Hepatitis C Virus RNA Load Research Articles

Role of Therapeutic Drug Monitoring in a Patient With Human Immunodeficiency Virus Infection and End-Stage Liver Disease Undergoing Orthotopic Liver Transplantation

Pharmacological interactions between protease inhibitors and tacrolimus require careful monitoring to prevent toxicity in the posttransplantation period. A 42-year-old man with human immunodeficiency virus (HIV) infection and end-stage liver disease due to hepatitis C virus (HCV) received an orthotopic liver transplant. At the time of surgery the patient was on triple antiretroviral therapy (tenofovir, lamivudine, and lopinavir/ritonavir) with a stable CD4 + count (>500 cells/mm 3) and HIV-1 RNA (<50 copies/mL). Immunosuppression was maintained with tacrolimus (0.5 mg at a single dose once per week). One month after surgery HCV recurrence was documented. Pharmacokinetic evaluation of lopinavir/ritonavir showed a rapid increase in the area under the curve. Drug concentrations returned to normal levels, with reduction in liver enzymes. At the same time, tacrolimus dosages were reduced to a maintenance dose of 0.5 mg every 2 weeks. The patient, at 17 months postoperatively, is alive in good health with normal liver function and HCV RNA load levels. This is the first case in which a profound change in the pharmacokinetics of a protease inhibitor caused by a drug-drug interaction was observed during transient liver damage. Because this clinical event is particularly common in HIV-infected patients, our findings suggest that therapeutic drug monitoring should be performed to determine the impact of potential drug interactions in the early posttransplantation period, at the time of resumption of therapy or introduction of new anti-retroviral therapy and during HCV recurrence in order to optimize both tacrolimus and protease inhibitor treatment.

Role of Hepatitis C Virus (HCV) Viremia and HCV Genotype in the Immune Recovery from Highly Active Antiretroviral Therapy in a Cohort of Antiretroviral-Naive HIV-Infected Individuals

The roles of hepatitis C virus (HCV) viremia and HCV genotype in the immune response to highly active antiretroviral therapy (HAART) are poorly understood. Our aim was to assess the CD4+ cell count recovery after HAART in human immunodeficiency virus (HIV)-infected patients with HCV viremia and HIV-infected patients who tested negative for HCV antibody (HCV-Ab). We also aimed to assess whether the response to HAART in these patients varied according to HCV genotype. The analysis focused on 1219 HCV-Ab-negative patients and 284 HCV-viremic patients from a cohort of HIV-infected subjects that includes persons who were antiretroviral naive before initiating HAART after cohort enrollment. HCV RNA load and HCV genotype were determined in plasma specimens obtained and stored during the 6-month period preceding the initiation of HAART. The chance of achieving a CD4+ cell count increase of > or = 100 cells/microL from the pre-HAART level tended to be poorer in HCV-viremic patients than in patients who tested negative for HCV-Ab (adjusted relative hazard [RH], 0.82; 95% confidence interval [CI], 0.66-1.01; P = .06). In contrast, a comparison of patients who had a HCV RNA load >1 x 10(6) IU/mL with patients who had a HCV RNA load of 5-1 x 10(6) IU/mL revealed no significant association between HCV RNA load and achievement of an increased CD4+ cell count (adjusted RH, 0.97; 95% CI, 0.75-1.27; P = .83). There was no clear association between HCV genotype and the probability of achieving a CD4+ cell count increase. An association between the presence of HCV-Ab and immune reconstitution after HAART has been shown elsewhere. Results of our large, prospective study support a direct role of HCV viremia in the CD4+ cell count response to HAART. Moreover, our results underline the fact that, in individuals coinfected with HIV and HCV, the goal of treating HCV infection is to eradicate HCV, to both slow the rate of HCV progression and limit potential interference with the response to HAART.

Usefulness of the Hepatitis C Virus Core Antigen Assay for Screening of a Population Undergoing Routine Medical Checkup

We studied the usefulness of the recently designed Trak-C assay for the detection and quantification of the hepatitis C virus (HCV) core antigen (Ag) for the screening of HCV infection in 4,201 subjects selected from 74,150 consecutive volunteers undergoing routine medical checkups. Subjects were selected for screening because they had risk factors (group II, n = 321) and/or elevated alanine transaminase activity (group I, n = 3847). Initially, the anti-HCV antibody assay and the Trak-C assay were performed on each patient. Subsequently, the Trak-C assay was performed only when the anti-HCV enzyme immune assay (EIA) was positive. Positive samples were further evaluated for anti-HCV antibodies by a third-generation strip immunoblot assay and for HCV RNA. Four samples (1.2%) from group II and 113 (2.9%) from group I were anti-HCV EIA positive. We also tested 33 subjects who previously tested positive for anti-HCV in our medical center. Among the 150 anti-HCV EIA-positive samples, the HCV core Ag result was in accord with the HCV RNA result in 146 cases (97.3%). When the EIA result was positive, the HCV core Ag concentration and the HCV RNA load were correlated (r(2) = 0.78; P < 0.001). Four samples with low viral loads were Trak-C negative but HCV RNA positive. Among the 2,395 anti-HCV EIA-negative serum samples collected during the first part of the study, 17 (0.7%) were found to contain very low levels of HCV core Ag (<8.5 pg/ml, the cutoff value being 1.5 pg/ml). All these samples were HCV RNA negative and considered to be false positives. This was confirmed by HCV core Ag neutralization analysis. The HCV core Ag assay is a useful method in the screening strategy of HCV infection and provides a reliable means of distinguishing between current and cleared HCV infections that is well correlated with HCV RNA testing.

Removal of Hepatitis C Virus by G-1 Beads in Sera from Patients with Chronic Hepatitis C

Recently, a new method of extracorporeal granulocyte depletion apheresis has been developed to treat inflammatory systemic diseases using an Adacolumn (Japan Immunoresearch Laboratories, Takasaki, Japan) that is filled with acetate cellulose beads (G-1 beads) to adsorb the granulocytes. We examined whether hepatitis C virus (HCV) is adsorbed after incubation of the Adacolumn with the sera from patients with HCV-RNA-positive chronic hepatitis C. Patients and Methods: A total of 10 patients with chronic hepatitis C, whose levels of HCV RNA were greater than 800 kIU/ml were examined. The serum was incubated with 500 G-1 beads in a syringe at 37°C for 1 h. After removal of the serum, the beads were washed with RNase-free water. The G-1 beads were removed from the syringe after centrifugation. RNA was extracted from 200 µl of the wash waste and from 10, 50, 100 and 200 beads, respectively, using TRIZol regent. Detection of HCV RNA was performed using the nested PCR method. Results: HCV RNA was detected from as few as 10 G-1 beads. HCV RNA was not detected from waste fluid collected after the last wash from any of the patients. Further, HCV RNA was detected in the initial waste fluid after the 37°C incubation with serum in all of the patients. Since HCV RNA was detected on the G-1 beads, but not from the last washing solution in the current examination, these results suggest that the G-1 beads adsorbed HCV RNA. Conclusions: Our in vitro study confirmed that G-1 beads adsorbed HCV; therefore, apheresis using a column filled with G-1 beads may reduce the HCV RNA load in the blood of patients with chronic hepatitis C.

Different mechanisms of steatosis in hepatitis C virus genotypes 1 and 3 infections.

This study reports evidence that hepatocellular steatosis, a frequent histological feature of chronic hepatitis C, is principally metabolic in hepatitis C virus (HCV) genotype 1-infected patients, whereas it is principally virus-induced in HCV genotype 3-infected patients. Multivariate analysis of data on 176 patients with chronic hepatitis C revealed that the severity of steatosis was independently related to HCV RNA load alone in patients infected by HCV genotype 3, whereas it was independently related to the body mass index, daily alcohol intake and histological activity grade (but not viral load) in patients infected by HCV genotype 1. These findings suggest that steatosis is a cytopathic lesion induced by HCV genotype 3, whereas HCV genotype 1 is not steatogenic per se or at the usual in vivo expression levels.

A 32‐Year‐Old Man with Skin Lesions

Diagnosis: Porphyria cutanea tarda (PCT). The diagnosis was based on the photodistributed pattern of blistering, chronic pruritic skin lesions, increased skin fragility, and bruising (figure 1). Serological tests for hepatitis detected antibody to hepatitis C virus (HCV), with an HCV RNA load of copies/mL and an HCV-1b genotype. The patient 6 1.18 10 tested negative for HIV, and results of iron studies were normal. The clearance rate of urinary uroporphyrin was 891 mg/day (normal range, 10-50 mg/day). Urinary uroporphyrin clearance rates of 1800 mg/day have been associated with photosensitivity [1]. PCT is the most common form of porphyria and is commonly found in adults with liver disease and hepatic iron overload (figure 2) [2–4]. In both familial and sporadic forms of this disease, the primary abnormal condition appears to be the reduced activity of uroporphyrinogen decarboxylase. Studies involving large groups of patients with PCT have found a high frequency of HCV infection [5]. The pathogenesis of the skin lesions remains unknown. The differential diagnosis of skin lesions in patients with HCV includes PCT, mixed cryoglobulinemia, lichen planus, leukocytoclastic vasculitis, polyarteritis nodosa, erythema multiforme, and erythema nodosum [6]. Treatment of PCT involves avoidance of precipitating factors, such as alcohol use, sun exposure, and estrogen therapy, together with treatment of HCV infection (if present). Phlebotomy can be attempted, because iron depletion—even in the absence of iron overload—often leads to improvement in both dermatological and hepatic manifestations [7, 8]. Chloroquine therapy has also been used successfully in cases of PCT that are refractory to phlebotomy [9, 10]. There is increasing evidence of the efficacy of IFN-a therapy in patients with chronic HCV infection, and case reports document successful treatment of HCV-associated PCT with INF-a [11, 12]. Our patient was advised to avoid triggering factors—namely, to cease consuming alcohol—and is being evaluated for combination IFN-a– ribavirin therapy for treatment of HCV infection.

PCR-detected hepatitis C virus RNA associated with human zona-intact oocytes collected from infected women for ART.

The aim of this study was to investigate the susceptibility of human oocytes from hepatitis C virus (HCV) RNA-positive women to HCV contamination during assisted reproductive technology (ART). A reverse transcriptase-PCR assay was used to test for the presence of HCV RNA associated with 24 unfertilized oocytes 48 h after follicular fluid aspiration in 10 IVF attempts (seven conventional IVF and three ICSI). Negative and positive controls (10 unfertilized oocytes from HCV-negative women and 20 unfertilized oocytes artificially contaminated with HCV RNA-positive plasma; HCV RNA was also quantified in plasma and follicular fluid) were included. HCV RNA was associated with 17/24 (70.8%) oocytes (6/7 after ICSI and 11/17 after conventional IVF) and was found in 19/20 (95%) follicular fluid samples. A weak correlation was found between plasma and follicular fluid HCV RNA loads (r = 0.73, P < 0.001). HCV associated with unfertilized oocytes surrounded by their intact zona pellucida from anti-HCV antibody-positive and viraemic women undergoing ART raises questions concerning the safe management of medically assisted procreation for these women and good practice of oocyte/embryo cryopreservation and donation.

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

A method for quantitation of hepatitis C virus (HCV) RNA was developed based on competitive reverse transcription polymerase chain reaction (RT-PCR) using in vitro transcribed mutated thio-RNA as a competitor template. The thio-RNA is more resistant to RNAse and is stable over a year. This assay was compared with the commercially available Roche Amplicor HCV Monitor assay V 2.0 and real time PCR using SYBR green 1 dye method. A total of 18 pre-therapy serum samples from chronic hepatitis C cases were tested in parallel by the three assays. All samples could be quantitated using the in-house competitive RT-PCR and real time PCR and there was a significant correlation in the virus titer ( P<0.05). However, 8 (44%) samples could not be quantified by Amplicor HCV Monitor assay, which has a lower detection range (10 2 to 10 5.5 copies/ml). The in-house method of competitive RT-PCR showed a detection range of 10 3 to 10 10 copies/ml. In the patients the mean viral titer was found to be (9.66±9.3)×10 6 copies/ml. Ten (55%) of the samples, assessed by the Amplicor HCV Monitor assay showed a mean viral titre of (1.13±0.75)×10 6 copies/ml, which was lower than the other two tests. The competitive PCR method and real time PCR could amplify all prevalent genotypes. This in-house quantitative competitive RT-PCR method is simple, cheap, reproducible and useful for estimation of HCV RNA load.

Sequence elements correlating with circulating viral load in genotype 1b hepatitis C virus infection☆

The correlation between hepatitis C virus (HCV) genomic sequences and circulating HCV RNA levels was assessed to investigate the genetic elements affecting viral load. The interferon sensitivity-determining region (ISDR) sequence and the serum viral load were strongly correlated in 226 patients examined. Analysis of the entire HCV genome from six patients (three with a high and the others with a low viral load) with similar ISDR sequences identified several candidate residues associated with viral load. The amino acid (aa) sequences of these candidate residues and flanking regions in 67 additional patients revealed that only the residue at aa 962 varied significantly between the HCV patients with low and high serum loads ( P = 0.042). At this position, alanine was observed more frequently in the patients with a high viral load. In conclusion, our results strongly suggest that serum HCV RNA loads are inversely correlated with amino acid substitutions in the ISDR, and aa 962 was identified as a possible second determinant of serum HCV RNA load.

Hepatitis C virus genotypes and hepatic fibrosis regulate 24‐h decline of serum hepatitis C virus RNA during interferon therapy in patients with chronic hepatitis C

Recently, hepatitis C virus (HCV) dynamics during interferon (IFN) therapy have been studied in detail. We examined factors that regulate the viral kinetics and the relationship between the viral kinetics and clinical effect of IFN therapy. Eighty-eight patients with chronic hepatitis C entered this study. All patients had been treated with 3 MU of IFN-beta twice a day for the first 2-4 weeks, then IFN-alpha for the next 20-22 weeks (three injections per week). The levels of serum HCV RNA were determined by Amplicor HCV Monitor version 1.0, before and 24 h after the first injection of IFN; then the decline of HCV was calculated. Liver inflammation and fibrosis were scored as 0 (none), 1 (mild), 2 (moderate) or 3 (severe) using biopsy specimens. The decline of serum HCV RNA was 1.42 +/- 0.65 log copies/mL in genotype 1b and 1.83 +/- 0.72 in genotype 2a or 2b (P < 0.01). By a logistic regression model, genotype (1b, 2a or 2b) and hepatic fibrosis (0 or 1, 2 or 3) associated with 24-h decline of serum HCV RNA, independently. As the predictor of IFN therapy, the decline of serum HCV RNA and serum HCV RNA levels before IFN therapy were the independent significant factors (P < 0.001). The decline of serum HCV RNA during the first 24 h of IFN therapy was regulated by genotypes and hepatic fibrosis. The decline of serum HCV RNA and initial HCV load were independent factors that can be the predictor of the subsequent sustained viral response to IFN therapy.

Influence of HGV super-infected with HIV or HCV on the virus replication

To realize human immunodeficiency virus(HIV) and hepatitis C virus(HCV) super-infected with hepatitis G virus(HGV or GBV/C) and to probe into the mechanism of these virus infection in the body. HIV and HCV load were tested by the quantitated RT-PCR in the HIV or HCV infected plasma samples respectively and the HGV RNA was detected in all of the samples. Then some of the HGV positive were sequenced. 123 of 317 HIV patients were positive for HGV, the positive rate was 38.8%. Among the 91 HCV patients, 19 were positive for HGV. The positive rate is 20.9% which was less than that of HIV patients. HIV load of the patients super-infected with HGV was less than that of those without HGV[(1.8+/-0.6)x10 copies/ml compared with (1.9+/-1.1)x10(2)copies/ml]; while HGV and HCV super-infection did not influence the HCV RNA load significantly [(1.5+/-0.6)x10(4) copies/ml compared with (5.4+/-1.8)x10(4)copies/ml]. The HGV sequences from HIV or HCV patients were compared and showed no difference markedly. The rate of the HIV and HGV super-infection is higher than that of HCV. HGV may inhibit HIV reproduction in the body while superinfection.

Hepatitis C virus and lymphomagenesis: Another piece of evidence

Some epidemiologic studies suggest a link between hepatitis C virus (HCV) infection and some B-cell non-Hodgkin’s lymphomas. We undertook this study after a patient with splenic lymphoma with villous lymphocytes had a hematologic response after antiviral treatment of HCV infection. Nine patients who had splenic lymphoma with villous lymphocytes and HCV infection were treated with interferon alfa-2b (3 million IU three times per week) alone or in combination with ribavirin (1000 to 1200 mg per day). The outcomes were compared with those of six similarly treated patients with splenic lymphoma with villous lymphocytes who tested negative for HCV infection. Of the nine patients with HCV infection who received interferon alfa, seven had a complete remission after the loss of detectable HCV RNA. The other two patients had a partial and a complete remission after the addition of ribavirin and the loss of detectable HCV RNA. One patient had a relapse when the HCV RNA load again became detectable in blood. In contrast, none of the six HCV-negative patients had a response to interferon therapy. In patients with splenic lymphoma with villous lymphocytes who are infected with HCV, treatment with interferon can lead to regression of the lymphoma.

Regression of Splenic Lymphoma with Villous Lymphocytes after Treatment of Hepatitis C Virus Infection

Some epidemiologic studies suggest a link between hepatitis C virus (HCV) infection and some B-cell non-Hodgkin's lymphomas. We undertook this study after a patient with splenic lymphoma with villous lymphocytes had a hematologic response after antiviral treatment of HCV infection. Nine patients who had splenic lymphoma with villous lymphocytes and HCV infection were treated with interferon alfa-2b (3 million IU three times per week) alone or in combination with ribavirin (1000 to 1200 mg per day). The outcomes were compared with those of six similarly treated patients with splenic lymphoma with villous lymphocytes who tested negative for HCV infection. Of the nine patients with HCV infection who received interferon alfa, seven had a complete remission after the loss of detectable HCV RNA. The other two patients had a partial and a complete remission after the addition of ribavirin and the loss of detectable HCV RNA. One patient had a relapse when the HCV RNA load again became detectable in blood. In contrast, none of the six HCV-negative patients had a response to interferon therapy. In patients with splenic lymphoma with villous lymphocytes who are infected with HCV, treatment with interferon can lead to regression of the lymphoma.

Intrahepatic HCV RNA loads in 37 HIV-HCV co-infected patients with controlled HIV infection.

Serum and intrahepatic hepatitis C virus (HCV) RNA were measured in 37 HIV-HCV co-infected patients with controlled human immunodeficiency virus (HIV) infection and correlated with clinical, biological, and histological parameters. Thirty-seven interferon-naive patients underwent liver biopsy. HCV-induced activity (A) and fibrosis (F) were evaluated with METAVIR score. The 37 patients included had HIV plasma loads < 10,000 copies/ml, CD4(+) count > 250/microl. All the patients but two were receiving antiretroviral treatment. Liver tissue and sera were used for measurement of HCV RNA by the Cobas Amplicor HCV Monitor. All patients had serum and liver HCV RNA, and both levels were correlated (r = 0.47; P = 0.003). Intrahepatic HCV load did not depend on age, sex, duration of HCV infection, CD4(+), HCV genotype, or fibrosis. AST levels correlated with intrahepatic HCV load (r = 0.52; P = 0.001). Patients with METAVIR A1/A2 had significantly lower levels of liver HCV-RNA than were found in patients with METAVIR A3 (P = 0.026). Highly active antiretroviral therapy (HAART) including protease inhibitors(PI)-treated patients had significantly lower intrahepatic HCV load (P = 0.04). A weak but significant correlation between serum and liver HCV RNA was found. The amount of hepatic HCV RNA was correlated with AST levels, histological activity, but not with HCV genotype or fibrosis. The immune improvement associated with PI regimens could help reduce HCV load, supporting a protective effect of PI-induced immune restoration.

Viral kinetics in genotype 1 chronic hepatitis C patients during therapy with 2 different doses of peginterferon alfa-2b plus ribavirin

Pegylated interferon (peginterferon) alfa-2b plus ribavirin achieves a higher sustained response rate in patients with genotype 1 chronic hepatitis C virus (HCV) than standard combination therapy. This study evaluated HCV kinetics throughout therapy with 2 doses of peginterferon alfa-2b and ribavirin in 55 patients. Twenty-eight patients were randomized to receive a high once-weekly dose of peginterferon alfa-2b (3 μg/kg for 1 week, 1.5 μg/kg for 3 weeks, and 1.0 μg/kg for 44 weeks), and 27 patients were randomized to receive a low dose (0.5 μg/kg) for 48 weeks. Both groups also received 800 mg ribavirin daily. Mean baseline HCV RNA load, measured by reverse-transcription polymerase chain reaction, was similar in both groups (5.32 ± 0.86 log vs. 5.15 ± 1.04 log). The 3-μg/kg dose of peginterferon alfa-2b inhibited HCV RNA more significantly than the 0.5-μg/kg dose during the first 48 hours (2.08 ± 0.93 log vs. 1.09 ± 0.80 log; P < .001) and both increased at 72 hours (0.54 ± 0.73 log vs. 0.03 ± 0.36 log; P = not significant [NS]), but the high dose showed a greater reduction at the end of the week (1.07 ± 0.99 log vs. 0.72 ± 0.73 log). Both doses showed a progressive, slower viral decrease throughout therapy; however, HCV RNA became undetectable faster and in more patients with the high dose (22% vs. 7% at week 4, 56% vs. 44% at week 12, 69% vs. 63% at week 24, and 71% vs. 61.5% at the end of therapy). In conclusion, peginterferon alfa-2b/ribavirin produces an initial rapid decline in HCV RNA levels, followed by a slower, progressive decrease, similar to the biphasic kinetic profile of standard combination therapy. Higher doses of peginterferon alfa-2b also accelerate viral clearance. (HEPATOLOGY 2002;35:930-936.)

Detection of hepatitis C virus in the bile and bile duct epithelial cells of hepatitis C virus–Infected patients

The pathobiology of hepatitis C virus (HCV) in the biliary system has not been clarified yet, although bile duct damage is a histological finding characteristic of chronic hepatitis C. In this study, we examined whether HCV infects bile ducts and is released into the bile. Twelve patients positive for serum HCV antibody were examined in this study, and eight were seropositive for HCV RNA by polymerase chain reaction (PCR). For those who underwent abdominal surgery, the bile was aspirated from the gall bladders by fine needle puncture. Five underwent wedge liver biopsy. Series of saline-diluted bile were assayed for HCV RNA by PCR to determine the HCV RNA titers. To examine HCV expression in the biliary system, the liver specimens were immunostained using monoclonal antibodies to the HCV proteins. HCV RNA was detected in the bile of 5 patients with high serum HCV RNA load (≥2.5 Meq/mL). Comparison of viral loads between serum and bile revealed that the HCV RNA level in the bile was as high as that in serum. Furthermore, immunohistological study showed that bile duct epithelial cells were infected with HCV. In contrast, HCV was not found in either the bile or bile duct of patients seronegative for HCV RNA or with low serum HCV load (≤1.1 Meq/mL). These findings suggest that the biliary system is involved in the pathobiology of HCV and that the bile is as highly infectious as the serum. (HEPATOLOGY 2001;33;977-980.)

Immunologic dynamics in hemophiliac patients infected with hepatitis C virus and human immunodeficiency virus: influence of antiretroviral therapy

Infection with hepatitis C virus (HCV) or human immunodeficiency virus (HIV) or both is common in hemophiliac patients due to putative transmission through clotting factor concentrates. Recently, highly active antiretroviral therapy (HAART) has been found to markedly improve viremia and immunologic parameters in patients infected with HIV. This report considers interactions between these viral infections, the immune system, and antiretroviral therapy. A total of 130 male hemophiliac patients were grouped according to type of viremia (HCV, HIV, both, or neither). Along with 30 healthy men age-matched to viremic patients, these groups were compared with respect to viral load and immunologic parameters. Thirty-five patients treated as above for HIV were serially followed up. HCV infection was associated with reduced peripheral B-cell and CD4(+)-cell counts and with increased serum IgG and IgM levels, whereas HIV infection was associated with reduced peripheral CD4(+)-cell counts and increased serum IgG and IgA levels. In patients with both viruses, HCV and HIV RNA load correlated inversely with peripheral B-cell and CD4(+)-cell counts, respectively. HAART reduced levels of both viruses in the blood. Of the 25 patients with both viruses, HAART eliminated HCV in 2. In conclusion, immunologic dynamics differed between hemophiliac patients infected with HCV, HIV, or both. The relative dynamics of HCV viral load, peripheral B-cell count, and serum IgM level were similar to those of HIV viral load, CD4(+)-cell count, and serum IgA. (Blood. 2000;96:4293-4299)

Immunologic dynamics in hemophiliac patients infected with hepatitis C virus and human immunodeficiency virus: influence of antiretroviral therapy

AbstractInfection with hepatitis C virus (HCV) or human immunodeficiency virus (HIV) or both is common in hemophiliac patients due to putative transmission through clotting factor concentrates. Recently, highly active antiretroviral therapy (HAART) has been found to markedly improve viremia and immunologic parameters in patients infected with HIV. This report considers interactions between these viral infections, the immune system, and antiretroviral therapy. A total of 130 male hemophiliac patients were grouped according to type of viremia (HCV, HIV, both, or neither). Along with 30 healthy men age-matched to viremic patients, these groups were compared with respect to viral load and immunologic parameters. Thirty-five patients treated as above for HIV were serially followed up. HCV infection was associated with reduced peripheral B-cell and CD4+-cell counts and with increased serum IgG and IgM levels, whereas HIV infection was associated with reduced peripheral CD4+-cell counts and increased serum IgG and IgA levels. In patients with both viruses, HCV and HIV RNA load correlated inversely with peripheral B-cell and CD4+-cell counts, respectively. HAART reduced levels of both viruses in the blood. Of the 25 patients with both viruses, HAART eliminated HCV in 2. In conclusion, immunologic dynamics differed between hemophiliac patients infected with HCV, HIV, or both. The relative dynamics of HCV viral load, peripheral B-cell count, and serum IgM level were similar to those of HIV viral load, CD4+-cell count, and serum IgA.

Mutations in the non-structural protein 5A gene in patients with chronic hepatitis C virus 1b infection during repeated interferon treatment

It has been previously reported that the non-structural region 5A (NS5A) of the hepatitis C virus (HCV) includes an interferon sensitivity determining region (ISDR) and that amino acid substitutions in this region are closely associated with the response to interferon (IFN) treatment. We assessed the clinical significance of serial changes of amino acid sequences in the ISDR during repeated IFN treatment in patients with chronic hepatitis C (genotype 1b), related to serum HCV RNA load. During treatment, additional amino acid substitutions in the ISDR were observed in four of eight patients (50% 2/5 of complete responders (CR); 2/3 of non-responders (NR). However, comparing these amino acid substitutions to wild-type ISDR, the number of amino acid mutations was limited to only one amino acid identified in two CRs. The virus load changed regardless of the amino acid substitutions in the ISDR during treatment, and the wild-type and intermediate type (with less than three amino acid substitutions) showed wide variations in virus load. These data indicate that amino acid mutations in the ISDR, which indicate the switch to mutant-type do not occur easily even during repeated IFN treatment, and the additional amino acid substitutions in the ISDR are not a sensitive marker during repeated IFN treatment. In cases where virus load is used as a marker of response to repeated UN treatment, serial examinations are necessary to determine the precise virus load levels.

Standardization of Hepatitis C Virus RNA Quantification

It was recently recommended that hepatitis C virus (HCV) RNA quantification be used to tailor the duration of combined interferon alfa (IFN-α)/ribavirin therapy in patients infected by HCV genotypes 1, 4, and 5. This recommendation has been difficult to implement in the absence of standardized quantitative units for HCV RNA. The aim of this work was to define clinically relevant HCV RNA loads in standardized international units (IU), for use in routine clinical and research applications based on standardized quantitative assays. Two hepatitis C virus RNA quantitative assays were used: (1) the Superquant assay (National Genetics Institute, Los Angeles, CA), for which possibly relevant thresholds were established; and (2) the semi-automated Cobas Amplicor HCV Monitor assay version 2.0 (Cobas v2.0, Roche Molecular Systems, Pleasanton, CA) that measures HCV RNA loads in IU/mL. Quantification in the Cobas v2.0 assay was linear over the entire range of values tested, including viral loads higher than 850,000 IU/mL after 100-fold dilution. The accuracy and precision of the measures in IU/mL were satisfactory with Cobas v2.0. The results obtained with Superquant and Cobas v2.0 correlated (r = .932; P < .0001). A value of 2,000,000 copies/mL (6.3 log10 copies/mL) with Superquant was converted to nearly 800,000 IU/mL (5.9 log10 IU/mL). In conclusion, all HCV RNA quantitative assays should give HCV RNA loads in international units and be validated with appropriate calibrated panels; 800,000 IU/mL in any of these assays should be used as the decision threshold to tailor the IFN-α/ribavirin treatment duration in patients infected by HCV genotypes 1, 4, and 5.(Hepatology 2000;32:654-659.)