Transmission of HCV between spouses.
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Female↗
Biomedical subjects
F Tsuda
Publications and source records attributed to F Tsuda.
Serodiagnosis of hepatitis C virus infection by ELISA for antibodies against the putative core protein (p20c) expressed in Escherichia coli.
The putative core gene of hepatitis C virus (HCV) was incorporated into a plasmid vector (pCC5-J4), and expressed in Escherichia coli. The product of 180 amino acids (p20c) was purified by gel electrophoresis in the presence of sodium dodecyl sulfate, and used in enzyme-linked immunosorbent assay for antibodies against the putative core protein of HCV (anti-p20c). Anti-p20c was detected in 13 (1.5%) of 873 apparently healthy blood donors. It was detected in 205 (86.5%) of 237 patients with acute or chronic non-A, non-B (NANB) hepatic disease, significantly more frequently (p less than 0.01) than antibodies against the C100-3 protein encoded by nonstructural regions of HCV (anti-C100-3) that was found in 178 (75.1%). Anti-p20c developed in the circulation of a patient with acute NANB hepatitis much earlier than anti-C100-3. HCV RNA was detected by polymerase chain reaction in serum samples from blood donors positive for anti-p20c in high titers, one of which was negative for anti-C100-3. These results indicated that anti-p20c would be useful in complementing anti-C100-3 for the diagnosis of NANB hepatitis and further decreasing the incidence of posttransfusion NANB hepatitis.
Adolescent↗
Antibodies against synthetic oligopeptides deduced from the putative core gene for the diagnosis of hepatitis virus infection.
Immunoassays were developed to detect antibodies against oligopeptides deduced from the putative core gene of hepatitis C virus, and their performances were compared with that of the commercial immunoassay for antibodies against the product of nonstructural regions of hepatitis C virus (anti-C100-3). A 19-mer oligopeptide (CP10) and a 36-mer oligopeptide (CP9) were chemically synthesized, which represented hydrophilic regions of the product of the hepatitis C virus core gene. They were used to capture corresponding antibodies, anti-CP10 and anti-CP9, by enzyme-linked immunosorbent assay in sera from patients with acute or chronic non-A, non-B liver disease and in blood donations. At the onset of acute non-A, non-B hepatitis, anti-CP10 was detected in 15 of 20 patients (75%), and anti-CP9 was detected in 14 patients (70%). This was more frequent than anti-C100-3, which was found in only 9 patients (45%). In 186 patients with chronic non-A, non-B liver disease, anti-CP9, anti-CP10 or both were detected in 170 patients (91%). This was more frequent than anti-C100-3, which was found in 138 patients (74%). Blood with anti-CP10 as the single serological marker for hepatitis C virus infection transmitted non-A, non-B hepatitis by needlestick exposure. In sera from 558 apparently healthy blood donors, anti-CP10 was detected in 55 donors (9.9%), anti-CP9 was detected in 26 donors (4.7%) and anti-C100-3 was detected in 7 donors (1.3%).(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗
Two distinct subtypes of hepatitis C virus defined by antibodies directed to the putative core protein.
Four distinct genotypes of hepatitis C virus types I, II, III and IV have been identified by comparison of nucleotide sequences of isolates from different areas of the world. We examined the possibility that hepatitis C virus may have serologically definable subtypes. Enzyme-linked immunosorbent assay systems were prepared by use of two synthetic peptides deduced from the putative core protein of hepatitis C virus. The following are the two peptides that were used: (a) IPKARRPEGRTWAQPGY (subtype-1) conserved in hepatitis C virus isolates with type I and type II genotypes; and (b) IPKDRRSTGKSWGKPGY (subtype-2) conserved in type III and type IV genotypes. With the enzyme-linked immunosorbent assays, the subtype-1 antibodies were detected in 26 (68%) of 38 subjects whose hepatitis C virus RNA had been genotyped as type I or type II, whereas subtype-2 antibodies were not detected. Inversely, the subtype-2 antibodies were detected in 10 (56%) of 18 subjects with hepatitis C virus RNA genotypes III or IV, whereas subtype-1 antibodies were detected in none of them. These results suggest that hepatitis C virus has two serologically distinguishable core antigen subtypes, corresponding to either genotype I/II or genotype III/IV. Subtyping of HCV by serological methods would contribute to tracking transmission routes of the virus, especially in cases where serum samples were not stored under conditions to preserve RNA or in infected hosts who have cleared the virus and therefore have only antibodies remaining to identify the infection.
Amino Acid Sequence↗
Hepatitis B surface antigen particles of subtypes adw and adr, and compound subtype (adwr) in symptom-free carriers in Japan.
Of sera from 1,878 Japanese blood donors who carried hepatitis B surface antigen (HBsAg), 420 were subtyped as adw (22.4%) and 1,443 as adr (76.8%); only 15 (0.8%) contained HBsAg of subtype ayw or ayr. Sera with HBsAg/adr had higher HBsAg titres than those with HBsAg/adw (geometric mean of haemagglutination titre: 10.1 +/- 2.4 vs. 9.7 +/- 2.4, p less than 0.01), and a higher prevalence of hepatitis B e antigen (24% vs. 13%, p less than 0.001). Carriers of HBsAg/adr progressively predominated over those of HBsAg/adw with increasing age. Of sera from 1,863 carriers of HBsAg/adw or HBsAg/adr, 182 (9.8%) contained HBsAg particles with both subtypic determinants in the w/r allele. The presence of w and r determinants on the same particles was ascertained by sandwiching them between monoclonal antibody with the specificity for w and that with the specificity for r. HBsAg particles of compound subtype (adwr) were found more often in sera with hepatitis B e antigen than those without it (145/403 [36.0%] vs. 37/1,460 [2.5%], p less than 0.001). Sera with HBsAg/adwr particles had HBsAg titres higher than those without them (12.4 +/- 1.9 vs. 9.7 +/- 2.3, p less than 0.001). HBsAg/adwr particles arise from phenotypic mixing of the S-gene product of wild-type virus and that of mutants with point mutations for subtypic changes. The results obtained indicated that HBV strains of subtype adr have a higher replicative activity than those of adw, and suggested that mutations in the S gene for subtypic changes would be associated with an active replication of hepatitis B virus.
Adult↗
Full-length sequence of a hepatitis C virus genome having poor homology to reported isolates: comparative study of four distinct genotypes.
Variable genomic sequences have been reported for RNA cloned from hepatitis C virus (HCV)-infected humans and chimpanzees. We found that four distinct genotypes of HCV could be differentially identified by PCR using type-specific primers. Full-length sequences have so far been reported for three of the four HCV genotypes, and we report herewith the sequence of the fourth type obtained from a Japanese blood donor. The entire nucleotide sequence of the HCV isolate (HC-J8) comprised 9481 bases plus a 3'-terminal poly(U) stretch of variable length. Like all previous isolates, the RNA contained a single, long open reading frame for a polyprotein of 3033 amino acids. HC-J8 differed from previously reported HCV isolates by 23.1-33.1% in nucleotide sequence and 15.9-28.8% in amino acid sequence. Based on genomic sequence homologies, a proposed phylogenetic tree of HCV, with a fourth branch represented by HC-J8, allowed a classification of all HCV isolates whose complete or partial sequences are now known. This classification suggests that all or most HCV genome sequences will fall into one of the proposed four types. The classification may be helpful in designing vaccine studies and for serological investigations of possible group- and type-specific antibodies.
Amino Acid Sequence↗
Typing hepatitis C virus by polymerase chain reaction with type-specific primers: application to clinical surveys and tracing infectious sources.
Based on variation in nucleotide sequence within restricted regions in the putative C (core) gene of hepatitis C virus (HCV), four groups of HCV have been postulated in a panel of 44 HCV isolates. They were provisionally designated types I, II, III and IV. A method for typing HCV was developed, depending on the amplification of a C gene sequence by polymerase chain reaction using a universal primer (sense) and a mixture of four type-specific primers (antisense). HCV types were determined by the size of the products specific to each of them. Type II was found in HCV samples from 131 (82%) of 159 blood donors, more often than in those from 48 (60%) of 80 patients with non-A, non-B (NANB) liver disease in Japan (P less than 0.01). In 11 haemophiliacs who had received imported coagulation factor concentrates, type I was found in five, as against type II in four. Double infection with two different HCV types was found in two patients with chronic NANB liver disease (types I and II; II and III) and two haemophiliacs (types I and II; I and III). HCV types were identical in mother and baby in each of two examples of perinatal transmission, and were also identical in donor and recipient in a case of accidental needle exposure.
Base Sequence↗
Correlation between anti-HBc titers and HBV DNA in blood units without detectable HBsAg.
Hepatitis B virus (HBV) DNA was tested for in 294 blood units which had antibody against hepatitis B core antigen (anti-HBc) as the isolated serological marker of HBV infection. After amplification by polymerase chain reaction, HBV DNA was detected in 12 (6.9%) of 175 units that were positive for anti-HBc with hemagglutination inhibition titers greater than or equal to 2(6), significantly more often than in none of 119 units with titers less than or equal to 2(5) (p less than 0.01). These results indicate that the exclusion of blood units with isolated high-titer anti-HBc would be effective for further decreasing the risk of posttransfusion hepatitis B.
Base Sequence↗
Mutations within the S gene of hepatitis B virus transmitted from mothers to babies immunized with hepatitis B immune globulin and vaccine.
A variant of hepatitis B virus (HBV) having a specific mutation within the S gene has been found to infect vaccinees. To know whether similar variants were involved in Japan, we analyzed two cases of maternal transmission of HBV in infants immunized with hepatitis B immune globulin and hepatitis B vaccine. DNA clones of HBV S genes were propagated from patients and family members and sequenced. In one family, the DNA clones from the baby patient had a Gly-to-Arg mutation at the 145th codon of the S gene, whereas those from her mother had no such mutations. In the other family, all the DNA clones obtained from the two infected children had the 145th codon intact, but they had a missense mutation at the 126th codon of the S gene, causing an amino acid substitution of Asn for Thr or Ile. This same mutation was observed in 12 of 17 clones of DNA obtained from their mother. In comparison with the wild type HBV-derived hepatitis B surface antigen, the two types of S gene mutations, either at the 145th or the 126th codon, were associated with a significant decrease in the antigenicity of some determinants on the hepatitis B surface antigen, measured by MAb. Amino acid substitution at these sites, therefore, would have induced the escape from conventional vaccines that were S gene products of wild type HBV and also from hepatitis B immune globulin, whose main components were probably also antibodies against the S gene products expressed by wild type HBV.
Adult↗
Hepatitis C virus infection in medical personnel after needlestick accident.
Hepatitis C virus infections in medical personnel after needlestick accidents have been documented generally by detection of seroconversion to a hepatitis C virus nonstructural region antigen, c100-3 (a marker of infection). We tested for hepatitis C virus core-derived antibodies and genomic RNA in addition to c100-3 antibody in 159 cases of needlestick exposure that did not involve patients positive for HBsAg. Of these we found 68 cases with index patients positive for both hepatitis C virus RNA and antibodies and members negative for antibodies to HCV core or c100-3 before the needlestick accidents. Seven of these medical personnel became infected with hepatitis C virus after the accidents. Their hepatitis was generally subclinical or self-limited and transient, except for one patient in whom liver enzyme elevation persisted along with the antibodies. In our study, the risk of hepatitis C virus transmission from a single needlestick accident with hepatitis C virus RNA-positive blood was 10%, considerably higher than the 4% estimated in a previous study. We found that donor blood with antibody to an hepatitis C virus core-derived peptide with enzyme-linked immunosorbent assay optical densities greater than 2.0 carried a significant risk of transmitting hepatitis C virus to needlestick victims. No hepatitis C virus seroconversions occurred in medical personnel exposed to hepatitis C virus antibody-negative or hepatitis C virus RNA-negative blood; however, one such exposure resulted in a very mild non-A, non-B, non-C hepatitis.
Health Personnel↗
Molecular heterogeneity of e antigen polypeptides in sera from carriers of hepatitis B virus.
Hepatitis B e Ag (HBeAg) was isolated from pooled sera of carriers, without abnormalities in liver function, by affinity column chromatography with mAb against HBeAg. HBeAg polypeptide with an estimated molecular size of 20,000 Da (p20e) was detected, in addition to regular HBeAg polypeptides (p17e/p18e). p20e, as well as p17e/p18e, did not bind with mAb against the carboxyl-terminal domain of the C-gene product. p20e disclosed an N-terminal sequence of MQLFHLXLII- (X unknown), whereas p17e had that of SKLXLGXLXGMDIDPXKEFG- (X's unknown). By comparing them with the amino acid sequence encoded by the precore region and C gene of hepatitis B virus DNA, p20e was deduced to possess amino acids 1 to 19 of the precore-region product at the N-terminus, which contains signal sequence and usually removed before the secretion of HBeAg. p17e had amino acids 20 to 29 of the precore-region product that continued to the C-gene product. Inasmuch as p20e was invariably detected in HBeAg preparations from carriers without evidence for liver disease, it would not have been released into the circulation from destructed hepatocytes. HBeAg polypeptide bearing an uncleaved signal sequence would help in further understanding the mechanism of HBeAg secretion.
Amino Acid Sequence↗
Seroepidemiology of hepatitis C virus infection in the Philippines: a preliminary study and comparison with hepatitis B virus infection among blood donors, medical personnel, and patient groups in Davao, Philippines.
To determine the seroprevalence of hepatitis C virus in the Philippines and compare it with the seroprevalence of hepatitis B virus infection, HBV and HCV markers in 594 serum samples collected from 392 blood donors, 123 medical and paramedical personnel, and 80 patients (45 liver diseases: 25 acute hepatitis, 9 liver cirrhosis, and 11 hepatocellular carcinoma; 28 hepatitis B carriers, and 7 chronic renal failure patients undergoing dialysis) in Davao, Mindanao Island, Philippines, were examined. HBsAg was determined by RPHA, anti-HBc by HI, anti-HBs by PHA, and HBsAg subtypes, HBeAg, and anti-HBe by EIA. HCV markers determined were anti-HCV (anti-C100-3) by ELISA (Ortho Diagnostic Systems), and anti-HCV core (anti-CP9 and/or anti-CP10) also by ELISA. Results showed that 9 (2.2%) blood donors were anti HCV positive; 69 (15.4%) were anti-HCV core positive Nine (2.2%) were HBsAg carriers; 240 (61.3%) were anti-HBs and/or anti-HBc positive (HBsAg carriers excluded from this group). Two of 123 medical and paramedical staff (1.6%) were anti-HCV positive; 11 (8.1%) were anti-HCV core positive; Eight (6.5%) were HBsAg carriers and 81 (65.8%) anti-HBs and/or anti-HBc positive. Five of 11 (45.4%) hepatocellular carcinoma patients were HBsAg carriers; 2 were anti-HCV core positive. Two of 9 liver cirrhosis patients were anti-HCV positive (1 to anti-HCV and the other to anti-HCV core).(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Fulminant hepatitis B: induction by hepatitis B virus mutants defective in the precore region and incapable of encoding e antigen.
Clones of hepatitis B virus were propagated from 10 cases of fulminant hepatitis B after amplification by polymerase chain reaction and their nucleotide sequences of the precore region were determined. All 113 clones from 9 cases had a point mutation from guanine to adenine at nucleotide 83 in the precore region, which converted codon 28 for tryptophan (TGG) to a stop codon (TAG) and prohibited the synthesis and secretion of hepatitis B e antigen. Precore-region defects were not detected in any of 23 clones from the remaining 1 case. By contrast, precore-region defects were not found in any of 180 clones from 8 cases of acute hepatitis B without hepatic failure serving as controls. The source of infection was traceable in 3 cases. The same precore-region defect, along with the sequence identity of 435 nucleotides, was observed in clones from the case of a baby and his grandmother, who carried the virus and was implicated in the transmission, and also in clones from two pediatricians and the carrier patients they attended. These findings support the hypothesis that precore-defective mutants have stronger activity to induce fulminant hepatitis than nondefective viruses.
Adolescent↗
Posttransfusion fulminant hepatitis B associated with precore-defective HBV mutants.
Fulminant hepatitis B developed in 8 recipients of blood units without detectable hepatitis B surface antigen on routine screening. All 124 hepatitis B virus (HBV) DNA clones propagated from their sera possessed defects in the precore region. A point mutation from guanine to adenine at nucleotide 83, converting codon 28 for tryptophan (TGG) to a stop codon (TAG), was the commonest, and it was found in all 113 clones from 7 cases. The remaining case displayed 1 clone with this point mutation and 10 clones with an insertion of 2 base pairs after nucleotide 26. Antibody to hepatitis B core antigen (anti-HBc) was detected in a high titer in 1 of 10 pilot plasma samples of blood units transfused to this case. HBV DNA clones propagated from it exhibited the same precore-region defects as those from the recipient. On the basis of these results HBV mutants, defective in the precore region, would appear to be responsible for posttransfusion fulminant hepatitis B, and the exclusion of blood units with high-titered anti-HBc would be efficacious in preventing it.
Amino Acid Sequence↗
Phosphorylation in the carboxyl-terminal domain of the capsid protein of hepatitis B virus: evaluation with a monoclonal antibody.
The capsid protein of hepatitis B virus (p21c) is made of 183 amino acids coded for by the C gene. By using p21c isolated from Dane particles (hepatitis B virus) as an immunogen, a monoclonal antibody (no. 2212) which recognized an epitope dependent on the phosphorylation of p21c was raised. The binding of no. 2212 antibody to authentic p21c was completely inhibited by a synthetic undecapeptide with a sequence of RRRSQSPRRRR, representing amino acids 165 to 175 of p21c, only when the peptide was phosphorylated. Either or both of Ser-168 and Ser-170 were phosphorylated in p21c in vivo, therefore, and contributed to the manifestation of the epitope. No. 2212 antibody bound to p21c from core particles derived from Dane particles or hepatocellular carcinoma tissues (PLC/342) propagated in nude mice but did not bind to p21c from core particles expressed in Escherichia coli or yeast cells, indicating different states of phosphorylation in them. Nonphosphorylated p21c showed a higher affinity for the viral DNA than did phosphorylated p21c. Since the serum from an asymptomatic carrier, with a high titer for antibody to hepatitis B core antigen, specifically bound to phosphorylated undecapeptide (amino acids 165 to 175), the epitope would stimulate humoral antibody responses in the human host.
Amino Acid Sequence↗
Hepatitis B virus mutants with precore-region defects in two babies with fulminant hepatitis and their mothers positive for antibody to hepatitis B e antigen.
Clones of hepatitis B virus (HBV) DNA were propagated from sera of two babies who developed neonatal fulminant hepatitis B, as well as from sera of their mothers who carried HBV with antibody to hepatitis B e antigen, and the precore-region sequences were determined. A point mutation from guanine to adenine, converting codon 28 for tryptophan (TGG) to a stop codon (TAG), was detected in 18 of 20 HBV DNA clones from mother and all 31 clones from baby in one family, and invariably in 55 clones from mother and three clones from baby in the other family. These results indicate that HBV mutants defective in the precore region in some carrier mothers with antibody to hepatitis B e antigen may transmit fulminant hepatitis B to their babies.
Amino Acid Sequence↗
Non-A, non-B hepatitis specific antibodies directed at host-derived epitope: implication for an autoimmune process.
A cDNA clone (GOR47-1) bearing an epitope with an aminoacid sequence GRRGQKAKSNPNRPL (GOR epitope) was isolated from the plasma of a laboratory chimpanzee infected with human non-A, non-B hepatitis (NANBH) agent. The epitope was not encoded by reported sequences of hepatitis C virus (HCV) but instead was coded for by a host cellular sequence. An enzyme-linked immunosorbent assay (ELISA) was developed for antibodies to the GOR epitope (anti-GOR). A patient with acute NANBH produced both IgM and IgG classes of anti-GOR in the acute phase of the illness, with concentrations of IgG class anti-GOR rising when anti-HCV became detectable. Anti-GOR was detected in serum from 59 (81%) of 73 patients with chronic NANBH, 40 (65%) of 62 with NANB liver cirrhosis, and 25 (63%) of 40 NANB patients with primary hepatocellular carcinoma, but in only less than 10% of patients with chronic liver diseases due to hepatitis B virus, alcohol, or an autoimmune disorder, and in only 2% of voluntary blood donors. Circulating HCV-RNA was detected by polymerase chain reaction (PCR) in most patients seropositive for anti-GOR but negative for anti-HCV. Detection of anti-GOR would therefore help in the diagnosis of NANBH and in reducing the occurrence of post-transfusion hepatitis.
Amino Acid Sequence↗
Synthetic oligopeptides bearing a common or subtypic determinant of hepatitis B surface antigen.
Two determinants of hepatitis B surface Ag (HBsAg), identified by mAb raised against polypeptide components, were characterized immunochemically. One was expressed on HBsAg irrespective of the four major subtypes, i.e., adw, adr, ayw, and ayr, whereas the other was subtypic but not identical to any of d, y, w, and r determinants. The common determinant was generated by a synthetic pentadecapeptide with a sequence of Thr-Thr-Ser-Thr-Gly-Pro-Cys-Lys-Thr-Cys-Thr-Ile-Pro-Ala-Gln representing amino acids 115-129 of the S gene product, and detected invariably in 366 HBsAg samples in sera from asymptomatic carriers in Japan. The activity of the S gene product, as well as the peptide (115-129), to bind with the mAb was not affected by alkylation alone, but was completely lost after reductive alkylation. The antigenic activity was lost when the S gene product was severed between Lys122 and Thr123 by trypsin. A microconformation maintained by the -Cys121-Cys124 bond, therefore, would be required for the common determinant. The other mAb identified an epitope of HBsAg that was mimicked by a synthetic tetradecapeptide with a sequence of Thr-Cys-Thr-Ile-Pro-Ala-Gln-Gly-Thr-Ser-Met-Phe-Pro-Ser, representing amino acids 123-136 of the S gene product. Among 16 HBsAg samples with known S gene sequences, 5 with Ile126 possessed this subtypic determinant, but the remaining 11 with Thr126 did not. The 5 hepatitis B virus genomes encoding the subtypic determinant differed less than 5.6% from each other in the entire nucleotide sequence, but by 8.0% or more from any of the other 11 genomes without the capacity to encode it.
Alkylation↗