Atsuko Hata

Comparison of Varicella-Zoster Virus-Specific Immunity of Patients with Diabetes Mellitus and Healthy Individuals

Cell-mediated immunity (CMI) has been shown to be critical for the prevention and control of varicella-zoster virus (VZV)-related diseases. Because a large population-based study has revealed that diabetes mellitus is a risk factor for herpes zoster, we studied VZV-specific immune responses of patients with diabetes mellitus and compared them with those of healthy individuals. In this study, we found that patients with diabetes mellitus had significantly lower CMI to VZV than did healthy individuals. These results suggest that the increased risk for herpes zoster among patients with diabetes mellitus may be related to decreased VZV-specific CMI.

Mycoplasma hominis meningitis in a neonate: Case report and review

Despite frequent colonization with Mycoplasma hominis, the invasive disease is rare in neonates. This study describes a neonatal case with meningitis in which M. hominis was isolated from a cerebrospinal fluid sample by culture and detected by PCR. The M. hominis infection was confirmed by elevated metabolic inhibition titers against the isolated M. hominis strain and anti-M. hominis antibodies in serum samples. Minocycline and moxifloxacin were effective against M. hominis, which caused meningitis in the patient. However, the patient exhibited left hemiplegia because of massive brain infarction. Based on data of the previously reported 28 cases in addition to our case, the high morbidity and mortality of the M. hominis central nervous system infection were confirmed; it was assumed to result from delayed diagnosis and ineffective initial therapy. Early diagnosis and prompt initiation of appropriate antimicrobial treatment are necessary for a favorable prognosis. Fourth-generation fluoroquinolones, especially moxifloxacin, deserve wider use in such cases.

Antigenic analysis of human herpesvirus 7 (HHV-7) and HHV-6 using immune sera and monoclonal antibodies against HHV-7

Using polyclonal and monoclonal (MAbs) antibodies to human herpesvirus 7 (HHV-7), we have studied HHV-7-specific polypeptides. Human sera were obtained during the convalescent phase from patients with exanthem subitum due to HHV-7, and at least 16 HHV-7-specific polypeptides with apparent molecular masses of 26-210 kDa were immuno-precipitated. Sera prepared in mice also precipitated at least 17 HHV-7-specific polypeptides with molecular masses of 26-210 kDa. Among them, the most commonly observed antigenic protein had an apparent molecular mass of 52 kDa. Forty-two clones secreting MAbs against HHV-7-specific proteins, as determined by immunofluorescence assays, were established from BALB/c mice immunized with HHV-7-infected cell extracts. Seven MAbs which immunoprecipitated HHV-7-specific polypeptides were further characterized. Two of these, MAbs 5E12 and 5F12, reacted predominantly with glyco-proteins of 78 kDa and 85 kDa, respectively, and possessed neutralizing activity. This suggests that there are at least two neutralization-inducing proteins in HHV-7. MAb 16B4 reacted with the major immunogenic protein of 52 kDa. Five of the 42 MAbs also reacted in immunofluorescence assays with HHV-6 antigens to the same degree as to HHV-7. Two other MAbs, 7C10 and 10F1, recognized an HHV-7 protein of 40 kDa, and only 7C10 cross-reacted with an HHV-6 protein of 45 kDa.

Benign acute myositis associated with rotavirus gastroenteritis

Acute myositis developed concomitantly with gastroenteritis in a 2-year-old girl. She had temporary pain and swelling of the calf muscles and transient marked elevation of serum creatine kinase values. Rotavirus antigen was detected in stool by latex agglutination, and there was seroconversion of complement-fixation antibody to rotavirus.

Identification and analyses of glycoprotein B of human herpesvirus 7.

The gene for the human herpes virus 7 (HHV-7) glycoprotein B (gB) has been identified by sequencing a molecularly cloned HHV-7 DNA fragment. A 2.5-kb open reading frame (ORF) encoded a protein of 822 amino acids with characteristics of a transmembrane glycoprotein, and showed the strongest similarity (56.5%) with the human herpesvirus 6 (HHV-6) gB. The genes for the transport/capsid assembly protein (tp/cap) and the DNA polymerase (pol) existed upstream and downstream of the gB gene, respectively. This arrangement was the same as that of HHV-6. Antisera were generated by immunizing mice with a glutathione S-transferase-carboxy terminal gB fusion protein. Immunofluorescent tests demonstrated that the antisera reacted specifically with HHV-7 antigens in cytoplasm of infected cells. The antisera immunoprecipitated proteins with apparent molecular masses of 51, 63 and 112 kDa from HHV-7 infected cells by pulse-chase analysis. In the presence of tunicamycin, the protein with a molecular mass of 112 kDa was replaced by a protein with a molecular mass of 88 kDa, and this size was consistent with the predicted size of the primary translation product of the HHV-7 gB gene. These results suggested that the protein with a molecular mass of 112 kDa was a glycoprotein synthesized by addition of N-linked oligosaccharides to a non-glycosylated precursor of the protein with a molecular mass of 88 kDa and then cleaved into the proteins with molecular masses of 51 and 63 kDa in HHV-7 infected cells.

Characterization of glycoprotein H and L of human herpesvirus 7.

The genes encoding the glycoproteins H (gH) and L (gL) of human herpesvirus 7 (HHV‐7) have been identified. The gH open reading frame (ORF) was 2,070 base pairs in length and encoded a predicted 690 amino‐acid protein. The gH contained characteristics of a transmembrane glycoprotein including 10 consensus N‐linked glycosylation sites, 12 cysteine residues, a potential amino‐terminal signal sequence and a predicted transmembrane segment located near the carboxyl terminus. The gL ORF was 738 base pairs in length and encoded a predicted 246 amino‐acid protein. Four possible N‐glycosylation sites and 6 cysteine residues existed within gL. The predicted amino‐acid sequences of the HHV‐7 gH and human herpesvirus 6 variant A (HHV‐6A) gH gene products exhibited 23.6% identity to each other, and those of the gL gene products had 26.0% identity. Upon in vitro translation of the gL gene, the addition of microsomal membranes resulted in two modified products with molecular weights of 32 kDa and 35 kDa from the unmodified initial translation product of 26 kDa. An amino‐terminal portion of gH and the full length of gL were expressed as glutathione S‐transferase fusion proteins, and these proteins were used to raise immune sera in mice. Lysates of cells infected with HHV‐7 were subjected to immunoprecipitation analysis. Approximate molecular weights of 33, 37, 80 and 90 kDa polypeptides were immunoprecipitated with antibodies against the gH protein. Antibodies against the gL protein polypeptides with the same molecular weights were also precipitated, and were observed with the antibodies against the gH protein. These results suggest that HHV‐7 gH and gL may form a heterodimeric complex with each other in HHV‐7 infected cells, as has been reported for other herpesviruses.

Safety, humoral and cell-mediated immune responses to herpes zoster vaccine in subjects with diabetes mellitus

OBJECTIVE To evaluate varicella zoster virus-specific cell-mediated immunity and humoral immunogenicity against the herpes zoster vaccine, which is licensed as the Live Varicella Vaccine (Oka Strain) in Japan, in elderly people with or without diabetes mellitus. METHODS A pilot study was conducted between May 2010 and November 2010 at Kitano Hospital, a general hospital in the city of Osaka in Japan. A varicella skin test, interferon-gamma enzyme-linked immunospot assay and immunoadherence hemagglutination tests were performed 0, 3, and 6 months after vaccination. Vaccine safety was also assessed using questionnaires for 42 days and development of zoster during the one-year observational period. We enrolled 10 healthy volunteers and 10 patients with diabetes mellitus aged 60-70 years. RESULTS The live herpes zoster vaccine boosted virus-specific, cell-mediated and humoral immunity between elderly people, with or without diabetes. Moreover, no systemic adverse reaction was found. None of the study participants developed herpes zoster. CONCLUSION The live herpes zoster vaccine was used safely. It effectively enhanced specific immunity to varicella zoster virus in older people with or without diabetes mellitus.

Depressed Levels of Interferon-Gamma and HLA-DR+CD3+ T Cells in Infants with Transient Hyperferritinemia

Familial hemophagocytic lymphohistiocytosis (FHL), which typically has its onset during infancy, is uniformly fatal if not treated. It therefore requires prompt therapeutic intervention. Although hyperferritinemia has been emphasized as a useful marker for FHL, some nonfatal cases in infants with spontaneous remission also manifest with hyperferritinemia. However, distinguishing them is difficult because initial clinical features of these infants are similar. The authors encountered 14 infants with hyperferritinemia (serum ferritin >674 ng/mL), which normalized within 3 weeks following a benign clinical course. The authors compared the levels of HLA-DR+CD3+ T-cell subsets and interferon-gamma (IFN-γ) in the peripheral blood between these infants and FHL cases: one of the authors’ own patients and others from the literature. Serum IFN-γ was not detected in infants with hyperferritinemia. Moreover, levels of HLA-DR+CD3+ T cells were extremely depressed. In contrast, serum IFN-γ was elevated and HLA-DR+CD3+ T cells were not depressed in FHL. Measurement of activated T cells and serum IFN-γ might help differentiate FHL in febrile infants with transient hyperferritinemia.

Vaccine-strain herpes zoster found in the trigeminal nerve area in a healthy child: A case report.

A previously healthy 2-year-old girl, vaccinated for varicella at 17 months, was admitted because of left-sided facial herpes zoster caused by vaccine-strain varicella-zoster virus (VZV). She recovered fully with no complication after intravenous treatment using acyclovir. Earlier reports have described that herpes zoster (HZ) rashes caused by vaccine-strain VZV tend to occur on the dermis corresponding to the skin area where the varicella vaccine was received. However, rashes appeared on this girl only in the trigeminal nerve area, which is unrelated to the vaccinated site. Results underscore the importance of distinguishing vaccine-strain VZV from wild-type VZV whenever encountering HZ cases after vaccination, even in immunocompetent children, irrespective of the skin lesion site. Monitoring vaccine-strain HZ incidence rates is expected to elucidate many aspects of varicella vaccine safety.

Low response to a monovalent inactivated unadjuvanted influenza A (H1N1) pdm09 vaccine in pediatricians of a general hospital in Japan

Immunization of health care personnel (HCP) is critically important to reduce healthcare-associated influenza infections substantially. During 2009–2010, 74% of all HCP at Kitano Hospital, Osaka, Japan, including 94% of pediatricians, received the monovalent unadjuvanted influenza A (H1N1) pdm09 vaccine. We evaluated the vaccine’s immunogenicity. Sixteen pediatricians received 15 μg hemagglutinin antigen subcutaneously. Antibody titer assays were conducted using hemagglutination-inhibition antibody assay on days 0 and 21 and at 5 mo after vaccination. Seroprotection rates, seroconversion rates, and geometric mean titer folds at 21 d were, respectively, 43.8%, 43.8% and 5.4 in all subjects, 70.0%, 70.0% and 8.0 in subjects aged 27–34 y, and 0.0%, 0.0% and 8.0 in subjects aged ≥ 35 y. None of the latter group met the European Medicines Agency criteria. We hope to adopt intradermal routes and further the development of the influenza vaccine using new technology to improve immunogenicity in Japan.