Margarita Pardo

Occult hepatitis C virus infection in patients in whom the etiology of persistently abnormal results of liver-function tests is unknown.

BACKGROUND There are patients in whom the etiology of long-standing abnormal results of liver-function tests is unknown (ALF-EU) after exclusion of all known causes of liver diseases. We analyzed the presence of hepatitis C virus (HCV) RNA in liver-biopsy specimens from 100 patients who were negative for anti-HCV antibodies and for serum HCV RNA and who had ALF-EU. METHODS HCV RNA status was tested by reverse-transcription polymerase chain reaction (RT-PCR) and by in situ hybridization, in liver and peripheral-blood mononuclear cells (PBMCs). RESULTS HCV RNA was detected in liver-biopsy specimens from 57 of 100 patients negative for anti-HCV antibodies and for serum HCV RNA (i.e., who had occult HCV infection). HCV RNA of negative polarity was found in the liver of 48 (84.2%) of these 57 patients with occult HCV infection. Nucleotide-sequence analysis confirmed the specificity of detection of HCV RNA and that patients were infected with the HCV 1b genotype. Of these 57 patients with intrahepatic HCV RNA, 40 (70%) had viral RNA in their PBMCs. With regard to liver histology, patients with occult HCV infection were more likely to have necroinflammatory activity (P=.017) and fibrosis (P=.022) than were patients without intrahepatic HCV RNA. CONCLUSIONS Patients with ALF-EU may have intrahepatic HCV RNA in the absence of anti-HCV antibodies and of serum HCV RNA.

In Situ Detection of Hepatitis C Virus RNA in Salivary Glands

Chronic hepatitis C virus (HCV) infection has been associated with several extrahepatic manifestations, among these, to diseases with oral manifestations such as Sjögrens 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 Sjögrens 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 Sjögrens 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 Sjögrens syndrome or chronic sialadenitis. However, its implication in the pathogenesis of these diseases deserves future research.

Hepatitis C virus replicates in peripheral blood mononuclear cells of patients with occult hepatitis C virus infection

Background: Occult hepatitis C virus (HCV) infection is characterised by the presence of HCV-RNA in the liver in the absence of anti-HCV, and serum viral RNA. Up to 70% of these patients also have HCV-RNA in peripheral blood mononuclear cells (PBMC) but it is not known if HCV is replicating in these cells. Aim: We studied possible HCV replication in PBMC of 18 patients with an occult HCV infection who were selected on the basis of HCV-RNA positivity in PBMC. Methods: Detection of HCV-RNA positive and negative strands in PBMC was done by strand specific reverse transcriptase-polymerase chain reaction (RT-PCR) and by in situ hybridisation. Results: The presence of HCV-RNA positive strand in PBMC was confirmed in all patients by strand specific RT-PCR and by in situ hybridisation. Mean percentage of PBMC which had the HCV-RNA positive strand was 3.3% (95% confidence interval (CI) 2.1–4.4) The HCV-RNA negative strand was found in the PBMC of 11/18 (61%) patients by strand specific RT-PCR and confirmed by in situ hybridisation, and the percentage of PBMC harbouring the HCV-RNA negative strand was 3.1% (95% CI 0.8–5.5). There was a significant correlation (p = 0.001, r = 0.84) between the percentage of PBMC with the HCV-RNA positive strand and that of PBMC with the HCV-RNA negative strand. Conclusion: HCV replicates in the PBMC of patients with occult HCV infection and thus, although these patients do not have serum HCV-RNA, they could be potentially infectious.

Detection of hepatitis C virus (HCV) RNA in the liver of healthy, anti-HCV antibody-positive, serum HCV RNA-negative patients with normal alanine aminotransferase levels

BACKGROUND It is unknown whether hepatitis C virus (HCV) is present in the liver of anti-HCV antibody-positive patients with persistently normal alanine aminotransferase (ALT) levels and undetectable serum HCV RNA levels. METHODS We determined the presence of genomic and antigenomic HCV RNA strands in liver biopsy specimens and peripheral blood mononuclear cell (PBMC) samples obtained from 12 anti-HCV antibody-positive patients who had normal ALT levels and who had been serum HCV RNA negative for at least 12 months, according to the results of quantitative, strand-specific, real-time reverse-transcription-polymerase chain reaction and, also, in situ hybridization of liver cells. Intrahepatic HCV RNA was cloned and sequenced. RESULTS All patients remained anti-HCV antibody positive and serum HCV RNA negative, and all had normal ALT values during follow-up (mean duration +/- SD, 29.2 +/- 19.8 months). Genomic HCV RNA was detected in liver biopsy specimens obtained from 10 (83%) of 12 patients, and the antigenomic strand was detected in 10 (100%) of 10 liver biopsy specimens in which genomic HCV RNA was detected. Results were confirmed by in situ hybridization. Intrahepatic HCV was of genotype 1b, and HCV sequencing demonstrated no cross-contamination among samples. Genomic HCV RNA was found in 6 (50%) of 12 PBMC samples, and antigenomic HCV RNA was also detected in 5 (83%) of these 6 PBMC samples. CONCLUSION HCV may persist and replicate in the liver and PBMCs of healthy, anti-HCV antibody-positive, serum HCV RNA-negative patients who have persistently normal ALT levels. These patients should be followed up, because they have an ongoing viral infection.

A phase I/II study of recombinant human interleukin-12 in patients with chronic hepatitis B*

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.

Cellular Immune Responses Associated with Occult Hepatitis C Virus Infection of the Liver

ABSTRACT Occult hepatitis C virus (HCV) infection is a type of recently identified chronic infection that is evidenced only by detection of HCV RNA in liver; patients consistently test negative for antibodies to HCV and HCV RNA in serum. Using ex vivo and in vitro measures of T-cell responses, we have identified functional virus-specific memory CD4+ and CD8+ T cells in the peripheral blood of patients with occult HCV infection. The features of the virus-specific T cells were consistent with immune surveillance functions, supporting previous exposure to HCV. In addition, the magnitudes of CD4+ and CD8+ T-cell responses were in parallel and correlated inversely with the extent of liver HCV infection. The detection of HCV-specific T cells in individuals in whom HCV RNA can persist in the liver despite the absence of viremia and antibodies indicates that HCV replication is prolonged in the face of virus-specific CD4+ and CD8+ T-cell responses. These findings demonstrate that HCV-specific cellular immune responses are markers not only of previous exposure to and recovery from HCV but also of ongoing occult HCV infection.

Serum levels of soluble immune factors and pathogenesis of chronic hepatitis C, and their relation to therapeutic response to interferon-α

To test the role of immune reactivity in the pathogenesis of hepatitis C, serum soluble immune factors were measured in a cohort of 57 patients with chronic hepatitis C, and in 20 healthy subjects. Levels of interleukin-1β, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-α, and interleukin-6 were detected in some, but not all, HCV patients and were in general undetectable in healthy subjects. Patients had significantly higher concentrations of neopterin (P=0.0026), β2-microglobulin (P=0.046), soluble interleukin-2 receptor (P=0.021), and soluble CD8 (P<0.039), than healthy controls; conversely, interferon-γ levels were significantly lower (P=0.023). Significant correlations were observed between β2-microglobulin concentration and Knodells index (r=0.638,P=0.00045), the score of piecemeal necrosis (r=0.572,P=0.0023), and the degree of fibrosis (r=0.527,P=0.0056). Interleukin-2 levels correlated significantly with Knodells index (r=0.412,P=0.037), and the degree of lobular cytolysis (r=0.389,P=0.048). According to therapeutic outcome, pretreatment levels of soluble CD8 were only significantly elevated (P=0.042) in patients with a sustained biochemical response. On interferon-α treatment, the levels of β2-microglobulin, neopterin, and soluble interleukin-2 receptor increased significantly (P<0.05), irrespective of therapy outcome. In summary, HCV patients have an altered immune reactivity that might play a role in the pathogenesis of chronic hepatitis C, and might influence the therapeutic outcome to interferon-γ.

Histological damage in chronic hepatitis C is not related to the extent of infection in the liver.

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.

Comparative study between occult hepatitis C virus infection and chronic hepatitis C.

Summary.  We have recently described the presence of occult hepatitis C virus (HCV) infection (HCV‐RNA in liver in the absence of anti‐HCV and serum HCV‐RNA) in patients with persistently abnormal liver function tests of unknown aetiology. The aim of this study was to compare the characteristics of patients with occult HCV infection vs those of patients with chronic hepatitis C. We compared clinical features of 68 patients with occult HCV infection and 69 untreated chronic HCV patients (anti‐HCV and serum HCV‐RNA positive), matched for age, gender, duration of abnormal liver function tests and body mass index. Aspartate aminotransferase and alanine aminotransferase were higher (P < 0.001) in chronic HCV, but cholesterol and triglycerides were significantly higher in patients with occult HCV infection (P < 0.001 and P = 0.002). Chronic HCV patients had higher gamma‐globulin (P = 0.005), alpha‐foetoprotein (P < 0.001) and iron (P < 0.001) levels. Percentage of patients with necroinflammatory activity and fibrosis was higher (P < 0.001) in chronic HCV than in occult HCV infection. Mean percentage of infected hepatocytes was higher (P = 0.001) in chronic HCV (10.1%) than in occult HCV infection (5.3%). This occult HCV infection is a milder disease than chronic HCV, and this could be related to the significantly lower number of infected hepatocytes observed in occult HCV.

Decreased nitric oxide production in chronic viral hepatitis B and C

Nitric oxide is a free radical gas molecule which may be implicated in antiviral defense. However, there is no information about its possible role in chronic viral hepatitis B and C. In this study we have analyzed the serum levels of NO2− (as an index of nitric oxide generation) from patients with chronic viral hepatitis B and C and relationship of same with the response to interferon therapy. Serum samples were analysed from 61 patients with chronic hepatitis B, 60 patients with chronic hepatitis C, 11 with chronic liver disease of nonviral origin, and 23 healthy controls. Levels of NO2− were statistically higher in healthy controls (P < 0.001) than in patients with chronic liver disease. No relation was found between NO2− and viremia or response to interferon therapy in patients with chronic hepatitis B. In contrast in chronic hepatitis C, responder patients had significantly higher NO2− than nonresponders (P < 0.01). With respect to the relation between NO2− levels and liver damage, patients with cirrhosis had lower NO2− levels than the rest of the patients (P < 0.001)2. In conclusion, patients with chronic viral hepatitis have low serum NO2− levels. J. Med. Virol. 51:326–331, 1997.