A Four-Plex Real-Time PCR Assay, Based on rfbE, stx1, stx2, and eae Genes, for the Detection and Quantification of Shiga Toxin-Producing Escherichia coli O157 in Cattle Feces.

Several real-time polymerase chain reaction (PCR) assays have been developed to detect and quantify Shiga toxin-producing Escherichia coli (STEC) O157:H7, but none have targeted the O-antigen specific gene (rfbEO157) in combination with the three major virulence genes, stx1, stx2, and eae. Our objectives were to develop and validate a four-plex, quantitative PCR (mqPCR) assay targeting rfbE(O157), stx1, stx2, and eae for the detection and quantification of STEC O157 in cattle feces, and compare the applicability of the assay to detect STEC O157 to a culture method and conventional PCR (cPCR) targeting the same four genes. Specificity of the mqPCR assay to differentially detect the four genes was confirmed with strains of O157 and non-O157 STEC with different profiles of target genes. In cattle feces spiked with pure cultures, detection limits were 2.8×10(4) and 2.8×10(0) colony-forming units/g before and after enrichment, respectively. Detection of STEC O157 in feedlot cattle fecal samples (n=278) was compared between mqPCR, cPCR, and a culture method. The mqPCR detected 48.9% (136/278) of samples as positive for E. coli O157. Of the 100 samples that were randomly picked from 136 mqPCR-positive samples, 35 and 48 tested positive by cPCR and culture method, respectively. Of the 100 samples randomly chosen from 142 mqPCR-negative samples, all were negative by cPCR, but 21 samples tested positive by the culture method. McNemar's chi-square tests indicated significant disagreement between the proportions of positive samples detected by the three methods. In conclusion, the mqPCR assay that targets four genes is a novel and more sensitive method than the cPCR or culture method to detect STEC O157 in cattle feces. However, the use of real-time PCR as a screening method to identify positive samples and then subjecting only positive samples to a culture method may underestimate the presence of STEC O157 in fecal samples.

Prevalence of Escherichia coli O-types and Shiga toxin genes in fecal samples from feedlot cattle.

While efforts to control foodborne illness associated with the Shiga toxin-producing Escherichia coli (E. coli) O157 through processes and procedures implemented at harvest facilities have been very successful, there is concern about the burden of illness associated with other Shiga toxin-producing E. coli. The U.S. Department of Agriculture Food Safety and Inspection Service announced plans to classify an additional six non-O157 Shiga toxin-producing E. coli as adulterants. Little is known about the prevalence and distribution of these E. coli in the animal production environment. An investigation of the prevalence of O157 and the six major non-O157 E. coli serogroups was conducted in 21 feedlots over the period July 2011 to October 2011. Individual fecal swabs were collected from cattle approximately 60 days after their arrival in the feedlot and were pooled for evaluation using a polymerase chain reaction assay to identify the presence of seven E. coli O-types (O157, O45, O103, O121, O145, O26, and O111) and four virulence genes (stx1, stx2, eaeA, and ehxA). Overall, 1145 fecal pools were evaluated, with 506 (44.2%) being positive for one or more of the E. coli O-serogroups. The pool prevalences for E. coli O157, O45, O26, O103, O121, O145, and O111 were 19.7%, 13.8%, 9.9%, 9.3%, 5.5%, 1.1%, and 0.5%, respectively. Nearly all pools were positive for ehxA (99.7%) or stx2 (98.6%). The pool level prevalence for stx1 and eae was 65.5% and 69.3%, respectively. Pools that were positive for one or more of the other E. coli O-serogroups were 1.37 times more likely to be positive for E. coli O157. Conversely, pools that were positive for E. coli O157 were 1.43 times more likely to be positive for at least one of the other E. coli O-serogroups evaluated. These data will be useful to understand the expected prevalence of potential Shiga toxin-producing E. coli in cattle feedlots.

The 20 years transition of clinical characteristics and metabolic risk factors in primary liver cancer patients from China.

Background: The clinical characteristics of primary liver cancer (PLC) patients are changing, maybe due to hepatitis viral vaccination and lifestyle changes, etc. The linkage between these changes and outcomes among these PLCs has not yet been fully elucidated. Methods: It was identified total of 1691 PLC cases diagnosed between 2000 ~ 2020. Cox proportional hazards models were utilized to determine the connections between the clinical presentations and their close risk factor(s) from PLC patients. Results: The average age of PLC patients increased gradually from 52.74 ± 0.5 years in 2000 ~ 2004 to 58.63 ± 0.44 years in 2017 ~ 2020, accompanied by an increased proportion of females from 11.11% to 22.46%, and non-viral hepatitis-related PLC was raised from 1.5% to 22.35%. 840 (49.67%) PLC patients with alpha-fetoprotein (AFP) < 20ng/mL (AFP-negative). The mortality was 285 (16.85%) or 532 (31.46%) PLC patients with alanine transaminase (ALT) between 40 ~ 60 IU/L or ALT > 60 IU/L. The PLC patients with pre-diabetes/diabetes or dyslipidemia also increased from 4.29% or 11.1% in 2000 ~ 2004 to 22.34% or 46.83% in 2017 ~ 2020. The survival period of the PLC patients with normoglycemia or normolipidemic was 2.18 or 3.14 folds longer than those patients with pre-diabetes/diabetes or hyperlipidemia (P<0.05). Conclusions: It was gradually increased that age, the proportion of females, non-viral hepatitis-related causes, AFP-negative, and abnormal glucose/lipids among PLC patients. Proper control of glucose/lipids or ALT may improve the prognosis of PLCs.

Evaluation of a multiplex real-time polymerase chain reaction for the quantification of Escherichia coli O157 in cattle feces.

Cattle are asymptomatic reservoirs for Escherichia coli O157, a major foodborne pathogen. The organism generally colonizes the hindgut of cattle and is shed in the feces at low concentrations. The objective of this research was to evaluate a multiplex, real-time polymerase chain reaction (mqPCR) assay for quantification of E. coli O157 in cattle feces using stx1, stx2, and rfbE gene targets. Primer efficiency and analytical sensitivity of the assay were evaluated with a single or pooled (five strain) culture of E. coli O157. In pure culture, the minimum detection limit of the assay was 1.4×10(3) CFU/mL and 3.6×10(3) CFU/mL for the single and five-strain mixture of E. coli O157, respectively. Diagnostic sensitivity was analyzed using DNA extracted from cattle feces spiked with E. coli O157. In feces spiked with the pooled mixture of five E. coli O157 strains, the minimum detection limit was 3.6×10(4) CFU/g. We also evaluated the assay with feces from cattle experimentally inoculated with E. coli O157 by comparing the results to a culture-based method. For the majority of samples tested, the concentration of E. coli O157 detected by the real-time and culture methods was within one log difference. However, the assay could only be evaluated for cattle shedding high concentrations of E. coli O157. In conclusion, the mqPCR quantifying E. coli O157 in cattle feces using stx1, stx2, and rfbE gene targets may have use in detecting and quantifying super shedders, but is not applicable for quantification in animals shedding low concentrations (10(2) to 10(3) CFU/g feces).

Applicability of a multiplex PCR to detect the seven major Shiga toxin-producing Escherichia coli based on genes that code for serogroup-specific O-antigens and major virulence factors in cattle feces.

An 11-gene multiplex polymerase chain reaction (mPCR) was developed based on genes that code for serogroup-specific O-antigens and four major virulence factors (intimin, enterohemorrhagic hemolysin, and Shiga toxins [Stx] 1 and 2), to detect O157 and the "top six" non-O157 (O26, O45, O103, O111, O121, and O145) Shiga toxin-producing Escherichia coli (STEC). The assay specificity was validated with pure cultures of seven major STEC (185 strains), 26 other STEC (65 strains), non-STEC (five strains), and 33 strains of other genera and species. Sensitivity of the assay with cattle fecal sample spiked with pooled cultures of seven major STEC was 105 colony-forming units (CFU)/g before enrichment and 10² CFU/g after enrichment. The applicability of the assay to detect STEC in fecal samples (n=50), before and after enrichment, was evaluated by comparing with culture-based methods for O26, O111, and O157. The mPCR assay of 50 fecal samples showed seven (14%) positive before enrichment and 23 (46%) positive after enrichment for one or more of the seven O-groups. Overall, 17 isolates from 17 fecal samples and 27 isolates (four for O26, three for O45, and 20 for O103) from 19 fecal samples were obtained, by culture-based methods, for O157 and non-O157 serogroups, respectively. None of the 27 non-O157 isolates possessed the stx genes, suggesting that cattle harbor Shiga toxin-negative E. coli belonging to the "top six" non-O157 serogroups. Our data, although based on a limited number of samples, suggest that the sensitivities of the mPCR and culture-based methods in detecting the seven serogroups of STEC in feces differed between O-groups. An obvious limitation of our mPCR is that the concurrent detection of virulence genes and the serogroups in a sample does not necessarily associate the virulence genes with the prevalent serogroups in the same sample. The major application of our 11-gene mPCR assay may be in identifying putative colonies of STEC obtained by culture-based methods.

A novel model based on qAnti-HBc and conventional biomarkers for identifying significant liver injury among CHB patients with ALT ≤ ULN.

BACKGROUND: Antiviral therapy is not routinely recommended for CHB patients with ALT ≤ ULN (CHB-NALT), based on current international guidelines. However, it is debatable if antiviral treatment should be offered for CHB-NALT patients, because significant liver injury is observed from liver biopsy of some CHB-NALT patients. Quantification of anti-HBc (qAnti-HBc) can predict antiviral response in CHB patients, while its role in CHB-NALT patients remains to be explored. AIM: To determine if it is reliable that the novel non-invasive model based mainly on qAnti-HBc and other conventional biomarkers for providing objective value among CHB-NALT patients with antiviral therapy, in direct comparison with liver biopsy. METHODS: 542 or 110 liver biopsied CHB-NALT patients from 2015 to 2020 or in 2021 were included in training set or validation set. Circulating IL-1ß, IL-2, IL-4, IL-12p70, IL-17, TNF and IFNα were determined in the training set. A non-invasive model was developed based on qAnti-HBc and other conventional biomarkers. RESULTS: Among 423/542 (78%) patients with significant liver injury in the training set, 47% were in grey-zone. Circulating IL-1ß, IL-12p70, IL-17 in the CHB-NALT patients with liver injury was significantly higher than these without liver injury in the training set (p < 0.01). No significant difference of IL-1ß, IL-12p70, IL-17 was observed between CHB-NALT patients with significant liver injury and active CHB with elevated ALT in the training set. There was inverse correlation between liver injury grades and IFNα, IL-4, or IL-2 in these patients (p < 0.05). Serum qAnti-HBc level was significantly higher with CHB-NALT patients with liver injury than these without in the training set (P < 0.01). ALT/ULN, AST, PLT and qAnti-HBc were identified as independent predictors for significant liver injury. Furthermore, our current model demonstrated a good performance in predicting significant liver injury, i.e. AUROCs of 0.95 or 0.86 in training set or validation set. The model cut-off value for anti-viral therapy at ≥1.471. CONCLUSIONS: qAnti-HBc appears to be well correlated with the hepatic damage, in direct comparison with liver biopsy from CHB-NALT patients. The novel model developed seems to be reliable for predicting liver injury in CHB-NALT patients. Such model also provides objective value for decision making of antiviral therapy.

COVID-19 vaccines in patients with decompensated cirrhosis: a retrospective cohort on safety data and risk factors associated with unvaccinated status.

BACKGROUND: Safety data reported from the large-scale clinical trials of the coronavirus disease 2019 (COVID-19) vaccine are extremely limited in patients with decompensated cirrhosis. The vaccination campaign in this specific population could be difficult due to uncertainty about the adverse events following vaccination. We aimed to assessed the COVID-19 vaccination rate, factors associated with unvaccinated status, and the adverse events following vaccination in patients with decompensated cirrhosis. METHODS: This is a retrospective study from Ruijin Hospial (Shanghai, China) on an ongoing prospective cohort designed for long-term survival analysis of decompensated cirrhotic patients who recovered from decompensating events or acute-on-chronic liver failure (ACLF) between 2016 and 2018. We assessed the COVID-19 vaccination rate, the number of doses, type of vaccine, safety data, patient-reported reasons for remaining unvaccinated, factors associated with unvaccinated status, and the adverse events of COVID-19 vaccine. Binary logistic regression was used for identifying factors associated with unvaccinated status. RESULTS: A total of 229 patients with decompensated cirrhosis without previous SARS-CoV-2 infection participated (mean age, 56 ± 12.2 years, 75% male, 65% viral-related cirrhosis). Mode of decompensation were grade II‒III ascites (82.5%), gastroesophageal varices bleeding (7.9%), hepatic encephalopathy (7.9%). Eighty-five participants (37.1%) received at least one dose of vaccination (1 dose: n = 1, 2 doses: n = 65, 3 doses: n = 19) while 62.9% remained unvaccinated. Patient-reported reasons for remaining unvaccinated were mainly fear of adverse events (37.5%) and lack of positive advice from healthcare providers (52.1%). The experience of hepatic encephalopathy (OR = 5.61, 95% CI: 1.24-25.4) or ACLF (OR = 3.13, 95% CI: 1.12-8.69) and post-liver transplantation status (OR = 2.47, 95% CI: 1.06-5.76) were risk factors of remaining unvaccinated independent of residential areas. The safety analysis demonstrated that 75.3% had no adverse events, 23.6% had non-severe reactions (20% injection-site pain, 1.2% fatigue, 2.4% rash) and 1.2% had a severe event (development of acute decompensation requiring hospitalization). CONCLUSIONS: Patients with decompensated cirrhosis in eastern China are largely remained at unvaccinated status, particularly those with previous episodes of ACLF or hepatic encephalopathy and liver transplantation recipients. Vaccination against COVID-19 in this population is safe.

Molecular detection and characterization of transient bovine viral diarrhea virus (BVDV) infections in cattle commingled with ten BVDV persistently infected cattle.

Fifty-three cattle of unknown serologic status that were not persistently infected (PI) with bovine viral diarrhea virus (BVDV) were commingled with 10 cattle that were PI with different strains of BVDV, and were monitored for an extended commingle period using a reverse-transcription real-time PCR (RT-rtPCR) BVDV assay on various sample types. Transient infections with BVDV were also assessed by virus isolation, virus neutralization (VN) assays, and direct buffy coat 5'-UTR sequencing. Infections were demonstrated in all cattle by RT-rtPCR; however, the detection rate was dependent on the type of sample. Buffy coat samples demonstrated a significantly greater number of positive results ( p ≤ 0.05) than either serum or nasal swab samples. Presence of elevated BVDV VN titers at the onset inversely correlated with the number of test days positive that an individual would be identified by RT-rtPCR from buffy coat samples, and directly correlated with the average Ct values accumulated over all RT-rtPCR test days from buffy coat samples. Both single and mixed genotype/subgenotype/strain infections were detected in individual cattle by direct sample 5'-UTR sequencing. A BVDV-2a strain from a PI animal was found to be the predominant strain infecting 64% of all non-PI cattle; BVDV-1b strains originating from 3 PI cattle were never detected in non-PI cattle. Although direct sample 5'-UTR sequencing was capable of demonstrating mixed BVDV infections, identifying all strains suspected was not always efficient or possible.

[Expression of Toll-like receptor 3 on peripheral blood dendritic cells in HBeAg positive patients with chronic hepatitis B].

OBJECTIVE: To elucidate the roles of Toll-like receptor 3 (TLR3) on dendritic cells (DCs) in HBV infection. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from 48 healthy volunteers (HV) and 50 chronically HBV-infected patients (CH). DCs were induced and proliferated in a culture medium with rhGM-CSF and rhIL-4. We stimulated DCs with poly I:C and then TLR3, HLA-DR, and CD86, and CD1a expressions were examined by flow cytometry at 0 h, 12 h, 24 h and 48 h. The mRNA expressions of TLR3 were quantified by real-time PCR. RESULTS: TLR3 expression on DCs before the poly I:C stimulation and afterwards on the 12 h, 24 h, and 48 h were 69.2%+/-20.4%, 76.0%+/-18.6%, 78.2%+/-19.5% and 85.5%+/-6.9% respectively in the CH group, and 70.8%+/-11.2%, 67.5%+/-20.9%, 86.3%+/-14.7%, 68.6%+/-16.9% in the HV group. The expressions of TLR3 were up-regulated significantly at 24 h and 48 h after stimulation with poly I:C in the HV group, and in the CH group they were not significantly increased at 24 h but obviously increased at 48 h. The mRNA expressions of TLR3 increased significantly at 12 h in the HV groups, and at 48 h in CH group. The rate of CD86 expressions increased after poly I:C stimulation, and the increased rates were 12.6%+/-9.8%, 23.8%+/-20.0%, 20.7%+/-14.3% in the CH group, and 31.0%+/-25.0%, 43.4%+/-24.7%, 44.6%+/-25.5% in the HV group at 12 h, 24 h and 48 h after poly I:C stimulation. There was a marked increase of the expression level of CD86 in the HV group. In contrast, the level was only slightly increased in the CH group (31.0% vs 12.6%). The differences between the two groups were significant at 24 h and 48 h. No significant differences were detected in HLA-DR and CD1a between the two groups. CONCLUSIONS: The increase of expression level of TLR3 is slower in the CH group than that in the HV group. A marked increase of the expression level of CD86 is observed in the HV group. Our results suggest that abnormal expression of TLR3 and CD86 may relate to the persistence of HBV infection.

Genotyping Brucella canis isolates using a highly discriminatory multilocus variable-number tandem-repeat analysis (MLVA) assay.

Differentiation of Brucella canis from other Brucella species are mainly performed through PCR-based methods and multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) procedures. Both PCR-based and MLVA methods are limited in discriminating B. canis strains. A new MLVA-13Bc method for B. canis genotyping was established by combining eight newly-developed VNTRs with five published ones. During 2010 and 2016, 377 B. canis PCR-positives were identified from 6,844 canine blood samples from 22 U.S. states, resulting in 229 B. canis isolates. The MLVA-13Bc method was able to differentiate each of these 229 isolates. The Hunter-Gaston Discriminatory Index of the individual VNTR loci ranged from 0.516 to 0.934 and the combined discriminatory index reached 1.000. Three major clusters (A, B and C) and 10 genotype groups were identified from the 229 B. canis isolates. Cluster A mainly contains genotype groups 1 and 2, and a few group 3 isolates; nearly all Cluster B isolates were from group 6; other genotype groups were classified into Cluster C. Our newly developed MLVA-13Bc assay is a highly discriminatory assay for B. canis genotyping, and can serve as a useful molecular epidemiological tool, especially for tracing the source of contamination in an event of a B. canis outbreak.

MicroRNA-9 controls apoptosis of neurons by targeting monocyte chemotactic protein-induced protein 1 expression in rat acute spinal cord injury model.

OBJECTIVE: For the purpose of an early identification of intervention targets for acute spinal cord injury (ASCI), we investigated the changes in expression levels of microRNA-9 (miR-9) and MCPIP1 in rat ASCI model. METHOD: A total of 108 healthy rats were randomly divided into non-ASCI group (n=18) and five ASCI groups, 6h, 12h, 24h, 3 days and 7 days, representing the experimental time points following ASCI (n=18 per group). Hematoxylin and eosin (HE) staining was used to assess the ASCI damage, and quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH) were employed for the detection of miR-9 and MCPIP1 mRNA expression. RESULTS: HE staining results showed normal neuronal morphology in the non-ASCI group, but spinal cord tissue at 6h after ASCI showed developing neuronal necrosis. Acute inflammatory response was evident at 12h and 24h, with immune cells infiltrating into the gray matter. Vascular permeability increased and the nerve cells in gray-white matter exhibited extensive damage and necrosis at 24h and 7 days after ASCI. MiR-9 expression in ASCI tissue was significantly lower than that in normal spinal cord tissue. Statistical analysis showed a significant decrease in miR-9 expression in all the ASCI groups, compared to the non-ASCI group. Results from real-time PCR analysis revealed that MCPIP1 expression in all the ASCI groups was significantly higher than the non-ASCI group, and MCPIP1 expressions gradually increased with times at 6h-24h after ASCI. ISH revealed the following results after ASCI (1) miR-9 and MCPIP1 mRNA expression mainly distributed in ventral horn motor neurons, (2) miR-9 expression was high at 7 day after ASCI and (3) in the non-ASCI group, MCPIP1 expression was high at 6h, 12h, 24h and 3 days. CONCLUSION: MCPIP1 is significantly up-regulated after ASCI. The negative relationship between MCPIP1 and miR-9 suggest that MCPIP1 mRNA could be a target of miR-9 during ASCI. Thus, miR-9 is a marker for apoptosis in neurons, and an excellent therapeutic target for ASCI patients.

Tissue localization, shedding, virus carriage, antibody response, and aerosol transmission of Porcine epidemic diarrhea virus following inoculation of 4-week-old feeder pigs.

We determined tissue localization, shedding patterns, virus carriage, antibody response, and aerosol transmission of Porcine epidemic diarrhea virus (PEDV) following inoculation of 4-week-old feeder pigs. Thirty-three pigs were randomly assigned to 1 of 3 groups for the 42-day study: inoculated (group A; n = 23), contact transmission (group B; n = 5), and aerosol transmission (group C; n = 5). Contact transmission occurred rapidly to group B pigs whereas productive aerosol transmission failed to occur to group C pigs. Emesis was the first clinical sign noted at 3 days postinoculation (dpi) followed by mild to moderate diarrhea lasting 5 more days. Real-time PCR detected PEDV in fecal and nasal swabs, oral fluids, serum, and gastrointestinal and lymphoid tissues. Shedding occurred primarily during the first 2 weeks postinoculation, peaking at 5-6 dpi; however, some pigs had PEDV nucleic acid detected in swabs collected at 21 and 28 dpi. Antibody titers were measurable between 14 and 42 dpi. Although feces and intestines collected at 42 dpi were PEDV negative by PCR and immunohistochemistry, respectively, small intestines from 70% of group A pigs were PCR positive. Although disease was relatively mild and transient in this age group, the results demonstrate that 4-week-old pigs are productively infected and can sustain virus replication for several weeks. Long-term shedding of PEDV in subclinically affected pigs should be considered an important source for PEDV transmission.

RNA silencing of Waxy gene results in low levels of amylose in the seeds of transgenic wheat (Triticum aestivum L.).

In this study, the level of amylose was reduced in wheat seeds by RNAi strategy. Because the synthesis of amylose is catalyzed by the granule-bound starch synthase I (GBSSI or WAXY protein), the Waxy gene of wheat was isolated from wheat seeds by using RT-PCR. Southern analysis confirmed that there were three Waxy genes in wheat genome. Northern hybridization showed that Waxy mRNA accumulated in seeds following pollination. By RNAi strategy,the 683 bp sense and antisense fragments in reverse orientation separated by a 150 bp intron were cloned into pCAMBIA 3300 just downstream of the maize ub/1 promoter. By Agrobacteriurn-mediated wheat transformation method, four transgenic plants (Cultivar Yangmai 10) were identified by PCR, RT-PCR and leaf painting assay. The level of amylose in the endosperm were significantly reduced in transgenic seeds as checked by iodine staining and analysis of amylose content. The results indicated that RNA silencing of Waxy gene resulted in low level of amylose in the seeds of transgenic wheat.

Association of IPS1 polymorphisms with peginterferon efficacy in chronic hepatitis B with HBeAg-positive in the Chinese population.

AIMS: To investigate whether IPS1 polymorphisms affect peginterferon alpha (PEG-IFN) efficacy in chronic hepatitis B (CHB) patients using a tag- single nucleotide polymorphism (SNP) approach. METHODS: A total of 212 hepatitis B e antigen (HBeAg)-positive patients treated with a 48weeks of PEG-IFN monotherapy were enrolled initially and 127 patients were followed for 48weeks posttreatment. Genotype analysis was performed for 10 tag-SNPs in IPS1. RESULTS: The end of virological response (EVR) rate was 45.8% (97/212) and the sustained virological response (SVR) rate was 45.7% (58/127). Meanwhile, 35.4% (75/212) achieved HBeAg seroconversion at the end of treatment. In a multivariate analysis, the rs2464 CC genotype was independently associated with EVR (OR 2.21, 95% CI 1.23-3.98, P=0.008) and SVR (OR 2.34, 95% CI 1.05-5.20, P=0.037) after adjustment for sex, age, HBV genotype, baseline levels of HBV DNA and ALT. Meanwhile, rs2464 CC genotype were also independently associated with decline of HBsAg levels below 1500IU/mL at 12weeks of treatment (OR 2.52, 95% CI 1.01-6.29, P=0.047). Furthermore, three SNPs were found to be independently associated with HBeAg seroconversion at the end of treatment. (1) The rs2326369 CC genotype was independently associated with no HBeAg seroconversion (OR 0.52, 95% CI 0.29-0.95, P=0.034); (2) The rs6515831 TT genotype was independently associated with HBeAg seroconversion (OR 2.11, 95% CI 1.14-3.90, P=0.017); (3) The rs2464 CC genotype was independently associated with HBeAg seroconversion (OR 2.36, 95% CI 1.26-4.42, P=0.007). CONCLUSIONS: Polymorphisms in IPS1 are independently associated with treatment response to PEG-IFN among Chinese HBeAg-positive CHB patients.

Impairment of the retinoic acid-inducible gene-I-IFN-ß signaling pathway in chronic hepatitis B virus infection.

Chronic hepatitis B (CHB) virus infection is caused by compromised host immunity, but the precise underlying mechanism remains unclear. Retinoic acid-inducible gene I (RIG-I) triggers antiviral immunity by inducing interferon-ß (IFN-ß) production following viral infection. To investigate the role of the RIG-I-IFN-ß signaling pathway in monocyte-derived dendritic cells (moDCs) during CHB infection, moDCs were generated by stimulating CD14+ monocytes in vitro. MoDCs from patients with CHB, acute hepatitis B (AHB) and healthy controls (HCs) were challenged with vesicular stomatitis virus (VSV) and the levels of RIG-I, IFN-ß promoter stimulator 1 (IPS-1) and IFN-ß in the stimulated moDCs were determined. Following 16 h of VSV stimulation, RIG-I expression was reduced by 50% in moDCs from CHB patients and by 70% in moDCs from AHB patients relative to HC moDCs, concomitant with a 20% decrease in IFN-ß expression in CHB patients relative to AHB patients and HCs. Additionally, a significant correlation between the RIG-I/IPS-1 ratio and alanine aminotransferase (ALT) level was observed. To further investigate the function of RIG-I in chronic hepatitis B virus (HBV) infection, HepG2 or HepG2.2.15 (HBV-transformed) cell lines were challenged with VSV following RIG-1 transfection. IFN-ß induction was suppressed in HepG2.2.15 cells, but was restored following RIG-I transfection. Taken together, these data indicate that compromised moDC function in CHB patients is attributable to an impaired RIG-I-IFN-ß signaling pathway, which results in compromised host viral clearance and HBV persistence in a susceptible population.

On-treatment serum HBsAg level is predictive of sustained off-treatment virologic response to telbivudine in HBeAg-positive chronic hepatitis B patients.

BACKGROUND: Effective management of chronic hepatitis B infection is still very challenging, despite decades of clinical research. Telbivudine is one of the most frequently used antiviral drug at the current stage, but its long-term effectiveness, particularly at off-treatment, is still unclear. OBJECTIVES: To assess on-treatment HBsAg kinetics in patients treated with telbivudine for 2 years, and predicting sustained virologic response (SR) at 2 years off-treatment. STUDY DESIGN: Serum HBV DNA/HBsAg levels were assessed from 17 HBeAg+ patients treated with telbivudine 600 mg/day for 104 weeks, at baseline, weeks 24, 52 and 104, as well as during off-treatment follow-up. RESULTS: HBsAg levels <2 log(10)IU/ml at treatment week 104 were highly predictive of SR (i.e., HBV DNA <300 copies/ml, HBeAg seroconversion, ALT normalization) at 2 years off-treatment (positive predictive value [PPV], 93%; negative predictive value [NPV], 100%). HBsAg levels consistently declined from baseline only in patients achieving SR during 2 years off-treatment. At weeks 24 and 52, HBsAg decline rate was a better predictor of off-treatment response than HBV DNA decline rate. HBsAg decline rates of >0.8 and >1 log(10)IU/ml at treatment weeks 24 and 52 were predictive of SR (PPV, 75%; NPV, 86% at week 24; PPV, 75%; NPV, 86% at week 52). CONCLUSIONS: Serum HBsAg levels <2 log(10)IU/ml at treatment week 104 are highly predictive of SR to telbivudine at 2 years off-treatment. HBsAg decline rate at on-treatment weeks 24 and 52 from baseline were also more predictive of SR than HBV DNA decline rate.

Patients with chronic hepatitis B infection display deficiency of plasmacytoid dendritic cells with reduced expression of TLR9.

Chronic hepatitis B virus (HBV) infection is a complex interaction between replicating noncytopathic virus and dysregulatory host antiviral immunity. Plasmacytoid dendritic cells (pDCs) contribute to innate antiviral immunity via secreting type I interferons. Toll-like receptor (TLR) 9 is involved in major pattern recognition receptors expressed in pDCs. The frequency of pDCs and TLR9 expression in peripheral blood mononuclear cells (PBMC) was determined, using flow cytometry. IFN-alpha production by PBMC was evaluated in vitro in the presence of cytidine phosphate guanosine (CpG) with/without pDCs. The correlation between TLR9, pDCs frequency and viral load was also evaluated. TLR9 expression in pDCs in chronic HBV patients was significantly ( approximately 50%) reduced, supported by approximately 70% reduction of TLR9 mRNA, in comparison to healthy controls, correlating with the impairment of IFN-alpha production in vitro. Furthermore, pDCs frequency in these patients was substantially reduced ( approximately 30%), inversely correlating with serum ALT levels and HBV viral load. HBsAg and HBcAg were detected by immunohistochemistry in pDCs in chronic HBV patients. We conclude that HBV infection results in reduced frequency of circulating pDCs and their functional impairment via inhibiting the expression of TLR9. These data may provide useful information in both basic research and clinical treatment of chronic HBV infection.