Search

Background: Despite their ease of use, lateral flow immunoassays (LFIAs) often suffer from poor quantitative discrimination and low analytical sensitivity. We explored the use of a novel class of europium chelate-loaded silica nanoparticles as labels to overcome these limitations. Methods: Antibodies were covalently conjugated onto europium chelate-loaded silica nanoparticles with dextran as a linker. The resulting conjugates were used as labels in LFIA for detection of hepatitis B surface antigen (HBsAg). We performed quantification with a digital camera and Adobe Photoshop software. We also used 286 clinical samples to compare the proposed method with a quantitative ELISA. Results: A detection limit of 0.03 μg/L was achieved, which was 100 times lower than the colloidal gold-based LFIAs and lower than ELISA. A precise quantitative dose-response curve was obtained, and the linear measurement range was 0.05–3.13 μg/L, within which the CVs were 2.3%–10.4%. Regression analysis of LFIA on ELISA results gave: log (LFIA) = −0.14 log (ELISA) + 1.03 μg/L with r = 0.99 for the quantification of HBsAg in 35 positive serum samples. Complete agreement was observed for the qualitative comparison of 286 clinical samples assayed with LFIA and ELISA. Conclusions: Europium chelate-loaded silica nanoparticle labels have great potential to improve LFIAs, making them useful not only for simple screening applications but also for more sensitive and quantitative immunoassays.

The national hepatitis B vaccination program in Taiwan is considered one of the most successful and effective public health programs to control chronic hepatitis B infection in the past 20 years. This review illustrates how to implement a successful hepatitis B vaccination program based on Taiwan's experience. Several important controlled randomized clinical trials on hepatitis B immunoglobulin and vaccine in Taiwan demonstrated an 80-90% protective effect among infants of mothers who were positive for either hepatitis B envelope antigen or hepatitis B surface antigen. A series of prevalence surveys on children born before and after the national vaccination program began disclosed a steady decrease in seroprevalence of hepatitis B surface antigen in Taiwan, with 78-87% effectiveness after the national vaccination program was launched. Studies on the secular trend of liver disease risk also documented a 68% decline in mortality from fulminant hepatitis in infants and a 75% decrease in the incidence of hepatocellular carcinoma in children 6-9 years of age after the national vaccination program began. In conclusion, since 1984, the national hepatitis B vaccination program has been successful in preventing acute and chronic liver diseases in Taiwan.

The etiology of non-A, non-B hepatitis (NANBH) in renal dialysis patients was determined. Hepatitis C virus was present in many, but its appearance did not correlate with elevated alanine aminotransaminase. When sera from these patients were tested for antibodies against hepatitis B virus (HBV) X antigen and polymerase, 70% were positive. HBV infection was confirmed by polymerase chain reaction using several HBV-specific primer pairs. However, amplification with X region primers failed to yield products in many patients. Cloning and sequencing of these products demonstrated deletions within the X region. Hence, X-deletion variants of HBV are strongly associated with NANBH in renal dialysis patients.

SUMMARY Complement activation at a low temperature in vitro and cryoglobulinaemia are associated with hepatitis C virus (HCV) infection. The frequency of HCV antibody positivity determined in serum specimens that showed the cold-dependent activation of complement was 100%, whereas it was 48% among sera with cryoglobulin. On the other hand, the frequency of cold activation among HCV-infected sera was 41%, and that of cryoglobulin 48%. Cold activation was not found in any HCV− sera studied, whereas cryoglobulin was found at a frequency of 14% in HCV− sera. Cold activation was also absent among hepatitis B virus (HBV) S antigen or antibody-positive sera, except a few that were both HBV+ and HCV+. Rheumatoid factor was also frequently detected in sera with cold activation or cryoglobulin. Cold activation and cryoglobulin may be generated by common mechanisms in which a low avidity, low temperature-preferring antibody may function. In sera with cold activation, fine particles of immune complexes, which do not form precipitates, may activate the complement system. HCV is a unique virus that coexists with antibody in the serum, therefore the avidity of the antibody for the virus antigen may be low, and occasionally react only at a low temperature. This may be why the in vitro phenomenon related to immune complexes occurs specifically in HCV-infected sera.

Serum HBV DNA from infants and children with fulminant hepatitis B (FHB) or acute self-limiting hepatitis B (AHB) and patients believed to be contamination sources was amplified by polymerase chain reaction (PCR) followed by direct sequencing of the precore region. A precore mutation from G to A at nucleotide 1896 was found in 5 of 14 FHB patients and in 3 of 10 AHB patients. Among the 10 infants who developed hepatitis during the first 6 months of age, the precore mutation was detected in only 2 of 7 with FHB and in 1 of 3 with AHB. In 1 infant with FHB, a shift from wild type to precore mutant predominance occurred in the serum virus population during the incubation period. Thus, the precore mutation is neither necessary nor sufficient to cause FHB in childhood, although its contributory role cannot be excluded. Factors other than precore mutations may be important in the pathogenesis of FHB.

Hepatic cellular and subcellular expression of hepatitis B virus (HBV) antigens--HBsAg, HBcAg, and HBeAg--in 143 Chinese patients with chronic HBV infection were studied by immunohistochemical techniques. Nuclear expression of HBcAg and nuclear and cytoplasmic expression of HBeAg showed a secular trend decreasing from the carrier state and chronic persistent hepatitis (CPH), through chronic active hepatitis (CAH), to cirrhosis with or without hepatocellular carcinoma. In contrast, cytoplasmic HBcAg expression was significantly greater in patients with CPH and CAH (P < .0108). In addition, cytoplasmic HBcAg correlated significantly with lobular activity, portal inflammation, and hepatitic activity (P < or = .007). Expression of cytoplasmic HBcAg also exceeded cytoplasmic HBeAg and nuclear HBcAg in liver specimens showing significant damage (P < .038). HBsAg, however, showed no secular trend and was not related to liver histology. The authors' findings support the theory that HBcAg is also the viral target antigen for immune-mediated liver damage in Chinese patients with chronic HBV infection.

Studies were carried out to test the hypothesis that exposure to aflatoxin B1 (AFB1) is common among individuals with hepatocellular carcinoma (HCC) who are also chronically infected with hepatitis B virus (HBV). Experiments were also carried out to determine whether there is a close association between the presence of AFB1-DNA adducts and the expression of one or more HBV antigens in the tumor or non-tumor regions of the liver. Twenty-seven paired tumor and non-tumor liver tissues of HCC patients from Taiwan were analyzed. Monoclonal antibody 6A10, generated against the imidazole ring-opened persistent form of the major N-7 guanine adduct of AFB1, was used for adduct detection by both indirect immunofluorescence and competitive enzyme-linked immunosorbent assay. An avidin-biotin complex staining method was used for the detection of HBsAg and HBxAg in liver sections. A total of 8 (30%) HCC samples and 7 (26%) adjacent non-tumor liver tissue samples from Taiwan were positive for AFB1-DNA adducts. For HBsAg, 10 (37%) HCC samples and 22 (81%) adjacent non-tumorous liver samples were positive while 9 (33%) HCC samples and 11 (41%) adjacent non-tumor liver samples were HBxAg-positive. No association with AFB1-DNA adducts was observed for HBsAg and HBxAg. These results suggest that both AFB1 exposure and carrier status of HBsAg/HBxAg may be involved in the induction of HCC in Taiwan.

To reduce the transmission of non-A, non-B (NANB) hepatitis, the American Association of Blood Banks (AABB) has recommended that donors be screened for elevated levels of alanine aminotransferase (ALT) and for the presence of antibody to hepatitis B core antigen (anti-HBc). In this survey of 5,336 donors, the authors report the impact of using both of these surrogate tests on a heterogeneous donor population that was composed of white, black, Hispanic, and Asian donors. Hispanic and male donors had relatively high ALT levels, and black and Asian donors had a higher prevalence of anti-HBc than their respective counterparts. The overall impact of using both surrogate tests resulted in a discard rate of 12.1% with a disproportionately high percentage of Hispanic and male donors excluded because of ALT testing and black and Asian donors because of anti-HBc testing. It appears that surrogate testing has a much greater impact on blood collection facilities that rely considerably on Hispanic, Asian, black, or male donors than those that largely draw white or female donors.

A study of 157 randomly selected pregnant women from Aligarh India determined that 16 (10%) were positive for hepatitis B surface antigen (HBsAg); 12 (75%) women also had circulating hepatitis B (HBc) antibodies. 15 of these women developed hepatitis B infection in the third trimester of pregnancy. All neonates born to infected women were screened for hepatitis markers: eight (5%) were HBsAg-positive and seven (88%) also had anti-HBc suggesting active in utero infection. Hepatitis B transmission was significantly higher (p < 0.001) in infants delivered vaginally compared to cesarean section infants. Of the eight infants who acquired in utero infection one was stillborn and another had anencephaly and spina bifida. The risk of maternal transmission of hepatitis B virus has been estimated in other studies at 80-90%; more than 85% of these infants become chronic HBsAg carriers.

We investigated hepatitis B virus (HBV) DNA in liver samples from 22 patients with acute benign hepatitis (AH) and 26 with acute fulminant hepatitis (FH) and compared the results with those obtained by detection of serum HBV DNA and HBV serological markers. Free HBV DNA forms were detected in 11 patients with AH and one with FH, a reflection of active HBV DNA replication in three patients and the end of viral multiplication in nine. Free monomeric HBV DNA was present in three patients with AH and six with FH, and free oligomers were identified in three patients with AH. Results from two patients with AH and seven with FH suggested the presence of dimeric or multimeric HBV DNA. Thus, the various forms of HBV DNA previously described in chronic HBV carriers may be observed at the acute stage of the viral infection. After comparing serological and hybridization data, we found that nine of 19 patients (one with AH and eight with FH) lacking serum HBV surface antigen might have had acute hepatitis related to infection with HBV or HBV variants.

Since the original observations by Blumberg [1] and Prince [2] that indicated the presence of a unique antigen in the circulation of individuals with viral hepatitis type B, the hepatitis B virus (HBV) and a number of virus-specific by-products have been identified [3-15]. Electron microscopy revealed the presence of three major morphologic forms in varying ratios in infected blood; these forms included (1) spherical particles with a diameter of approximately 22 nm; (2) filaments with a diameter of 22 nm and an average length of 200-400 nm; and (3) double-membraned, virus-like particles with a diameter of approximately 42 nm, which have been termed Dane particles (figure 1, top) [3-6]. Purified 22-nm particles are shown in the lower left portion of figure 1. The inner core of the Dane particle or nonenveloped cores derived from nuclei of infected liver have a diameter of 24-27 nm (figure 1, lower right) [4, 11, 16, 17]. A schematic illustration of the components of the coat protein and of Dane particles is shown in figure 2 [18]. The antigenic determinants of the 22-nm spheres, the filaments, and the envelope of the Dane particle are related and are collectively termed hepatitis B surface antigen (HB, Ag). Further analysis of HB, Ag reveals that it is com

Hepatitis B surface antigen (HBs Ag) was not detected in sewage by means of a sensitive affinity chromatography method combined with radioimmunoassay. The antigen was also absent from the feces and urine of 23 patients with HBs Ag antigenemia; this observation indicates that HBs Ag is rarely discharged into sewage. The absence of HBs Ag from feces is ascribed to antagonists of an enzymatic nature or to carboxypeptidase A, which destroys the antigen. Antagonists with similar effects were produced by three species of Pseudomonas but were not produced by various other bacteria. HBs Ag was also destroyed by two subtilisin enzymes. When hepatitis B sera were incubated with these enzymes or with the antagonists, small spherical particles, tubules, and the coats of Dane particles disappeared first, and Dane cores disappeared later. Although sewage or activated sludge did not affect the stability of HBs Ag, the results indicate that even Dane cores are not excreted in feces and that sewage plays a negligible role in the spread of HBs Ag, Dane cores, and viral hepatitis type B.

A simple, rapid hepatitis B antigen card test (card test III) with third-generation sensitivity has been developed. This test is a modification of the charcoal-particle agglutination-inhibition procedure. Sera from voluntary blood donors and hospital patients were tested by the new procedure, by the original inhibition technic, by reversed passive hemagglutination, and by radioimmunoassay. This comparison showed that CT III has a specificity equal to that of radioimmunoassay and is almost as sensitive.

subtyped; 66 (54%) were of the ad type and 56 (46%) of the ay type. "Cluster" cases (from a dialysis unit) were not considered. During the first period, subtype ad predominated, whereas in the second year there was a clear predominance of the ay subtype; the difference was statistically significant (P < 0.02). In yearly periods the differences were significant between the years 1970 and 1974 (P < 0.05), 1972 and 1974 (P < 0.05), and 1972 and 1973 (P < 0.05). If only patients without parenteral exposure are considered, there was clearly a shift between 1970-1972 and 1973-1974 in favor of the ay subtype (P < 0.01). Since epidemiological factors such as injections and transfusions seem not to be responsible, it is suggested that a change of virus strain may be responsible for the different distribution of subtypes of hepatitis B surface antigen in the last year. Heterogeneity of the hepatitis B surface antigen (HB, Ag) may indicate the complex constitution of the virus [1]. Striking geographical differences exist in the distribution of the two major antigenic determinants, ay and ad [2]. In the eastern Mediterranean area subtype ay seems to predominate [3, 4], but in the western Mediterranean area both subtypes are distributed similarly [5]. Epidemiological factors are considered responsible, although the evidence is not conclusive [6]. It has also been suggested that a change of subtype may occur in the future [7]. We report such a change in the subtype of acute type B hepatitis during a five-year period in the area of Barcelona, Spain.

A prevalence serosurvey was performed on an 11.7% sample of the 6,503 adult male inmates in Tennessee prisons. On the basis of the sample, 0.9% of the prisoners possessed hepatitis B surface antigen, and 29.5% had one or more serum markers for hepatitis B virus (HBV). Thirty-two possible risk factors were analyzed for association with possession of HBV serum markers. The significant risk factors for possession of HBV markers in this population were found to be age, intravenous drug use while not incarcerated, intravenous drug use while incarcerated, race, education, military service history, and duration of prior and current imprisonments, in that order of importance. Given the modest contribution of incarceration to overall risk, mass immunization of prisoners against HBV seems unwarranted. Prisoners with unusually long sentences or who use intravenous drugs in prison are subgroups at particularly high risk. The logistic model can be used to target a serological screening and immunization program.

Antibody to hepatitis B core antigen in the sera of 10 patients with acute viral hepatitis B, 20 patients with chronic hepatitis B, and 30 carriers of chronic hepatitis B surface antigen was assayed by the indirect immunofluorescence test. The activity of antibody to hepatitis B core antigen in the sera of these three groups of patients was identified as belonging to immunoglobulin classes G, M, A, and D. Antibody to hepatitis B core antigen was predominantly of IgG and IgM classes in all three groups of patients.

Between August 1972 and January 1974, the Burear of Biologics distributed four panels of 20 coded serum samples to all federally licensed blood banks for hepatitis B antigen testing. Initially, all but six blood banks reported results by counterelectrophoresis (CEP) only, but by January 1974, 152 of 247 banks reported results by radioimmunoassay (RIA). On the four panels distributed, correct results were reported for 63 to 83% of all potentially detectable samples by CEP and for 98 to 100% of all samples potentially detectable by RIA. Perfect scores were obtained by only 5 to 25% of blood banks using CEP but by 77 to 100% using RIA. Nonreproducible results on duplicate reactive samples, included to evaluate internal consistency, ranged from 0.5 to 25% by CEP and from zero to 5% by RIA. These results demonstrate greater reliability in addition to greater sensitivity of "third generation" RIA testing in comparison with "second generation" CEP testing.

A sensitive red cell agglutination (RCA) method for the detection of hepatitis B antigen (HB Ag) was adapted for subtyping. The technique used human type O, Rh-negative erythrocytes stabilized with pyruvaldehyde and formaldehyde and coated with IgG containing monospecific anti-d or anti-y hepatitis B antibody prepared from antiserum produced in guinea pigs. Optimal coating of stabilized erythrocytes occurred at 25 C and at pH 4.0 with a concentration of IgG of 0.25-0.5 mg/ml and a 60-min incubation period. The coated cells were stable for at least one month when stored at 4 C or for at least four months when frozen at -70 C or -196 C. The RCA test was conducted at 25 C and read after 3 hr. Nonspecific agglutination was not observed at serum dilutions of > 1:10. Results were verified by agar gel diffusion or by a more sensitive double antibody radioimmunoassay method that was modified to detect subspecificities of HB Ag. HB Ag endpoint titrations can be obtained within 3 hr, and the test is 100to 200-fold more sensitive than the agar gel diffusion technique.

The diagnostic and epidemiologic significance of antibody to hepatitis B core antigen (anti-HBc) detected by complement fixation was studied in a sample of 412 healthy persons, 0-70 years old of both sexes living in the Athens area. The prevalence of hepatitis B virus (HBV) infections was found to be very high (26.5%) and the hepatitis B surface antigen (HBsAg) carrier rate (4.1%) among the highest in Europe. Anti-HBc was detected in 63 (15.3%) of the examined infection. The prevalence of anti-HBc (without HBsAg or anti-HBs) increased with age, while the HBsAg carrier rate declined in older age groups. It was also found that the frequency of anti-HBc persists for a shorter period than the anti-HBs after HBV infection. These data stress the importance of anti-HBc testing in increasing the sensitivity of the detection of potentially infective HBV carriers as well as in studying various epidemiologic aspects of HBV infection.

Delayed hypersensitivity to hepatitis B surface antigen (HBAg) in patients with disease from the clinical spectrum of hepatitis and in controls was examined by an indirect assay of macrophage migration inhibitory factor. Activity was demonstrated in cases of acute or persistently active hepatitis. Steroids and pregnancy had a suppressive effect. Samples from a patient with transfusion-related HBAg hepatitis were also assayed. A broad clinical spectrum of disease is associated with the presence of hepatitis B surface antigen (HBAg) in the blood. It has been suggested that the host's immune response is related to the clinical type of disease [1-4]. Delayed hypersensitivity, a cellular immune response to antigenic stimulation, is recognized as an important immunological phenomenon in the pathogenesis and/or prevention of many diseases. Skin testing has been the classical method of studying delayed hypersensitivity to many anti

The relative sensitivities of radioimmunoassay, crossoverelectrophoresis, and agar gel immunodiffusion for detecting HBAg in unconcentrated versus concentrated serum samples are compared and discussed. The sensitivities of the various immunologic methods were enhanced severalfold in concentrated serum samples. This is a fundamental consideration in designing a screening program for detecting HBAg and anti-HBAg antibody in hospital patients and donors. The authors propose that serum samples that have marginal reactions or low counts (RIA) be concentrated with Lyphogel or MiniconTM-125 concentrator and retested before test results are reported. Specificity of positive results was studied by neutralization tests with human serum containing antibodies to HBAg.

One hundred fifty asymptomatic patients who were carriers of hepatitis B surface antigen (HBsAg) were studied serologically for up to 11.3 years (mean, 6.1 years). Only 9 (6.0%) lost HBsAg during the study period, for a mean annual clearance rate of 1.0%. We found no difference in the clearance of HBsAg by age, but a higher percentage of females lost HBsAg than did males (P less than .02). Hepatitis B e antigen (HBeAg) was found in 102 (68.5%) of the 149 carriers of HBsAg who were tested. Carriers of HBsAg who were seropositive for HBeAg were younger than those who were seronegative for HBeAg (P less than .01). The prevalence of HBeAg was not affected by the patients' sex. The clearance of HBeAg was gradual; 9.6% of the HBsAg carriers lost HBeAg each year. Females were more likely to clear HBeAg than were males (P less than .01), and those who cleared HBeAg were older than those who did not (P less than .01). Three (2.0%) of the HBsAg carriers developed primary hepatocellular carcinoma during the study period.

Sera collected in 1973-1975 from 3053 residents of 12 selected Alaskan Eskimo villages were tested for evidence of hepatitis B virus infection. Overall, hepatitis B surface antigen (HBsAg) was found in 6.4% of those tested. Evidence of hepatitis B infection (positive for HBsAg or antibody to hepatitis B surface antigen (anti-HBs] varied considerably by village, from 4.6% to 69.9%, and increased with advancing age. The proportion with HBsAg was significantly higher in those under the age of 13 years, and the male/female ratio varied from 0.9 to 1.5 to 1.5 in the prepubertal, postpubertal-premenopausal, and postmenopausal age groups, respectively. The prevalence of hepatitis B e antigen (HBeAg) in HBsAg-positive persons decreased with advancing age, and conversely, the prevalence of antibody to hepatitis B e antigen (anti-HBe) increased with age. Hepatitis B infection was found to be sporadically distributed, with great village-to-village variation and further variation by household within most villages. The high HBsAg and HBeAg seropositivity observed in children suggests that children are both more recently infected with hepatitis B and are more involved in hepatitis B transmission in these villages.

Hepatitis B (HBV) markers were studied in 710 subjects who had been on active duty for over 6 months in the Italian Armed Forces. The prevalence of HBsAg carriers was found to be 4.4%, while 31.6% of the subjects were positive for various HBV antibodies. A total of 137 subjects were vaccinated with an anti-HBV vaccine (HB-VAX, MSD). The percentages of non-responders and low responders were 13.86% and 13.14%, respectively. Boosters administered 3 months post-vaccination schedule, with or without immunostimulatory treatment, resulted in seroconversions and/or substantial increases in HBsAb levels in 50% of these subjects.

The distribution of hepatitis B surface antigen and antibody (HBsAg and anti HBs), hepatitis B core antibody (anti-HBc), and the heaptitis B associated "e" antigen-antibody system (HBeAg and anti-HBe) were studied in three areas in Greenland previously shown to be endemic for hepatitis B. Overall prevalence of HBsAg and anti-HBs ranged from 47 - 81%, thus confirming the existence of a hyperendemicity of the hepatitis B agent in some polar areas. Anti-HBc occurred closely correlated to HBsAg and anti-HBs but appeared to be a less sensitive indicator of previous infection. HBeAg and anti-HBe were found in HBsAg-positive sera only. The presence of HBeAg correlated to a high titer of HBsAg and to young age and it occurred more frequently in east coast than in northwest coast Greenlanders. The "e"-antibody in contrast prevailed in old age groups and in sera with a low titer of HBsAg.

Partially purified hepatitis B e antigen (HBeAG) was prepared by ultracentrifugation, ammonium sulfate precipitation, and molecular sieve chromatography of sera obtained from asymptomatic carriers of hepatitis B surface antigen. The antigenic specificity of the HBeAG preparations was investigated further with affinity chromatography. The results indicated that HBeAG is distinct and separable from DNA polymerase activity. Columns coupled with either goat IgG prepared from antiserum to human IgG or antibody to HBeAg bound all detectable HBeAg and bound 31% and 100% of the IgG, respectively, from a partially purified HBeAg preparation. Rate zonal sucrose sedimentation and molecular sieve and ion-exchange chromatography indicated a variability in molecular weight and charge; this finding suggested a heterogenous population of immunoreactivities containing HBeAg. Our preliminary results suggest the existence of an HBeAg-IgG complex.

Tissue sections from 42 specimens of liver were examined by indirect immunofluorescence microscopy for the presence of hepatitis B antigen (HB Ag). In all cases the serologic status of HB Ag was known. Fourteen of the specimens were also examined by electron microscopy. In four biopsies from three patients positive cytoplasmic fluorescence was detected using antisera prepared in animals and 20-nm. nuclear particles were found by electron microscopy. These patients were all seropositive for HB Ag, all had chronic aggressive hepatitis or active cirrhosis, and all were receiving immunosuppressive therapy at the time of examination. Nuclear fluorescent staining was demonstrated when one of these biopsies was re-examined using a human antiserum.

Hepatitis B virus markers were studied in 2,842 Philippine rural subjects from four villages in 1979-1982. The prevalence of hepatitis B surface antigen (HBsAg) and all markers for hepatitis B virus averaged 12% and 58%, respectively, in these rural populations. It is estimated that five million Filipinos are HBsAg positive. The rural age-specific HBsAg prevalence shows an "early peak" (in persons 3-4-years-old) in two communities and a "late peak" (in persons 30-40-years-old) in the other two communities. Family studies suggest that the prevalence of HBsAg and hepatitis B e antigen (HBeAg) among parents of the young children in an "early peak" and a "late peak" village cannot fully account for the difference in the patterns of prevalence of all markers, or the HBsAg marker. Horizontal intrafamilial and extrafamilial transmission may also be significant. Further research is needed on risk factors for hepatitis B virus infection.

Thirty-four chimpanzees were inoculated with sera containing the adw, ayw, adr, or ayr subtype of hepatitis B surface antigen (HBs Ag). Twenty-nine of the animals became infected with hepatitis B virus, and in every instance the subtype of HBs Ag in the infected animal was the same as the subtype in the inoculum. Infectivity titers were established for the adw and ayw inocula. The patterns of serologic events varied in the infected animals but included most of the typical patterns of serologic change seen in human cases of type B hepatitis. Mild disease, manifested by elevated concentrations of serum enzymes and changes detected by liver biopsy, occurred in 23 of the 29 infected animals.

The relationship of e antigen (eAg) and its antibody (anti-e) to vertical transmission of hepatitis B surface antigen (HBsAg) from chronic asymptomatic HBsAg carrier women to their children was investigated in Taiwan. Sera from 20 of the 62 women studied were positive for eAg (32%); serum from only one woman was positive for anti-e (2%). A total of 85% of the babies born to eAg positive mothers became HBsAg carriers, while only 31% of the babies became carriers when the mother was eAg negative. Maternal e antigenemia correlated with a high HBsAg titer, and both parameters were equally good predictors of vertical transmission.

A sustained outbreak of viral hepatitis occurred at an Army base in Texas between January 1971 and June 1973. Seven hundred ninety-two admissions but no deaths were recorded in a military population of 35,000. Cases were sporadic, with highest attack rates in low-ranking soldiers with disciplinary problems. Twenty-nine per cent of patients had histories of intravenous drug use within six months prior to hospitalization; most of the rest had close personal contact with jaundiced persons. Of 505 patients tested, 31% were seropositive for hepatitis B antigen (HBSAg) by counterelectrophoresis. Comparison of 38 hepatitis patients (cases) to 34 orthopedic patients (controls) revealed marked differences in rates of exposure to jaundiced persons are shared needles. Sixteen (94%) of 17 antigenemic cases tested were of subtype ayw. Seven (78%) of nine NBSAg-negative cases tested were antibody (anti-HBS) positive three months later.

Discordant results for e antigen, DNA polymerase activity, and Dane particle frequency were noted in the sera of two patients representing an index case-contact case pair with chronic aggressive hepatitis B. The lack of correlation between presence of e antigen and the infecting viral strain, as well as the strong relationship of e antigen to persistent and significant viremia, emphasize the role of the host's immune response in the expression of this antigen.

Inoculation of hepatitis B surface antigen (HBsAg)-positive sera from patients with chronic liver disease and intrahepatic delta (delta) into chimpanzees susceptible to infection with hepatitis B virus (HBV) resulted in type B hepatitis and delta markers (delta antigen and antibody to delta) in recipient animals. A dilution (10(-8)) of serum induced type B hepatitis without delta markers in another HBV-susceptible animal. HBV infection and delta markers did not develop in animals with preexisting titers of antibody of HBsAg. In chimpanzees with circulating HBsAg at the time of inoculation, synthesis of delta occurred earlier and its extent and duration were greater than in animals previously unexposed to HBV; coincident with synthesis of delta, hepatitis occurred in chronic HBsAg carriers, and synthesis of preexisting HBV gene products (HBsAg and hepatitis B core antigen) was diminished. Delta appears to be a marker of a transmissible pathogenic agent, either an HBV variant or another agent that requires the helper functions of HBV, that is defective and interferes with HBV replication.

Hepatitis B e antigen (HBeAg) was detected by agar gel diffusion in the serum of four Ugandan adults (three patients with tropical splenomegaly syndrome and one healthy adult) who did not have detectable hepatitis B surface antigen (HBsAg) by radioimmunoassay. Two of them had antibody to hepatitis B core antigen, and the other two had antibody to HBsAg. Detection of HBeAg by a relatively insensitive immunodiffusion test in the absence of HBsAg detectable by a sensitive radioimmunoassay suggested that production or removal of these two antigens may occur independently.

In the routine screening of blood donors, 30 asymptomatic donors were found to be positive for hepatitis-B antigen (HB Ag). They had no history suggestive of hepatitis in the past. None had antibody to HB Ag (HB Ab). Three were heroin addicts. All 30 donors were found to have demonstrable biochemical and histologic abnormalities of the liver. However, they have remained asymptomatic throughout the periods of HB antigenemia, which have ranged from 13 to 72 weeks. The immunoglobulins were normal in all of the donors. The cell-mediated immune response (CMIR), as tested by leukocyte migration inhibition, was normal in 16 subjects and was only slightly depressed in four, indicating that depression of CMIR is not the cause of this clinical state. Long-term observation of these individuals will be continued, with regular biochemical and histologic assessment to determine the natural course of this condition.

An outbreak of type B hepatitis followed transfusion with a single lot of plasma protein fraction (PPF) at a 1200-bed hospital in June and July 1973. Of 51 recipients of the product, 31 were available as a study population and 19 (61%) had an illness compatible with hepatitis. Epidemiologic and serologic investigations provided firm evidence that this material was the vehicle for transmission of disease to its recipients. Recipients of four other PPF lots from the same manufacturer were studied. Two of these lots were also associated with extremely high clinical hepatitis attack rates (45% and 55%). The other two lots, which had been prepared from donor plasma contributing to the composition of the initially-studied PPF lot, failed to produced clinical illness, although one of these lots was associated with a high prevalence of hepatitis B seropositivity in recipients. Thus, a broad spectrum of clinical and serologic responses was evident in PPF produced from similar donor plasma and pasteurized in the same bulk container. This study is the first to incriminate heat-treated PPF in transmission of type B hepatitis and suggests the need for further studies of the effect of pasteurization cycles on inactivation of hepatitis B virus.

sented four study groups: prostitutes, nuns, persons associated with institutions, and a control group of persons from the population whose age and socioeconomic status were comparable to those of the prostitutes. HB Ag was detected in 5% of the prostitutes, 9% of the control group, 18% of the nuns, and 10% of the residents of institutions. HB Ab was detected in 20% of the prostitutes, 12% of the control population group, 16% of the nuns, and 23% of the residents of institutions. In contrast to the high frequency of infection for herpesvirus type 2 among the prostitutes and the virtual absence of antibodies to herpesvirus type 2 among the nuns, no significant differences between the groups were observed for type B hepatitis infections. The data indicate that in Cali, venereal transmission is not a major mode of spread of type B hepatitis.

A study of 58 random recipients of single or multiple blood transfusions revealed post-transfusion hepatitis in 18·9%, based upon clinical and biochemical assessment. Using counter-immunoelectrophoresis, hepatitis associated antigen (HAA) alone was detected in 27·2% of cases, HAA and/or anti-HAA was found in 45·4% cases of hepatitis, and 13·7% of all the recipients. Out of 8 patients with HAA and/or anti-HAA, 3 remained normal clinically as well as biochemically, while the remaining 5 developed either icteric or anicteric hepatitis. Of the latter, one subject was associated with both antigen and antibody, 2 with antigen and2 with antigen and 2 with antibody alone. Among 306 asymptomatic blood donors, HAA and anti-HAA were found in 16 (5·2%) and 2 (0·65%) cases respectively, without any striking difference in the percentage of HAA in voluntary and professional donors. Of the 102 donors tested for transaminases, 4 showed a minimal abnormality in transaminases, only 2 of which were associated with the antigen. A control group of 1,156 subjects showed antigen in 2·76%.

The electrochromatography column is a unique glass device designed to function both as a chromatography column and as an electrophoresis column; it can also be operated so that both column chromatography and electrophoresis can take place in one simultaneous operation (electrochromatography). When the column is used for electrochromatography, proteins of the same molecular size, but with different electrophoretic mobilities, will be separated by electrophoresis, whereas proteins with the same electrophoretic mobilities but of different molecular size will be separated by molecular sieving. If proteins vary only slightly in these physical properties, separation is greatly enhanced by the action of the electric field on the filtering molecules. Thus, electrochromatography allows proteins to be separated simply, rapidly, and with greater resolution than other systems currently available. Electrochromatography has been used successfully for the purification of hepatitis B antigen, which is not separated from closely related serum immunoglobulins by either chromatography or electrophoresis. This method may become an important tool for the isolation and purification of a large number of proteins and viruses not easily separated by means of current technology.

A survey of 128,000 volunteer blood donors from the Greater New York metropolitan area revealed that first-time male donors were positive for hepatitis B surface antigen (HBsAg) 2.5 times more frequently than were first-time female donors; Negroes and Mongols were positive four to 20 times more frequently than Caucasians. The ratio of ad to ay seemed to be higher in non-Caucasian antigen carriers than in Caucasian carriers. Among both Caucasians and non-Caucasians the rate of positivity declined after the age of 50. An excess prevalence of HBsAg was observed in donors with the lowest level of education and in those with the highest level. HBsAg was detectable nine times less frequently among repeat donors than among first-time donors (0.2 vs.1.90 per 1,000). Detection of HBsAg was unrelated to ABO-Rh blood groups. Several mechanisms for these wide variations of antigen detection are possible.

The serotypes of hepatitis B surface antigen present in patients at the Lynchburg Training School and Hospital were determined by counterelectrophoresis. Hepatitis B surface antigen was detected by counterelectrophoresis in 72 of 82 samples that were positive by complement fixation or passive hemagglutination techniques. Of the isolates that were serotyped, 51 (71 percent) were ad, and 21 (29 percent) were ay; thus the ad:ay ratio was about 2.4:1. The incidence of the ay serotype was significantly higher in females and in patients with Down's syndrome. The ay serotype was not randomly distributed in the institution but was clustered in two of seven female wards and four of 11 male wards, all of which contained younger patients who had been institutionalized at an early age.

The role of antibodies to the surface antigen of hepatitis B virus (HBsAg) and to the hepatitis B core antigen (HBcAg) and of cell-mediated immunity in hepatitis B virus infections and in resistance to challenge was studied in six chimpanzees. Two chimpanzees were studied during primary hepatitis B virus infection while being treated with cyclophosphamide (5-15 mg/kg im three times per week). Cyclophosphamide treatment may have predisposed these chimpanzees to chronic hepatitis B virus infections. Four other chimpanzees convalescent from primary hepatitis B virus infection (subtype ayw) were challanged with hepatitis Bvirus; two were callenged with heterologous virus (subtype adw) without immunosuppression, and two were challenged with homologous virus (subtype syw)while being treated with cyclophosphamide. Chimpanzees with residual humoral immunity, demonstrable by serum antibodies against the group determinant a and subdeterminant y of HBsAg, resisted challenge with either heterologous or homologous hepatitis B virus despite cyclophosphamide immunosuppression in the latter case. Antibodies to the hepatitis B virus core did not appear necessary for protection against hepatitis B virus infection in these chimps.

This appears to be the first reported case of membranous glomerulonephritis in a pediatric asymptomatic carrier of hepatitis B virus in North America. Routine immunofluorescent methods were used to identify the hepatitis B surface antigen in glomeruli. In addition, the glomerular immune deposits were searched for the known ultrastructural forms of the virus.

Peripheral blood lymphocytes from a patient chronically infected with hepatitis D virus (HDV) were immortalized by Epstein-Barr virus transformation. Two stable monoclonal cell lines, derived from the same parent culture, were established and produced antibodies of the IgG isotype that were specific for the hepatitis delta antigen (HDAg). Both monoclonal antibodies (MAbs) recognized the major HDAg polypeptides of 24 kilodaltons and 27 kilodaltons that were previously detected by polyclonal antibodies to HDAg in both liver and serum from HDV-infected humans, chimpanzees, and woodchucks. This result indicates that the major polypeptides of HDAg share common epitopes. The MAbs also reacted with minor polypeptides of lower molecular weight, which were present in infected liver. In vitro translation products of HDV-specific RNA from infected liver were also detected by the MAbs; these polypeptides were 24 kilodaltons and 27 kilodaltons, respectively, and comigrated with liver- or serum-derived HDAg. In contrast, HDV RNA isolated from virions in serum was not translated into HDAg polypeptides in the in vitro system.

Chronic carriers of hepatitis B surface antigen (HBsAg) who were positive for antibody to hepatitis B e antigen were tested for precipitating specificities of the antibody and for rheumatoid factor (RF) over a two-year period. Twenty-one of 69 carriers were RF-positive by the latex-RF test with human IgG, but all were negative by the hemagglutination-RF test with rabbit IgG. Antibody to e/1 antigen was identified as an IgM antibody reactive in the latex-RF test, whereas antibody to e/2 antigen belonged to the IgG class and showed no RF reactivity. Antibody production seems to follow a sequential evolution: antibody to e/1 antigen appears early and that to e/2 antigen follows shortly thereafter. Antibody to e/2 antigen remains as the permanent antibody, whereas that to e/1 antigen sometimes disappears. The fact that antibody to e/1antigen is present only in certain chronic carriers of HBsAg would account for discrepancies in reported results of RF test in viral hepatitis.