Chronic infection with the hepatitis B virus (HBV) is associated with a significantly higher risk of non-Hodgkin’s lymphoma, particularly for diffuse large B-cell lymphoma and follicular lymphoma, a new study revealed.
The study, “Hepatitis B virus and risk of non-Hodgkin lymphoma: An updated meta-analysis of 58 studies,” was published in the Journal of Viral Hepatitis.
Recent epidemiological studies have suggested that chronic infection with HBV, a virus that targets the liver to establish infection, increases the risk of non-Hodgkin’s lymphoma (NHL). But analysis of specific NHL subtypes has yielded conflicting results.
To clarify how chronic HBV infection affects NHL risk, researchers at the Shanghai Jiao Tong University School of Medicine conducted a meta-analysis of original studies exploring this correlation.
After searching for published studies in several databases, including PubMed, EMBASE, and the China National Knowledge Infrastructure database, researchers ended up with 58 studies meeting criteria for inclusion. They included nine group studies covering 1,585 NHL cases from a total of 2.7 million subjects, and 49 case-control studies with 52,129 NHL cases and 1.8 million controls.
A pooled analysis revealed that HBV-infected individuals were 2.5 times more likely to develop NHL compared to healthy controls. This association was independent of study type, regardless of whether they were case-control or cohort (group) studies.
NHL subtype was a major factor affecting the association between HBV and NHL and played a strong role in the considerable heterogeneity observed across studies.
“Because the NHL subtype was shown to have a substantial influence on the association between HBV infection and NHL, we first stratified the analysis by NHL subtype,” researchers wrote.
Looking at the immune cells affected in each NHL case — either B-cells or T-cells — researchers found that HBV infection increased the risk for B-cell NHL by 2.46-fold, compared to a 1.67-fold increased risk for T-cell NHL.
Within B-cell NHL subtypes, there was also significant heterogeneity. While HBV infection was significantly associated with diffuse large B-cell lymphoma and follicular lymphoma, it did not affect the chances of developing chronic lymphocytic leukemia or Burkitt lymphoma.
Different geographical locations also affected the association of HVB and NHL risk. In Asian and European countries, where HBV infection is more prevalent, the association was stronger than in American countries where HBV infection has a lower prevalence.
Overall, “the results of this meta-analysis support a positive link between HBV infection and NHL development. Further investigations for the mechanisms underlying HBV-induced NHL are warranted,” the study concluded.