6 is a proinflammatory cytokine that participates in stimulation of immune responses against viral infections. In addition, it has been documented that IL-6 can play key roles in induction of fibrosis and cancers. Therefore, the aim of this article is to clarify the main roles of IL-6 in stimulation of appropriate immune responses against hepatitis B virus and induction of hepatitis B-dependent cirrhosis as well as HCC.

Overproduction of CXC chemokines CXCL1, CXCL9, CXCL10 and CXCL12 in β-thalassemia major or patients

BACKGROUNDS AND OBJECTIVES

B-thalassemia major is one of the most frequent hematological genetic disorders, worldwide. Chemokines are the main components of the immune system and play fundamental roles in pathogenesis of inflammatory disorders. Therefore, the present study aimed to examine whether serum CXC chemokines are altered in b-thalassemia major patients.

DESIGN AND SETTINGS

We enrolled 63 b-thalassemia patients and 80 controls in this cross-sectional study, which was performed during 2012-2013 in Kerman, Iran.

METHODS

We enrolled 63 b-thalassemia patients and 80 controls in the present study. Patients were selected from referrals to Samenolhojaj clinic for thalassemia, Kerman, Iran. The circulating levels of CXCL1, CXCL9, CXCL10, and CXCL12 were detected by enzyme-linked immunosorbent assay in thalassemia patients and healthy controls immediately after blood collection. Data were analyzed by c2, t-test, and analysis of variance statistical methods and using SPSS, version 13 (SPSS Inc., Chicago, IL).

RESULTS

The results of the study demonstrated a significant elevation of CXCL1, CXCL9, CXCL10, and CXCL12 in thalassemia patients than in control. These results also demonstrated that serum chemokine levels are related to transfusion duration and post-transfusion viral infections.

CONCLUSION

According to the results obtained, it can probably be concluded that chemokines are also involved in the pathogenesis of b-thalassemia major and its clinical complications in addition to several other parameters.

CCR5 plays important roles in hepatitis B infection

In humans, hepatitis B virus (HBV) is the most prevalent and the main infectious agent that leads to liver disease. Previous investigations identified that long-term HBV-infected patients are unable to eradicate HBV completely from hepatocytes. The main mechanisms responsible for long-term forms of the infections are yet to be clarified. However, researchers believe that the differences in genetic and immunological parameters in the patients in comparison to subjects who successfully clear HBV infections may be the causes for long-term infection. Previous studies demonstrated that chemokines play important roles in the regulation of immune cell migration and activation, which is crucial for a comprehensive immune response against HBV. RANTES, MIP-1α, and MIP-1β are important CC chemokines which act through CC chemokines receptor 5 (CCR5). This receptor is expressed on several effector immune cells including NK cells, T lymphocytes, and macrophages, and plays a crucial role in the regulation of activation and migration of the immune cells during immune responses against viruses, including HBV. Therefore, alterations in its expression or functions could be associated with attenuated immune responses against HBV. In addition, previous studies identified that a 32 base pair deletion (Δ32) in exon 1, as well as three polymorphisms in the promoter region of the CCR5 gene results in downregulation of the molecule. Previous studies revealed that CCR5 expression was altered in hepatitis B but the role of the CCR5 Δ32 mutation and CCR5 promoter polymorphisms in this disease is controversial. This review addresses the recent information regarding the status of CCR5 expression on immune cells and the association of CCR5 promoter polymorphisms with HBV-infected patients.

Important roles played by TGF-β in hepatitis B infection

Hepatitis B virus (HBV) which includes, fulminant, acute, chronic, asymptomatic, and occult HBV infection is the most prevalent virus that leads to human liver diseases. Chronic, asymptomatic, and occult infection can induce further sever diseases such as hepatocellular carcinoma (HCC) and cirrhosis of the liver. The underlying mechanisms that allow progression of the prolonged forms of the infection and subsequent HCC or cirrhosis of the liver are yet to be clarified. However, many researchers have suggested that immunological and genetic parameters may play important roles in the etiology of hepatitis B. Transforming growth factor beta (TGF-β) is an important cytokine with dual regulatory functions in the immune system and in the responses against viral infections. However, the pathways and mechanisms controlling these are not fully understood. The crucial roles of TGF-β in the development of Th17 and T regulatory lymphocytes, the main cell types involved in autoimmunity and destructive immune related diseases, have been documented and this provides insights into TGF-β function during hepatitis infection and subsequent HCC and cirrhosis of the liver. Recent findings also confirm that TGF-β directly alters hepatocyte function during hepatitis B, hence, the aim of this review is to address the current data regarding the association and status of TGF-β with hepatitis B infection and its related disorders including HCC and cirrhosis of the liver.

Current information on the immunologic status of occult hepatitis B infection

Hepatitis B is one of the most frequently occurring posttransfusion infections. Occult hepatitis B (OB) is a form of hepatitis B in which, despite the presence of hepatitis B virus (HBV) DNA in the serum and hepatocytes of a carrier, hepatitis B surface antigen is absent. In addition to the risk of transfusion of infection, OB can lead to cirrhosis, hepatic cancer, and reactivation of the viral duplication process in the carrier. The mechanisms responsible for progression of OB are yet to be clarified; however, some investigators have suggested that genetic and immunologic variables may play a significant role in the resistance of some individuals and sensitivity of other patients. This review addresses the current information regarding immunologic status of OB-infected patients.