Development and evaluation of a quantitative competitive reverse transcription polymerase chain reaction (RT-PCR) for hepatitis C virus RNA in serum using transcribed thio-RNA as internal control

Hepatitis C and Human Pegivirus Coinfection in Patients with Chronic Hepatitis C from the Brazilian Amazon Region: Prevalence, Genotypes and Clinical Data

Coinfection of HPgV-1 with hepatitis C virus (HCV) is common due to shared modes of transmission, with a prevalence of HPgV-1 viremia of approximately 20% among individuals with chronic HCV infection. The aim of the present study was to estimate the prevalence of HPgV-1 RNA and circulating genotypes in patients with hepatitis C from a health service located in the city of Belém, in the state of Pará, Northern Brazil. A total of 147 samples were included in the study from February to December 2019. Among the participants, 72.1% (106/147) were monoinfected with HCV, with detectable HCV viral RNA, and 27.9% (41/147) were coinfected with HCV/HPgV-1. The most frequently found genotypes were HPgV-1 genotypes 1 and 2 (36.6% and 63.4%), respectively. While for HCV there was a predominance of genotypes 1 and 3 (58.5% and 41.5%). No significant differences were found when comparing any risk, sociodemographic, or clinical factors between groups. Also, there was no statistically significant difference when relating the viral genotypes of both agents. This study indicated that the prevalence of infection by HPgV-1 is high in HCV carriers in Belém, Pará, and probably does not change the clinical course of HCV infection, however, further studies are still needed.

Comparison of Patients Monoinfected with Hepatitis C Virus and Coinfected with Hepatitis B/C in the Amazon Region of Brazil

Hepatitis B and C are the most common causes of liver disease worldwide. The two infections share many similarities such as a global distribution, the same routes of transmission, hepatotropism, and the ability to cause chronic infection. The consequences of HBV/HCV coinfection are still being studied. The aim of this study is to describe and compare the epidemiological and laboratory profile and the degree of hepatic fibrosis between HCV-monoinfected and HBV/HCV-coinfected patients in the Brazilian Amazon region. ELISA tests were used for the investigation of HBV and HCV serological markers, and molecular tests were used for the detection and genotyping of these viruses. Additionally, transaminases were measured, and a FibroScan was performed for the analysis of liver function. A total of 328 patients with HCV participated in the study. The serological prevalence of HCV/HBV coinfection was 10.77%. A comparison of risk factors between the monoinfected and coinfected groups showed that illicit drug use, sharing sharp instruments, and tattooing/piercing are significantly associated with coinfection. The monoinfected patients had a higher HCV load than the coinfected patients. A viral interaction was observed in this study in which the presence of a coinfection with HBV appears to influence HCV replication. Further studies are necessary to better understand this interaction.

Demographic profile, host, disease & viral predictive factors of response in patients with chronic hepatitis C virus infection at a tertiary care hospital in north India

Background & objectives:

Standard of care for chronic hepatitis C (CHC) in India is peginterferon and ribavirin (RBV). The response to treatment in real life stetting is unclear. The objectives of this study were to evaluate the demographic profile and assess the virological response and predictors of response in CHC patients.

Methods:

Consecutive patients with CHC were included in this study. Detailed clinical history, risk factors, and predictive factors of response were noted. Patients were treated with peginterferon α2b (1.5 µg/kg/wk) and RBV (12 mg/kg/day) for 6 to 18 months based on response.

Results:

A total of 211 patients were included in the analysis, mean age 40.6±12.3 yr, 144 (68%) were males and 71 (34%) had compensated cirrhosis. Commonest risk factor for acquiring CHC was previous transfusion and surgery (51%). Genotype 3 (72%) was most common followed by genotype 1 (23%). Overall sustained virologic response (SVR) was 64 per cent [95% CI 57.1%-70.4%]. The SVR was 66.5 per cent [95% CI 58.34-73.89%] for genotype 3 and 61.2 per cent [95% CI 46.23 to 74.80%] for genotype 1. Non-cirrhotics had better SVR rates compared to cirrhotics (76 vs 41%, P<0.001). On multivariate analysis, BMI ≥23 kg/m², HOMA-IR ≥2, compliance (≤80%), and fibrosis >2 were predictors of low SVR.

Interpretation & conclusions:

Genotype 3 was the commonest HCV genotype. The commonest source of infection was previous transfusion and surgery. SVR rates for genotypes 3 were better than genotype 1 patients. Predictors of non-response were high BMI, insulin resistance, significant fibrosis and inadequate compliance.

ANALYSIS OF POLYMORPHISMS IN THE INTERLEUKIN 18 GENE PROMOTOR (-137 G/C AND -607 C/A) IN PATIENTS INFECTED WITH HEPATITIS C VIRUS FROM THE BRAZILIAN AMAZON

BACKGROUND

The hepatitis C virus has been recognized as the leading cause of chronic liver disease in the world. Host genetic factors have been implicated in the persistence of hepatitis C virus infection. Single nucleotide polymorphisms at positions -607 C/A (rs1946518) and -137 G/C (rs187238) in the IL-18 gene promoter have been suggested to be associated with delayed hepatitis C virus clearance and persistence of the disease.

OBJECTIVE

Identify these polymorphisms in a population infected with hepatitis C virus from the Brazilian Amazon region.

METHODS

In a cross-sectional analytical study conducted in Belém, Pará, Brazil, 304 patients infected with hepatitis C virus were divided into two groups: group A, patients with persistent infection; group B, patients with spontaneous clearance. The control group consisted of 376 volunteers not infected with hepatitis C virus. Samples were analyzed by RT-PCR for the detection of viral RNA and by RFLP-PCR to evaluate the presence of the -137 G/C and -607 C/A IL-18 gene promoter polymorphisms.

RESULTS

Comparison of polymorphism allele frequencies between the patient and control groups showed a higher frequency of allele C at position -607 among patients (P=0.02). When the association between the polymorphisms and viral infection was analyzed, patients carrying genotype C/A at position -607 were found to be at higher risk of persistent hepatitis C virus infection (P=0.03).

CONCLUSION

The present results suggest a possible role of the -607 IL-18 gene promoter polymorphism in the pathogenesis of hepatitis C virus infection.

Incidence and risk factors of hepatocellular carcinoma in patients with hepatic venous outflow tract obstruction

BACKGROUND

Frequency of hepatocellular carcinoma (HCC) in hepatic venous outflow tract obstruction (HVOTO) is unclear and risk factors in HVOTO associated with HCC are unknown.

AIM

To assess the incidence of HCC and to identify risk factors for HCC in primary HVOTO.

METHODS

In the consecutive primary HVOTO patients evaluated between 1989 to 2013, the incidence of HCC among HVOTO was assessed in a retrospective cohort study and identification of the risk factors for HCC in HVOTO patients done by a case-control study.

RESULTS

Of the 421 HVOTO patients, 8 had HCC at presentation (prevalence 1.9%). Another 8 of the remaining 413 developed HCC during 2076.2 person-years follow-up (mean 5.03 + 4.65 years, range 0.08-20 years). The cumulative incidence of HCC was 3.5% (95% CI 1.28-9.2%) at 10 years. The case-control study included 16 HCC as cases and remaining 405 as controls. Controls were predominantly males (M:F - 230:175), mean age 29 ± 10.3 years. Cases were predominantly females with an older age of 36.2 ± 11.4 years (P < 0.01, OR = 1.06, CI 1.0-1.10%). Presence of cirrhosis (P < 0.001), combined inferior vena cava (IVC) and hepatic vein (HV) block (P < 0.03, OR = 5.58, CI 1.43-25.30%) and long-segment IVC block (P < 0.02, OR = 6.50, CI 1.32-32.0%) were significantly higher among cases than controls.

CONCLUSIONS

Hepatic venous outflow tract obstruction is a risk factor for HCC. The cumulative incidence of HCC in HVOTO is low and progressively increases over time. Those with liver cirrhosis, combined IVC and HV block and long-segment IVC block are at risk to develop HCC and need active surveillance.

Association between histological findings, aminotransferase levels and viral genotype in chronic hepatitis C infection

INTRODUCTION

The genomic heterogeneity of hepatitis C virus (HCV) influences liver disorders. This study aimed to determine the prevalence of HCV genotypes and to investigate the influence of these genotypes on disease progression.

METHODS

Blood samples and liver biopsies were collected from HCV-seropositive patients for serological analysis, biochemical marker measurements, HCV genotyping and histopathological evaluation.

RESULTS

Hepatitis C virus-ribonucleic acid (HCV-RNA) was detected in 107 patients (90.6% with genotype 1 and 9.4% with genotype 3). Patients infected with genotype 1 exhibited higher mean necroinflammatory activity and fibrosis.

CONCLUSIONS

HCV genotype 1 was the most prevalent and was associated with greater liver dysfunction.

Prevalence of viral hepatitis B and C in riverside communities of the Tucuruí Dam, Pará, Brazil

Epidemiologically, the relevance of infection caused by hepatitis viruses is related mainly to their wide geographic distribution and the large number of infected individuals in all parts of the world. In this study, 668 residents from the islands around the Tucuruí Dam were selected. Blood samples were collected for investigation of serological markers (HBsAg, total anti-HBc, anti-HBS, and anti-HCV) by enzyme immunoassays. HCV-positive subjects were tested using RT-PCR and RFLP for the identification of viral genotypes. Among the 668 subjects studied, 1.9% were HBsAg positive, 28% were total anti-HBc positive, and 41.9% were anti-HBs positive. The anti-HBs marker alone (vaccine response) was detected in 25.7% of the volunteers. Anti-HCV antibody was detected in 2.2% of the subjects and genotype 1 was the predominant genotype (70%). The results indicate an intermediate level of HBV and HCV endemicity in the region studied, as well as low HBV vaccination coverage.

Generation of HIV-1 and Internal Control Transcripts as Standards for an In-House Quantitative Competitive RT-PCR Assay to Determine HIV-1 Viral Load

Human immunodeficiency virus type-1 (HIV-1) viral load is useful for monitoring disease progression in HIV-infected individuals. We generated RNA standards of HIV-1 and internal control (IC) by in vitro transcription and evaluated its performance in a quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay. HIV-1 and IC standards were obtained at high RNA concentrations, without DNA contamination. When these transcripts were included as standards in a qRT-PCR assay, it was obtained a good accuracy (±0.5 log(10) unit of the expected results) in the quantification of the HIV-1 RNA international standard and controls. The lower limit detection achieved using these standards was 511.0 IU/mL. A high correlation (r = 0.925) was obtained between the in-house qRT-PCR assay and the NucliSens easyQ HIV-1 test (bioMerieux) for HIV-1 RNA quantitation with clinical samples (N = 14). HIV-1 and IC RNA transcripts, generated in this study, proved to be useful as standards in an in-house qRT-PCR assay for determination of HIV-1 viral load.

Strategic approach to produce low-cost, efficient, and stable competitive internal controls for detection of RNA viruses by use of reverse transcription-PCR

Molecular diagnostics based on reverse transcription (RT)-PCR are routinely complicated by the lack of stable internal controls, leading to falsely negative results. We describe a strategy to produce a stable competitive internal control (CIC) based on a Qbeta phage derivative (recombinant Qbeta [rQbeta]) bearing primers KY78 and KY80, which are widely used in the detection of hepatitis C virus (HCV). rQbeta was RNase resistant and stable at 4 degrees C for 452 days in SM medium (0.1 M NaCl, 8 mM MgSO(4).7H(2)O, 50 mM Tris HCl [pH 7.5], 2% gelatin) and for 125 days after lyophilization and reconstitution. rQbeta performance as a CIC was evaluated. rQbeta was added to HCV-positive samples, followed by RNA extraction and a CIC-HCV RT-PCR assay. This method combines RT-PCR, liquid hybridization with nonradioactive probes, and enzyme immunoanalysis. No influence of the CIC on qualitative HCV detection was observed independently of viral load, and results had high concordance with those of commercial kits. In conclusion, we describe a versatile, low-cost alternative strategy to armored RNA technology that can be adapted for detection or real-time applications of any RNA target. Moreover, the CIC reported here is an essential reagent for HCV screening in blood banks in resource-limited settings.

Endothelin 1, its Endothelin Type A Receptor, Connective Tissue Growth Factor, Platelet-Derived Growth Factor, and Adrenomedullin Expression in Lungs of Pulmonary Hypertensive and Nonhypertensive Chickens

Twenty-four 1-d-old broilers were distributed in 2 groups, pulmonary hypertensive broilers (PHB) and pulmonary nonhypertensive broilers (NPHB), to estimate possible differences between them in the expression of endothelin 1 (ET-1) and its type A receptor, connective tissue growth factor, platelet-derived growth factor, and adrenomedullin expression in the lungs. For this purpose, total RNA extraction and real-time PCR analysis were used. Endothelin 1 mRNA levels in the lungs of PHB were significantly higher than the corresponding level in NPHB (P < 0.001). In contrast, the opposite was true for ET-1 type A receptor mRNA levels (P < 0.001). Connective tissue growth factor mRNA levels in the lungs of PHB were significantly higher than in the lungs of NPHB (P < 0.01). However, no differences were encountered between the 2 groups of broilers in platelet-derived growth factor mRNA expression (P > 0.05). Adrenomedullin mRNA levels in the lungs of PHB were significantly higher than in NPHB (P < 0.01). It has been demonstrated for the first time that ET-1, connective tissue growth factor, and adrenomedullin are upregulated in the lungs of PHB. Furthermore, it is suggested that these peptides may play a major role in pulmonary hypertension pathophysiology. Present data might provide clues for future research directions such as genetic selection and therapeutic intervention to revert the process of pulmonary vasoconstriction and vascular remodeling. Major research goals could be to find endothelium-derived factors that probably trigger endothelial dysfunction, as well as possible interactions with already identified molecules which also intervene in the pulmonary response to hypoxia.

Detection and monitoring of virus infections by real-time PCR

The employment of polymerase chain reaction (PCR) techniques for virus detection and quantification offers the advantages of high sensitivity and reproducibility, combined with an extremely broad dynamic range. A number of qualitative and quantitative PCR virus assays have been described, but commercial PCR kits are available for quantitative analysis of a limited number of clinically important viruses only. In addition to permitting the assessment of viral load at a given time point, quantitative PCR tests offer the possibility of determining the dynamics of virus proliferation, monitoring of the response to treatment and, in viruses displaying persistence in defined cell types, distinction between latent and active infection. Moreover, from a technical point of view, the employment of sequential quantitative PCR assays in virus monitoring helps identifying false positive results caused by inadvertent contamination of samples with traces of viral nucleic acids or PCR products. In this review, we provide a survey of the current state-of-the-art in the application of the real-time PCR technology to virus analysis. Advantages and limitations of the RQ-PCR methodology, and quality control issues related to standardization and validation of diagnostic assays are discussed.

Treatment of hepatitis C virus infection in patients of northern India

BACKGROUND AND AIM

The purpose of the present study was to evaluate the therapeutic response of north Indian patients with chronic hepatitis C (CH-C) to two different treatment regimens of interferon and ribavirin.

METHODS

Consecutive patients with a diagnosis of CH-C attending the Liver Clinic at the All India Institute of Medical Sciences, New Delhi between April 1999 and April 2002 were included in the study. A competitive reverse transcription-polymerase chain reaction (RT-PCR) method developed in the authors' laboratory was used for quantification of hepatitis C virus (HCV)-RNA. Genotyping of HCV was also determined. The clinical, biochemical, virological and histological parameters were used to assess the therapeutic response among a clinical cohort of patients with chronic hepatitis C. They were treated with two different protocols (interferon [IFN]-alpha-2b, 3 million units daily and ribavirin 10.6 mg/kg daily in two divided doses for 6 months or IFN-alpha-2b, 3 million units thrice weekly and ribavirin 10.6 mg/kg daily for 6 months).

RESULTS

Sixty-five patients with CH-C were included in the study. Blood transfusion (n = 28, 43%) and community-acquired (n = 23, 35%) HCV infections were the commonest. The mean HCV load was high (24.14 +/- 12.5 x 10(8) copies/mL). Genotype 2 and 3 were prevalent in 80% (41/51) of the patients. Forty-five patients received 3 million units of IFN thrice weekly and 20 received the same dose daily. All received the same dose of ribavirin. A sustained virological response (SVR) of 95% (19/20) was achieved among patients receiving daily IFN, whereas 64.4% (29/45) of those who received IFN thrice weekly had SVR. The virological relapse was significantly lower among patients who received daily IFN than in those treated with thrice weekly IFN (n = 1/20, 5% vs 10/39, 25.6%; P = 0.015). The proportion of patients receiving daily IFN among those achieving SVR (19/48, 40%) was significantly higher than the proportion of patients receiving similar therapy among patients without SVR (1/17, 6%; P = 0.02).

CONCLUSIONS

Transfusion and community-acquired HCV infection were the major causes of CH-C. Genotype 2 and 3 HCV were most prevalent among these patients. Despite high viral load, these patients responded well to a combination of daily IFN-alpha-2b and ribavirin.