Search PubMed⌕ Search

Biomedical subjects

Harutaka Katano

Publications and source records attributed to Harutaka Katano.

27 records · Page 2Linked to original sources
PubMed2003

Chronic active Epstein-Barr virus infection associated with mutations in perforin that impair its maturation.

Chronic active Epstein-Barr virus infection (CAEBV) is a rare disease in which previously healthy persons develop severe, life-threatening illness. Mutations in the perforin gene have been found in familial hemophagocytic lymphohistiocytosis, which shares some features with CAEBV. We studied a patient who died at age 18, 10 years after the onset of CAEBV. The patient had high titers of antibodies to EBV, EBV RNA in lymph nodes, T-cell lymphoproliferative disease, and hemophagocytic lymphohistiocytosis. DNA sequencing showed novel mutations in both alleles of the perforin gene that resulted in amino acid changes in the protein. The quantity of the native form of perforin from the patient's stimulated peripheral blood mononuclear cells (PBMCs) was extremely low and immunoblotting showed accumulation of an uncleaved precursor form of perforin. Stimulated PBMCs from the patient were defective for Fas-independent cytotoxicity. These data imply that mutations in this patient resulted in reduced perforin-mediated cytotoxicity by his lymphocytes. This is the first case in which perforin mutations have been shown to result in accumulation of the uncleaved, immature form of perforin. Mutations in the perforin gene are associated with some cases of CAEBV with hemophagocytic lymphohistiocytosis.

Adolescent↗
PubMed2003

Latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus interacts with human myeloid cell nuclear differentiation antigen induced by interferon alpha.

Kaposi's sarcoma-associated herpesvirus (KSHV)/human herpes virus type 8 (HHV-8) is tightly linked to the development of Kaposi's sarcoma, primary effusion lymphoma (PEL) and some cases of multicentric Castleman's disease. Latency-associated nuclear antigen (LANA) is one of a limited number of KSHV genes consistently expressed in these diseases as well as in KSHV-infected cell lines derived from PEL, and has been shown to play crucial role in persistence of KSHV genomes in the infected cells. In this study, we explored the cellular factors that interact with LANA using yeast two-hybrid screening, and isolated a part of gene encoding human myeloid cell nuclear differentiation antigen (MNDA). MNDA is a hematopoietic interferon-inducible nuclear proteins with a HIN-200 family member with conserved 200-amino acid repeats. Immunoprecipitation assay revealed that LANA interacted with MNDA in a mammalian embryonic kidney cell line. MNDA transcript was undetectable in three PEL cell lines by reverse-transcription polymerase chain reaction, but it was induced by interferon alpha (IFNalpha). Moreover, LANA and MNDA were co-localized in the nuclei of MNDA-expressing PEL cells. Our results suggest that LANA interacts with MNDA in KSHV-infected cells exposed to IFNalpha. Such interaction may modulate IFN-mediated host defense activities.

Antigens, Differentiation, Myelomonocytic↗
PubMed2003

Rapidly progressive human herpesvirus 8-associated solid anaplastic lymphoma in a patient with AIDS--associated Kaposi sarcoma.

We report a case of rapidly progressive solid lymphoma with anaplastic large cell morphology, followed by systemic Kaposi sarcoma in an adult patient with AIDS. The lymphoma cells expressed human herpesvirus 8 (HHV-8)-encoded latent and lytic proteins and Epstein-Barr virus-encoded small RNA, suggesting that this case could be categorized into HHV-8-associated solid lymphoma, a recently identified disease entity.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Secretion of interleukin-6 and vascular endothelial growth factor by spindle cell sarcoma complicating Castleman's disease (so-called 'vascular neoplasia').

So-called 'vascular neoplasia' (VN) is a rare tumour of unknown origin that complicates hyaline vascular type Castleman's disease (CD). This paper reports a case of VN complicating CD of hyaline vascular type, in which neoplastic cells were shown to secrete interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF). In this case, VN first occurred in the retroperitoneum of a 60-year-old male. The lesion showed typical morphology, with three distinct areas: (1) a lymph node-like area with regressively transformed lymph follicles showing hyaline vascular changes and with a hypervascular interfollicular region filled with slit-like vascular channels; (2) an area composed of spindle cell sarcoma; and (3) an area showing angiolipomatous hamartoma. A proportion of the cells in the spindle cell area showed severe pleomorphism. Subcutaneous recurrence after 8 months was composed purely of pleomorphic spindle cells. A karyotypic analysis of the recurrent tumour showed 47, XXY with some instability. Supernatant from primary culture contained high levels of IL-6 and VEGF, suggesting high secretion of these cytokines from neoplastic cells. Immunohistochemically, p53 overexpression was identified only in the pleomorphic spindle cells of the primary lesion and metastatic tumour. No features suggestive of vascular origin were shown on immunohistochemical or electron microscopic analysis of the neoplastic cells. Human herpesvirus type 8 was not detected by immunohistochemistry or PCR analysis. High levels of IL-6 and/or VEGF have been reported to play a role in CD. This is the first case report that clarifies the site of such cytokine production, showing the possibility of CD as a paraneoplastic phenomenon.

Castleman Disease↗
PubMed2002

AIDS presenting with cutaneous Kaposi's sarcoma and bacillary angiomatosis in the bone marrow mimicking Kaposi's sarcoma.

Kaposi's sarcoma (KS) and bacillary angiomatosis (BA) may be histologically similar. A precise diagnosis is required because of the different management of these diseases. KS or BA involving bone marrow is rare in patients with and without acquired immune deficiency syndrome (AIDS). We report the case of a 40-year-old human immunodeficiency virus (HIV)-positive homosexual male who presented with small KS lesions in the skin and BA in the bone marrow that histologically were similar. Laboratory evaluation revealed anemia and thrombocytopenia; CD4 count was 103/mm3, and the viral load was 750,000 HIV-1 mRNA copies per milliliter in plasma. Bartonella henselae, the etiologic agent of BA, was isolated from a blood culture. DNA sequences of human herpesvirus-8 (HHV-8), the putative etiologic agent of KS, were identified by polymerase chain reaction (PCR) in skin and bone marrow specimens, but antibody anti-HHV-8-encoded protein ORF73, localized signals only in the skin-KS lesion. The patient received clarithromycin and cefotetan for the BA, and antiretroviral therapy for the HIV infection. The skin lesions gradually regressed, the HIV-1 mRNA copy number decreased to less than 400 per milliliter and the CD4 lymphocyte count increased to 665/mm3. In conclusion, vascular lesions of BA and KS may be clinically and histologically similar, both may be associated with advanced AIDS, and an accurate diagnosis is required because of their different management.

AIDS-Related Opportunistic Infections↗
PubMed2002

The seroprevalence of human herpesvirus 8 infection in the Thai population.

The seroprevalence of human herpesvirus 8 (HHV-8) infection in the Thai population was investigated. Sera from 1,018 human immunodeficiency virus 1 (HIV-1)-negative and 436 HIV-1-positive individuals were tested for antibodies to latent and lytic HHV-8 antigens by indirect immunofluorescence assay (IFA) and an enzyme-linked immunosorbent assay (ELISA) using mixed recombinant orf HHV-8 proteins. The positive sera were further tested with recombinant HHV-8 protein expressed 293T cells by IFA. The seroprevalence of HHV-8 infection was determined by the concordant reactivity of sera among antibody testing assays. The results showed a low rate of HHV-8 seropositivity in both HIV-1-negative healthy individuals (0.6%) and HIV-1-infected patients (0.7%). These results are consistent with the fact that a small number of patients with AIDS-associated KS have been reported in Thailand and that HHV-8 is an uncommon pathogen in this country. Interestingly, we found that sera from the general population living in the north, but not other regions of Thailand, had antibodies to HHV-8.

Antibodies, Viral↗
PubMed2001

Molecular characterization of strains of Human herpesvirus 8 from Japan, Argentina and Kuwait.

Current genotyping systems for Human herpesvirus 8 (HHV-8) are based on the highly variable gene encoding the K1 glycoprotein. Most strains collected worldwide cluster into two subtypes (I/A and II/C). Sequenced African strains have belonged to subtypes I/A and IV/B. Members of all three of these subtypes can have either the M or P allele at the right-hand side (RHS) of the genome. Strains obtained predominantly from aboriginal or relatively isolated populations have formed clades that branch at a distance from subtypes I/A and II/C, all being of the RHS P allele. The characterization is reported here of 16 Japanese, two Kuwaiti and five Argentine HHV-8 strains obtained from human immunodeficiency virus-infected and non-infected patients with Kaposi's sarcoma (KS), primary effusion lymphoma, multicentric Castleman's disease or renal transplants. K1 sequences of five Japanese, one Kuwaiti and two Argentine strains were identified as subtype I/A and eight Japanese, one Kuwaiti and three Argentine strains were subtype II/C. Three strains from elderly classic KS patients originally from Hokkaido, a northern Japanese island, were relatively closely related to strains of subtypes III/D and E. Consistent with previous observations, both the M and P alleles were identified at the RHS of subgroup I/A and II/C genomes; only the P allele was detected among the three Hokkaido strains. Distances among the Hokkaido strains were similar to the distance between subtypes I/A and II/C, suggesting that the Hokkaido strains may represent two distinct subtypes and that, as more strains are analysed, the currently recognized III/D subgroups will probably emerge as independent subtypes.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Human herpesvirus-8 in Kaposi's sarcoma of the conjunctiva in a patient with AIDS.

PURPOSE: To demonstrate human herpesvirus-8 (HHV-8) in Kaposi's sarcoma (KS) of the conjunctiva in a patient with acquired immunodeficiency syndrome (AIDS). METHODS: Clinical observation, pathologic findings of conjunctival specimens, immunohistochemical staining for HHV-8-specific antigen, polymerase chain reaction (PCR) analysis of HHV-8 DNA, and detection of specific antibody in patient's serum at appropriate times. RESULTS: In the conjunctival specimen, swollen endothelial-like cells were found with slit-like vessels. CD 31-positive cells were noted on the inner surface of the slit-like vessels, and HHV-8 latency-associated nuclear antigen was detected. The presence of HHV-8 DNA was demonstrated by PCR. Anti-HHV-8 antibody was found in the patient's serum. CONCLUSIONS: This is the first case report in the ophthalmology literature that provides histological, DNA, and serological evidence that HHV-8 is involved in the pathogenesis of conjunctival KS.

Acquired Immunodeficiency Syndrome↗