The prevalence, the epidemiology, the clinical and biochemical characteristics of hepatitis delta virus (HDV) infection were studied in patients with HBsAg-positive acute hepatitis, in those with chronic liver disease, and in apparently healthy carriers in Turkey.

The pattern of the immunoglobulin M antibody to the hepatitis delta virus distinguishes acute from chronic hepatitis D. Expression of the immunoglobulin M antibody to the hepatitis delta virus is relatively weak and short-lived in self-limited hepatitis but strong and persistent in chronic forms. To study the nature of the immunoglobulin M antibody to the hepatitis delta virus in acute hepatitis D and in chronic hepatitis D, antibody-positive sera were submitted to rate zonal centrifugation to separate monomeric 7S from pentameric 19S immunoglobulin M antibodies. Sera were from 6 patients with acute self-limited hepatitis, 4 patients with chronic hepatitis D, and 6 patients with hepatitis D progressing to chronicity. The immunoglobulin M reactivity was measured by a specific immunoassay based on capture of μ-chains by anti-μ linked on a solid phase. Only 19S antibody was found in acute hepatitis D. In contrast, all patients with chronic hepatitis D circulated 7S antibody in addition to the 19S antibody. In patients with progressive hepatitis D, both the 7S and 19S antibody variants were present at the onset of the disease. The difference in the antibody response between acute hepatitis D and chronic hepatitis D is not only temporal and quantitative but also qualitative. The expression of 7S antibody seems to be an immunologic event specific for chronic hepatitis D.

In a multicentre trial, 82 patients known to be hepatitis B e antigen and hepatitis B virus DNA positive for at least 1 year, with elevated serum alanine aminotransferase levels and chronic liver lesions on biopsy, were randomized to receive either recombinant interferon alfa-2a at a dose of 4.5 million units thrice weekly for 4 months or no treatment. At the end of therapy, viral DNA clearance and aminotransferase normalization were significantly (p < 0.05) more frequent in treated patients than in controls. After 16 months' follow up, the difference was still significant for hepatitis B e antigen clearance and transaminase normalization. Hepatitis B virus DNA reactivation was observed during follow up in 43% of treated patients and 50% of controls. Improvements in liver inflammation were observed in patients on interferon. High pre-treatment serum aminotransferase levels, female sex and a low score for fibrosis in the initial biopsy were predictive factors significantly (p < 0.05) associated with termination of hepatitis R virus replication in treated cases. These results indicate that interferon is effective in inducing clearance of HBV from serum and improvement of biochemical and histological parameters of liver disease. However, a more prolonged regimen of therapy may be required to obtain stable suppression of hepatitis B virus replication.

L'interference de l'infection par le virus delta de l'hepatite sur la replication du virus de l'hepatite B pourrait etre responsable de la frequence plus grande que prevue de l'hepatite B dans HBsAg

We describe here two cases of delta hepatitis (a coninfection and a superinfection) presenting as acute HBsAg-negative hepatitis. The first patient, a parenteral drug abuser, had a biphasic course of the disease, with HBsAg detectable transiently only during the relapse. Testing for delta markers on stored sera gave evidence of HBV/HDV coinfection. The other patient, a hospital nurse, chronic asymptomatic carrier of HBsAg, developed fulminant hepatitis with the transient appearance of antibody to HBsAg. She survived massive liver necrosis, and serological analysis of HDV markers documented a hepatitis delta virus superinfection. These cases demonstrate the possible substantial repression of HBV gene products exerted by the replication of delta virus, with a likely misdiagnosis if delta markers are not determined in serial serum samples.

Of 377 cases of fulminant hepatitis in persons positive for hepatitis B surface antigen (HBsAg) in Greece, Italy, the United States, the United Kingdom, the Central African Republic, Taiwan, Egypt, and India, only 52% could be attributed to infection with hepatitis B virus, which was defined as the presence of the IgM antibody to the hepatitis B core antigen (IgM anti-HBc) and the absence of serum markers of infection by extraneous viruses. Thirty percent of cases were caused by coinfection with hepatitis B virus and hepatitis delta virus or by infection with hepatitis delta virus superimposed on carriers of chronic HBsAg. In 18.5% of the patients, the absence of IgM anti-HBc indicated that they were not known to carry HBsAg, but no obvious superimposed factor of hepatitis could be identified. The cause of fulminant hepatitis is complex, and major risk factors are a pre-existing HBsAg state and hepatitis delta virus infection. Superinfection of HBsAg carriers by non-A, non-B viruses seems to be the cause in a consistent proportion of cases.

Sera from 74 hepatitis B surface antigen-positive individuals, who presented with acute hepatitis delta virus (HDV) infection which ran a self-limited course in 58 and progressed to chronicity in 16, were tested over time for HDV markers. In self-limited disease the serum pattern varied from early HD-antigenaemia followed by IgM and IgG anti-HD seroconversion, to the appearance of IgM and IgG anti-HD without antigenaemia, or the isolated expression of either the IgM or the IgG antibody. The typical case of IgM anti-HD was transient and appeared with a mean delay of 10-15 days from admission in the different serological subgroups. The IgG antibody usually developed several weeks later during convalescence. In contrast, patients with disease destined to become chronic had a brisk IgM antibody response and IgG anti-HD was detectable with a mean delay of 15 days; generally, the IgM and the IgG antibody persisted over the follow-up time. IgM antibody to HDV is often the only serological test positive in the clinical stage of hepatitis D and repeated testing for this marker is necessary to diagnose acute HDV co-infection. The serological follow-up provides important prognostic information: waning of IgM confirms resolution of HDV infection, persistence predicts chronicity.

Serum or liver markers of hepatitis delta virus (HDV) infection were found in 20 of 22 (90%) Italian patients presenting with an ostensible type B hepatitis that ran an accelerated course to cirrhosis. The features of the illness conformed to a syndrome of HDV infection in young males carrying the hepatitis B surface antigen (HBsAg); a latent HBsAg state was documented in many patients by a history of prior exposure to the hepatitis B virus (HBV) or by the absence of IgM antibodies to the HB core antigen. Characteristic of the disease were the clinical overture as a severe hepatitis, the lobular involvement by an extensive necroinflammatory reaction, the exuberant expression of intrahepatic hepatitis delta antigen and an atypical HBV profile of inactive infection or accelerated seroconversion from HBeAg to anti-HBe. Superimposed upon HBV infection, HDV may create a rapidly progressive course which resembles very aggressive hepatitis B but is infrequently observed in hepatitis B alone.