Shigeo Hino

Prospective Reevaluation of Risk Factors in Mother-to-Child Transmission of Hepatitis C Virus: High Virus Load, Vaginal Delivery, and Negative Anti-NS4 Antibody

Of 21,791 pregnant women screened in Tottori Prefecture, Japan, 127 (0.58%) were positive for anti-hepatitis C virus (HCV) antibody and 84 (0.39%) were positive for HCV RNA. Of 84 children followed up for at least 6 months, 7 (8%) were infected. All of them were born to 26 mothers with a high virus load (HVL; >/=2.5x106 RNA copies/mL [27%]), compared with 0 of 58 children born to non-HVL mothers (P<.001). Because all the infected children were vaginally delivered, the infection rate among 16 vaginally delivered children born to the HVL mothers was as high as 44%. The prevalence of anti-NS4 antibody in the mothers with an infectious HVL was significantly lower than that in the mothers with a noninfectious HVL (P=.048). Analysis of our results suggests that maternal HVL, vaginal delivery, and negative anti-NS4 antibody are significant risk factors for the mother-to-child transmission of HCV.

Maternal Transmisson of HTLV-1 Other than through Breast Milk: Discrepancy between the Polymerase Chain Reaction Positivity of Cord Blood Samples for HTLV-1 and the Subsequent Seropositivity of Individuals

We used a nested polymerase chain reaction (PCR) to diagnose HTLV‐1 carriers. The DNA isolated from the nuclear extract obtained from frozen whole blood was found appropriate for PCR study both qualitatively and quantitatively. The use of freshly frozen whole blood made the field work much easier, and the use of a nuclear extraction procedure allowed DNA isolation in just 4 microcentrifuge tubes. We could not attain sufficient sensitivity to detect a single molecule with single‐step PCR, but nested PCR was confirmed to detect a single molecule/reaction. All samples of the seropositive group including 94 blood donors, 66 mothers, and 13 children were positive in the nested PCR, while none of the seronegative group, including 198 blood donors and 285 children, was positive. Although 18/717 (2.5%) cord blood samples obtained from babies born to carrier mothers were PCR‐positive, none of 5 formula‐fed children tested who had been PCR‐positive in the cord blood gave evidence of infection later on. Furthermore, all of 4 seropositive infected children who were formula‐fed had been PCR‐negative in their cord blood. The results are not consistent with intrauterine infection, but suggest the presence of a perinatal or postnatal infection route other than through breast milk.

High frequency of postnatal transmission of TT virus in infancy

Abstract. DNA of TT virus (TTV), a novel human circovirus, was tested for in 116 mother-infant pairs who had participated in the adult T-cell leukemia prevention program (APP) in Nagasaki, Japan, and refrained from breast-feeding. By polymerase chain reaction with Okamoto’s seminested primers, 36 of the 115 (31%) mothers were positive. At the age of 6–8 months, 7 of 29 (24%) and 6 of 72 (8%) infants born to infected and uninfected mothers were positive, respectively (P = 0.047; RR, 2.90). Maternal TTV DNA load did not correlate with infantile infections. Since 99 of 100 (99%) cord blood samples were negative and all the mothers refrained from breast-feeding, the infantile TTV transmission would not be intrauterine or milk-borne. Between 6–8 and 12–21 months of age, 4 of 12 (33%) and 5 of 22 (23%) children born to infected and uninfected mothers turned positive, respectively (NS). At 12–21 months of age, 8 of 21 (38%) and 12 of 32 (38%) children born to infected and uninfected mothers were positive, respectively (NS). These results indicate that the TTV infection prevails in children at a frequency comparative to that in their mothers within the first 2 years of life, regardless of the maternal TTV status.

HTLV-I proviral DNA in umbilical cord blood of babies born to carrier mothers

Human T-lymphotropic virus type I (HTLV-I) in cord blood raises the possibility of intrauterine transmission as an alternative pathway to transmission via breast milk. However, none of 7 children with HTLV-I proviral DNA positive cord blood had seroconverted by 24-48 months. Contamination of cord blood by maternal blood was precluded on the basis of viral load and IgA concentration. Thus cord blood proviral DNA is not a hallmark of intrauterine infection. Moreover, none of the cord blood samples of 9 formula-fed children later confirmed to be infected was positive for HTLV-I, indicating that intrauterine infection is not a likely candidate as an alternative pathway.

Risk factors for mother-to-child transmission of hepatitis C virus : Maternal high viral load and fetal exposure in the birth canal

Aim:  Mother‐to‐child transmission (MTCT) is the major transmission pathway of hepatitis C virus (HCV) in children. However, its risk factors remain unsettled for introduction of putative intervention.

Replication of chicken anemia virus (CAV) requires apoptin and is complemented by VP3 of human torque teno virus (TTV)

To test requirement for apoptin in the replication of chicken anemia virus (CAV), an apoptin-knockout clone, pCAV/Ap(-), was constructed. DNA replication was completely abolished in cells transfected with replicative form of CAV/Ap(-). A reverse mutant competent in apoptin production regained the full level of DNA replication. DNA replication and virus-like particle (VLP) production of CAV/Ap(-) was fully complemented by supplementation of the wild-type apoptin. The virus yield of a point mutant, CAV/ApT(108)I, was 1/40 that of the wild type, even though its DNA replication level was full. The infectious titer of CAV was fully complemented by supplementing apoptin. Progeny virus was free from reverse mutation for T(108)I. To localize the domain within apoptin molecule inevitable for CAV replication, apoptin-mutant expressing plasmids, pAp1, pAp2, pAp3, and pAp4, were constructed by deleting amino acids 10-36, 31-59, 59-88 and 80-112, respectively. While Ap1 and Ap2 were preferentially localized in nuclei, Ap3 and Ap4 were mainly present in cytoplasm. Although complementation capacity of Ap3 and Ap4 was 1/10 of the wild type, neither of them completely lost its activity. VP3 of TTV did fully complement the DNA replication and VLP of CAV/Ap(-). These data suggest that apoptin is inevitable not only for DNA replication but also VLP of CAV. The common feature of apoptin and TTV-VP3 presented another evidence for close relatedness of CAV and TTV.

Evaluation of a new, fully automated immunoassay for detection of HTLV-I and HTLV-II antibodies.

Screening blood donations for human T‐lymphotropic virus types I and II (HTLV‐I/II) continues to be important in protecting the safety of blood products and controlling the global spread of these retroviruses. We have developed a fully automated, third generation chemiluminescent immunoassay, ARCHITECT rHTLV‐I/II, for detection of antibodies to HTLV‐I/II. The assay utilizes recombinant proteins and synthetic peptides and is configured in a double antigen sandwich assay format. Specificity of the assay was 99.98% (9,254/9,256, 95% CI = 99.92–100%) with the negative specimens from the general population including blood donors, hospital patients and pregnant women from the US, Japan and Nicaragua. The assay demonstrated 100% sensitivity by detecting 498 specimens from individuals infected with HTLV‐I (n = 385) and HTLV‐II (n = 113). ARCHITECT rHTLV‐I/II results were in complete agreement with the Murex HTLV‐I/II reference assay and 99.7% agreement with the Genelabs HTLV Blot 2.4 confirmatory assay. Analytical sensitivity of the assay was equivalent to Murex HTLV‐I/II assay based on end point dilutions. Furthermore, using a panel of 397 specimens from Japan, the ARCHITECT rHTLV‐I/II assay exhibited distinct discrimination between the antibody negative (Delta Value = −7.6) and positive (Delta Value = 7.6) populations. Based on the excellent specificity and sensitivity, the new ARCHITECT rHTLV‐I/II assay should be an effective test for the diagnosis of HTLV‐I/II infection and also for blood donor screening. J. Med. Virol. 80:484–493, 2008.

Shift in the buoyant density of hepatitis C virus particles in infants infected by mother-to-infant transmission

Abstract Background: Hepatitis C virus (HCV) particles in sera can be divided into two classes: low‐density free particles and high‐density immune complex particles. Previous studies have revealed that the clinical progression of HCV infection is closely associated with the occurrence of the former class, rather than the latter, in an experimental chimpanzee model and in HCV‐infected adult cases.

Deleted HTLV-1 provirus in cord-blood samples of babies born to HTLV-1-carrier mothers

We screened 596 cord‐blood samples by nested short PCRs for the gag and pX regions of HTLV‐1 which are capable of detecting a single copy. The samples were derived from 449 and 147 babies born to seropositive and seronegative mothers respectively. Of these, 20 samples were positive in at least one of the PCRs: 9 (45%) were positive in both PCRs, but 10 and 1 samples in either the pX or the gag PCR respectively. These samples were tested further in nested long PCRs directed for gag‐pX, gag‐pol and pol‐pX regions capable of detecting 8, 1 and 2 copies respectively. Of 9 dually positive samples, 7 (77%) showed the predicted 6.2‐kbp band in the gag‐pX PCR; only 2 of them had the predicted band alone; 7 samples had discrete bands shorter than the predicted size. In the gag‐pol PCR, all 9 samples showed the predicted 2.2‐kbp band alone. In the pol‐pX PCR, 8/9 samples showed the predicted 4.2‐kbp band, including one with an additional 2.1‐kbp band, and the last a 1.0‐kbp band alone. Thus, all of the dually positive samples had proviruses harboring gag, pol and pX priming sites. In contrast, none of the 11 singly positive samples showed the predicted band in the gag‐pX PCR: 5 had no visible band, and the other 6 had shorter bands only. None of these 11 samples showed any positive signal in either gag‐pol or pol‐pX PCR. Our results suggest that HTLV‐1 proviruses in the cord blood are frequently defective. Int. J. Cancer 77:701–704, 1998.