Immunopathologic aspects of the HBsAg carrier state in chimpanzees

The tissue distribution of hepatitis B virus antigens was correlated with the distribution of immunoglobulins and complement and with histopathological changes. Although no circulating antibody was detected, the participation of humoral immune mechanisms in the elimination of HBsAg from the circulation was suggested by presence of HBsAg, immunoglobulins, and C'3 in germinal centers of mesenteric lymph nodes and HBsAg mixed with immunoglobulins in the mesangium of kidney glomeruli. The results support the hypothesis that the immune status of HBV chimpanzee carriers is associated with hyporesponsiveness rather than tolerance.     

Immune complexes with cationic antibodies deposit in glomeruli more effectively than cationic antibodies alone

In previously published studies, highly cationized antibodies alone and in immune complexes bound to glomeruli by charge-charge interaction, but only immune complexes persisted in glomeruli. Because normal IgG does not deposit in glomeruli, studies were conducted to determine whether cationized antibodies can be prepared which deposit in glomeruli when bound to antigen but not when free in circulation. A series of cationized rabbit antiHSA was prepared with the number of added amino groups ranging from 13.3 to 60.2 per antibody molecule. Antibodies alone or in preformed soluble immune complexes, prepared at fivefold or 50-fold antigen excess, were administered to mice. With the injection of a fixed dose of 100 micrograms per mouse, antibodies alone did not deposit in glomeruli with less than 29.6 added amino groups by immunofluorescence microscopy. In contrast, 100 micrograms of antibodies with 23.5 added amino groups in immune complexes, made at fivefold antigen excess, formed immune deposits in glomeruli. With selected preparations of cationized, radiolabeled antibodies, deposition in glomeruli was quantified by isolation of mouse glomeruli. These quantitative data were in good agreement with the results of immunofluorescence microscopy. Immune complexes made at 50-fold antigen excess, containing only small-latticed immune complexes with no more than two antibody molecules per complex, deposited in glomeruli similar to antibodies alone. Selected cationized antibodies alone or in immune complexes were administered to mice in varying doses. In these experiments, glomerular deposition of immune complexes, made at fivefold antigen excess, was detected with five- to 10-fold smaller doses than the deposition of the same antibodies alone. These studies demonstrate that antibody molecules in immune complexes are more likely to deposit in glomeruli by charge-charge interactions than antibodies alone.     

Hepatitis A and B: serologic survey of human and nonhuman primate sera

Sera of humans and seven species of nonhuman primates were tested by radioimmunoassay and enzyme immunoassay for the presence of hepatitis A antibody, hepatitis B surface antigen and antibody to hepatitis B surface antigen. The outcome of testing a total of 276 serum or plasma specimens was as follows: with the exception of squirrel monkeys (0%) and cotton-top marmosets (0%), a considerable percentage of all other species tested had detectable antibodies to hepatitis A virus: humans 45.9%, chimpanzees 36.6%, baboons 38.2%, vervets 57.9%, cebus monkeys 40.0% and common marmosets 50.0%. Only one human and two chimpanzees were carriers of hepatitis B surface antigen. Antibodies to hepatitis B surface antigen were detected in human (11.3%), chimpanzees (29.9%), baboons (36.2%) and squirrel monkeys (5%). Chimpanzees showed an increasing prevalence of antibodies to hepatitis A virus and hepatitis B surface antigen with age.     

Arthritis and Hepatitis

The evidence relating four clinically distinct rheumatologic syndromes to infection by the hepatitis B virus is reviewed. Acute hepatitis B is not infrequently heralded by a prodromal rash and rheumatoidlike polyarthritis. Chronic active hepatitis B more rarely is associated with transient arthritis or arthralgias. Polyarteritis nodosa may be a manifestation of hepatitis B infection in as many as 40 percent of cases, and recently the syndrome of “essential” mixed cryoglobulinemia has also been linked to infection with this virus. The finding of immune complexes of varying composition, sometimes with the viral antigen or its antibody (or both) contained in both the serum and synovial fluid suggests that these four syndromes are clinical manifestations of immune complex disease resulting from hepatitis B infection.     

Surface antigenic determinants of mammalian "hepadnaviruses" defined by group- and class-specific monoclonal antibodies

The hepatitis B-like viruses (human hepatitis B virus, woodchuck hepatitis virus, ground squirrel hepatitis virus, and duck hepatitis B virus) are hepatotropic DNA viruses which have been referred to collectively as "hepadnaviruses." Using a murine monoclonal antibody (101-2) to the surface antigen of woodchuck hepatitis virus, we have shown that the surface antigens of mammalian hepadnaviruses (HBsAg, WHsAg, and GSHsAg) are antigenically related via a common determinant (HV/101). Furthermore, analysis with other monoclonal antibodies to WHsAg revealed that WHsAg and GHsAg are antigenically distinct, although the antigens had more determinants in common with each other than with HBsAg. The hepadnavirus group-specific antibody (101-2) reacted with HBsAg subtypic variants in a group-specific rather than subtype-specific manner. In conjunction with observations with an HBsAg-specific, group-reactive monoclonal antibody (BX259), the present data suggest that there are at least two group-reactive epitopes of HBsAg: one which is virus specific (HBV/259) and one which is common to two other mammalian hepadnaviruses (HV/101).     

Detection of core antibody in hepatitis B infection.

Hepatitis B core antigen (HBcAg) is found on the decoated Dane particle and on a morphologically similar particle detected mainly in the nucleus of hepatocytes of patients with hepatitis B. HBcAg prepared from the liver of a chimpanzee infected with hepatitis B virus was used to test human serum for core antibody (anti-HBc) by complement fixation. Anti-HBc was found in serum collected from patients with hepatitis B in both the acute and convalescent stages, from carriers of hepatitis B surface antigen (HBsAg) and from patients with chronic liver or renal disease who were carriers of HBsAg. It was not found in patients with hepatitis A or infectious mononucleosis, or in healthy persons who were not carriers of HBsAg.     

An evaluation of elution techniques in the study of immune complex glomerulonephritis.

Antigen and antibody from glomerular immune complex deposits in rabbits with experimental bovine serum albumin-(BSA) induced chronic serum sickness (CSS) were quantitated in elutes from kidneys in which a portion of the antigen and antibody had been radiolabeled. The largest quantities of 125I BSA eluted with 1 M roprionic acid at pH 2.7 (86%) and 0.1 M borate buffer at pH 11.25 (80%). However, these buffers yielded less functional anti-BSA antibody than 0.02 M citrate buffer at pH 3.2 (344 mug/g kidney). Citrate buffer-eluted anti-BSA antibody was reactive in immunodiffusion, immunofluorescence, and radiolabeled BSA binding test systems, but complement fixation was impaired relative to chaotropic ion-eluted antibody. It was found that up to 75% of the eluted antibody was lost to further study by recombination with eluted BSA. This could be prevented by fractionation of the dissociated eluate before neutralization. IgG fractionated eluates were successfully fluorescein conjugated or radiolabeled for use as reagents. Elution of cryostat sections of CSS kidney was also studied; BSA, IgG, and complement (C3) eluted in parallel, and sub-microgram quantities of anti-BSA antibody were recovered.     

Serological relationship of woodchuck hepatitis virus to human hepatitis B virus.

Two antigenic systems of the woodchuck hepatitis virus have been identified. The relationship between viral antigens of the woodchuck hepatitis virus and the human hepatitis B virus was determined by using immunoprecipitation, hemagglutination, and immune electron microscopy techniques. Antigens found on the cores of the two viruses were cross-reactive. Lack of cross-reactivity between the surface antigens of the two viruses in immunodiffusion experiments suggested that the major antigenic determinants of the viral surfaces are different; however, results of passive hemagglutination tests indicated that there are common minor determinants. Nucleic acid homology, as measured by liquid hybridization, was found to be 3 to 5% of the viral genomes. The results of this study provide further evidence that woodchuck hepatitis virus is the second member of a new class of viruses represented by human hepatitis B virus. Since virus-infected woodchucks may acquire chronic hepatitis and hepatocellular carcinoma, these antigens and their respective antibodies will be useful markers for following the course of virus infection in investigations of the oncogenic potential of this class of viruses. The nucleocapsid antigen described may be a class-specific antigen of these viruses and, thus, may be useful in discovering new members of the group.     

Prevalence of hepatitis C virus antibody among healthy blood donors and non-A, non-B hepatitis patients in Thailand

With the antigen expressed in yeast from a cDNA clone encoding a non-structural region of newly discovered hepatitic C virus (HCV) genome, the prevalence of HCV antibody in people in Thailand was investigated. Antibody was detected in 2.6% of healthy blood donors and in 2.8% of healthy pregnant women. These prevalence rates were higher than those reported previously from Japan, USA and European countries. Among community-acquired, sporadic cases of acute and chronic non-A, non-B hepatitis, however, only 5.7% and 15.4% were shown to possess the antibody, respectively. Among hepatocellular carcinoma patients who were negative for hepatitis B surface antigen in the sera, 11.1% had antibody to HCV. These seroepidemiological data suggest that HCV plays an important role as an etiological agent in Thailand; however, other agents must also be involved in etiologic agents of viral hepatitis and chronic liver disease.     

中缅树鼩自然感染六种病毒的血清流行病学

中缅树鼩作为一种新型实验动物,在医学生物学上,尤其是病毒学方面的应用受到越来越多的重视.实验动物自身病毒感染会影响动物健康和干扰实验结果,甚至危害实验人员生命安全.所以,实验动物病毒检测一直是动物质量控制的重要部分.中缅树鼩研究迄今缺乏清晰的病毒自然感染资料.为调查中缅树鼩的病毒感染状况,采集野生俘获和人工繁殖的中缅树鼩血清样本272份,全部血清样本通过ELISA方法对乙型肝炎病毒(HBV)表面抗原,丙型肝炎病毒(HCV)总抗体,以及戊型肝炎病毒(HEV)、腺病毒(ADV)、单纯疱疹病毒1型(HSV-1)和2型(HSV-2)的IgG抗体进行了检测.结果表明,ELISA初筛HBV表面抗原有3份阳性样本,但通过乙型肝炎两对半定量检测进一步确认为阴性:抗HCV抗体和抗HEV、ADV、HSV-1 IgO抗体检测均为阴性;抗HSV-2 IgG检测有1份阳性样本.提示仪抗原或抗体血清学指标检测树鼩肝炎结果并不能反应个体携带病毒的状态,应该再进行病毒学指标确认.同时建议中缅树嗣繁殖群应进行HSV-2的筛选,以便杜绝和控制该病毒的感染.     

Spread of bloodborne viruses among Australian prison entrants.

OBJECTIVES--To assess spread of bloodborne viruses among prison entrants in Victoria, Australia. DESIGN--Voluntary confidential testing of all prison entrants for markers of exposure to bloodborne viruses with collection of minimal data on demography and risk factors over 12 months. SETTING--Her Majesty''s Prisons, Pentridge and Fairlea, Victoria, Australia. SUBJECTS--3429 male and 198 female prison entrants (> 99% of all prison entrants); 344 entered prison and were tested more than once. MAIN OUTCOME MEASURES--Prevalence and incidence of antibodies to HIV, hepatitis B, and hepatitis C viruses, and minimal data on risk factors. RESULTS--1562 (46%) gave a history of use of injected drugs, 1171 (33%) had antibody to hepatitis B core antigen, 1418 (39%) were anti-hepatitis C positive including 914 (64%) of the men who injected drugs, 91 (2.5%) were positive for hepatitis B surface antigen, and 17 (0.47%) were positive for antibody to HIV. Incidence rates for infection with hepatitis B and C virus were 12.6 and 18.3 per 100 person years, respectively; in men who injected drugs and were aged less than 30 years (29% of all prison entrants) these were 21 and 41 per 100 person years. Seroconversion to hepatitis B or C was associated with young age and shorter stay in prison. Only 5% of those who were not immune to hepatitis B reported hepatitis B immunisation. CONCLUSIONS--Hepatitis B and C are spreading rapidly through some populations of injecting drug users in Victoria, particularly among men aged less than 30 years at risk of imprisonment in whom rates of spread are extreme; this group constitutes a sizeable at risk population for spread of HIV. This spread is occurring in a context of integrated harm reduction measures outside prisons for prevention of viral spread but few programmes within or on transition from prisons; it poses an urgent challenge to these programmes.     

Extralymphatic virus sanctuaries as a consequence of potent T-cell activation

T helper cells can support the functions of CD8(+) T cells against persistently infecting viruses such as murine lymphocytic choriomeningitis virus (LCMV), cytomegalovirus, hepatitis C virus and HIV. These viruses often resist complete elimination and remain detectable at sanctuary sites, such as the kidneys and other extralymphatic organs. The mechanisms underlying this persistence are not well understood. Here we show that mice with potent virus-specific T-cell responses have reduced levels and delayed formation of neutralizing antibodies, and these mice fail to clear LCMV from extralymphatic epithelia. Transfer of virus-specific B cells but not virus-specific T cells augmented virus clearance from persistent sites. Virus elimination from the kidneys was associated with the formation of IgG deposits in the interstitial space, presumably from kidney-infiltrating B cells. CD8(+) T cells in the kidneys of mice that did not clear virus from this site were activated but showed evidence of exhaustion. Thus, we conclude that in this model of infection, site-specific virus persistence develops as a consequence of potent immune activation coupled with reductions in virus-specific neutralizing antibodies. Our results suggest that sanctuary-site formation depends both on organ anatomy and on the induction of different adaptive immune effector mechanisms. Boosting T-cell responses alone may not reduce virus persistence.     

IL-12增强HBV融合抗原DNA疫苗在小鼠诱导的细胞免疫应答

乙型肝炎病毒(hepatitis B virus,HBV)极易形成慢性感染,主要机制在于感染者不能产生强有力的细胞免疫应答以清除病毒[1].慢性HBV感染者体内虽然存在HBV抗原特异性T淋巴细胞,但对HBV抗原的反应性较低.研究发现,增强这类T淋巴细胞的反应性,可以促进HBV的清除[2].     

Prevalence and determinants of antibodies to hepatitis C virus and markers for hepatitis B virus infection in patients with HIV infection in Aquitaine. Groupe d'Epidémiologie Clinique du SIDA en Aquitaine.

OBJECTIVE: To evaluate the prevalence of antibodies to hepatitis C virus and serological markers for hepatitis B virus infection in patients with HIV. DESIGN: Cross sectional survey. SETTING: Aquitaine, southwestern France, 1991-94. SUBJECTS: 1935 HIV positive patients seen at least once since June 1991. MAIN OUTCOME MEASURES: Presence of antibodies to hepatitis C virus were detected by second or third generation enzyme linked immunosorbent assay (ELISA) and recombinant immunoblot assay (RIBA) and markers for hepatitis B virus detected by ELISA. RESULTS: The prevalence was 42.5% (823) for antibodies to hepatitis C virus, 56.4 (507) for antibodies to hepatitis B core antigen, 6.9% (133) for hepatitis B surface antigen, 30.2% (584) for antibodies to hepatitis B core and surface antigen with no detectable surface antigen, 26.2% (507) for antibodies to core antigen only, and 4.8% (92) for antibodies to surface antigen only. The prevalence of antibodies to hepatitis C virus was 86.1% (726/843) in subjects who had bloodborne HIV infection and 7.3% (66/899) in those with sexually acquired infection. The prevalence of markers for hepatitis B was higher among homosexuals than in the other groups of patients, except for antibodies to surface antigen alone. The relation between markers for hepatitis B and hepatitis C virus was negative among men but positive among women. CONCLUSIONS: The results favour the hypothesis that hepatitis C virus is sexually transmitted much less commonly than either HIV or hepatitis B virus.     

Detection of hepatitis B virus DNA in mononuclear blood cells.

The Southern transfer hybridisation technique was used to test mononuclear blood cells for hepatitis B virus DNA. Viral DNA sequences were detected in mononuclear cells of 10 out of 16 patients with hepatitis B virus infection and in none of 21 normal controls. Blood contamination was excluded by the absence of hepatitis B virus DNA in the corresponding serum samples in all cases. Free monomeric hepatitis B virus DNA was found in three patients positive for hepatitis Be antigen (HBeAg) and one positive for anti-HBe, and integrated hepatitis B virus DNA was present in four patients positive for anti-HBe. In two other patients the small size of the samples did not allow a distinction between free and integrated viral DNA. The state of the virus in the mononuclear cells seemed to correlate with the HBeAg or anti-HBe state, as has been noted in the liver. These results indicate that hepatitis B virus may infect mononuclear blood cells, thereby expanding the tissue specificity of this agent beyond the liver, as has been reported for pancreatic, kidney, and skin tissue. They also suggest that hepatitis B virus infection of mononuclear cells might be related to immunological abnormalities observed in carriers of the virus.     

Vaccine- and hepatitis B immune globulin-induced escape mutations of hepatitis B virus surface antigen

Hepatitis B virus surface antigen (HBsAg) vaccination has been shown to be effective in preventing hepatitis B virus (HBV) infection. The protection is based on the induction of anti-HBs antibodies against a major cluster of antigenic epitopes of HBsAg, defined as the 'a' determinant region of small HBsAg. Prophylaxis of recurrent HBV infection in patients who have undergone liver transplantation for hepatitis B-related end-stage liver disease is achieved by the administration of hepatitis B immune globulins (HBIg) derived from HBsAg-vaccinated subjects. The anti-HBs-mediated immune pressure on HBV, however, seems to go along with the emergence and/or selection of immune escape HBV mutants that enable viral persistence in spite of adequate antibody titers. These HBsAg escape mutants harbor single or double point mutations that may significantly alter the immunological characteristics of HBsAg. Most escape mutations that influence HBsAg recognition by anti-HBs antibodies are located in the second 'a' determinant loop. Notably, HBsAg with an arginine replacement for glycine at amino acid 145 is considered the quintessential immune escape mutant because it has been isolated consistently in clinical samples of HBIg-treated individuals and vaccinated infants of chronically infected mothers. Direct binding studies with monoclonal antibodies demonstrated a more dramatic impact of this mutation on anti-HBs antibody recognition, compared with other point mutations in this antigenic domain. The clinical and epidemiological significance of these emerging HBsAg mutants will be a matter of research for years to come, especially as data available so far document that these mutants are viable and infectious strains. Strategies for vaccination programs and posttransplantation prophylaxis of recurrent hepatitis need to be developed that may prevent immune escape mutant HBV from spreading and to prevent these strains from becoming dominant during the next decennia.     

乙型肝炎病毒相关性肾炎发病机制研究进展

乙型肝炎病毒相关性肾炎(hepatitis B virus-associated glomerulonephritis,HBV-GN)的发病机制尚未完全清楚,主要包括:①免疫复合物沉积介导的肾损伤是公认的主要发病机制。②乙型肝炎病毒(hepatitis B virus,HBV)直接感染肾脏,可原位表达其HBV抗原(HBAg)及其他产物介导肾损伤。③HBV感染后可导致宿主免疫功能缺陷,病毒不能被清除,体内持续存在的病毒可造成肾脏损伤迁延进展。④HBV基因变异可导致病毒致病力改变,并影响机体清除病毒。⑤遗传因素相关研究表明存在HBV-GN的易感基因。     

The epidemiological aspects of viral hepatitides in Estonia]

The etiological structure of viral hepatitides among the adult population of Tallinn and the occurrence of markers of hepatitis B and hepatitis C virus infections in medical workers, addict introducing drugs intravenously and hemodialysis patients were studied. Changes in the etiological structure of viral hepatitides were established: they took the form of a decrease in the level of hepatitis A morbidity and the considerable growth of the role of hepatitides B and C, as well as the newly detected circulation hepatitis D virus. About one-third in the structure of morbidity in viral hepatitides were hepatitis cases without markers of hepatitis A, B or C viruses (non-A, non-B, non-C). The highest rates of hepatitis B virus infection (78.9%) and hepatitis C virus infection (82.5%) were detected among drug addicts. Their level of HBsAg was 8.8%. In the group of medical workers, 25% of the examinees, i.e. every fourth person, had markers of hepatitis B virus, while antibodies to hepatitis C virus were detected in 5% of cases. Among hemodialysis patients these rates were 21.4% and 10.7% respectively.