A novel approach for the diagnosis of hepatitis B virus infection using nails and hair

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K08451
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 54030:Infectious disease medicine-related
• 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) ; 星野 廣樹 東邦大学, 医学部, 助教 (90810531)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: B型肝炎ウイルス / HBV DNA / 爪 / 毛髪 / HBs抗原 / 系統樹解析

Outline of Final Research Achievements

Hepatitis B virus (HBV) is detected in extrahepatic tissues of individuals with HBV infection. Whether nails and hair contain HBV has been unknown. Methods: We examined patients with chronic HBV infection. HBV DNA in the patients' fingernails and hair were measured by real-time PCR. Hepatitis B surface antigen (HBsAg) of fingernails was evaluated by an enzyme immunoassay. Immunochemical staining was performed on nails. Results： Of those 70 nail samples, 65 (93%) were HBV DNA-positive. Of the 60 hair samples, 49 (82%) were HBV DNA-positive. The nail HBV DNA level was significantly higher than the hair HBV DNA level. The nails and hair HBV DNA levels were correlated (r=0.325, p<0.05). A phylogenetic tree analysis of the complete genome sequence of HBV isolated from nails and hair identified the infection source. HBsAg was detected in the nails by immunochemical staining. Conclusions: Nails and hair were the reservoir of HBV DNA. Moreover, nails can contain HBsAg.

Free Research Field

感染症

Academic Significance and Societal Importance of the Research Achievements

医療資源が限られている国や地域ではB型肝炎ウイルス（HBV）感染の検査が受けられない場合も少なくない。血液はさまざまな病原体を含む検体であり、保存状態も制約を受けるため検査検体として扱いに注意を要する。爪や毛髪は高度にケラチン化された生体試料であり、疫学的には感染源とは考えられていない。感染性が低く、取り扱いが容易な検体を用いたHBV感染の診断方法が開発できれば、医療資源が限られている地域に対して貢献できる。また、国内でも血液検体を得られずHBV感染源特定が困難な場合、爪・毛髪は感染源特定の有用な試料となり得る。