Genetic variability of hepatitis B virus in acute and in different phases of chronic infection in Brazil

The selection pressure imposed by the host immune system impacts on hepatitis B virus (HBV) variability. This study evaluates HBV genetic diversity, nucleos(t)ide analogs resistance and HBsAg escape mutations in HBV patients under distinct selective pressures. One hundred and thirteen individuals in different phases of HBV infection were included: 13 HBeAg-positive chronic infection, 9 HBeAg-positive chronic hepatitis, 47 HBeAg-negative chronic infection (ENI), 29 HBeAg-negative chronic hepatitis (ENH) and 15 acute infected individuals. Samples were PCR amplified, sequenced and genetically analyzed for the overlapping POL/S genes. Most HBV carriers presented genotype A (84/113; 74.3%), subgenotype A1 (67/84; 79.7%), irrespective of group, followed by genotypes D (20/113; 17.7%), F (8/113; 7.1%) and E (1/113; 0.9%). Clinically relevant mutations in polymerase (tL180M/M204V) and in the Major Hydrophilic Region of HBsAg (sY100C, T118A/M, sM133T, sD144A and sG145R) were observed. Our findings, however, indicated that most polymorphic sites were located in the cytosolic loops (CYL1-2) and transmembrane domain 4 (TMD4) of HBsAg. Lower viral loads and higher HBV genetic diversity were observed in ENI and ENH groups (p < 0.001), suggesting that these groups are subjected to a higher selective pressure. Our results provide information on the molecular characteristics of HBV in a diverse clinical setting, and may guide future studies on the balance of HBV quasispecies at different stages of infection.

Applicability of oral fluid samples for tracking hepatitis B virus mutations, genotyping, and phylogenetic analysis

Little is known about the usefulness of saliva samples for hepatitis B virus (HBV) genotyping and mutation analysis. The aim of this study was to evaluate the usefulness of oral fluid samples to determine HBV genotype distribution, S/polymerase mutations, and HBV subpopulation diversity among chronically HBV-infected individuals. Serum and oral fluid samples were obtained from 18 individuals for PCR and nucleotide sequencing of the HBV surface antigen gene. Biochemical analysis of liver enzymes (ALT, AST, GGT) and HBV, HCV, and HIV serological tests were also performed. All serum samples were HBsAg (+), anti-HBc (+), and anti-HBs (-); 55.6% were HBeAg (+)/anti-HBe (-), and 11.1% were anti-HIV (+). The mean HBV DNA viral load was 6.1 ± 2.3 log IU/mL. The HBV genotype distribution was as follows: A, 72.2%; D, 11.1%; E, 5.6%; F, 11.1%. A concordance of 100% in genotype classification and 99.8% in sequence similarity between paired oral fluid and serum samples was observed. HBsAg mutations were detected in all samples, but no resistance mutations were found in the polymerase gene. This study demonstrates that oral fluid samples can be used reliably for tracking HBV mutations, genotyping, and phylogenetic analysis. This could be important for molecular epidemiology studies with hard-to-reach populations.

High prevalence of hepatitis A in indigenous population in north Brazil

Objectives

Little is known about hepatitis A virus (HAV) prevalence in indigenous communities. This study aims to evaluate the prevalence of HAV in indigenous community compared to urban population located at Western Amazon in Brazil.

Results

A total of 872 serum samples were obtained from 491 indigenous and 381 non indigenous individuals aging 0 to 90 years. Samples were tested for total and IgM anti-HAV and positive IgM samples were tested for HAV RNA. The overall prevalence of total anti-HAV was 87%, increased according age showing 100% of prevalence in those aging more than 30 years (p < 0.0001) and it was similar among indigenous and urban population. Total anti-HAV prevalence varied between tribes (p < 0.0001) and urban sites (p = 0.0014) and spatial distribution showed high prevalence in homes that received up to 100 dollars. IgM anti-HAV prevalence was 1.7% with predominance in males, those aging more than 41 years. No HAV RNA was detected. In conclusion, high overall anti-HAV prevalence was found in indigenous communities in North Brazil demonstrating the importance of universal vaccination in this group.

Prevalence of hepatitis B and hepatitis C among diabetes mellitus type 2 individuals

Diabetes mellitus type 2 (DM2) patients have higher risk to be infected with parenterally transmitted viruses, like hepatitis B or C virus. This study aims to determine HBV and HCV infection prevalence in DM2 patients from Northeast and Southeast Brazil. A total of 537 DM2 patients were included, 194 (36.12%) males and 343 (63.87%) females, with mean age of 57.13±11.49 years. HBV and HCV markers were determined using serological and molecular analysis, and risk factors were evaluated in a subgroup from Southeast (n = 84). Two HBV acute (HBsAg+/anti-HBc -) and one HBV chronic case (HBsAg+/anti-HBc+) were found. Six individuals (1.1%) were isolated anti-HBc, 37 (6.9%) had HBV infection resolved (anti-HBc+/anti-HBs+), 40 (7.4%) were considered HBV vaccinated (anti-HBc-/anti-HBs+). Thirteen patients (2.42%) had anti-HCV and 7 of them were HCV RNA+. In the subgroup, anti-HBc positivity was associated to age and anti-HCV positivity was associated to age, time of diabetes diagnosis, total bilirubin, indirect bilirubin, alkaline phosphatase at bivariate analysis, but none of them was statistically significant at multivariate analysis. As conclusion, low prevalence of HBV and high prevalence HCV was found in DM2 patients.

Comparison of the performance of enzyme immunoassays for hepatitis B and C detection in dried blood spot

Dried blood spots (DBSs) could be an alternative to serum for hepatitis B virus (HBV) and hepatitis C virus (HCV) diagnosis. This study aims to evaluate two enzyme immunoassays (EIAs) for HBsAg and anti-HCV detection using DBS. Serum was tested using commercial EIA. DBS was tested using optimized EIA developed for serum and commercial EIA developed for DBS (Imunoscreen). Concordances between DBS and serum samples for both markers and EIAs were higher than 97%. Both EIAs demonstrated good performance for HBsAg and anti-HCV detection using DBS, and these methods could be used unchangeably increasing the access for HBV and HCV diagnosis.

Performance of point of care assays for hepatitis B and C viruses in chronic kidney disease patients

AIMS

Point of care testing (POCT) has been used for hepatitis B and C diagnosis in general population, but little is known about the influence of clinical conditions in the accuracy of these assays. This study aims to evaluate the performance of POCTs for detection of hepatitis B virus surface antigen (HBsAg) and antibodies to Hepatitis C Virus (anti-HCV) in Chronic Kidney Disease (CKD) patients.

METHODS

A total of 286 subjects were included in this study. HBsAg and anti-HCV were detected using commercial EIAs and four POCTs: HBsAg (WAMA Imuno-Rápido HBsAg and VIKIA HBsAg) and anti-HCV (DOLES HCV teste rápido and WAMA Imuno-Rápido anti-HCV) in serum and whole blood.

RESULTS

Using EIA, HBsAg and anti-HCV prevalence was 4.5% and 16.1% in CKD patients. HBsAg and anti-HCV POCTs had sensitivities from 92.3% to 100% and 84.8% to 89.1% while specificities were 99.3% to 100% and 99.2% to 99.6%, respectively. POCT using serum samples performed well compared with whole blood samples and true positive samples of POCTs had high optical density to cut-off (OD/CO) values compared with EIA.

CONCLUSIONS

This study demonstrates good performance of HBsAg and anti-HCV POCTs in CKD patients, especially in serum samples indicating low interference of this disease in the performance of these assays. POCTs could be an important tool for HBV and HCV screening in high-risk populations.

High prevalence of insulin resistance among Brazilian chronic hepatitis C patients

OBJECTIVE

This study aims to estimate the prevalence of insulin resistance (IR) among chronic hepatitis C (CHC) patients and their related laboratory and demographic data.

SUBJECTS AND METHODS

In this study, non-diabetic CHC patients referred to Viral Hepatitis Ambulatories from Rio de Janeiro (Brazil) donated blood samples. Insulin was measured using a chemiluminescence immunoassay. IR was determined by HOMA-IR, where HOMA-IR > 2 was defined as IR.

RESULTS

A total of 214 CHC patients were recruited (123 females aged 53.6 years ± 10.9 years). IR was present in 133 patients (62.1%) and was associated in bivariate analysis to higher mean values of age (p = 0.040), triglycerides (p = 0.032), glucose (p = 0.000), insulin (p = 0.000), waist circumference (p = 0.001), and body mass index (p = 0.007); however, none of these variables were significant in the multivariate analysis.

CONCLUSIONS

The high prevalence of IR was observed among CHC patients, and there was no difference in clinical or laboratory parameters when both groups were compared in the multivariate analysis. This high IR prevalence could lead to a high risk for development of cardiovascular disease and metabolic disorders.

Comparison of oral fluid collection methods for the molecular detection of hepatitis B virus

BACKGROUND

This study aims to compare the efficiency of four oral fluid collection methods (Salivette, FTA Card, spitting and DNA-Sal) to detect HBV DNA by qualitative PCR.

MATERIALS AND METHODS

Seventy-four individuals (32 HBV reactive and 42 with no HBV markers) donated serum and oral fluid. In-house qualitative PCR to detect HBV was used for both samples and commercial quantitative PCR for serum.

RESULTS

HBV DNA was detected in all serum samples from HBV-infected individuals, and it was not detected in control group. HBV DNA from HBV group was detected in 17 samples collected with Salivette device, 16 samples collected by FTA Card device, 16 samples collected from spitting and 13 samples collected by DNA-Sal device. Samples that corresponded to a higher viral load in their paired serum sample could be detected using all oral fluid collection methods, but Salivette collection device yielded the largest numbers of positive samples and had a wide range of viral load that was detected.

CONCLUSION

It was possible to detect HBV DNA using all devices tested, but higher number of positive samples was observed when samples were collected using Salivette device, which shows high concordance to viral load observed in the paired serum samples.

Performance of rapid diagnostic tests for detection of Hepatitis B and C markers in HIV infected patients

There is little information describing the influence of HIV infection upon the performance of rapid diagnostic tests (RDTs) for hepatitis B and C virus diagnosis. This study aims to evaluate the performance of RDTs for HBsAg and anti-HCV detection among HIV-infected individuals. A total of 362 HIV infected individuals were recruited from clinics between January 2013 to November 2014 in the southeast and northeast of Brazil. HBsAg and anti-HCV were detected using commercial EIAs and four RDTs: HBV (Vikia HBsAg^® and Wama Imuno-Rapido HBV^®) and HCV (Bioeasy Teste Rápido HCV^® and Wama Imuno-Rapido HCV^®). Reactive HBsAg and anti-HCV serum samples were tested for HBV DNA and HCV RNA. Sensitivity, specificity and kappa statistic were determined. Using EIA, HBsAg and anti-HCV were detected in 14 (3.9%) and 37 (10.2%) serum samples respectively. Using serum only, HBsAg RDTs demonstrated sensitivities and specificities above 92.0% and Kappa values above 89.0%. Anti-HCV RDTs demonstrated sensitivity and specificities above 82.0% and Kappa higher than 89.0%. Using whole blood samples, Vikia HBsAg^® and Wama Imuno-Rapido HCV^® showed sensitivity and specificity above 99.0% with Kappa of 66.4% and 100%, respectively. HIV viral load was higher among discordant results for anti-HCV RDT. RDTs demonstrated good performance in HIV infected individuals showing the usefulness of assays in this population.

Performance of ANTI-HCV testing in dried blood spots and saliva according to HIV status

The use of saliva and dried blood spots (DBS) could increase access to HCV diagnosis for high-risk populations, such as HIV-infected individuals, but the performance of these assays has not been well established in this group. This study aims to evaluate HIV status, particularly TCD4⁺ cell count and viral load, in the performance of anti-HCV testing using DBS and saliva. A total of 961 individuals classified as HCV+, HIV+, or HIV/HCV+, as well as negative controls, donated serum, DBS, and saliva samples for anti-HCV testing using a commercial enzyme immunoassay. Sample volume was modified for DBS and saliva, and an ROC curve was used for cut-off determination in saliva. Anti-HCV sensitivities were greater than 93% using DBS and saliva in the HCV+ group, while they were 83.3% and 95.6% for HCV/HIV+ individuals for DBS and saliva assays, respectively. Specificity varied from 91.7% to 100% using saliva and DBS in HIV monoinfected and control subjects. When only anti-HCV/HCV RNA+ serum samples, that is, true positives, were considered, the sensitivities were 98.3% and 100% for DBS and saliva, respectively, in the HCV+ group and 91.6% and 94.8% for DBS and saliva, respectively, in the HIV/HCV+ group. High absorbance values were observed among those presenting with HCV RNA in serum and low HIV viral load (less than 50 copies/mL). In conclusion, DBS and saliva samples could be used for anti-HCV detection, particularly to identify active HCV cases, but low sensitivity was observed for anti-HCV testing using DBS in the HIV/HCV+ group.

Evaluation of dried blood spot samples for hepatitis C virus detection and quantification

BACKGROUND

Dried blood spots (DBS) could be an excellent alternative for HCV diagnosis, since it is less invasive and can be stored and transported without refrigeration.

OBJECTIVES

The aim of this study was to optimize quantitative and qualitative methods for HCV detection in DBS.

STUDY DESIGN

DBS and serum samples were collected from 99 subjects (59 anti-HCV/HCV RNA positive and 40 seronegative samples). Seven extraction methods and different PCR parameters were evaluated in DBS samples in the quantitative RT-PCR (qRT-PCR) developed to amplify the 5' noncoding region of HCV. A qualitative PCR for amplification of NS5B region of HCV was also valued and the nested-PCR sequenced.

RESULTS

The qRT-PCR showed good correlation to commercial assay for HCV viral measurement in serum. To quantify HCV RNA in DBS, it was necessary to increase reverse transcriptase and cDNA concentration. HCV RNA quantification in DBS demonstrated sensitivity of 65.9%, 100% of specificity and kappa statistic of 0.65. The median viral load of DBS samples was 5.38 log10 copies/ml (minimum value=1.76 and maximum value=10.48 log10 copies/ml). HCV RNA was detected in NS5B regions and nucleotide sequences obtained in 43 serum and 11 DBS samples. The presence of the same subtype was observed in paired serum and DBS samples.

CONCLUSIONS

In this study, it was possible to demonstrate that, despite the low sensitivity, the optimized protocol was able to determine the viral load, as well as, the infecting HCV genotype, validating the usefulness of DBS for viral load determination and molecular epidemiology studies of HCV.

Performance of rapid hepatitis C virus antibody assays among high- and low-risk populations

BACKGROUND

Rapid tests for the detection of antibodies to hepatitis C virus (anti-HCV) can facilitate access to diagnosis.

OBJECTIVES

This study aimed to evaluate the performance of rapid tests for anti-HCV detection in the sera, whole blood, and oral fluid samples from individuals with different endemicity profiles and risk behaviors.

STUDY DESIGN

Three groups donated biological samples that were tested using three anti-HCV rapid tests (WAMA, Bioeasy and OraSure): (I) suspected cases of hepatitis C, (II) individuals who were living in remote areas in Brazil and (III) crack users and beauty professionals. Reproducibility, repeatability and cross-reactivity to other infectious agents (dengue, HIV, malaria, and syphilis) were also evaluated.

RESULTS

In group I, specificities varied from 93.75% to 100% and sensitivities varied from 76.03% to 93.84% according to the EIA results. When anti-HCV/HCV RNA-reactive sera samples were considered true-positive HCV cases, the sensitivities and specificities varied from 86.3% to 99.09% and 93.75% to 100%, respectively. In group II, the OraSure rapid test presented the best performance. In group III, the Bioeasy assay performed best using saliva and whole blood and the OraSure assay performed best using oral fluid samples. The reproducibility and repeatability of the WAMA and Bioeasy tests were excellent. The level of concordance between the HCV EIAs and the rapid tests using samples that were reactive for other infectious agents varied from 82.35% to 100% for the WAMA assay and 94.11% to 100% for the Bioeasy assay.

CONCLUSION

All of the rapid tests could be used to identify active HCV infection among individuals with different endemicity profiles and risk behaviors.

Analysis of hepatitis C virus (HCV) RNA load in platelets of HCV-monoinfected patients receiving antiviral therapy

INTRODUCTION

Detection of hepatitis C virus (HCV) has been reported in extrahepatic sites such as peripheral blood mononuclear cells and platelets. Quantitation of HCV-RNA in platelets from patients under antiviral therapy has not been reported.

MATERIAL AND METHODS

HCV-RNA levels in paired serum and platelet samples of 17 chronically HCV-infected patients were determined at baseline, week 12, end-of-treatment, and 24 weeks after completion of treatment with pegylated interferon plus ribavirin. Quantitation of HCVRNA load was performed using COBAS® TaqMan® HCV Test v 2.0 (lower limit of detection, 25 IU/mL). The cohort predominantly consisted of female (59%) with a mean age of 50.7 ± 10.0 years.

RESULTS

Measurements of HCV-RNA in relation to different timepoints of therapy revealed baseline viral load was most frequently detected in higher levels in serum than in platelets (5.6 x 104 IU/mL vs. 379.0 IU/mL; p = 0.0002), a trend also demonstrated in most samples throughout the study. HCV-RNA was also found at low levels (< 25.0-314.0 UI/mL) persistently in platelets of three patients who have lost detectable HCV-RNA in serum during antiviral therapy, resulting in virological relapse.

CONCLUSION

HCV-RNA levels are most frequently detected in higher levels in serum than in platelets, independent of timepoint of antiviral therapy. Further studies with an increase in size of the samples are needed to better evaluate whether or not patients who presented HCV-RNA at low levels in platelets after having lost detectable HCV-RNA in serum during antiviral therapy are at increased risk of relapse of HCV infection during follow-up evaluation.

Simultaneous detection of hepatitis C virus antigen and antibodies in dried blood spots

BACKGROUND

Enzyme immunoassays (EIA) designed to detect hepatitis C virus (HCV) core antigen and anti-HCV antibodies (HCV AgAb) simultaneously can improve the early detection of HCV infection when molecular diagnostic methods are not widely available.

OBJECTIVES

To evaluate the suitability of dried blood spot (DBS) samples for detecting HCV AgAb using commercial EIAs.

STUDY DESIGN

Paired serum and DBS samples were assayed using two commercial EIAs for HCV AgAb (Monolisa™ HCV AgAb ULTRA and Murex HCV AgAb). Manufacturer's recommendations were followed for sera while sample volume, incubation time and cut-off (CO) determination were evaluated for the DBS samples. The values of sensitivity, specificity, inter-rater agreement, detection limit, assay precision and stability of DBS samples at different conditions (22-26°C, 2-8°C and -20°C) were determined.

RESULTS

It was necessary to increase the DBS sample volume fourfold compared to the sera samples to approximate the DBS Optical Density (OD) values to the sera OD values. Using ROC curve to recalculate CO values for the DBS samples, sensitivity was 97.5% for both EIAs, while the specificity was 99.71% for Monolisa™ HCV AgAb ULTRA and 95.95% for Murex HCV AgAb. Accurate testing results were obtained with DBS samples for 60 days at all conditions evaluated; storage at -20°C resulted in low OD variation. Both EIAs demonstrated the same limit of detection among DBS samples [estimated viral load of 3.1 International Units per millilitre (IU/mL)] and low OD value variability in repetitivity and reproducibility studies.

CONCLUSION

DBS samples can be used for the detection of HCV AgAb by EIA as they present comparable performance characteristics and excellent stability among various storage conditions.

Dried blood spot samples: optimization of commercial EIAs for hepatitis C antibody detection and stability under different storage conditions

This study was undertaken to optimize and compare the efficiency of two commercial EIAs for anti-HCV detection (HCV Ab Radim, Pomezzia, Italy and ETI-AB-HCVK-4 DiaSorin, Vercelli, Italy), in dried blood spot (DBS) samples. The long-term stability of anti-HCV on DBS samples stored at three environmental conditions was also evaluated at: 2-8 °C, 20-25 °C, and -20 °C. Paired DBS and serum samples were obtained from individuals with or without anti-HCV. The type of elution buffer, sample and conjugate volume, sample incubation time and cut-off values were evaluated. For both EIAs, a larger sample volume was used, and the cut-off value determined by the manufacturer was employed for Radim EIA; however, ROC curve analysis was used for the DiaSorin EIA. The sensitivity and specificity of Radim EIA on DBS were 97.5% and 99.5%, respectively, and of DiaSorin EIA were 88.9% and 98.9%, respectively. Accurate results were obtained for a period of 117 days using DBS samples stored at all storage conditions, but storage at -20 °C resulted in the lowest variation among the absorbance values. Both EIAs demonstrated the same limit of detection (until dilution of 1:10(4) with estimated viral load of 3.1 × 10(-1) UI/ml), but the Radim EIA was associated with the best performance because a low coefficient of variation was observed in the repetition and reproducibility studies. In conclusion, commercial EIAs can be optimized for anti-HCV detection in DBS samples that are extremely stable at different conditions for more than 100 days.

An evaluation of different saliva collection methods for detection of antibodies against hepatitis C virus (anti-HCV)

BACKGROUND

Saliva samples can be used as an alternative fluid for against hepatitis C virus (anti-HCV) detection owing to the ease of collection and excellent acceptability. This study was conducted to optimize a commercial enzyme immunoassay (EIA) to detect anti-HCV in saliva samples.

METHODS

Ninety-six individuals donated paired serum and saliva samples that were obtained, using a commercial device (Salivette) and spitting into a sterile container. Initially, elution buffer for the Salivette samples, sample volume, incubation time and temperature, and two different anti-HCV EIAs were evaluated. Using the optimized assay, three methods for cut-off calculation were also evaluated.

RESULTS

A 20-fold increase in the sample volume for both collection methods was needed. Moreover, the Radim assay was the most appropriate assay for anti-HCV detection in saliva samples, and the quality parameters were increased when a ROC curve was used to determine the cut-off value. Using this optimized assay, the sensitivities, specificities, accuracies, positive and negative predictive values were above 90% for saliva obtained using both the Salivette and spitting methods. Using this assay, discordant false-negative results were obtained for only two Salivette samples and five spitting samples. The concordance kappa was 93% for the Salivette method and 86.1% for the spitting method, demonstrating excellent performance.

CONCLUSIONS

Saliva samples obtained for both methods can be employed for anti-HCV detection among HCV-infected or HCV-suspected cases, but several modifications must be performed on commercial EIAs to obtain good results. Moreover, samples obtained with commercial devices are more appropriate for anti-HCV detection in saliva samples.