Teresa Cotonat

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.

Hepatitis E virus seroprevalence in acute viral hepatitis in a developed country confirmed by a supplemental assay

Hepatitis E virus (HEV) infection is prevalent among cases of acute viral hepatitis in young adults in developing countries. HEV infection is not restricted to endemic areas, but would appear to be worldwide in distribution. In order to document the incidence of HEV infection in acute hepatitis cases in a developed country, IgG and IgM anti‐HEV antibodies and HEV RNA were tested in 101 Caucasian patients with acute viral hepatitis; 92 of these cases had markers of acute viral hepatitis other than HEV. Forty‐seven (46.5%) cases had IgG anti‐HEV; IgM anti‐HEV and HEV viremia were not detected. As the incidence of anti‐HEV was higher than would be expected, the possibility of the occurrence of false positive results was subsequently investigated. Supplemental antibody testing, using a broadly reactive epitope region, reduced the frequency of anti‐HEV to 17%. Therefore, supplemental antibody testing confirms the hepatitis E virus seroprevalence in a developed country. Since IgM anti‐HEV and HEV viremia were not detected, persons with IgG anti‐HEV may be “subclinical HEV cases,” or have long‐lived antibodies in their circulation.

Analysis of hepatitis B precore region in serum and liver of chronic hepatitis B virus carriers

Using an oligonucleotide hybridization assay we studied the prevalence of wild-type and the predominant pre-core mutant hepatitis B virus in serum and liver of 49 antibody to hepatitis B e antigen carriers and three hepatitis B e antigen positive patients. Of the 45 serum samples from the anti-HBe carriers analyzed (no serum sample was available in four patients), 36 (80%) had hepatitis B virus DNA. In 26 of these 36 patients (72%) a mixed population was detected, wild-type genome alone was found in six patients (16%), the single mutant (nucleotide position 1896), in three cases (8%) and in one patient (2%) the viral DNA had the two nucleotide mutation (1896 and 1899). Of the liver biopsies from the 36 anti-HBe patients studied (no liver biopsy was available in 13 patients), 33 (92%) had hepatitis B virus DNA. A mixed viral population was detected in 23 patients (69%), only wild-type virus or a single mutation was found in eight (34%) and two patients (8%), respectively. In all cases, wild-type was the predominant genome. In serum and liver samples from the same patient, we found a concordance of the presence of wild-type HBV and the pre-core mutants studied in 23/26 (88%) of the patients. Alanine aminotransferase levels were higher (p < 0.01) and the duration of hepatitis B surface antigen carrier lower (p < 0.02) in patients with a predominance of precore mutant in comparison to wild-type.(ABSTRACT TRUNCATED AT 250 WORDS)

Impaired interferon induction of human MxA protein in chronic hepatitis B virus infection

MxA protein is interferon inducible, and its role as an antiviral mediator is being studied in various viral diseases. Several cytokines, including type I interferons (α and B), interleukins 2 and 12, and granulocyte, macrophage, and granulocyte‐macrophage colony‐stimulating factors, were tested for their ability to induce human MxA protein synthesis in peripheral blood mononuclear cells from 15 chronic hepatitis B virus‐infected patients and 6 healthy subjects as controls. Constitutive MxA expression was scarce in patients and controls but increased significantly in response to type I interferons. MxA responsiveness to interferon α was diminished significantly in chronic hepatitis B patients, compared with healthy donors (P < 0.05); this effect was more marked in patients with high viremia levels. Interleukins 2 and 12, and none of the colony‐stimulating factors tested, induced low, but detectable, MxA protein levels. These results indicate that chronic infection by hepatitis B virus may impair activation of the immune cells and their capacity to respond to type I interferons. J. Med. Virol. 51:332–337, 1997.

Analysis of the Hepatitis B Virus Precore and ORF-X Sequences in Patients With Antibody to Hepatitis B e Antigen With and Without Normal ALT Levels

Serum samples from 20 anti‐hepatitis B e antigen‐positive patients with and without normal alanine aminotransferase (ALT) levels who had serum hepatitis B virus (HBV) DNA detectable only by polymerase chain reation (PCR) were examined. Viral DNA was amplified by PCR, using primers that encompassed precore and ORF‐X regions and sequenced directly, to investigate whether mutations in the nucleotide sequences of X and precore gene regions of HBV‐DNA might be responsible for the difference in the activity of disease and in the levels of viral replication. The HBV‐DNA concentration in patients with abnormal ALT levels was higher than in those with normal ALT. The amount of HBV‐DNA correlated with the ALT levels (P < 0.05). Seventy‐two percent of patients had HBV‐DNA harboring the 1896 precore stop mutation, and there was a negative correlation between the percentage of precore mutant genotype and the HBV‐DNA concentration (P < 0.05). Thirty percent of patients had mutations in ORF‐X. Patients with ORF‐X mutations had lower levels of HBV‐DNA than those who had wild‐type virus. The presence of mutations in precore and X regions may be related to a low HBV‐DNA concentration and reduced biochemical activity in patients with anti‐HBe. J. Med. Virol. 56:294–299, 1998.

Activation of liver disease in healthy hepatitis B surface antigen carriers during interferon-alpha treatment

Fifty percent of healthy hepatitis B surface antigen carriers may have histologically proven chronic hepatitis. Our aim was to study the benefit of interferon‐alpha in healthy patients. Twenty‐nine hepatitis B surface antigen carriers with normal liver enzymes and with serum hepatitis B virus DNA were randomized into two groups: Group I, 14 patients treated with 9 megaunits of interferon alpha‐2a thrice weekly for six months, and Group II, 15 control patients. A liver biopsy was obtained from each patient at study initiation. A second biopsy was available in nine treated patients and six controls. During treatment, a significant increase in alanine amino transferase levels was observed in treated patients as compared with the controls (P < 0.05). After treatment, transaminase levels decreased to normal values. No differences between treated and control patients were observed in clearance of hepatitis B virus markers. A significant increase in the total histological activity index between base line and final liver biopsies was observed in treated patients (P < 0.05). It is concluded that interferon alpha treatment may induce a biochemical and histological activation of liver disease. Accordingly, interferon alpha should not be administered to healthy hepatitis B surface antigen carriers, at least with the schedule used in this work. J. Med. Virol. 53:76–80, 1997.

Significance of low HDV replication levels during the natural history of HDV infection: Long-term follow-up

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.