Related Experiment Video
Updated: Sep 24, 2025
Author Spotlight: Advancements and Challenges in Hepatitis B Virus Detection
Published on: December 15, 2023
Signature of chronic hepatitis B virus infection in nails and hair
Haruki Komatsu1, Ayano Inui2, Enkhtaivan Odmaa3
1Department of Pediatrics, Toho University, Sakura Medical Center, 564-1 Shimoshizu Sakura, Chiba, 285-8741, Japan. haruki-komatsu@chive.ocn.ne.jp.
Insights
Hepatitis B virus (HBV) DNA was detected in 93% of nails and 82% of hair samples from infected individuals. Nails also contained Hepatitis B surface antigen (HBsAg) and Hepatitis delta virus (HDV) RNA, suggesting they are reservoirs.
Area of Science:
- Virology
- Hepatology
- Infectious Diseases
Background:
- Hepatitis B virus (HBV) is known to exist in extrahepatic tissues.
- The presence and role of HBV in nails and hair remained uninvestigated.
Purpose of the Study:
- To determine if HBV DNA, HBsAg, and HDV RNA are present in human nails and hair.
- To investigate nails and hair as potential reservoirs for HBV and HDV.
Main Methods:
- Real-time PCR was used to detect HBV DNA and HDV RNA in nail and hair samples from patients with chronic HBV and/or HDV infections.
- Enzyme immunoassay detected HBsAg in fingernails.
- Immunochemical staining and phylogenetic analysis were performed.
- Chimeric mice with humanized livers were used to assess infectivity.
Main Results:
- HBV DNA was detected in 93% of nail samples and 82% of hair samples.
- HBsAg was found in 59% of nail samples, and HDV RNA in 20% of nail samples from co-infected patients.
- Nail HBV DNA levels were significantly higher than hair HBV DNA levels.
- Chimeric mice were not infected by nail-derived HBV DNA or HBsAg.
Conclusions:
- Nails and hair serve as reservoirs for HBV DNA.
- Nails can harbor HBsAg, HDV RNA, and HD antigen, indicating their potential role in HBV/HDV persistence.
Background:
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 two patient groups: those with chronic HBV infection alone (n = 71), and those with both chronic HBV and hepatitis delta virus (HDV) infections (n = 15). 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. HDV RNA in fingernails was measured by real-time PCR. Immunochemical staining was performed on nails. We used chimeric mice with humanized livers to evaluate the infectivity of nails.
Results:
Of the 71 pairs of HBV-alone nail and hair samples, 70 (99%) nail and 60 (85%) hair samples were positive for β-actin DNA. Of those 70 nail samples, 65 (93%) were HBV DNA-positive. Of the 60 hair samples, 49 (82%) were HBV DNA-positive. The serum HBV DNA level of the nail HBV DNA-positive patients was significantly higher than that of the nail HBV DNA-negative patients (p < 0.001). The hair HBV DNA-positive patients' serum HBV DNA level was significantly higher compared to the hair HBV DNA-negative patients (p < 0.001). The nail HBV DNA level was significantly higher than the hair HBV DNA level (p < 0.001). 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. Of the 64 nail samples, 38 (59%) were HBsAg-positive. All 15 pairs of chronic HBV/HDV infection nail and hair samples were β-actin DNA-positive. However, nail HBV DNA was detected in two patients (13%). None of the 15 patients were positive for hair HBV DNA. Nail HDV RNA was detected in three patients (20%). Of the 15 patients, eight (53%) were nail HBsAg-positive. HBsAg and hepatitis delta (HD) antigen were detected in the nails by immunochemical staining. Chimeric mice were not infected with PBS containing HBsAg and HBV DNA elucidated from nails.
Conclusions:
Nails and hair were the reservoir of HBV DNA. Moreover, nails can contain HBsAg, HDV RNA, and HD antigen.
Related Concept Videos
01:25Endocarditis II: Clinical Features of Infective Endocarditis
01:05Accessory Structures of the Skin: Nails
The main components of a nail include the following.
Nail Plate: The nail plate is the visible portion of the nail that extends beyond the fingertips or toes. It is a hard, translucent...
01:26Diseases of the Liver and Gallbladder
Cirrhosis is characterized by the scarring of hepatic lobules in the liver, which are replaced by fibrous tissue, affecting the liver's normal functioning. NAFLD, on the other hand, is caused by an excessive build-up of fat in the liver, not...