Mieko Goto

Polymorphism in the Interleukin-4 Promoter Affects Acquisition of Human Immunodeficiency Virus Type 1 Syncytium-Inducing Phenotype

ABSTRACT The emergence of syncytium-inducing (SI) variants of human immunodeficiency virus type 1 (HIV-1) in infected individuals is an indicator of poor prognosis and is often correlated with faster CD4+ cell depletion and rapid disease progression. Interleukin-4 (IL-4) is a pleiotropic cytokine with various immune-modulating functions including induction of immunoglobulin E (IgE) production in B cells, down-regulation of CCR5 (a coreceptor for HIV-1 non-SI [NSI] strains), and up-regulation of CXCR4 (a coreceptor for HIV-1 SI variants). Here we show that homozygosity of a polymorphism in the IL-4 promoter region, IL-4 −589T, is correlated with increased rates of SI variant acquisition in HIV-1-infected individuals in Japan. This mutation was also shown to be associated with elevated serum IgE levels in HIV-1-infected individuals, especially in those at advanced stages of disease. In contrast, neither a triallele polymorphism in IL-10, another Th2 cytokine, nor a biallele polymorphism in the RANTES promoter affected acquisition of the SI phenotype. This finding suggested that IL-4-589T increases IL-4 production in the human body and thus accelerates the phenotypic switch of HIV-1 from NSI to SI and possibly disease progression of AIDS.

Multicenter Study To Evaluate Bloodstream Infection by Helicobacter cinaedi in Japan

ABSTRACT Helicobacter cinaedi has being recognized as an important human pathogen which causes bloodstream infections. Although the first case of bacteremia with this pathogen in Japan was reported in 2003, the true prevalence of H. cinaedi as a pathogen of bloodstream infections in this country is not yet known. Therefore, the aim of our study was to assess the incidence of bacteremia with H. cinaedi in Japan. We conducted a prospective, multicenter analysis in 13 hospitals during 6 months in Tokyo, Japan. Among positive blood cultures from 1 October 2003 to 31 March 2004, isolates suspected of being Helicobacter species were studied for further microbial identification. Identification of the organisms was based on their biochemical traits and the results of molecular analysis of their 16S rRNA gene sequences. A total of 16,743 blood culture samples were obtained during the study period, and 2,718 samples (17.7%) yielded positive culture results for coagulase-negative staphylococci. Among nine isolates suspected to be Helicobacter species, six isolates were finally identified as H. cinaedi. The positivity rate for H. cinaedi in blood culture was 0.06% of total blood samples and 0.22% of blood samples with any positive culture results. All patients with bacteremia with H. cinaedi were found to have no human immunodeficiency virus (HIV) infection, but many of them had complications with either malignancy, renal failure, or a history of surgical operation. Therefore, our results suggest that bacteremia with H. cinaedi is rare but can occur in compromised hosts other than those with HIV infection in Japan.

Pneumocystis carinii carriage in immunocompromised patients with and without human immunodeficiency virus infection

Eighty-one bronchoalveolar lavage (BAL) specimens obtained from 26 HIV-infected, 45 non-HIV immunosuppressed and 10 immunocompetent patients with primary pulmonary diseases were analysed for the presence of Pneumocystis carinii by staining and by P. carinii 5S rDNA determined by PCR. P. carinii was observed by staining of BAL specimens from HIV-infected patients significantly more frequently than those from immunocompromised hosts without HIV infection (57.7% versus 20.0%, respectively). P. carinii 5S rDNA was detected by PCR assay in seven (26.9%) HIV-infected individuals, which was significantly more frequent than for four (8.9%) immunosuppressed patients without HIV infection, for whom staining was negative. None of these patients developed P. carinii pneumonia (PCP) within the follow-up period. BAL specimens from 10 immunocompetent patients with pulmonary disorders were negative for PCP by both staining and PCR assay.

Detection of Toxoplasma gondii by polymerase chain reaction in cerebrospinal fluid from human immunodeficiency virus-1-infected Japanese patients with focal neurological signs

We aimed to determine the effectiveness of using the polymerase chain reaction (PCR) to detect Toxoplasma gondii in cerebrospinal fluid (CSF) specimens from Japanese patients infected with human immunodeficiency virus (HIV)-1. Twenty-six HIV-positive individuals presenting with focal neurological signs and a possible diagnosis of T. gondii encephalitis (TE) were enrolled in the study between April 1997 and March 2003. Eight patients were diagnosed as having TE using the accepted diagnostic criteria; PCR amplified the T. gondii B1 gene in CSF samples from five of these eight patients. CSF samples from the 18 patients without TE were negative for T. gondii DNA. The sensitivity, specificity and positive and negative predictive values for detecting T. gondii in CSF using PCR were 62.5%, 100%, 100% and 85.7%, respectively. These results suggest that PCR might be a clinically useful technique for detecting T. gondii DNA in patients infected with HIV showing focal neurological signs. Improvements in sensitivity are needed, however.

Molecular Analysis of Human Herpesvirus 8 by Using Single Nucleotide Polymorphisms in Open Reading Frame 26

ABSTRACT Human herpesvirus 8 (HHV-8) can be classified into distinct subtypes on the basis of sequence polymorphisms in several open reading frames (ORFs). We analyzed the subtypes of HHV-8 in 59 human immunodeficiency virus-infected Japanese patients by using polymorphisms in ORF26 and found that over two-thirds of the HHV-8 isolates fell into major subtype A. We also found that single nucleotide polymorphisms (SNPs) at nucleotide positions 1032 (C-to-A substitution) and 1055 (G-to-T substitution) in HHV-8 ORF26 were correlated with increased susceptibility to Kaposis sarcoma, compared to the results obtained with HHV-8 with wild-type nucleotides at these positions (P = 0.0106). This observation suggests that molecular heterogeneity of the HHV-8 genome affects the biological properties of HHV-8, resulting in different clinical phenotypes of HHV-8 infection. Since sensitive PCR of ORF26 allowed us to analyze the SNPs by using peripheral blood from HHV-8-infected patients, the ORF26 SNPs will be a potent tool for investigating the pathogenesis of HHV-8 infection.

Novel polymorphisms in human macrophage inflammatory protein-1 alpha (MIP-1alpha) gene.

Human macrophage inflammatory protein-1 alpha (MIP-1α) is a chemotactic cytokine, which binds to macrophages, T cells, and B cells affecting their activation. We found novel polymorphisms at four sites within MIP-1α gene in Japanese population: C to T in exon 2; A to G in intron 2; C to G and A to G in exon 3. They occurred on the same allele. Although MIP-1α effectively suppresses the replication of HIV-1 in vitro, we observed no statistically significant difference in the allele frequency of this polymorphism between HIV-1-infected and uninfected individuals in Japanese population. Since an increased transcription level of MIP-1α has been reported to be associated with inflammatory diseases such as atopic dermatitis, we also investigated the frequency of these polymorphisms among patients with atopic dermatitis, HIV-1-infected individuals (with a normal IgE level), and healthy donors. A small increase in ratio of homozygotes to other genotypes was observed in patients with atopic dermatitis (P = 0.04).

Quantitative and qualitative abnormalities in HIV-1-specific T cells.

ObjectiveTo assess the characteristics of CD4 and CD8 T cells specific for HIV-1 and cytomegalovirus (CMV) antigens in untreated and treated HIV-1-infected patients. MethodsAntigen-specific T cell frequencies were determined by flow cytometric detection of antigen-induced intracellular cytokines. ResultsIn untreated patients, HIV-1-specific CD4 T cell counts in peripheral blood were less than one tenth of CMV-specific CD4 T cell counts, while the number of specific CD8 T cells was approximately the same for both HIV-1 and CMV. In patients treated with highly active antiretroviral therapy (HAART) for less than 1.5 years, HIV-1-specific CD4and CD8T cell counts were significantly lower than those in untreated patients. Perforin expression in HIV-1-specific CD8 T cells was significantly lower than that in CMV-specific CD8 T cells. ConclusionThese data indicate that HIV-1-specific T cells in HIV-1-infected patients have quantitative and qualitative abnormalities.

Utility of Testing Bronchoalveolar Lavage Fluid for Cryptococcal Ribosomal DNA

Bronchoalveolar lavage (BAL) specimens from 88 patients (33 infected with human immunodeficiency virus [HIV], 45 non-HIV immunosuppressed patients and 10 immunocompetent patients with primary pulmonary disease) were analysed for the presence of Cryptococcus neoformans. Staining, culture and an antigen testing were performed, and C. neoformans ribosomal DNA (rDNA) detected using the polymerase chain reaction (PCR). C. neoformans was detected, by staining and culture, in BAL specimens from two HIV-infected patients with pulmonary cryptococcosis, and the antigen test and rDNA assay were also positive in these samples. C. neoformans rDNA was detected by PCR in a non-HIV immunocompromised patient with Pneumocystis pneumonia, whose staining, culture and antigen tests were negative. The antigen test was positive for an immunocompetent patient with sarcoidosis, while staining, culture and the PCR assay were negative. These results do not support routine testing of BAL specimens for C. neoformans rDNA.

The IgM Antibody Level against Ganglioside GM2 Correlates to the Disease Status of HIV-1-Infected Patients

HIV‐1 infection induces the expression of high level of GM2 ganglioside on infected cells and IgM antibody (Ab) against GM2 can cause complement (C)‐mediated cytolysis of HIV‐1‐infected cells. Since GM2 is immunogenic in human, we proposed that an anti‐GM2 IgM Ab may be produced by some HIV‐1‐infected patients and the titer of this Ab might provide some insight into the progress of the disease. On this premise, the amount of IgM Ab against GM2 was determined in 124 HIV‐1‐infected patients and 111 seronegative donors. As expected, the anti‐GM2 IgM Ab titers of the patients was significantly higher than that of the seronegative donors while the total IgM levels remained unchanged. In addition, we determined the CD4+ cell count and the HIV‐RNA load in the HIV‐1‐infected patients. The results showed a positive correlation between the anti‐GM2 IgM Ab titer and CD4+ cell count but a negative correlation between the anti‐GM2 IgM Ab titer and HIV‐RNA load. These suggest that anti‐GM2 IgM Ab induced and/or enhanced by HIV‐1 infection causes C‐mediated cytolysis of HIV‐1‐infected cells in vivo to a certain extent, and may help lower the plateau level of the HIV‐RNA load. Therefore, the amount of IgM Ab against GM2 may be related to the prognosis of HIV‐1 infected patients.

Herpesvirus-like DNA Sequences in Japanese Patients with AIDS-related Kaposi's Sarcoma

The cause and origin of Kaposis sarcoma (KS) remain an enigma. Recently, Chang et al. reported a DNA fragment resembling human gamma herpesvirus that was specifically associated with KS tissue. In this paper, we report examination of three Japanese patients for presence of the KS-associated herpesvirus-like (KSHV) sequences. KSHV sequences were present in two of these patients, but could not be confirmed in the third because of DNA degradation. The KSHV sequences appeared to be present mainly in those tissues with KS invasion. Our results further demonstrate the presence of KSHV in KS lesions and support its role in the pathogenesis of KS.