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The association of hepatitis C virus (HCV) infection and glomerulonephritis is well known. However, the relationship between immune-mediated glomerulonephritis and occult HCV, characterized by the presence of HCV-RNA in liver or in peripheral blood mononuclear cells in the absence of serological markers, is unknown. We tested this in 113 anti-HCV-negative patients; 87 with immune-mediated glomerulonephritis and 26 controls with hereditary glomerular nephropathies. All patients were serum HCV-RNA negative by conventional real-time PCR. Significantly, occult HCV-RNA (detectable viral RNA in peripheral blood mononuclear cells or in serum after ultracentrifugation) was found in 34 of 87 patients with immune-mediated glomerulonephritis versus 1 of 26 control patients. The serum creatinine levels were significantly higher in patients with immune-mediated glomerulonephritis with than in those without occult HCV (1.5 versus 1.1 mg/dl, respectively). A multivariate analysis adjusted for gender showed a significantly increased risk of occult HCV in patients with immune-mediated glomerulonephritis versus the controls (odds ratio of 13.29). Progression to end-stage renal disease tended to be faster in patients with immune-mediated glomerulonephritis and occult HCV than in the negative cases. Thus, occult HCV is strongly associated with immune-mediated glomerulonephritis and may have a role in the progression of the disease.

Background/aims: Occult HCV infection has been described among anti-HCV-HCV RNA-negative individuals with abnormal transaminase values in whom HCV RNA is detected in liver., Methods: IgG antibody to an HCVcore-derived peptide (anti-HCVcore) was investigated in 145 patients with serologically silent occult HCV infection., Results: At the time of the diagnostic biopsy 45/145 (31%) occult HCV-infected patients tested IgG anti-HCVcore-positive but none of the 140 patients with HCV-unrelated liver disease (P<0.001). Among 23 IgG anti-HCVcore-positive patients at baseline, 22 remained antibody-reactive (one became antibody-negative). Similarly, 17/31 baseline anti-HCVcore-negative patients remained non-reactive whereas 14 seroconverted to IgG anti-HCVcore (although transiently in 10 patients). Thus, a total of 59/145 (40.7%) patients with occult HCV infection showed IgG anti-HCVcore reactivity at any time point analyzed, including 14 initially non-reactive patients. By supplemental immunoblot assay 16 sera reacted weakly with an HCVcore-peptide band (indeterminate result) of which 10 (62.5%) reacted in the IgG anti-HCVcore assay. Occult HCV-infected patients who tested anti-HCVcore-positive showed more frequently signs of necro-inflammation (P=0.035) and greater percentages of HCV RNA-positive hepatocytes (P=0.004) compared with those anti-HCVcore-negative., Conclusions: This work documents that IgG anti-HCVcore testing identifies occult HCV infection among seronegative, non-viremic patients using screening tests and may be useful in tracking anti-HCV-negative infections.

Pegylated alpha-interferon plus ribavirin is the current therapy for chronic hepatitis C virus (HCV) infection. Serum HCV-RNA concentration before treatment has been identified as an independent predictive factor of response. We have compared the percentage of HCV-infected hepatocytes with the concentration of serum HCV-RNA in baseline samples as predictors of response. We included 97 patients with chronic HCV infection (genotype 1), treated with pegylated-interferon-alpha2b plus ribavirin. Of these 97, 38 (39%) were sustained responders and 59 (61%) were not. Statistical differences between responders and nonresponders were found regarding the percentage of infected hepatocytes (6.83+/-4.50% versus 13.44+/-10.05%; P=0.00003) but not in serum HCV-RNA concentration [1.71+/-2.70 (x10(6) IU/L) versus 1.32+/-1.86 (x10(6) IU/L); P=0.40694]. Other factors associated with response were age, gamma-glutamyl transpeptidase level, and absence of previous therapy. Logistic regression demonstrated that percentage of infected hepatocytes (odds ratio, 1.160; 95% confidence interval, 1.065-1.264) and previous therapy (odds ratio, 0.294; 95% confidence interval, 0.109-0.795) were significant predictive factors for response. Therefore, the percentage of infected hepatocytes in liver biopsy before treatment is a better predictive factor of sustained response to 48 weeks of therapy with pegylated alpha-interferon plus ribavirin than serum HCV-RNA concentration in baseline serum sample.

This study analyzes if the profibrogenic factors nitric oxide and transforming growth factor-beta1 (TGF-beta1) affect hepatocyte nuclear factor-4alpha (HNF-4alpha) function. For this purpose, HepG2 cells were treated with TGF-beta1 or with a nitric oxide donor to determine mRNA levels of coagulation factor VII and HNF-4alpha. Treatment effect on factor VII gene promoter was assessed by chloramphenicol acetyl-transferase assays in cells transfected with the pFVII-CAT plasmid. HNF-4alpha binding and protein levels were determined by gel shift assays and Western blot. TGF-beta1 and nitric oxide downregulated factor VII mRNA levels by inhibiting its gene promoter activity. This inhibition is caused by a decrease in the DNA binding of HNF-4alpha. TGF-beta1 induces degradation of HNF-4alpha in the proteasome while nitric oxide provokes nitrosylation of cysteine residues in this factor. TGF-beta1 and nitric oxide inhibit HNF-4alpha activity. These findings may explain the loss of liver functions that occurs during fibrosis progression.

The viric infections influence morbi-mortality in Chronic kidney Disease patients in hemodialysis therapy and can affect to the Staff of the Units. The guides considered the most relevant virus at the present moment: C Virus, B Virus and HIV. To prevent horizontal nosocomial transmission is necessary the observance always the universal precautions in the HD units, although sometimes can appeared seroconversions and epidemic bud when exist a break of these. Is analyzed different situations with special focus in units for acute patients. The following steps under the suspicious of the epidemic bud appeared in one of the annexes together with legislation according to this case. Respect to the staff in every one of the virus is shown prevention patterns, serologic markers to perform when an accident with infected blood occur, also is considered when treatment is indicated. The guides considered too the conditions necessary for include these patients on waiting list for kidney transplantation.

Intrahepatic levels of the inducible nitric oxide synthase (iNOS) are increased in chronic hepatitis C patients. As iNOS gene promoter contains Nuclear Factor (NF)-kappaB binding sites and hepatitis C virus (HCV) core protein activates NF-kappaB, the aim of this work was to study if HCV core protein transactivates iNOS promoter through NF-kappaB activation. iNOS mRNA and protein were determined by RT-PCR and western blot in HepG2 cells. The effect of HCV core protein on iNOS promoter was assayed by cotransfecting HepG2 cells with the core protein expression plasmid pHCV-Co and p1iNOS-CAT or p2iNOS-CAT plasmids. Formation of NF-kappaB-DNA complexes was determined by electrophoretic mobility shift assay. Transfection of HepG2 cells with pHCV-Co plasmid results in an increase in iNOS mRNA and protein levels. Cotransfection with pHCV-Co and p1iNOS-CAT or p2iNOS-CAT plasmids results in a transactivation of iNOS promoter, the presence of the proximal NF-kappaB binding site in the promoter being sufficient for the transactivation. Furthermore, the HCV core protein increases the formation of complexes between NF-kappaB and its binding sequence in the iNOS promoter. The expression of the NF-kappaB inhibitor IKB reverts the effect of the HCV core protein on the iNOS promoter. In conclusion, HCV core protein transactivates iNOS gene promoter through NF-kappaB activation.

Cutaneous lichen planus has been associated in patients with chronic hepatitis C virus infection. It is still unknown whether hepatitis C virus infects keratinocytes of lichen planus lesions. In this report we have analyzed the presence of genomic and anti-genomic hepatitis C virus RNA in skin biopsies from 26 patients with chronic hepatitis C and healthy skin and from 24 patients with cutaneous lichen planus (five with and 19 without hepatitis C virus infection) by in situ hybridization. Hepatitis C virus RNA was detected in the keratinocytes of 69% of the patients with healthy skin and chronic hepatitis C, in 100% of the patients with lichen planus and hepatitis C virus infection, and in none of lichen planus patients without hepatitis C virus infection. The percentage of keratinocytes showing genomic or anti-genomic hepatitis C virus RNA was statistically lower (p < 0.01 in all cases) in patients with healthy skin (mean +/- SD: 5.7 +/- 3.5% and 2.7 +/- 3.1% of keratinocytes with genomic or anti-genomic hepatitis C virus RNA, respectively) than in those with lichen planus lesions (31.7 +/- 7.9% and 18.8 +/- 7.4%, mean +/- SD) or the unaffected adjacent skin (24.8 +/- 6.9% and 14.3 +/- 3.8%, mean +/- SD). In conclusion, we have demonstrated that hepatitis C virus infects keratinocytes from patients with lichen planus and hepatitis C virus infection.

Background/aims: The liver is the primary site of hepatitis C virus (HCV) replication; intrahepatic T-cell responses may influence liver disease severity., Methods: HCV-specific CD4(+) T-cell reactivity was investigated ex vivo in paired liver tissue and peripheral blood from 42 chronic HCV patients., Results: The frequencies with which HCV-specific HLA class-II-restricted CD4(+) T-cell proliferation were observed were 29% in liver and 36% in peripheral blood. Among responses, non-structural-3 protein (NS3)-specific T-cell proliferation was dominant but non-exclusive and did rarely occur concurrently in liver infiltrate and peripheral blood suggesting liver compartmentalization of a CD4(+) T-cells population. Compared with 24 patients with abnormal ALT levels, 18 HCV carriers with persistently normal ALT levels had similar serum and liver viral loads but showed: (i) a low-activity grade and stage chronic hepatitis (P<0.001); (ii) less intrahepatic CD4(+) T-lymphocytes (P<0.01); (iii) less frequent intrahepatic (17 vs. 33%) and peripheral (17 vs. 38%) NS3-specific CD4(+) T-cell proliferation; (iv) less often in vitro T-helper (Th)1 (interferon-gamma) cytokine production (2 vs. 18%; P<0.001)., Conclusions: Our data show a low frequency of intrahepatic HCV-specific HLA class-II-restricted CD4(+) Th1 responses in patients with chronic HCV. However, these Th1 responses are detected more often in those patients with overt clinical and histological disease.

During recent years, the treatment of chronic hepatitis C has increased in efficacy. Initially, the only approved treatment for this disease was interferon-alpha (IFN-alpha) monotherapy, achieving a 15% rate of sustained response. Subsequently, a combination of IFN-alpha plus ribavirin showed a greater efficacy: up to 40% success with 3 MU of IFN-alpha three times weekly and 1000-1200 mg of ribavirin daily in naive patients and in those who had relapsed after a course of IFN-alpha therapy. Pegylated interferon (PEG-IFN), due to its better efficacy and tolerance, has displaced the use of recombinant IFN. Nevertheless, the sustained response rate mainly depends on HCV RNA load and HCV genotype. Presumably, in future, new strategies based on gene therapy will play an important role in the treatment of chronic hepatitis C.

In a pilot study of combination therapy with ribavirin and IFN alpha conducted in anti-HBe-positive individuals with chronic hepatitis B, 21% of patients achieved a sustained ALT normalization and clearance of hepatitis B virus (HBV) DNA as measured by PCR. The present work has assessed whether these sustained responses are lasting long-term. In addition, IFN gamma levels were tested serially in serum as a measure of the immune system activation during treatment. By extending the post-treatment follow-up period 2 years the occurrence of delayed HBV DNA relapses was observed. A low serum level of IFN gamma was detected during and after treatment. IFN gamma demonstrated a multiphasic time-course: the amount of IFN gamma increased in parallel with reductions in HBV DNA but also with ALT flare-ups. In conclusion, the extended follow-up study of anti-HBe-positive patients after combined treatment with ribavirin and IFN alpha has shown that sustained responses are lasting in 17% patients but also that a late onset HBV DNA relapse may occur.

Interleukin-12 plays a central role in mounting an effective cellular immune response directed towards elimination of intracellular pathogens. In two open label, multicenter, dose-escalation phase I/II studies tolerability, pharmacokinetics, pharmacodynamics, and efficacy of subcutaneously administered recombinant human interleukin-12 (rHuIL-12) was assessed in the treatment of chronic hepatitis B and C. Forty-six patients with chronic hepatitis B and 60 patients with chronic hepatitis C were treated for 12 and 10 consecutive weeks, respectively. rHuIL-12 was generally well tolerated, but was associated with temporary decreases in neutrophils and lymphocyte counts, and with elevations in serum transaminases and bilirubin. Serum IL-12 levels observed were higher at 0.5 microg/kg compared with 0.25 microg/kg doses, suggesting a dose-related increase in systemic exposure of IL-12. Measurable levels of interferon-gamma were also observed at the highest dose of 0.5 microg/kg. At the end of treatment HBV DNA clearance was greater in patients treated with 0.50 microg/kg (25%) or with 0.25 microg/kg (13%) compared with those given 0.03 microg/kg. In patients with chronic hepatitis C, HCV RNA remained detectable in all patients. A more than 50% decrease in pretreatment HCV RNA levels was observed in 3/16 patients (0.03 microg/kg), in 3/14 (0.10 microg/kg), in 6/15 (0.25 microg/kg), and in 8/15 patients of the 0.5 microg/kg dose group. In conclusion, antiviral activity of rHuIL-12 in patients with chronic hepatitis B or C does not appear to be advantageous in comparison to other currently available treatments.

Chronic hepatitis C virus (HCV) infection has been associated with several extrahepatic manifestations, among these, to diseases with oral manifestations such as Sjögren's syndrome or sialadenitis. HCV-RNA has been detected in saliva and in salivary glands from patients with sialadenitis by polymerase chain reaction. However, morphological evidence of HCV replication in salivary gland cells is needed to support a role for HCV in causing sialadenitis or Sjögren's syndrome. We have used in situ hybridization and immunohistochemistry to analyze the presence of HCV-RNA of sense and antisense polarity and HCV core antigen, respectively, in salivary gland biopsies from 19 patients with chronic sialadenitis or Sjögren's syndrome (eight anti-HCV-positive; 11 anti-HCV-negative). HCV-RNA of both positive and negative polarity as well as HCV core antigen were detected in the epithelial cells of the salivary gland biopsies from all of the anti-HCV-positive patients but in none of the anti-HCV-negative cases. The percentage of HCV-infected cells ranged from 25 to 48.8% in the patients studied. In conclusion, we have shown that HCV infects and replicates in the epithelial cells from salivary glands of patients with Sjögren's syndrome or chronic sialadenitis. However, its implication in the pathogenesis of these diseases deserves future research.

Background/aims: There are no data about the influence of handling conditions of liver biopsies on the integrity of viral RNAs. We studied the influence of the time delay between obtaining and freezing the liver biopsy on the stability of intrahepatic positive and negative hepatitis C virus RNA (HCV-RNA) strands., Methods: Liver samples from 30 anti-HCV patients were included. For each case, one portion of the liver biopsy (first sample) was immediately frozen (20-28 s), while the other section (second sample) was kept at room temperature (1-30 min) before freezing. Each experimental time point was performed in triplicate using liver samples from three different patients. Semi-quantitative analysis of the positive and negative HCV-RNA strands and of the al-antitrypsin mRNA was performed by a Tth-based reverse-transcription polymerase chain reaction., Results: A significant time-related decrease in both positive (r=-0.8412, p=0.001) and negative (r=-0.8539, p=0.001) HCV-RNA strand titres was found in the second liver fractions. There were no appreciable changes in RNA titres in those samples frozen after less than 3 min. The RNA titres decreased in all but two samples incubated for 4-30 min. Thus, 3/15 (20%) and 7/11 (64%) of these samples lost positive and negative HCV-RNA strands, respectively. Alpha-1-antitrypsin mRNA titres decreased significantly (r=-0.8935, p=0.01) in those samples kept at room temperature for more than 4 min., Conclusion: Freezing of liver samples immediately after extraction is crucial to avoid false negative HCV-RNA detection results, especially for the antigenomic RNA strand.

A novel hepatitis-associated virus named TT virus (TTV) has been isolated. However, its hepatotropism has not been proven. We have retrospectively analyzed the presence of TTV-DNA by polymerase chain reaction (PCR) and in situ hybridization in liver biopsies from 30 patients with liver disease (15 TTV-DNA-positive and 15 TTV-DNA-negative in serum), and prospectively in serum and liver from eight patients with normal liver histology. TTV-DNA was detected by PCR in the liver from the 15 patients with serum TTV-DNA and in serum and liver of two of the eight patients without liver disease. TTV-DNA titers in liver were 10 times higher than in serum, although no correlation between TTV-DNA titers in serum and liver were observed. In situ hybridization shows positive signals in the hepatocytes of the 17 patients infected by TTV but in none of the TTV-DNA-negative patients by PCR. No morphological changes were observed in the hepatocytes showing hybridization signals. The percentage of positive hepatocytes ranged from 2.1% to 30% and correlated with the TTV-DNA titers in liver (r = 0.54; P = 0.037). In conclusion, our results show that TTV is able to infect liver cells although they do not support a role for TTV in causing liver disease.

Background/aims: Interleukin-12 (IL-12) may be active against hepatitis B virus (HBV). The objective of the study was to assess the tolerability, activity, pharmacokinetics, and pharmacodynamics of three dose levels (0.03 microg/kg b.w., n=15; 0.25 microg/kg b.w., n=15; 0.50 microg/kg b.w., n=16) of recombinant human (rHu) IL-12 given s.c. once a week for 12 consecutive weeks., Methods: Forty-six patients with chronic hepatitis B, HBV DNA positivity and aminotransferase elevation were included in a multicenter prospective randomized phase I/II study., Results: Compared with the baseline, HBV DNA levels had decreased significantly at the end of rHuIL-12 treatment and after the 12-week follow-up period (p<0.001). The response to rHuIL-12 treatment was dose-dependent: at the end of the study HBV DNA clearance was greater in patients treated with 0.50 microg/kg b.w. (25%) or with 0.25 microg/kg b.w. (13%) compared with those given 0.03 microg/kg b.w. (7%). Moreover, HBeAg became undetectable at the end of follow-up in five of the patients given the 0.25microg/kg (2/15) or the 0.50 microg/kg (3/16) dose. The drug pharmacology showed that IL-12 had an estimated half-life of 30 h with levels remaining detectable for more than 48 h after rHuIL-12 administration. The serum levels of IL-12, interferon-gamma, IL-10, neopterin and beta2-microglobulin as well as the area under the curve (AUC) were rHuIL-12 dose-related. Side effects were observed more frequently with higher doses, including moderate decreases in lymphocyte and neutrophil counts; three patients withdrew prematurely from treatment. The local reaction observed at the injection site was unrelated to the drug dose. Only one patient showed detectable antibody levels to rHuIL-12 without clinical impact., Conclusions: Treatment with rHuIL-12 at the doses investigated is safe and tolerable, and appears to be active against HBV in patients with chronic hepatitis B.

Background: Hemodialysis patients are at high risk of hepatitis B, C, and G virus infection. The prevalence of GBV-C/HGV-RNA was analyzed in serum and peripheral blood mononuclear cells (PBMCs) from 52 hemodialysis patients., Methods: GBV-C/HGV-RNA detection was performed by reverse transcription-polymerase chain reaction (RT-PCR) with primers of 5'-noncoding (5'-NC) and NS3 regions of the GBV-C/HGV genome. To increase sensitivity, serum samples were ultracentrifuged prior to the RT-PCR to concentrate the viral particles. The amplified products from 20 serum and 5 peripheral blood mononuclear cells (PBMC) samples were sequenced., Results: GBV-C/HGV-RNA was detected in sera of 9 (17%) and in PBMCs of 30 (58%) patients. After serum ultracentrifugation, GBV-C/HGV-RNA was positive in 20 (95%) of the patients, with GBV-C/HGV-RNA only in PBMCs. Thus, GBV-C/HGV-RNA was detected in serum and PBMCs from 29 (56%) patients, four of whom had antibodies against GBV-C/HGV E2 protein (anti-HGE2); one patient (2%) had GBV-C/HGV-RNA only in PBMCs, but was anti-HGE2 positive. Seven (32%) patients who did not have GBV-C/HGV-RNA were anti-HGE2 positive. The nucleotide sequence homology between serum samples from the patients who were GBV-C/HGV-RNA positive after ultracentrifugation, and paired serum and PBMCs from five of them, ranged from 90 to 96% and from 92 to 98%, respectively., Conclusions: We found a high prevalence of GBV-C/HGV-RNA in serum and PBMC samples from hemodialysis patients. Whether or not this finding can be extended to other populations requires further study.

It has not been completely elucidated whether the liver injury induced by the hepatitis C virus (HCV) is due to direct cytopathic damage or to an immune-mediated response against HCV-infected hepatocytes. In this work, we have determined the percentage of HCV-infected hepatocytes, the histological activity index, and the viremia levels in chronically HCV-infected patients with different grades of liver injury to investigate any possible correlation between them. For that purpose, liver biopsies from 27 patients with HCV chronic hepatitis were analyzed by in situ hybridization. This technique revealed that the percentage of infected hepatocytes ranged from 0.04% to 83.6%. Regarding the viremia levels, HCV RNA concentration ranged from 1.8 x 10(3) to 1.4 x 10(6) genome copies/ml. A significant correlation (r = 0.54; P = 0.003) between the percentage of infected hepatocytes and the viremia levels was found. In contrast, no correlation was observed between the percentage of HCV-infected hepatocytes or the viremia levels and the histological activity index. In conclusion, we have shown that the HCV viremia reflects the extent of the infection in the liver and that the liver injury in chronic HCV infection is not directly related to either the number of infected hepatocytes or the serum HCV RNA concentration.

The effects of amantadine (1-5 microM) and interferon alpha (IFNalpha)-2a alone (1000 IU/ml) and combined, have been studied in cultured peripheral blood mononuclear cells (PBMC) from 15 chronic hepatitis C patients and ten healthy donors. Amantadine itself did not affect cell viability and had minor effects on the response to mitogens by PBMC. Four patients (27%), but no donors, had hepatitis C virus (HCV) core and NS3-specific proliferative responses. Amantadine suppressed these responses in all cases and its antiproliferative effect was greater than that of IFNalpha (Mann-Whitney's U-test: P < 0.05 in both cases). All PBMC cultures from patients, but none from donors, were HCV RNA positive. Amantadine alone or combined with IFNalpha dose-dependently reduced HCV RNA content in individual PBMC (Wilcoxon's signed rank test: 1 microM, P < 0.05; 2 microM, P < 0.02; and 5 microM, P = 0.16) with respect to untreated cultures. In addition, 7, 13 and 20% of PBMC cultures became HCV RNA negative with 2 microM amantadine alone, IFNalpha alone and their combination, respectively. Finally, in contrast to IFNalpha, amantadine did not modify expression of 2',5'-oligoadenylate synthetase activity or the spontaneous or mitogen-stimulated IFNgamma and interleukin 10 production. In conclusion, these effects in PBMC from HCV patients suggest that the amantadine/IFNalpha combination might be considered a therapeutic option for treating chronic hepatitis C patients.

Background: Cytokines are regulatory factors of erythropoiesis, especially in pathologic conditions. Even though a relevant role for a deranged cytokine production in the pathogenesis of dialysis anemia has been suggested, no data are available that analyze the role of cytokines in the key therapeutic issue of the needs of erythropoietin. The aim of the present study in hemodialysis patients was, therefore, to examine the relationship between the dose of recombinant human erythropoietin (EPO) and the production of cytokines by peripheral blood mononuclear cells (PBMC)., Methods: After the exclusion of subjects with major active causes of EPO resistance, data from 34 hemodialysis patients were available for analysis. Cytokine levels were measured in the supernatants of stimulated [with bacterial lipopolysaccharide and interferon gamma (IFN-gamma)] and unstimulated PBMC. Mean yearly values of hematocrit, hemoglobin, transferrin saturation, ferritin, parathormone (PTH) and aluminum levels and EPO doses (U/kg/week) were calculated. For analysis, the 34 patients were divided according to their cutoff requirements for EPO: patients with requirements of EPO > or = 60 U/kg/week (group A1, 26 subjects) versus EPO < 60 U/kg/week (group B1, 8 subjects) and patients with requirements of EPO > or = 100 U/kg/week (group A2, 18 subjects) versus <100 U/kg/week (group B2, 16 subjects)., Results: A significant direct correlation between interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-a) production values and EPO doses was found (P = 0.039 and P = 0.02 respectively). On the other hand, there was a significantly negative correlation between interleukin-12 (IL-12) production values and EPO doses (P = 0.029). Patients of groups A1 and A2 had spontaneously higher tumor necrosis factor-alpha (TNF-alpha) and lower IL-12 and IFNgamma production compared to patients from groups B1 and B2., Conclusions: Our data disclose a previously undescribed pattern of cytokine alteration that is relevant to determine increased needs of EPO in hemodialysis patients. The present results have potential applicability in designing strategies to improve EPO resistance.

Background/aims: In this study, the inhibition of hepatitis delta virus replication mediated by trans-ribozyme and antisense probes, alone or in combination with recombinant interferon alpha-2a, has been assayed., Methods: A 60-nucleotide-long designed trans-ribozyme, which contains the catalytic core of the hammerhead ribozyme, and a 163-nucleotide-long antisense probe were directed against the same region of the viral genome in in vitro and cell culture systems., Results: The ribozyme activity, assayed in a chemically isolated system, resulted in the trans-cleavage of 10-20% of the 40-nucleotide-long RNA substrate. A 5-nucleotide deletion in one of the flanking arms, obtained by random mutagenesis, resulted in enhancement of the trans-cleavage activity in as many as 40-60% of the substrate molecules. The efficiency of the optimized trans-ribozyme and antisense probes against the complete viral genome was assayed in a cell culture system. The inhibitory efficacy (25%) of the trans-ribozyme is lower than that of the antisense probe (35%) or interferon at 1000 U/ml (47%). An enhancement of the interferon efficacy was achieved when it was administered in cells having a previous basal expression of ribozyme (70%) or antisense probes (83%)., Conclusions: These results suggest that the combination of ribozyme or antisense probes with interferon could be a promising approach to the treatment of RNA virus infections.

Acute and chronic liver dysfunction is common after allogeneic bone marrow transplantation (BMT). Although toxicity, graft versus-host disease (GVHD), and viral infections are the major causes, etiologic diagnosis is difficult and often remains unknown. We conducted a prospective study to establish the role of the infection with both the hepatitis C virus (HCV) and the recently discovered hepatitis G virus (HGV) in liver dysfunction after BMT. From January 1994 to December 1995, 59 patients who had undergone an allogeneic BMT at our institution were enrolled in the study. HGV-RNA was identified in serum by nested polymerase chain reaction (PCR), and HCV was studied by the presence of second generation enzyme-linked immunosorbent assay (ELISA)-antibodies and HCV-RNA by nested PCR. HGV-RNA was detected in 25 patients (42%) (before BMT in 18 and after BMT in 7). HCV-RNA was present in 12 patients (20%) (before BMT in 11 and after BMT in one). The presence of HCV-RNA and HGV-RNA was clearly associated with a previous history of blood transfusions. No significant association was found between viral infection and acute liver toxicity. Some degree of liver dysfunction was present 6 months after BMT in 25 of 40 evaluable patients (62%). Long-term liver dysfunction was more common among patients infected with HCV alone (3 of 4) or with both HCV and HGV (3 of 3) than in those infected with either HGV alone (eight of 13) or with no virus infection (10 of 20). We found a high prevalence of HGV infection in our BMT population. However, no role for HGV in liver disease could be established in this study, and the relationship between HGV infection and liver dysfunction requires further clarification.

At present, routine screening for hepatitis C virus (HCV) infection is based on the detection of antiviral antibodies. Underdiagnosis of HCV infection by using HCV antibody tests, however, still occurs. Additional diagnostic means are provided by the polymerase chain reaction (PCR). The measurement of aminotransferase (ASAT and ALAT) has served as an auxiliary, less specific test. The present research aimed to design practical and low cost strategies to diminish underdiagnosis of HCV infection in dialysis patients. With this purpose in mind, we examined whether aminotransferases values in HCV antibody-negative patients could be related to undiagnosed HCV infection, by using HCV RNA testing by PCR as the gold standard. In 112 hemodialysis patients, we found 78 negative and 34 positive for HCV antibodies. A major finding was that 222 (28.2%) out of the 78 HCV antibodies-negative patients had positive HCV RNA by PCR. In repeated samples taken at six months follow-up from 19 out of these 22 patients, only one of them was positive for anti-HCV antibodies; moreover, a positive HCV RNA by PCR was confirmed in 13 (68.5%) of them. Within the HCV antibody-negative group, the mean values of ASAT, ALAT and gammaglutamiltransferase were higher (P < 0.001, P < 0.001 and P < 0.02, respectively) in the HCV PCR-positive versus the HCV PCR-negative patients. No significant differences were found in the liver enzyme values between the HCV antibody-negative, HCV RNA positive and the HCV antibody positive, HCV RNA positive individuals. Histological samples from two HCV RNA positive, HCV antibody-negative patients disclosed the presence of a mild liver disease. In conclusion, the present study demonstrates the critical importance of HCV RNA determination by PCR in hemodialysis patients who have no detectable circulating antibodies against the HCV. Furthermore, in conditions in which PCR technology is not readily available, we have established that the existence of a moderate increase of aminotransferases is a helpful clue to detect patients with absent HCV antibodies, and might represent an useful, low cost tool for HCV screening in dialysis patients.

Therapies for chronic viral hepatitis B and C are aimed at clearing the virus and producing a sustained immunity. Manipulation of the biological response would confer an antiviral state and modulate the immune responses. For the development of new therapeutic agents against hepatitis viruses, reliable in vitro models are needed to study drug effects. Forthcoming therapies might combine natural or synthetic antiviral compounds and cytokines, together with novel approaches including anti-sense oligonucleotides and ribozymes.

Background/aims: The efficacy of interferon therapy in Caucasian children with chronic hepatitis B is similar to that in adults. However, little information is available about factors predicting response to this therapy in children. We have performed a univariate analysis to assess the strength of association between basal variables and response, and a multivariate analysis to determine the combination of basal variables which give the best prediction of response in terms of sensitivity and specificity., Methods: The basal parameters were studied in 50 children included in three different trials of interferon alpha therapy (360-700 MU/square meter of body surface, 2 or 3 times weekly for 12 to 24 weeks)., Results: Of these, 18 (36%) were responders. In the univariate analysis, a higher histological activity (p < 0.05), a lower percentage of HBcAg-stained hepatocytes (p < 0.001), aspartate amino transferase and alanine aminotransferase levels (p < 0.05) and alanine aminotransferase peak prior to serum HBV-DNA clearance (p < 0.05), were associated to the response. In the multivariate analysis, the combinations of the percentage of HBcAg stained cells with alanine aminotransferase levels and with the histological activity index were the best variables for predicting response (sensitivity: 100% and specificity: 89% and 86%, respectively)., Conclusions: Factors predictive of response in children with chronic hepatitis B are similar to those found in adults, and may help in identifying those children with a better chance of responding.

Biologic response modifiers include various colony-stimulating factors and interleukins such as granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, and interleukin-2. Their use as therapy has proven to be beneficial in the treatment of various diseases, and in preventing hematologic disorders. Their biologic effects and the rationale for their use in chronic viral hepatitis, alone or in combination with interferon-alpha, are reviewed with respect to the treatment of chronic hepatitis C.

Ribozymes are RNA molecules that can cut or ligate other RNA molecules catalytically. Several different ribozymes have been studied. In this paper, the hammerhead and the hepatitis delta virus (HDV) ribozymes are described, as well as their possible use as antiviral therapy.

In this study, 42 hepatitis C virus (HCV)-infected patients included in different treatment protocols were assessed by semiquantitative Amplicor assay to evaluate the changes in HCV-RNA titer during antiviral therapy. Amplicor detected change to negative HCV-RNA at the end of treatment in four biochemically responding patients; a decrease in HCV-RNA titer from base line was observed in 2/6 complete responder patients, in 7/11 responders with relapse, and in 6/21 nonresponder patients. Furthermore, Amplicor also detected an increase in HCV-RNA titer from the end of treatment to the follow-up samples in 3/6 complete responder patients, in 7/11 responders with relapse, and in 3/6 nonresponder patients in whom HCV-RNA titer at the end of treatment was lower than in the basal sample. None of the nonresponder patients showed a change to negative HCV-RNA either at the end of treatment or at follow-up. When comparing the detection of HCV-RNA by this semiquantitative method and by nested-PCR, we found a concordance in 113/118 polymerase chain reaction (PCR) results (96%), including three negative results by both methods. With respect to the noncorrelated results, negative PCR samples were found to be positive by Amplicor assay in three cases (correspondent to final samples of treatment); by contrast, two positive PCR samples were found to be negative by Amplicor assay (correspondent to final and follow-up samples of different patients).

To investigate the replicative hepatitis C virus status and its relation to liver damage, serum, peripheral blood mononuclear cells and liver-paired samples from 45 untreated hepatitis C virus infected patients (38 with chronic hepatitis, three with minimal changes, and four with normal liver) were studied by nested polymerase chain reaction, using primers from the 5' untranslated region. Positive HCV-RNA strand was detected in serum (69%), peripheral blood mononuclear cells (100%) and liver samples (100%). The presence of negative HCV-RNA strand was confirmed using specificity controls assays and was only detected in liver and peripheral blood mononuclear cells samples, (95% and 82%, respectively). No correlation between the presence of negative HCV-RNA strand in peripheral blood mononuclear cells and positive HCV-RNA strand in serum was found, whereas serum HCV-RNA was not detected in patients without negative HCV-RNA strand in the liver. Both positive and negative HCV-RNA strands were found in liver and peripheral blood mononuclear cells of four patients with normal liver histology, and three with minimal changes. Furthermore, the presence of HCV-RNA in serum did not correlate with the alanine aminotransferase values and the histological activity index. These data confirm the existence of replicative intermediates in the liver, not only from patients with histologically proven chronic hepatitis, but also from those with normal liver, suggesting the existence of hepatitis C virus in true healthy carriers.

To compare the efficacy and tolerance of the simultaneous administration of levamisole plus IFN versus treatment with IFN alone in chronic hepatitis B, 39 patients were randomly assigned into two groups. Nineteen patients received 15 million units of recombinant alpha interferon 2b (rIFN-alpha 2b) 3 times a week for 4 months. The other 20 patients were treated with the same dose and schedule of rIFN-alpha 2b and 150 mg of levamisole simultaneously given during the first 6 weeks of treatment. At the end of the study (thirteenth month), serum HBV-DNA was negative in 59% of patients treated with interferon alone and in 37% of those treated with interferon and levamisole. HBeAg was negative in a similar percentage in the two groups (41% vs. 37%). Serum alanine aminotransferase levels decreased in patients who lost viral DNA. These data demonstrate that the combination of alpha interferon and levamisole, at the doses and under the schedule used in this study, does not achieve better results than the treatment with alpha interferon alone. Although tolerance to the simultaneous administration of alpha interferon and levamisole is good, secondary effects may be hazardous.

Thirty-two patients with chronic hepatitis B were randomly assigned to two groups. Sixteen patients received 10 million units of alpha-interferon per square meter of body surface (MU/m2), three times weekly for 4 months. Sixteen patients were treated simultaneously with gamma-interferon at a dose of 2 MU/m2, and 10 MU/m2 of alpha-interferon. At the end of the study (13th month), hepatitis B virus DNA was negative in 50% of the patients treated with alpha-interferon and in only 25% of those treated with alpha- and gamma-interferon. A similar trend was observed with respect to the hepatitis B e antigen negativization (31% and 19% of HBeAg negativization in patients treated with alpha- and gamma-interferon, respectively). In summary, these data demonstrate that, at the doses used in this study, the combination of alpha- and gamma-interferon does not give better results than the administration of alpha-interferon alone. The tolerance to simultaneous alpha- and gamma-interferons is poor and may decompensate the liver disease.

Interferon-alpha (IFN-alpha) has proven useful in the treatment of chronic hepatitis C, but a relapse in response is frequently observed. The possible benefit of daily administration of recombinant IFN-alpha 2A at an escalating (from 1.5 to 9 MU) regime depending on the evolution of serum aminotransferase (ALT) levels was evaluated in 31 adult patients with chronic hepatitis C. At the end of the first month with 1.5 MU of rIFN-alpha 2A, 9/31 (29%) had normal ALT values. Then, 22 patients were given 3 MU daily and at the second month 4 patients (18%) normalized ALT values. The 18 non-responders received 6 MU and 4 of them (22%) normalized ALT values (1 patient dropped out). Finally, the remaining 13 non-responders were given 9 MU and in 4 (30%) ALT fell to normal ranges. Three non-responders to 1.5 MU normalized ALT values when the dose of rIFN-alpha 2A was increased (n = 2, 3 MU; n = 1, 9 MU). The overall response achieved was 68%. Within 3 months after cessation of treatment, 12/20 (60%) responder patients had a relapse in ALT levels. Therefore, although daily administration of rIFN-alpha 2A does not improve the results obtained with a thrice-weekly schedule, a proportion of non-responders could benefit from an escalating dose to a high amount (63 MU/week) of rIFN-alpha 2A.

Hepatitis C virus (HCV) RNA is the most reliable marker of HCV infection. However, because of HCV genome heterogeneity and the procedures used to isolate the viral genome and to perform the amplification steps, results do not accurately reflect the actual rate of HCV infection. In this study, several isolation procedures and sets of primers to perform PCR were compared for the detection of HCV-RNA in serum and peripheral blood mononuclear cells (PBMC) of patients with HCV infection. It was found that the extraction with guanidinium isothiocyanate prior to cDNA synthesis followed by PCR amplification of the 5'-UTR region gave the best results in serum and PBMC. The presence of the viral genome in PBMC is a frequent event during HCV infection and this has important consequences for the understanding of the viral pathogenesis.

The use of genetic amplification of the hepatitis delta virus (HDV) genome reveals the existence of different HDV replicative behaviours during the natural history of chronic HDV infection. While some of the patients (8/19, 42%) presented high and long-term maintained levels of HDV replication, as detected by slot-blot hybridization, others showed fluctuations from positive to negative, and in 5/7 (71%) polymerase chain reaction (PCR) demonstrated the presence of the HDV genome. Finally, 4 patients were persistently slot-blot-negative and in 3 of them HDV-RNA was detected by PCR in all samples tested. The correlation observed between the low levels of HDV replication and the ALT values, as well as the reactivation observed in one of the patients, suggests that PCR is useful in the virological surveillance of HDV infection, and indicates its usefulness in evaluating the effectiveness of antiviral therapy for chronic hepatitis D.

The histological features of chronic viral hepatitis differ according to etiological agent and replicative phases. Thus, in chronic HBV hepatitis with a high level of HBV replication the histological lesion is generally mild. During the seroconversion phase, a lobular lesion is present in the liver biopsy followed by amelioration of the disease. Chronic delta hepatitis is very aggressive histologically, progression to cirrhosis is frequent, and sanded nuclei are often observed in liver biopsies of patients with anti-HIV. In contrast, chronic hepatitis C shows a milder histological picture and immunohistochemical techniques to detect HCV-Ag in the liver tissue should be developed. In summary, the majority of cases of chronic viral hepatitis have distinctive histological features that may be identified in liver biopsies.

Liver transplantation is a valid treatment in chronic viral B and C hepatitis. But disease recurrence is very frequent in HBV hepatitis after the procedure, and its prevention and treatment are unresolved problems. Hepatitis C recurrence in the graft seems also to be common, and further studies of its pathobiology are needed.

Interferon (IFN) therapy of chronic hepatitis C has proved useful in recent years. A major goal in the treatment of hepatitis C is the prevention of the high relapse rate after cessation of therapy and the improvement of the response rate in non-responders. Several approaches can be tried. The administration of higher doses of IFN results in an increase in the response rate, but does not prevent ultimate relapse. Similarly, prolongation of the treatment period gives better results, but one third of cases still relapse. In these cases, re-treatment results in ALT normalization once again, but does not prevent subsequent relapse; in non-responders to IFN, re-treatment will not lead to improvement of the response rate. Analysis of the viral genome reveals its presence in serum in spite of the normalization of ALT values. The role of HCV genome heterogeneity in the response to IFN needs to be assessed and it is necessary to find other antiviral agents that are able to clear HCV from all relevant hosts (serum, liver tissue and mononuclear cells).

We studied the long-term outcome of patients with chronic hepatitis B virus (HBV) infection who responded to interferon (IFN) therapy. Between 1983 and 1988, 120 patients were included in 5 different protocols; 94 patients were treated with IFN and 26 were controls. Loss of serum HBV-DNA was considered a partial response and occurred in 34 of the treated patients and in 10 of the controls. Only the partial-response patients were followed up for 14-64 months (mean 46 months). HBeAg disappeared in 32/34 of the partial-response treated patients and in 9/10 of the controls. During the follow-up period, 6/34 (18%) treated patients and 1/10 controls suffered a reactivation of the disease with reappearance of HBV-DNA. Only 8/34 (23%) treated patients and 1/10 of the controls lost HBsAg; no statistical differences were observed in baseline characteristics between HBsAg-negative patients and patients who remained HBsAg-positive. Of eight HBsAg-negative treated patients, four were serum HBV-DNA-negative upon polymerase chain reaction and thus formed the HBsAg-negative control cases. Although the frequency of HBsAg loss in treated patients is relatively low, the improvement in liver disease obtained from IFN therapy is sustained over a long period.

In this paper, we studied the usefulness of polymerase chain reaction (PCR) in HDV-RNA detection. Using serial dilutions of serum samples of known concentrations of HDV-RNA, PCR was 10,000-times more sensitive than slot-blot hybridization. PCR was used for the detection of HDV-RNA in 33 serum samples negative to HDV-RNA by conventional slot-blot hybridization. HDV-RNA was detected in 18/33 (54%) of the samples included in this study using PCR. When positivity to a viral genome was related to other viral replication markers, it was found that among the 18 patients positive to the viral genome, 13 (72%) had hepatitis delta antigen in the liver, and five (28%) were negative. In conclusion, HDV-RNA detection by gene amplification is 10,000-times more sensitive than slot-blot hybridization, and allows the detection of viral replication in patients without other viral replication markers.