Evaluation of the escape mutant of the hepatitis B virus as a minor strain in mother-to-child transmission

• Project/Area Number: 15K09701
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Pediatrics
• Research Institution: Toho University
• Principal Investigator: KOMATSU Haruki 東邦大学, 医学部, 准教授 (80424711)
• Co-Investigator(Kenkyū-buntansha): 舘野 昭彦 東邦大学, 医学部, 教授 (10138993)
• Research Collaborator: INUI Ayano
• Project Period (FY): 2015-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2017: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2016: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2015: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
• Keywords: B型肝炎ウイルス / 母子感染 / ワクチン / HBIG / S抗原 / 変異株 / minor clone / 予防不成功 / 遺伝子変異 / 感染予防 / B型肝炎 / 変異ウイルス

Outline of Final Research Achievements

The frequency of the G145R mutant as a minor as well as major strain was approximately 25% in children who were infected due to immunoprophylaxis failure. HBeAg positivity and high viremia were closely related to the detection of the G145R mutant as a minor population in patients without a history of HB vaccinations, HBIG, or antiviral treatment. Although the G145R mutant as a minor population was detected in pregnant women who were HBeAg-positive and had a high viral load, none of the infants born to the mothers infected with the G145R mutation showed breakthrough infection. Thus, the pre-existence of the G145R mutation as a minor population in mothers does not always cause immunoprophylaixs failure after birth. However, treatment with nucleotide analogues for HBV carrier pregnant women, based on an HBeAg-positive status and the level of HBV DNA, should be encouraged to reduce the risk of breakthrough infection.

Research Products

• [Journal Article] 急性肝炎 (2017)
  • Author(s): 小松 陽樹, 乾 あやの, 梅津 守一郎, 十河 剛, 藤澤 知雄
  • Journal Title: 小児科 Volume: 58 Pages: 1519-1522
• [Journal Article] ウイルス性肝炎 (2017)
  • Author(s): 小松 陽樹, 乾 あやの, 梅津 守一郎, 十河 剛, 藤澤 知雄
  • Journal Title: 小児内科 Volume: 49 Pages: 1629-1633
• [Journal Article] Evaluation of the G145R Mutant of the Hepatitis B Virus as a Minor Strain in Mother-to-Child Transmission (2016)
  • Author(s): Komatsu H, Inui A, Umetsu S, Tsunoda T, Sogo T, Konishi Y, Fujisawa T.
  • Journal Title: PLoS One Volume: 11 Issue: 11 Pages: e0165674-e0165674
  • DOI: 10.1371/journal.pone.0165674
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Presentation] B型肝炎母子感染におけるG145R変異株の検討 (2016)
  • Author(s): 小松陽樹、乾あやの、藤沢知雄
  • Organizer: 第52回日本肝臓学会総会
  • Place of Presentation: 東京ベイ幕張ホール （千葉県、千葉市）
  • Year and Date: 2016-05-19
• [Presentation] Evaluation of the G145R mutant as a minor form in mother-to-child transmission of hepatitis B virus (2016)
  • Author(s): Haruki Komatsu, Ayano Inui, Shuichiro Umetsu, Kentaro Iwasawa, Tomoyuki Tsunoda, Tsuyoshi Sogo, Tomoo Fujisawa
  • Organizer: 34th European Society for Pediatric Infectious Diseases
  • Place of Presentation: ブライトン（英国）
  • Year and Date: 2016-05-12
  • Int'l Joint Research