Shinya Yamaguchi

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Publications (2)2.35 Total impact

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    Article: High CD4/CD45RO+ and CD8/CD45RO+ frequencies in children with vaccine-modified measles.
    Michael M Addae, John K A Tetteh, Naruhiko Ishiwada, Yasuhiro Komada, Shinya Yamaguchi, David Ofori-Adjei, Hitoshi Kamiya, Bartholomew D Akanmori
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    ABSTRACT: Despite availability and wide vaccine coverage, measles infections still occur especially in developing countries. An outbreak of measles occurred among previously immunized older Ghanaian children who had milder clinical symptoms with measles-specific IgG antibodies that could have been attributed to secondary vaccine failure, suggesting that the infection was vaccine-modified measles (VMM). Two-color immunophenotyping of the peripheral blood mononuclear cells was performed at acute, recovery and convalescence phases for 19 VMM patients (mean age 6.2 +/- 3.5 years) using flow cytometry, and compared with that of 20 healthy, sex- and age-matched controls. The results showed a significantly higher memory helper (CD4(+)/CD45RO(+)) cell frequency and increased suppressor cell (CD8(+)/CD45R0(+)) frequency in VMM patients compared to healthy controls. There were no complications and all the patients recovered completely. These findings show that the mild symptoms in patients with VMM may have correlated with the increase of memory T cells, which is in sharp contrast with previous reports on acute measles infection. This may suggest that the intact immunologic memory cells could have been crucial for the resolution of VMM.
    Pediatrics International 11/2006; 48(5):449-53. · 0.63 Impact Factor
  • Article: Plasma levels of Th1 and Th2 cytokines in Ghanaian children with vaccine-modified measles.
    John K A Tetteh, Mark M Addae, Naruhiko Ishiwada, Sena M Yempewu, Shinya Yamaguchi, David Ofori-Adjei, Hitoshi Kamiya, Yoshihiro Komada, Bartholomew D Akanmori
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    ABSTRACT: To understand the pathogenesis of vaccine-modified measles (VMM), we measured plasma levels of IFN-gamma and IL-2 (Th1 cytokines), IL-4 and IL-10 (Th2 cytokines), IL-12, TNF-alpha and TGF-beta1 in children with uncomplicated measles, who had anti-measles IgG antibodies and with a history of immunization on admission (day 0), day 14 and day 60. We compared these to levels in healthy, age-matched, immunized children. Plasma levels of IFN-gamma, IL-2 and IL-12 were significantly higher in VMM patients on day 0 compared to healthy controls (p = 0.023; p = 0.018; p = 0.001) respectively. In contrast, plasma IL-4 was lower in VMM patients on day 0 when compared to the controls (p = 0.009). Plasma levels of IL-12 remained consistently high on days 14 and 60 (p = 0.001; p = 0.04), whilst IL-10 levels fell significantly on the same days (p = 0.002; p = 0.001) respectively. Kinetically, IFN-gamma and IL-10 levels decreased consistently from day 0 to days 14 and 60 in VMM patients. In contrast, IL-4 levels increased from day 0 to day 14 and day 60. Our results therefore suggest that VMM is associated with an early up-regulation of Th1 cytokine production and a down-regulation of Th2 cytokine production. The strong Th1 response may be associated with the induction of IL-12 and memory cells, thus contributing to the early resolution of the infection and lack of complications.
    European cytokine network 14(2):109-13. · 1.73 Impact Factor
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