20-fold increase in risk of lamivudine resistance in hepatitis B virus subtype adw

We investigated subtype-dependent development of lamivudine resistance in hepatitis B virus (HBV) longitudinally in 26 consecutive patients (13 adw and 13 ayw carriers) during antiviral treatment of chronic hepatitis B. Lamivudine resistance developed in seven adw carriers and one ayw carrier. Risk of lamivudine resistance was significantly higher for adw carriers than for ayw carriers (p=0.03). We believe that the adw subtype of HBV is associated with a high risk of lamivudine resistance, which might be linked to simultaneous changes of the HBsAg that occurs with the emergence of resistance.     

w Variants of the Hepatitis B Surface Antigen in Israeli Populations

A survey of w variants of the hepatitis B surface antigen (HBsAg) among native and immigrant Israelis revealed that the subtype ayw2 predominated among asymtpomatic HBsAg carriers (69%), and patients with acute (83%) and chronic active hepatitis B (81%). The subtypes ayw3, ayw4 and adw2, uncommon in native populations, were detected in carriage by immigrants and transients. Nevertheless, the high prevalence of ayw2 among native Israeli carriers (87%), and in particular natives with acute 93%) and chronic active hepatitis B (86%), indicates that the introduction of nonindigenous viral strains has not overtly altered the anticipated geographic distribution of hepatitis B viruses.     

Endemoepidemic non-parenteral type B hepatitis in Costa Rica.

In an endemic area of Costa Rica nonparenteral type B hepatitis occurs at a yearly rate of 160/100,000, in an endemoepidemic pattern with periodic localized outbreaks. In a recent episode in the village of San Rafael, 23 clinical and 67 subclinical cases, all subtype adw, originated from two carriers living in opposite ends of the village. Contact transmission was identified as the mode of spread. In a coincidental outbreak in another village, San Juan, 17 clinical and 40 subclinical cases were observed. Thirty-seven cases of HBs Ag/ayw positive hepatitis occurred in the Western sector of the village, apparently originating from contact with three HBs Ag/ayw carriers found in that area. There were also 20 cases of HBs Ag/adw positive hepatitis, but these occurred almost exclusively in the Eastern sector, where subtype adw disease has been prevalent in previous years. The geographic distribution of antibody subtypes found in the two separated sectors of the village coincided fully with that of the antigen subtypes. These observations show that personal contact is definitely a mode of transmission of hepatitis B.     

adw亚型HBV突变体与ayw亚型辅助质粒之间相互包装的研究

目的探讨adw亚型HBV突变体与ayw亚型辅助质粒之间相互包装。方法构建C基因截短adw亚型HBV表达载体pHBV-ΔC。重组载体与ayw亚型辅助质粒pHBV3142共转染HepG2细胞。以与PGEm共转染为对照。用PCR检测细胞核内重组HBV载体cccDNA生成和培养上清中rcDNA的形成,用Native westernblot和Soutern blot检测重组HBV载体在辅助质粒pHBV3142辅助下的包装。结果在实验组细胞核内可检测到cccDNA、培养上清中可检测到rcDNA,对照组中无此结果。实验组Soutern blot见阳性信号而对照组无阳性信号。结论重组adw亚型HBV载体在辅助质粒ayw亚型pHBV3142辅助下能进行有效复制且有效完成病毒包装。     

Molecular epidemiology of hepatitis B virus in Indonesia

The S-gene sequences of hepatitis B virus (HBV) from 22 carriers in several islands of Indonesia were amplified by polymerase chain reaction, and XbaI-SpeI fragments corresponding to nucleotides 93-529 (437 base pairs) in the S gene were sequenced. The 22 sequences, along with the 5 reported sequences from Indonesia, were compared with each other, and with the corresponding sequences of 20 clones from other countries including China, France, Great Britain, Japan, Kenya, Papua New Guinea, Philippines, USA and USSR. When the 27 HBV DNA clones of various subtypes from Indonesia were classified by the homology in the nucleotide sequence into the five genotypes, twelve belonged to genotype B (subtype adw 7 and ayw 5), 13 to genotype C (adw 1, adr 10, ayr 1 and ar 1), and 2 to genotype D (ayw); none belonged to genotype A or E. Different subtypes of clones in the same genotype indicated that point mutations inducing d-to-y or w-to-r phenotypic changes would be common among Indonesian carriers. Comparison of the translation products of XbaI-SpeI fragments, now available for 47 HBV DNA clones of different genotypes (A 4; B 14; C 21; D 7; E 1), identified several amino acids characteristic to or influenced by the five genotypes as well as those highly conserved by clones of different genotypes.     

Biological therapy in inflammatory bowel diseases:Access in Central and Eastern Europe

Biological drugs opened up new horizons in the management of inflammatory bowel diseases(IBD).This study focuses on access to biological therapy in IBD patients across 9 selected Central and Eastern European(CEE)countries,namely Bulgaria,the Czech Republic,Estonia,Hungary,Latvia,Lithuania,Poland,Romania and Slovakia.Literature data on the epidemiology and disease burden of IBD in CEE countries was systematically reviewed.Moreover,we provide an estimation on prevalence of IBD as well as biological treatment rates.In all countries with the exception of Romania,lower biological treatment rates were observed in ulcerative colitis(UC)compared to Crohn’s disease despite the higher prevalence of UC.Great heterogeneity(up to 96-fold)was found in access to biologicals across the CEE countries.Poland,Bulgaria,Romania and the Baltic States are lagging behind Hungary,Slovakia and the Czech Republic in their access to biologicals.Variations of reimbursement policy may be one of the factors explaining the differences to a certain extent in Bulgaria,Latvia,Lithuania,and Poland,but association with other possible determinants(differences in prevalence and incidence,price of biologicals,total expenditure on health,geographical access,and cost-effectiveness results)was not proven.We assume,nevertheless,that healthdeterioration linked to IBD might be valued differently against other systemic inflammatory conditions in distinct countries and which may contribute to the immense diversity in the utilization of biological drugs for IBD.In conclusion,access to biologicals varies widely among CEE countries and this difference cannot be explained by epidemiological factors,drug prices or total health expenditure.Changes in reimbursement policy could contribute to better access to biologicals in some countries.     

Changing Patterns in the Distribution of Hepatitis B Subtypes

From July 1, 1969, to June 30, 1977, 4,413 patients with acute viral hepatitis were admitted to Fairfield Hospital, Melbourne, of whom 1,128 (25.6%) had hepatitis type B. Only two of the four major subtypes of hepatitis B surface antigen (HBsAg) were detected, HBsAg/ayw and HBsAg/adw, and of these HBsAg/ayw was present in 80.4% of cases. Over the 8-year period, hepatitis B became more common in Melbourne and the proportion of patients infected with the ayw subtype increased from 75 to 91%. Approximately 50% of the patients with hepatitis B were intravenous drug abusers. In most of the others the source of infection was unknown.     

Genotype A2/adw2 Strain of Hepatitis B Virus in Turkey

Background and Aims

Previous studies have demonstrated the dominance of genotype D subtype ayw in patients with hepatitis B virus infection in Turkey. The aim of the present study is to report, for the first time, genotype A2 subtype adw2 of hepatitis B virus in a patient who is an inactive hepatitis B carrier in Turkey.

Materials and Methods

Hepatitis B virus DNA isolated from the serum sample was amplified by polymerase chain reaction. The polymerase gene segment of the hepatitis B virus was directly sequenced. A distance matrix/UPGMA comparison was used for phylogenetic analysis, and the genotype of the virus was identified accordingly. The subgenotype and subtype of hepatitis B virus were also detected.

Results

The genotyping of the patient revealed that the isolated hepatitis B virus was genotype A2/adw2.

Discussion

The subtype is inconsistent with the previous data from Turkey; specifically, the identification of the A2/adw2 subtype of the hepatitis B virus in an inactive carrier is the first such case in Turkey. This finding suggests that the transmission of another genotype besides genotype D subtype ayw of the hepatitis B virus is possible in Turkey.     

HBs Antigen Subtypes among Acute Hepatitis Patients in Japan: Evidence of Imported Hepatitis

HBs antigen subtypes were determined among 137 acute hepatitis patients in Japan. The distribution among the 99 male patients was 40 adr, 37 adw, one ayw, and 21 undetermined while that among the 38 female patients was 19 adr, 11 adw, and eight undetermined. The distribution among the male patients was different from that among HBs antigen carriers in Japan, suggesting that they were exposed not only to domestic HBs antigen carriers, but also to other sources. Thirty-one (29 males and two females) of the 137 patients (22.6%) were found to have been abroad at some time during the incubation period. the distribution among them was seven adr, 21 adw, and three undetermined. the majority bad the same subtypes that are prevalent in the countries they visited, supporting the hypothesis that most of them bad contracted the disease overseas. The remaining 106 patients bad a distribution of the subtypes similar to that of domestic HBs antigen carriers. "Imported hepatitis" would be an important cause of acute type B hepatitis in Japan.     

Determination of hepatitis B virus subtypes by an enzyme immunoassay method using monoclonal antibodies to type-specific epitopes of HBsAg

We described a Hepatitis B surface antigen (HBsAg) subtyping method based on a commercial enzyme immunoassay (EIA) for detection of HBsAg in which the procedure was modified to include the use of monoclonal antibodies with restricted anti-HBs specificities. This method, which was able to classify HBsAg as: ayw1, ayw2, ayw3, ayw3 * (intermediate between ayw3 and ayw4 ), ayw4, ayr, adw2, adw4 and adr , was compared to counter electrophoresis procedure (CEP) by testing HBsAg positive sera from blood donors included in a prospective national epidemiological survey. Among the 256 HBsAg positive samples tested with both techniques, 111 (43.3%) could not be subtyped with CEP vs 10 (3.9%) with our modified EIA. This difference was related to the serum HBsAg concentration which must be greater than 3000 ng/mL and 100 ng/mL for CEP and EIA, respectively. The results obtained from 145 sera with both methods were concordant. Seventeen out of 18 samples partially classified as ay with CEP were completely determined with EIA.
This reliable procedure, derived from commercially available reagents, can be easily used in several applications such as large epidemiologic studies and as a substitute for nucleotide sequencing genotyping which is not adapted for large-scale screening and not applicable on samples from nonviremic hepatitis B virus (HBV) carriers.     

Hepatitis B virus infection in chimpanzees: titration of subtypes.

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 HIV type 1 epidemic in Bulgaria involves multiple subtypes and is sustained by continuous viral inflow from West and East European countries

Little is known about the HIV-1 epidemic in Balkan countries. To fill the gap, we investigated the viral genetic diversity in Bulgaria, by sequencing and phylogenetic characterization of 86 plasma samples collected between 2002 and 2006 from seropositive individuals diagnosed within 1986-2006. Analysis of pol gene sequences assigned 51% of the samples to HIV-1 subtype B and 27% to subtype A1. HIV-1 subtype C, F, G, H, and a few putative recombinant forms were also found. Phylogenetic and molecular clock analysis showed a continuous exchange of subtype A and B between Bulgaria and Western as well as other Eastern European countries. At least three separate introductions of HIV-1 subtype A and four of HIV-1 subtype B have occurred within the past 25 years in Bulgaria. The central geographic location of Bulgaria, the substantial genetic heterogeneity of the epidemic with multiple subtypes, and the significant viral flow observed to and from the Balkan countries have the potential to modify the current HIV-1 epidemiological structure in Europe and highlight the importance of more extensive and continuous monitoring of the epidemic in the Balkans.     

Recombinant Semliki Forest virus vectors encoding hepatitis B virus small surface and pre-S1 antigens induce broadly reactive neutralizing antibodies

Summary. Most hepatitis B virus (HBV) vaccines consist of viral small surface (S) protein subtype adw2 expressed in yeast cells. In spite of good efficacy, HBV‐genotype and subtype differences, escape mutants and insufficient Th1 activation remain potential problems. To address these problems, we generated recombinant Semliki Forest virus (rSFV) vectors encoding S protein, subtype adw2 or ayw2, or a fragment of the large surface protein, amino acids 1–48 of the pre‐S1 domain, fused to S (pre‐S1.1–48/S). The antigen loop in S protein and the selected pre‐S1 sequences are known targets of neutralizing antibodies. BALB/c mice were immunized intravenously with 10⁷ rSFV particles and 10⁸ rSFV particles 3 weeks later. Antibodies induced by rSFV encoding S proteins reacted preferentially with subtype determinants of yeast‐derived S antigen but equally well with patient‐derived S antigen. Immunization with rSFV encoding pre‐S1.1–48/S resulted in formation of pre‐S1‐ and S‐specific immunoglobulin G (IgG), while immunization with the isogenic mutant without S start codon induced pre‐S1 antibodies only. Neutralizing antibodies were determined by mixing with plasma‐derived HBV/ayw2 and subsequent inoculation of susceptible primary hepatocyte cultures from Tupaia belangeri. S/adw2 antisera neutralized HBV/ayw2 as effectively as antisera raised with S/ayw2. The pre‐S1 antibodies also completely neutralized HBV infectivity. The IgG1/IgG2a ratios ranged from 0.28 to 0.88 in the four immunized groups and were lowest for the pre‐S1.1–48/S vector, indicating the strongest Th1 response. This vector type may induce subtype‐independent and S‐escape‐resistant neutralizing antibodies against HBV.     

Selective transmission of variant genomes from mother to infant in neonatal fulminant hepatitis B

Hepatitis B virus (HBV) nucleotide sequences isolated from mother/child pairs were analyzed in three cases of neonatal fulminant hepatitis B (FHB). Heterogeneous HBV sequences consistent with both adw2 and ayw subtype were found in all three mothers. In one case, in which the child survived, both subtypes were transmitted. By contrast, only the ayw subtype was present in the two other children with a fatal course of FHB. In one fatal case, studied in greater detail, multiple HBV variants (viral quasi-species) were identified in both mother and child. A direct sequence comparison showed that only a subfraction of the virus pool from the mother was transmitted and that multiple new mutations emerged in the child. These data suggest that a minor HBV subpopulation from the mother may prevail as the dominant species in the child and that neonatal FHB is associated with the selection of mutant strains.     

Combined treatment including postoperative chemotherapy in lung cancer patients

The results of a cooperative randomized study performed in Poland, Bulgaria, Czechoslovakia, Hungary, and the Soviet Union on the treatment of lung cancer patients are presented. Three hundred and sixty patients were treated only surgically, 360 patients received combined therapy. Adjuvant chemotherapy was performed using 3 preparations (cyclophosphane, methotrexate, 5-fluorouracil) within 2-3 weeks after operation (first course) followed by another 3 courses at intervals of 8-9 weeks. The combined therapy increased the 5-year survival rate of patients with Stage III squamous cell carcinoma with thoracic lymph node metastases. Better results were achieved when 3-4 courses of adjuvant chemotherapy were performed. In patients with Stage I-II squamous cell carcinoma of the lung without regional lymph node metastases the used regimen of combined therapy had no significant effect.     

Warsaw conference on emerging infections in central and eastern Europe

On March 28-29, 2000, epidemiologists and microbiologists convened in Warsaw, Poland, to discuss emerging, re-emerging, and drug-resistant infections in central and eastern Europe. Delegates were from the Czech Republic, Greece, Hungary, Latvia, Poland, Romania, Russia, and Yugoslavia, with the exception of the US and the UK and other worst affected countries in central-eastern Europe. It has been documented that the cause of diphtheria epidemics in several countries in the mid-1990s resulted from the breakdown of vaccination campaigns following social dislocation. Currently, diphtheria morbidity has declined through targeted vaccination programs, although fundamental socioeconomic problems continue to threaten public health. Other infectious diseases raised during the conference were the evolution of tuberculosis and HIV/AIDS, which remains largely unpredictable. In addition, the growing incidence of multidrug-resistant tuberculosis is documented in several countries. Among the major problems in tuberculosis control include late diagnosis, nonexistent or erratic drug supplies and unreliable reporting. The syringe ecosystem in both healthcare settings and injecting drug users were singled out as the vectors of sharp increase in HIV/AIDS infection. Throughout the conference, the recurrent theme was on the overriding importance of providing specialized training and the building up of networks of public health specialists.     

Some epidemiological and clinical aspects of hepatitis B antigen and its subtypes.

The close association between hepatitis B antigen (HBAg) and the infectious agent of hepatitis B is clear. Many investigations have shown HBAg to be a useful tool for epidemiological studies of hepatitis B. The relation between HBAg and the postulated hepatitis B virus (HBV) is as yet not clear. In light of recent results a possible candidate could be the so-called Dane particle, which has HBAg reactivity on the surface, but possesses an antigenically distinct core. The core has been shown to have associated DNA polymerase activity. The particles which carry HBAg reactivity have surfaces which are antigenically complex. One common specificity a and 2 pairs of mutually exclusive determinants have been recognized namely d and y and w and r but further possible specificities are under investigation. Four different phenotypes have been described, adw, adr, ayw and ayr. Present evidence indicates that adw, adr and ayw are the phenotypic expression of 3 different transmissible strains of HBV. Studies on the epidemiology of these subtypes have shown 3 different geographic patterns. In the USA and Northern Europe both Dw (adw) and YW (ayw) are common, but in the Eastern Mediterranean and Middle East Yw is practically the only type found. In the Far East DR (adr) is the dominating subtype. Investigations have been done to determine whether there are any clinical differences in hepatitis caused by the different tubtypes. No certain differences have been shown.     

Significance of the minor i and t determinants of hepatitis B virus in hepatocellular carcinoma

Stored sera from asymptomatic hepatitis B virus (HBV) carriers and hepatitis B virus surface antigen-positive hepatocellular carcinoma (HCC) patients were tested for HBV subtypes, such as subtype determinants d, y, w, r and also antigenic determinants isoleucine (i) and threonine (t) by direct S gene nucleotide sequencing. Significant changes in minor i and t determinants in hepatocellular carcinoma patients with adr hepatitis B carriers were seen. The adr subtype with t determinant was present in 14/25 (56%) of HCC patients compared with only two of 28 (7%) in asymptomatic hepatitis B carriers ( P < 0.001). However, the adr subtype with i determinant was present in nine of 25 (36%) of the HCC patients and also present in 24/28 (86%) of asymptomatic carriers ( P < 0.001). No significant changes were seen with the adw subtypes. These results show that i and t minor determinant changes are more common with adr subtypes associated with HCC than with the adw subtype. Whether these subtle changes are pathologically relevant or only a polymorphism of hepatitis B genotypes will depend on subsequent follow-up studies.     

Hepatitis B surface antigen disappearance and hepatitis B surface antigen subtype: a prospective, long-term, follow-up study of Japanese residents of Okinawa, Japan with chronic hepatitis B virus infection.

To determine the natural course of hepatitis B surface antigen (HBsAg) disappearance in chronic hepatitis B virus (HBV) infection and the factors related to its disappearance, 946 HBsAg carriers in Okinawa, Japan were prospectively followed for up to 19 years (mean = 9.2 years). The disappearance of HBsAg, as determined by radioimmunoassay (RIA), was observed in 62 (6.6%) and the overall annual disappearance rate was 0.79%/year. Its disappearance was more frequent in 60 (7.4%) of 815 serum samples negative for hepatitis B e antigen (HBeAg) by RIA at entry compared with only two (1.5%) of 131 serum samples that were HBeAg positive by RIA at entry (P < 0.05). Stepwise logistic regression analysis showed that age and HBsAg subtype were significantly associated with HBsAg disappearance (both P < 0.05), and that carriers with subtype adr (odds ratio = 2.87) had an increased probability of clearing HBsAg compared with carriers with subtype adw. Conversely, HBeAg disappearance was earlier in those with the adw subtype than in those with adr. Hepatitis B virus DNA was not detected by the polymerase chain reaction after HBsAg disappearance in any of the 62 from whom it had disappeared. The HBsAg titer, as measured by reverse passive hemagglutination, was related to the time to its disappearance; the higher the titer, the longer the time to disappearance. These findings suggest that HBeAg negativity, a more advanced age, and low titers of HBsAg are favorable factors for HBsAg disappearance in the natural course of chronic HBV infection. Moreover, HBsAg subtype adr was a predictive factor for HBsAg disappearance, whereas subtype adw was predictive of early HBeAg disappearance.