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Hepatitis C virus has been proven to be the major cause of NANB hepatitis, cirrhosis and hepatocellular carcinoma worldwide. Based on the genome similarities between HCV and flavivirus or pestivirus, this agent has been included within the family Flaviviridae as a separate genus. Among the analogies between HCV and the other members of the same family there is the possibility of infecting blood cells. In particular, significant evidence obtained through studies performed in vivo and in vitro support the concept that HCV is not only a hepatotropic but also a lymphotropic virus. This suggests that, in addition to playing a role in inducing hepatic diseases (both of a non-tumoral and a neoplastic nature), HCV infection may also play a role in extrahepatic pathologies. The striking association observed between HCV infection and some autoimmune-lymphoproliferative disorders of either benign or neoplastic nature is consistent with this hypothesis. However, in analogy with what has been observed in the case of liver disease, the mechanisms involved in the pathogenesis of HCV-related extra-hepatic manifestations have to be more deeply analysed and clarified.

The mechanisms underlying chronicity of hepatitis C virus (HCV) infection are poorly understood, but the importance of impaired viral clearance by the immune system has been suggested. The prevalence of HCV infection of peripheral blood mononuclear cells (PBMC) was in investigated in 34 persistently infected patients with anti-HCV (7 with liver cirrhosis, 10 with chronic active hepatitis, 5 with chronic persistent hepatitis, 4 with chronic lobular hepatitis, and 8 healthy carriers) by polymerase chain reaction (PCR). HCV infection of 116 T cell clones derived from liver infiltrating mononuclear cells obtained from 3 patients with chronic liver disease was examined using the same methods. HCV genomic sequences were found in fresh, unstimulated PBMC from 20 patients with cirrhosis, and chronic active and persistent hepatitis, but in none of the healthy carriers and only in mitogen-activated cells from 1 out of 4 patients with autoresolving chronic lobular hepatitis. Active PBMC infection was confirmed by identification of anti-genomic HCV sequences in the majority of HCV RNA-positive cells (fresh or mitogen-stimulated). A high percentage of T cell clones obtained from liver infiltrates were found to be infected by HCV. These findings suggest that HCV infection of lymphatic cells plays a role in the pathogenesis of chronically evolving liver damage. PBMC may represent a reservoir for latent infection and a site for viral multiplication.

Liver transplantation for liver diseases related to hepatitis B virus (HBV) and hepatitis delta virus (HDV) remains problematic because of the risk of viral recurrence. We report here the long-term virological outcome of patients transplanted for HDV-related liver cirrhosis (HDV cirrhosis). From December 1984 to December 1990, 76 patients with HDV cirrhosis underwent liver transplantation. Before transplantation, all the patients were HBsAg-positive/anti-HDV positive, and all but one were HBV DNA-negative by dot blot hybridization. HDV RNA was detected by HDV RT-PCR and liver HDAg by fluorescent HDV Ab. After transplantation, all the patients except four received continuous long-term anti-HBs passive immunoprophylaxis. The actuarial 5-year survival was 88%. All patients who did not receive anti-HBs immunoprophylaxis remained HBsAg-positive and developed hepatitis. Among the 68 patients receiving antiHBs immunoprophylaxis with a minimum follow-up of 2 months, HBsAg reappeared in 7 (10.3%) after a mean of 17 months. These seven patients developed hepatitis, with simultaneous HBV and HDV replication; and four cleared later HBsAg. Patients without HBV reinfection were studied for HDV reinfection: liver HD Ag or serum HDV RNA were present in 88% of the patients during the first year, without developing hepatitis; however, they were no longer detectable after 2 years in 95% of the patients. In conclusion, liver transplantation for HDV cirrhosis gives good results, with a 5-year actuarial survival of 88%.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis C virus (HCV), which is both a hepatotropic and a lymphotropic virus, has been proposed as a possible causative agent of mixed cryoglobulinaemia. This 'benign' lymphoproliferative disorder can switch over to a malignant B-cell non-Hodgkin's lymphoma (NHL). Therefore HCV infection has been investigated in a series of 50 unselected Italian patients with B-cell NHL. Antibodies against HCV were found in 30% of NHL and HCV viraemia in 32% of cases. HCV-related markers were detected in 34% (17/50) of our NHL patients; this prevalence is particularly significant when compared with HCV seropositivity in Hodgkin's lymphoma (3%) and healthy controls (1.3%).

Objectives: Mixed cryoglobulinaemia (MC) and autoimmune chronic hepatitis (AI-CH) are frequently associated with hepatitis C virus (HCV) chronic infection. Because HCV represents a possible common aetiological factor, the aim of the present study is to investigate the clinico-serological alterations of both MC and AI-CH and to verify a possible overlap between these disorders., Setting: Patients from three tertiary referral centres., Subjects: Two Italian series of 88 MC patients and 30 AI-CH type 1 were studied., Results: MC and AI-CH share several clinico-serological features. The patients' mean age (MC vs. AI-CH: 60 +/- 9 vs. 57 +/- 13 years), disease duration (10.5 +/- 5 vs. 9.6 +/- 6 years), and female/male ratio (3.4 vs. 3.3) were very similar in the two series. Typical hallmarks of MC, i.e. purpura, arthralgias, and weakness, circulating mixed cryoglobulins with rheumatoid factor activity, and hypocomplementemia were also recorded in a significant number of AI-CH patients. Similarly, chronic active hepatitis was found in 68% of MC patients and its histological and serological alterations were comparable with those of AI-CH; moreover, amongst various autoantibodies, antinuclear antibodies and/or anti-smooth-muscle antibodies were detected in half of the cases of MC. Anti-HCV antibodies, detected by second-generation Chiron ELISA and RIBA, were present in a high percentage of both MC and AI-CH (94 vs. 80%), and frequently associated with HCV viraemia (86 vs. 77%). Finally, anti-GOR, the HCV-related autoantibodies, were found in half cases of MC and AI-CH., Conclusions: On the whole, these data suggest that HCV in combination with other infectious and environmental and genetic factors can trigger a complex immunological disorder with different clinical patterns.

We evaluated hepatitis B virus DNA and hepatitis C virus RNA in sera from 110 HBsAg and IgM HBc antibody-negative heavy drinkers (50 cirrhosis, 13 chronic active hepatitis, 25 fatty liver with or without mild to moderate fibrosis, alcoholic hepatitis or both and 22 healthy alcoholic subjects) with polymerase chain reaction. Results of hepatitis C virus polymerase chain reaction were compared with those obtained with two tests (second generation recombinant immunoblot assay and enzyme-linked immunosorbent assay) used to detect hepatitis C virus antibodies. Hepatitis B virus DNA was found in three (2.7%) patients. Hepatitis C virus RNA was detected in 29 (29.8%) of the 97 subjects whose sera were well preserved for RNA extraction (42.5% cirrhosis, 83.3% chronic active hepatitis, 8% fatty liver and 0% healthy alcoholic subjects). Results obtained with second-generation recombinant immunoblot assay and enzyme-linked immunosorbent assay had a high degree of agreement with polymerase chain reaction as expected, the kappa indexes being 0.76 and 0.61, respectively. Nevertheless, five hepatitis C virus RNA-positive patients had negative recombinant immunoblot assay results, whereas all hepatitis C virus RNA-positive patients had positive or borderline enzyme-linked immunosorbent assay results. We conclude that, in Italian HBsAg-negative alcoholic patients, "inapparent" hepatitis B virus infection is rare. On the contrary, hepatitis C virus infection, as detected on hepatitis C virus polymerase chain reaction, is quite frequent, especially in patients who have cirrhosis and chronic active hepatitis.(ABSTRACT TRUNCATED AT 250 WORDS)

A striking association between hepatitis C virus (HCV) infection and mixed cryoglobulinemia (MC) has been shown; thus, HCV seems to play an important etiopathogenetic role in this lymphoproliferative disorder. Because HCV is both a hepatotropic and lymphotropic virus, this study aimed to investigate the prevalence of HCV infection of peripheral blood mononuclear cells (PBMCs) in a series of 16 patients with type II (IgMk) MC. Antibodies against HCV were detected by commercially available kits (Second Generation Chiron enzyme-linked immunosorbent assay [ELISA] and recombinant-based immunoblot assay [RIBA]), and the presence of HCV RNA was evaluated in both sera and isolated PBMCs using the polymerase chain reaction technique. A previous exposure to HCV was shown by ELISA and confirmed by RIBA in all cases (100%). Moreover, HCV RNA was present in the sera of 8 of 16 patients (50%), whereas its frequency markedly increased (13 of 16 [81%]) when genomic sequences were detected in peripheral lymphocytes. HCV RNA was never detected in the PBMCs of 20 control subjects. These findings showed that HCV infection, alone or in combination with other factors, may be responsible for the clonal B-cell expansion underlying the systemic manifestations of MC, and may explain the appearance of a malignant non-Hodgkin's lymphoma in some subjects.

Hepatitis C virus (HCV) infection is frequently found in autoimmune hepatitis and mixed cryoglobulinaemia. In these conditions HCV could be responsible for immuno-mediated organ alterations. The aim of this study was to evaluate the presence of immunological alterations in PCT patients, in which HCV infection has been frequently found. Twenty-three PCT patients were evaluated for clinical and serological alterations, including: chronic hepatitis, other systemic symptoms, serum cryoglobulins and rheumatoid factor (RF), haemolytic complement, serum immunoglobulins, anti-nuclear (ANA), anti-smooth muscle (ASMA), anti-liver-kidney-microsomal (anti-LKM1), anti-soluble-liver-antigen (SLA), anti-mitochondrial (AMA), anti-GOR antibodies, anti-HCV and HCV RNA. Abnormal serum ALT were present in the majority of cases (20/23, 87%), while liver biopsy revealed a chronic persistent hepatitis or chronic active hepatitis in 15/20 (75%) PCT patients. In a high percentage of subjects (91%) the presence of anti-HCV was detected by ELISA and RIBA II (Chiron, Emeryville CA, USA). In 17/22 (77%) cases the ongoing HCV replication in the serum was demonstrated by the detection of HCV genomes (polymerase chain reaction). The prevalence of both anti-HCV and HCV RNA in PCT was significantly higher if compared to 22 systemic immunological diseases (P < 0.001) and 47 healthy subjects (P < 0.001). A possible HCV-induced autoimmunity in PCT was suggested by the presence of the following immunological parameter alterations: anti-GOR in 13/23 (57%), ANA in 4/23 (17%), ASMA in 18/23 (78%), anti-LKM1 in 1/23 (4%), RF in 23/23 (100%), mixed cryoglobulins in 4/23 (17%), complement consumption in 10/23 (43%).(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of interferon-alpha (IFN-alpha) on clinical and serologic manifestations of mixed cryoglobulinemia (MC) were investigated by randomized, crossover-controlled trial in 26 patients. The trial alternated 6 months with and 6 months without IFN-alpha therapy (2 x 10(6) IU daily for a month, then every other day for 5 months). In 22 patients, pretreatment steroid dosage remained unchanged during the study. Six patients dropped out (three because of side effects), whereas another 20 patients experienced a significant improvement of purpura (P < .02) and serum transaminases (P < .005) during IFN-alpha treatment. The presence of clinical improvement was supported by the outcome measurements of several immunologic parameters. In particular, serum cryoglobulins were significantly reduced (P < .04) during IFN-alpha therapy. A rebound phenomenon of clinical and serologic parameters was observed after IFN-alpha discontinuation. In addition, no variations were recorded during 6 months without therapy. Hepatitis C virus (HCV) RNA was detected in 91% (20/22) of our MC patients; in 2/13 cases HCV RNA was no longer detectable in serum samples after IFN-alpha therapy. Thus, IFN-alpha could be considered as treatment for MC in patients with HCV seropositivity.

Since a striking association between hepatitis C virus (HCV) infection and mixed cryoglobulinemia has been demonstrated, the aim of this study is to investigate the effect of alpha-interferon (alpha-IFN) on HCV viraemia and clinico-serological manifestations of 15 patients (ten female and five male, mean [+/- SD] age 53 +/- 7 years). In 14/15 patients pre-study steroid dosage remained unchanged during treatment. alpha-IFN was administered at a dose of 2 x 10(6) IU daily for a month, then every other day for five months. On the whole, a statistically significant improvement of purpura (p < 0.001), serum transaminases (p < 0.001), and cryocrit (p < 0.01) was observed after alpha-IFN treatment. HCV viraemia was detected by polymerase chain reaction technique in 13/15 patients with mixed cryoglobulinemia and anti-GOR antibodies, expression of HCV-related autoimmunity, were present in 8/15. After alpha-IFN treatment, HCV RNA levels showed a clear-cut reduction in five persons and disappeared in another, while anti-HCV antibodies (Chiron ELISA and RIBA II) did not change after the six-month period of therapy. These data further support the possible etiopathogenetic role of HCV in patients with mixed cryoglobulinemia and suggest that alpha-IFN may be regarded as the elective treatment in this disease.

Viral recurrence is the limiting factor in orthotopic liver transplantation (OLT) for hepatitis B virus (HBV) related liver disease. In fact, high rates of HBV infection of the transplanted liver are reported, followed by the recurrence of liver disease in a high percentage of cases. The importance of reinfection stimulates the study of its modalities and mechanisms in order to better identify preventive measures and better select patients for OLT. In HBV and HDV positive patients, the outcome of liver transplantation appears significantly better than in patients that are solely HBV positive, in spite of a high rate of HDV reinfection. Long-term analysis (5 years) of HBV and HDV infection, using the PCR technique, in 15 patients transplanted for an HBV/HDV positive liver disease and treated with anti-HBs immunoglobulin (HBIG), revealed that all patients experienced an HDV reinfection, but only about 7 were still harboring the virus after four years of follow-up. HDV reinfection was either associated to HBV reinfection or isolated whereas no cases of HBV isolated reinfection was observed. Isolated HDV reinfection was frequent and transient in all but one case that was superinfected by HBV. Infected peripheral blood mononuclear cells seem to be implicated in HBV superinfection of HDV infected liver. Liver damage was observed only in cases of HBV/HDV co-infection, suggesting that, in vivo, HBV is necessary to produce liver damage although it is not essential for HDV absorption to target cells, HDV penetration of these cells or HDV genomic replication. In addition, in isolated HDV infection, transient HDV viraemia and its low levels suggest that, perhaps in these patients HDV uses a very limited presence of HBV or alternative ways which are not efficient enough for envelope production. These data suggest that, particularly in HDV positive patients, antiHBs Ig administration, which has previously been proven to significantly reduce HBV reinfection in HBsAg-positive patients, may be useful in changing the natural history of repetition of the original viral infection and liver disease after OLT.

We investigated the infection of peripheral blood mononuclear cells (PBMNC) by hepatitis C virus (HCV) in 5 patients with HCV-related chronic hepatitis. The presence of HCV-RNA-positive and -negative strands was tested with the polymerase chain reaction (PCR) method. In all subjects, HCV-RNA was shown in PBMNC. In 3 cases, HCV-RNA was shown in the T- and B-cell populations, with viral RNA also present in the monocyte-macrophage fraction of two of these. HCV-RNA-negative stranded molecules, indicative of the viral multiplication, were significantly increased in cells maintained in cultures with PHA/PMA stimulation. The results indicate that HCV infect blood mononuclear cells, thus suggesting that this cellular tropism may play a role in HCV infection.

We have investigated the extent of hepatitis delta virus (HDV) genetic variability after serial passages in chimpanzees and woodchucks and between different human isolates. A complete HDV genome, isolated from a woodchuck liver, was cloned after five serial transmissions. The 1679 nucleotide long genome revealed only point mutations and a nucleotide divergence of 0.65% and 0.89% with previously published sequences of two epidemiologically related HDVs. We have obtained partial nucleotide sequences of two unrelated human HDV cDNAs by using the polymerase chain reaction. When compared to the woodchuck HDV strain and other previously reported isolates, a perfectly conserved region of 90 nucleotides was shown in the region encompassing the delta antigen antigenomic self-cleavage site. In woodchuck and human HDV strains, the two forms of delta protein (195 and 214 amino acids) were potentially expressed. Our study indicates that only a limited genetic variability is generated by several passages in animals despite significant modification of pathogenicity during these transmissions.

We have investigated hepatitis B virus (HBV) infection in systemic necrotizing vasculitis (SNV). Our approach included the detection of the viral surface antigen (HBsAg) with a radioimmunoassay employing monoclonal anti-HBs (m-RIA); in addition, HBV DNA was looked for in serum and peripheral mononuclear blood cells. Among 28 subjects with SNV, 12 were found to be positive for HBsAg with the conventional test (p-RIA) and 7 additional subjects had anti-HBc and/or anti-HBs. From the 16 HBsAg negative individuals, 9 had HBsAg epitopes identified in serum with the m-RIA test and 1 had a low amount of circulating viral DNA. In contrast, only 1 among 6 subjects with other systemic vasculitis showed a positive test for m-RIA and HBV DNA assays; this individual had acquired HIV infection through transfusions which were also probably the source of his HBV infection. HBV DNA sequences were identified in peripheral mononuclear blood cells of 9 from the 37 tested, including 2 individuals who were HBsAg positive only with m-RIA. Therefore, our study indicates a much higher rate of HBV infection in patients with polyarteritis nodosa than previously suspected.

We have investigated the usefulness of serum hepatitis delta virus (HDV) RNA detection using a slot hybridization analysis of serum samples from ten patients with acute hepatitis and delta markers (group I), from 28 patients with chronic delta hepatitis (group II) and from seven liver graft recipients with hepatitis B virus (HBV) and HDV related cirrhosis or fulminant hepatitis (group III). The slot-blots were hybridized with both HDV-complementary DNA and single-stranded RNA probes. With the single-stranded RNA probe, HDV RNA was detected in the first serum sample available in 9/10 of the patients with acute hepatitis (group I). In addition, HDV RNA was detected in 8/9 and 7/8 of the samples obtained within and after 1 month of the onset of hepatitis. Five of the ten patients scored positive for HDV RNA and negative for hepatitis delta antigen (HDAg) while one was negative for HDV RNA and positive for HDAg. The same RNA probe enabled the detection of serum HDV RNA in 21/28 chronic hepatitis patients (liver HDAg and/or IgM anti-HD positive) (group II). Among the liver graft recipients (group III), 7/7 had a recurrent delta infection. Serum HDAg, liver HDAg and anti-HD IgM were identified in 3/7, 6/7 and 5/7 of the patients, respectively. HDV RNA was detected in the seven patients with either persistent (4/7) or transient (3/7) positivity. In addition, HBsAg and HBV RNA were persistently shown in 4/7 patients with continuous HDV replication. In the remaining three patients, HDV RNA was detectable despite the absence of HBsAg.(ABSTRACT TRUNCATED AT 250 WORDS)

We have investigated the recurrence of Hepatitis B virus (HBV) in 30 patients treated by orthotopic liver transplantation and given high doses of anti-HBs immunoglobulin. The polymerase chain reaction (PCR) assay showed no evidence of HBV DNA sequences in the liver of 23/24 patients who remained serum HBsAg-negative during a mean follow-up of 13 months (2-24 months) after OLT. However, the liver scored positive in all the 6 individuals in whom HBsAG reappeared. The PCR assay identified HBV DNA sequences in the peripheral blood mononuclear cells of 7 of 11 subjects who were serum HBsAG-negative and liver HBV DNA-negative by PCR. Therefore, this application of the sensitive PCR assay demonstrates persistent infection of PBMC in the absence of liver HBV--thus OLT provides a model for studying the interaction between HBV, PBMC, and the liver.

In this investigation we have evaluated the feasibility of using the polymerase chain reaction (PCR) for hepatitis delta virus (HDV) RNA detection, cloning and sequencing. Total RNA from HDV-infected liver and serum samples was purified and Moloney murine leukaemia virus (M-MLV) reverse transcribed. HDV cDNA was then directly amplified with Taq polymerase using three pairs of specific primers. It was possible to amplify a region of about 1200 bp in three partially overlapping fragments including the whole HDAg-ORF. A DNA fragment of the expected size was repeatedly obtained from an initial sample of less than 0.1 pg of liver RNA and from 10 pl of infected serum. An amplified fragment of 359 bp obtained by PCR from an infected woodchucks' liver was sequenced. The sequence was 91.8% and 98.6% identical to previously published HDV sequences. In addition, amplified and 32P-radiolabelled HDV sequences were shown to hybridize specifically to HDV RNA extracted from HDV-infected liver and serum. In conclusion this technique promises to be of great value in the appraisal of HDV infection, rapid synthesis of HDV probes and analysis of the genetic variability of the virus.