Yuu Shimozuma

Showa University, Shinagawa, Tōkyō, Japan

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Publications (5)7.83 Total impact

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    ABSTRACT: Hepatitis C virus (HCV) infects and associates with B cells, leading to abnormal B-cell activation and development of lymphoproliferative and autoimmune disorders. This immune perturbation may in turn be associated with the resistance of HCV against the host immune system. The objective of this study was to analyse the effects of HCV infection of B cells on the efficacy of interferon (IFN)-based therapy. The study enrolled 102 patients with chronic hepatitis C who were treated with pegylated IFN plus ribavirin. HCV RNA titres in B cells were compared in patients with rapid viral responder (RVR) vs non-RVR, sustained viral responder (SVR) vs non-SVR and null viral responder (NVR) vs VR. The levels of HCV RNA in B cells were significantly higher in non-RVR, non-SVR and NVR groups. Association between the therapy outcome and the positive B-cell HCV RNA was also investigated in relation to other known viral and host factors. Multivariable analyses showed that the positive B-cell HCV RNA and the minor single-nucleotide polymorphism near the IL28B gene (rs8099917) were independent factors associated with NVR in patients infected with HCV genotype 1. When these two factors were combined, the sensitivity, specificity, positive and negative predictive values for NVR were 92.3%, 98.2%, 92.3% and 98.2%, respectively. Genotype 1 and the presence of one or no mutations in the IFN-sensitivity determining region were associated with higher levels of B-cell HCV RNA. B-cell-tropic HCV appears to have an IFN-resistant phenotype. B-cell HCV RNA positivity is a predictive factor for resistance to IFN-based therapy.
    Journal of Viral Hepatitis 04/2012; 19(4):254-62. · 3.08 Impact Factor
  • Nippon rinsho. Japanese journal of clinical medicine 05/2011; 69 Suppl 4:302-8.
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    ABSTRACT: Hepatitis C virus (HCV) infection is associated with lymphoproliferative disorders. HCV infection of B cells is a predictive factor for lymphoproliferative disorders in patients with chronic hepatitis C, although its molecular mechanisms remain unknown. Epstein-Barr virus (EBV) is a B cell-tropic virus with the potential to cause lymphoproliferative disorders, and its reactivation is induced by several viruses and cytokines. The possibility that HCV infection triggers reactivation of EBV and induces lymphoproliferative disorders were investigated. Expression of EBV mRNAs was analyzed by RT-PCR in patients infected with HCV and control subjects, and correlations between reactivation of EBV and markers for lymphoproliferative disorders were investigated. BZLF1 mRNA, a starter molecule of reactivation, was detected in peripheral blood mononuclear cells from 12 of 52 (23%), patients infected with HCV and the frequency was higher than in healthy subjects [3 of 43 (9%), P = 0.032]. But the presence of the BZLF1 mRNA was not associated with an abnormality of markers for lymphoproliferative disorders. This study on BZLF1 mRNA expression among lymphoid cell subsets showed that reactivation of EBV was observed specifically in B cells. The BZLF1 mRNA disappeared following anti-viral therapy and remained negative after eradication of HCV in patients with a sustained viral response, while the EBER1 RNA, a marker for persistence of EBV, was detected throughout the therapy. Infection with HCV induces reactivation of EBV in B cells, but this reactivation was not associated directly with lymphoproliferative disorders triggered by HCV. J. Med. Virol. 82:2064-2072, 2010. © 2010 Wiley-Liss, Inc.
    Journal of Medical Virology 12/2010; 82(12):2064-72. · 2.37 Impact Factor
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    ABSTRACT: Infection with hepatitis C virus (HCV) is associated with lymphoproliferative disorders, represented by essential mixed cryoglobulinemia and B-cell non-Hodgkin's lymphoma, but the pathogenic mechanism remains obscure. HCV may infect B cells or interact with their cell surface receptors, and induce lymphoproliferation. The influence of HCV infection of B cells on the development of lymphoproliferative disorders was evaluated in 75 patients with persistent HCV infection. HCV infection was more prevalent (63% vs. 16%, 14%, or 17% P < 0.05 for each), and HCV RNA levels were higher (3.35 +/- 3.85 vs. 1.75 +/- 2.52, 2.15 +/- 2.94 or 2.10 +/- 2.90 log copies/100 ng, P < 0.01 for each) in B cells than CD4(+), CD8(+) T cells or other cells. Negative-strand HCV RNA, as a marker of viral replication, was detected in B cells from four of the 75 (5%) patients. Markers for lymphoproliferative disorders were more frequent in the 50 patients with chronic hepatitis C than the 32 with chronic hepatitis B, including cryoglobulinemia (26% vs. 0%, P < 0.001), low CH(50) levels (48% vs. 3%, P = 0.012), and the clonality of B cells (12% vs. 0%, P < 0.01). By multivariate analysis, HCV RNA in B cells was an independent factor associated with the presence of at least one marker for lymphoproliferation (odds ratio: 1.98 [95% confidence interval: 1.36-7.24], P = 0.027). Based on the results obtained, the infection of B cells with HCV would play an important role in the development of lymphoproliferative disorders.
    Journal of Medical Virology 03/2009; 81(4):619-27. · 2.37 Impact Factor
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    ABSTRACT: We present two cases of tuberculous peritonitis with liver cirrhosis complicated by refractory ascites. Case 1 was a 59-year-old female with alcoholic liver cirrhosis. She was admitted to our hospital because of diarrhea, anorexia and inflammatory reactions on a blood test. She had a high fever of 38°C or more and refractory ascites. Tubercle bacilli infection was suspected based on increased levels of serum CA125 and adenosine deaminase (ADA) in ascites. Laparoscopic examination showed white nodules on the peritoneum, and histologic study confirmed tuberculous nodules. The same bacteria were isolated from culture of ascites. Case 2 was a 55-year-old female with hepatitis C virus-infected liver cirrhosis. She was admitted because of high fever and abdominal fullness due to ascites. High levels of serum CA125 and ADA in ascites and ineffectiveness of treatment with antibiotics plus diuretics led us to start anti-tuberculous therapy before definitive diagnosis. Tuberculus bacillus was later isolated from culture of ascites. It is difficult to make early diagnosis of tuberculous peritonitis in cirrhotic patients with ascites due to a lack of specific symptoms. However, determination of serum CA125 and ADA in ascites and the acid-fast bacterial culture of ascites are useful for early diagnosis.
    Clinical Journal of Gastroenterology 2(4):300-305.