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Background: Epidemiologic reports suggest that the most severe or fatal adenoviral disease in children might be associated with human adenovirus (HAdV) type 7. However, the pathogenesis of HAdV-7-induced severe disease remains poorly understood.Methods: HAdV-3 and HAdV-7 replication kinetics and the host response to infection were compared using ex vivo human lung tissue cultures. Furthermore, cytokine and chemokine levels and the presence of adenovirus DNA in the serum of hospitalized children infected with HAdV-7 (n = 65) or HAdV-3 (n = 48) were measured (using a multiplex immunoassay and Taqman real-time polymerase chain reaction, respectively).Results: Among 471 HAdV-positive specimens, HAdV-3 or HAdV-7 was the most prevalent genotype during 2014-2016 or 2018, respectively. The incidence of severe pneumonia was higher in HAdV-7-infected than in HAdV-3-infected individuals (30.1% vs 4.5%, respectively). HAdV-7 replicated more efficiently than HAdV-3 ex vivo. Interferon-induced protein 10, interleukin 6, and monocyte chemoattractant protein 1 levels were significantly higher in HAdV-7-infected than in HAdV-3-infected children. Adenovirus DNA was detected in serum samples from 40% and 4.2% of HAdV-7- and HAdV-3-infected children, respectively. Furthermore, viremia was strongly associated with severe clinical presentations.Conclusions: The pathogenesis of HAdV-7-induced severe disease was probably associated with high replication competence and hyperinflammatory responses. The detection of adenovirus DNA in blood may be useful in assessing risk for severe disease. [ABSTRACT FROM AUTHOR]

Background: Currently, the association between human immunodeficiency virus (HIV) infection and subsequent development of autoimmune hemolytic anemia (AIHA) remains unclear. This nationwide population-based cohort study aimed to determine the association between incident AIHA and HIV infection in Taiwan.Methods: During 2000-2012, we identified people aged ≧15 years living with HIV (PLWH) from the Taiwan Centers for Disease Control HIV Surveillance System. Individuals were considered to be infected with HIV on the basis of positive results of an HIV type 1 Western blot. Age- and sex-matched controls without HIV infection were selected from the Taiwan National Health Insurance Research Database for comparison. All patients were followed until 31 December 2012 and observed for occurrence of AIHA.Results: Of 171468 subjects (19052 PLWH and 152416 controls), 30 (0.02%) had incident AIHA during a mean follow-up of 5.45 years, including 23 PLWH (0.12%) and 7 controls (0.01%). After adjustment for age, sex, and comorbidities, HIV infection was found to be an independent risk factor of incident AIHA (adjusted hazard ratio, 20.9; 95% confidence interval, 8.34-52.3). Moreover, PLWH who were receiving highly active antiretroviral therapy were more likely to develop AIHA than those who were not receiving these drugs (adjusted hazard ratio, 16.2; 95% confidence interval, 3.52-74.2).Conclusions: Our study suggests that HIV infection is an independent risk factor for incident AIHA. [ABSTRACT FROM AUTHOR]

Background: Mechanisms by which spontaneous clearance of acute hepatitis C occurs are unclear. A critical role for the innate immune system and IFNL4 polymorphisms has been proposed. This study investigates whether Toll-like receptor (TLR) expression and signaling during acute hepatitis C correlates with clinical outcomes.Methods: Participants identified from the Australian Trial in Acute Hepatitis C and the Networks study were followed longitudinally from the time of diagnosis of acute hepatitis C. Peripheral blood mononuclear cells (PBMCs) and plasma were collected at and 2 time points after diagnosis. At each time point, TLR2, TLR4, and CD86 expression on peripheral blood monocytes, natural killer (NK) cells, and NK T cells was measured, as well as the response of PBMCs to stimulation with TLR ligands. Cytokine and chemokine levels were measured in stimulated PBMCs and plasma.Results: We identified 20 participants with acute hepatitis C (10 with hepatitis C virus [HCV] monoinfection and 10 with HCV and human immunodeficiency virus coinfection). Eleven participants (55%) spontaneously cleared HCV. Acute hepatitis C and spontaneous clearance was associated with lower TLR4 expression on monocytes (P = .009) and NK cells (P = .029). Acute hepatitis C and spontaneous clearance was also associated with a reduced interferon γ response to TLR4 (P = .038) and TLR7/8 stimulation (P = .035), a reduced interleukin 6 response to TLR7/8 stimulation (P = .037), and reduced IFN-γ-inducible protein 10 (IP-10) response to TLR2 stimulation (P = .042). Lower plasma IP-10 levels were associated with spontaneous clearance (P = .001).Conclusions: These findings implicate TLR4 signaling as playing a critical role in the outcome of acute hepatitis C. [ABSTRACT FROM AUTHOR]

Background: Clinical factors associated with hepatocellular carcinoma (HCC) have been extensively studied in antiviral treatment-naive patients with chronic hepatitis B virus (HBV) infection but not in treatment-experienced patients. Owing to the wide availability of antiviral agents that effectively suppress HBV replication, we investigated HCC risk factors in treatment-experienced patients.Methods: In a cohort of 330 patients who underwent pretherapeutic liver biopsy, we analyzed the HCC incidence in relationship to clinical parameters. Ultra-deep sequencing of the viral genome was performed on 11 entecavir-treated and pegylated interferon (peginterferon)-treated patients.Results: Initial univariate/multivariate explorations indicated that cirrhosis and antiviral treatment were independently associated with HCC occurrence. The peginterferon-experienced patients had a lower HCC incidence than the nucleos(t)ide analogue-treated patients (P = .011). The peginterferon and entecavir monotherapy groups also differed in HCC incidence (P = .018). Results of analysis of baseline-matched subgroups concurred with cohort analysis (P = .009 for comparison of peginterferon-experienced vs nucleotide analogue-treated patients; P = .022 for comparison of peginterferon- vs entecavir-treated patients). Viral loads of entecavir-treated patients were constantly suppressed to levels lower than those of peginterferon-treated patients (P < .001). Oncogenic surface antigen truncation mutations were detected in entecavir-treated patients with HCC but not in peginterferon-treated patients (P = .015).Conclusions: Treatment by peginterferon was associated with a lower HCC incidence than nucleos(t)ide-analogue treatment in chronic HBV infection. [ABSTRACT FROM AUTHOR]

Background. Previously, we reported that there was an outbreak of human immunodeficiency virus type 1 (HIV-1) circulating recombinant form (CRF) 07_BC among injection drug users (IDUs) in Taiwan in 2004. The objectives of the present study were to conduct a molecular epidemiological analysis and to characterize the fulllength genome of the Taiwanese CRF07_BC. Methods. Three hundred and fifty-eight patients with HIV-1/AIDS from hospitals and 133 HIV—1-infected inmates from detention centers were recruited. DNA sequencing and phylogenetic analysis were conducted to determine subtypes and evolutionary relationships. Recombination breakpoints of 2 full-length CRF07_BC strains were elucidated using a bootscanning method. Results. Of 206 HIV-1-infected patients who received a diagnosis in 2004, 44.7% were infected with subtype B, 53.4% with CRF07_BC, and 1.5% with CRF01_AE. Ninety-eight percent (109/111) of IDUs were infected with CRF07_BC. Deletions of 7-11 amino acids in both p6gag and p6pol proteins were noted among the Taiwanese CRF07_BC strains. The CRF_07BC strains belonged to 2 phylogenetic clusters, and the first cluster contained only CRF07_BC strains from the southern part of Taiwan. Conclusions. The Taiwanese CRF07_BC strains had 97% full-length sequence homology with the prototype from mainland China. CRF07_BC was first introduced into the southern region in 2002 and then spread to other regions in Taiwan in 2004. [ABSTRACT FROM AUTHOR]

Background: In 2003, Taiwan experienced a series of outbreaks of severe acute respiratory syndrome (SARS) and 1 laboratory-contamination accident. Here we describe a new phylogenetic analytical method to study the sources and dissemination paths of SARS-associated coronavirus (SARS-CoV) infections in Taiwan.Methods: A phylogenetic analytical tool for combining nucleotide sequences from 6 variable regions of a SARS-CoV genome was developed by use of 20 published SARS-CoV sequences; and this method was validated by use of 80 published SARS-CoV sequences. Subsequently, this new tool was applied to provide a better understanding of the entire complement of Taiwanese SARS-CoV isolates, including 20 previously published and 19 identified in this study. The epidemiological data were integrated with the results from the phylogenetic tree and from the nucleotide-signature pattern.Results: The topologies of phylogenetic trees generated by the new and the conventional strategies were similar, with the former having better robustness than the latter, especially in comparison with the maximum-likelihood trees: the new strategy revealed that during 2003 there were 5 waves of epidemic SARS-CoV infection, which belonged to 3 phylogenetic clusters in Taiwan.Conclusions: The new strategy is more efficient than its conventional counterparts. The outbreaks of SARS in Taiwan originated from multiple sources. [ABSTRACT FROM AUTHOR]

Antibody-dependent cellular cytotoxicity (ADCC) against human T lymphotropic virus (HTLV) types I and II was investigated using sera obtained from infected individuals or from rabbits immunized with HTLV-I or -II envelope peptides. Target cells included an HTLV-I-transformed cell line (C91/PL), an HTLV-II-transformed cell line (729pH6neo), and Epstein Barr virus (EBV)-transformed B lymphocytes expressing HTLV-lor -II env or gag gene products after infection with vaccinia/HTLV recombinants. ADCC activity was directed at HTLV-I and -II envelope glycoproteins but not against core (gag)components. In contrast to the human immunodeficiency virus system, significant cross-reactivity between HTLV-I- and -II-directed ADCC activity was observed. Epitope mapping studies using sera from rabbits that had been immunized with HTLV-I or -II envelope peptides suggested that the critical epitopes for ADCC activity are located primarily in hydrophilic regions of the exterior (gp46) part of the envelope glycoprotein. [ABSTRACT FROM PUBLISHER]

Adult T cell leukemia (ATL) is caused by the human T cell leukemia virus type I (HTLV-I). Although the mechanisms of the leukemogenic process are unknown, the tax gene may have a role in this process. Because clustering occurs with HTLV-I and ATL, members of ATL families were examined for antibodies to the tax protein and compared with matched HTLV-I-positive blood donors. To investigate the antibody response to this protein, a plasmid, pBHX-4, was constructed to express a recombinant tax protein (r-tax). For ATL patients and their HTLV-I antibody-positive blood relatives, the rate of seroreactivity with the r-tax protein was 67.3% (35/52), compared with 51.6% (97/188) for HTLV-I antibody-positive control blood donors (P less than .05). The difference between direct offspring of ATL patients and matched HTLV-I blood donors was even greater (84.2% [16/91] vs. 44.2% [42/95]; P less than .005). Thus, tax antibody positivity in direct offspring of ATL patients may reflect differences in time or route of HTLV-I infection. Alternatively, it might reflect genetic differences in host susceptibility or virus strain. [ABSTRACT FROM AUTHOR]