NKG2C+ natural killer cell function improves the control of HBV replication in individuals with acute HIV infection coinfected with HBV

Individuals infected with hepatitis B virus (HBV) are often coinfected with human immunodeficiency virus (HIV). However, individuals with chronic HBV infection living with acute HIV infection have a significantly lower HBV viral load, along with higher HBeAg and HBsAg loss than HBV-infected individuals alone. Here, we investigated the possible role of natural killer cells (NK cell) function in this progressive course to explore the relationship between phenotypic/functional changes in NK cells during acute HIV infection and HBV clearance in patients with HIV/HBV coinfection.Peripheral blood NK cells from 38 patients with primary HIV infection, including 20 with untreated HIV infection and 18 treatment-naïve patients with HIV/HBV coinfection and 16 patients with chronic HBV infection, were enrolled in this study.We found that the HIV/HBV-coinfected individuals had higher levels of NK cells than the HBV-infected individuals, due to expansion of the CD56 NK cell population. The proportion of NK cells in CD56 and CD56 NK subsets was not found significant difference between HIV/HBV-coinfected and HBV-infected individuals. However, NKG2C levels on NK cells and subsets were significantly higher in HIV/HBV-coinfected individuals than in HBV-infected individuals, whereas NKG2A levels were unaffected or decreased. In addition, the levels of degranulation CD107a, cytotoxicity and IFN-γ production of NK cells were increased in HIV/HBV-coinfected individuals than in HBV-infected individuals. The level of IL-10 production of NK cells was decreased in HIV/HBV-coinfected individuals than in HBV-infected individuals. Furthermore, the level of HBV-DNA was inversely correlated with the proportion of NKG2C and NKG2CNKG2A NK cells, while positively correlated with the proportion of NKG2A and NKG2CNKG2A NK cells. IFN-γ production was inversely correlated with levels of HBV-DNA, but the CD107a expression and IL-10 production of NK cells were not correlated with HBV-DNA levels.These results demonstrate that the upregulation of NKG2C expression, but not of NKG2A expression on the surface of NK cells increases cytolytic capacity and the amounts of cytokines produced and may play a crucial role in HBV clearance during HIV/HBV-coinfection.

Methylation status of the stimulator of interferon genes promoter in patients with chronic hepatitis B

The stimulator of interferon genes (STING) plays a crucial role in the recognition of a viral infection and subsequent stimulation of an immune response. However, it is unclear whether methylation of the STING promoter affects STING transcription and response to antiviral therapy. The present study determined the methylation status of the STING promoter in patients with chronic hepatitis B (CHB).This study included 198 participants, of which 159 participants had CHB and 39 were healthy controls (HCs). Methylation-specific polymerase chain reaction was performed to detect the methylation status of the STING promoter. Reverse transcription-quantitative polymerase chain reaction was performed to determine STING mRNA level in peripheral blood mononuclear cells.The methylation frequency of the STING promoter was significantly higher and STING mRNA level was lower in the patients with CHB than in the HCs. Presence of hepatitis B virus (HBV) DNA was independently correlated with an increased risk of STING promoter methylation. Virological response frequency was higher in the patients with CHB receiving entecavir (ETV) than in those receiving adefovir (ADV). In the ETV group, the virological response frequency was evidently lower in the patients with CHB having methylated STING promoters than in those having unmethylated STING promoters. However, there was no significant difference in the virological response frequency between ADV-treated patients having methylated and unmethylated STING promoters.These results indicate that the hypermethylation of the STING promoter and thus the transcriptional repression of STING weaken the effect of STING in inhibiting HBV replication and decreases the effectiveness of antiviral therapy.

An epidemiological survey of HBV infection and low-level HBsAg in military camps in eastern China

This study aimed to investigate hepatitis B virus (HBV) infection in military personnel in eastern China, which will provide a basis for the prevention of HBV infection.A total of 15,508 soldiers and 2386 officers were recruited from military camps in eastern China. The markers, deoxyribonucleic acid, serotypes, and genotypes of HBV in serum were detected and analyzed.Hepatitis B surface antigen (HBsAg) positive rate was 0.44% in soldiers, in whom the low-level HBsAg accounted for 88.24%. The HBsAg positive rate was 1.72% in officers in whom the low-level HBsAg accounted for 12.20%. There were significant differences in the prevalence of high-level and low-level HBsAg, HBV serotypes, HBV DNA positive rate, and mean log HBV DNA between officers and soldiers (P < .05). Compared with the conventional method for HBV DNA extraction, the enrichment method for HBV DNA extraction could significantly improve the positive rate and quantification of HBV DNA by real-time fluorescence quantitative polymerase chain reaction (P < .05). Sequencing of S gene in HBV was used for the determination of serotype and genotype of HBV. The sequencing success rate was significantly different between soldiers and officers (P < .05) as well as between high-level HBsAg group and low-level HBsAg group (P < .05). Significant difference was also observed in the genotype distribution between soldiers and officers (P < .05).HBV infection displays a low prevalence and a low epidemic state, and the prevalence of low-level HBsAg is higher in soldiers. We should pay attention to improve the quality of conscription examination as well as emphasize the surveillance, prevention, and protection of HBV infection in military officers.

Adherence to chronic hepatitis B treatment guideline recommendations for laboratory monitoring of patients who are not receiving antiviral treatment

BACKGROUND

Hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) levels predict future complications in chronic hepatitis B (CHB) patients. To determine when to initiate antiviral therapy, treatment guidelines recommend monitoring of HBV DNA and ALT levels at least annually. This study aimed to assess adherence to treatment guideline-recommended monitoring of CHB patients not receiving antiviral treatment and to identify predictors of laboratory monitoring and subsequent initiation of antiviral therapy.

METHODS

This retrospective cohort study used data from a large US health care claims database over a 5-year period (January 1, 2003 to December 31, 2007). The study population included patients 18-65 years of age with at least two paid medical claims with an ICD-9 code for CHB, at least one positive hepatitis B surface antigen test, and at least 12 months of continuous health plan enrollment after initial diagnosis. Descriptive statistics assessed the proportion of patients with claims for ALT and/or HBV DNA monitoring. Multivariate logistic regression models were used to determine predictors of monitoring and subsequent antiviral therapy.

RESULTS

The study included 1,168 CHB patients, with a mean follow-up of 728 days (median = 696 days). The proportion monitored at least every 12 months was 53.3% for ALT, 39.0% for HBV DNA, and 35.1% for both. Significant predictors of monitoring were a higher Deyo-Charlson Comorbidity Index (DCCI) score for ALT (OR 1.90, p < 0.001), male gender for HBV DNA (OR 1.49, p < 0.01), and a higher DCCI score (OR 1.10, p < 0.05) and male gender (1.46, p < 0.01) for both. Significant predictors of subsequent initiation of antiviral treatment were HBV DNA monitoring (OR 2.08, p < 0.001), a higher DCCI score (OR 1.24, p < 0.001), and male gender (OR 1.53, p < 0.01).

CONCLUSIONS

Laboratory monitoring of CHB patients not receiving antiviral treatment is below guideline recommendations, suggesting that initiation of antiviral therapy may also be delayed, leaving patients at risk for disease progression.

Recovery efficiences on nucleic acid extraction kits as measured by quantitative LightCycler PCR

AIMS

To compare the efficiency of five nucleic acid extraction kits for processing clinical material for the diagnosis of infection.

METHODS

Five nucleic acid extraction kits for processing clinical material for the diagnosis of infection were compared for their relative efficiencies in purifying and recovering either viral DNA or RNA from serum samples. Quantitative polymerase chain reaction (PCR) assays for hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA were performed on the Light-Cycler instrument to determine the relative concentrations of the viral nucleic acids recovered by the various protocols.

RESULTS

Large differences between kits in recovery efficiencies were observed for HBV DNA, with those protocols using enzyme digestion in addition to chaotropic solutions performing better than those using chemical disruption alone.

CONCLUSIONS

There were large differences between the kits and it appeared that those extraction kits containing a proteolytic enzyme and carrier nucleic acid (and that are supplied RNase free) have the widest potential application in the routine microbiology laboratory.

Comparison of the nucleic acid-based crosslinking hybridization assay and the branched DNA signal amplification assay in the quantitative measurement of serum hepatitis B virus DNA

Quantitative measurement of hepatitis B virus (HBV) DNA has become important in the clinical diagnosis of patients with chronic hepatitis B, especially in patients with hepatitis B e antigen (HBeAg)-negative precore mutant and in patients who received treatment with interferon or antiviral agents. Two different hybridization assays for quantitative measurement of HBV DNA: Naxcor crosslinking assays and Chiron branched DNA signal amplification (bDNA) assay, were applied to 158 serum samples which were positive for HBV DNA by polymerase chain reaction. Among 158 serum samples, 135 samples (85.4%) were positive by the crosslinking assay and 129 samples (81.6%) were positive by the bDNA assay in the quantification of serum HBV DNA (P > 0.05). Serum HBV DNA levels obtained from both assays showed a good linear correlation (r = 0.91, P < 0.001). The sensitivity of both assays in HBeAg-positive samples was 90.5%, significantly higher than in HBeAg-negative samples (69.6% for the crosslinking assay and 56.5% for the bDNA assay, P < 0.05). In HBeAg-negative patients with elevated serum alanine transaminase levels, the so-called precore HBV mutant, the detection sensitivity for HBV DNA was better in the crosslinking assay (83%) than in the bDNA assay (61%). The crosslinking assay was less time consuming than the bDNA assay in performing the measurement of serum HBV DNA (6 hours vs. 20 hours). In conclusion, Naxcor crosslinking hybridization assay was equally as sensitive as Chiron bDNA assay in the quantitative measurement of serum HBV DNA. Less time-consuming procedures and better sensitivity in the detection of HBeAg-negative samples with elevated serum alanine transaminase levels may favor the clinical use of the crosslinking assay.