Performance evaluation of the HepB Typer-Entecavir kit for detection of entecavir resistance mutations in chronic hepatitis B.
OBJECTIVE
Molecular diagnostic methods have enabled the rapid diagnosis of drug-resistant mutations in hepatitis B virus (HBV) and have reduced both unnecessary therapeutic interventions and medical costs. In this study we evaluated the analytical and clinical performances of the HepB Typer-Entecavir kit (GeneMatrix, Korea) in detecting entecavir-resistance-associated mutations.


METHODS
The HepB Typer-Entecavir kit was evaluated for its limit of detection, interference, cross-reactivity, and precision using HBV reference standards made by diluting high-titer viral stocks in HBV-negative human serum. The performance of the HepB Typer-Entecavir kit for detecting mutations related to entecavir resistance was compared with direct sequencing for 396 clinical samples from 108 patients.


RESULTS
Using the reference standards, the detection limit of the HepB Typer-Entecavir kit was found to be as low as 500 copies/mL. No cross-reactivity was observed, and elevated levels of various interfering substances did not adversely affect its analytical performance. The precision test conducted by repetitive analysis of 2,400 replicates with reference standards at various concentrations showed 99.9% agreement (2398/2400). The overall concordance rate between the HepB Typer-Entecavir kit and direct sequencing assays in 396 clinical samples was 99.5%.


CONCLUSIONS
The HepB Typer-Entecavir kit showed high reliability and precision, and comparable sensitivity and specificity for detecting mutant virus populations in reference and clinical samples in comparison with direct sequencing. Therefore, this assay would be clinically useful in the diagnosis of entecavir-resistance-associated mutations in chronic hepatitis B.
Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea. ; Liver Cirrhosis Clinical Research Center, Seoul, Korea. ; Brain Korea 21 Project for Medical Science, Seoul, Korea.
Sang Hoon
SH
Ahn
Research and Development Center, GeneMatrix Inc., Seongnam, Korea.
Ji-Yong
JY
Chun
Research and Development Center, GeneMatrix Inc., Seongnam, Korea.
Soo-Kyung
SK
Shin
Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea. ; Liver Cirrhosis Clinical Research Center, Seoul, Korea.
Jun Yong
JY
Park
Research and Development Center, GeneMatrix Inc., Seongnam, Korea.
Wangdon
W
Yoo
Research and Development Center, GeneMatrix Inc., Seongnam, Korea.
Sun Pyo
SP
Hong
Research and Development Center, GeneMatrix Inc., Seongnam, Korea.
Soo-Ok
SO
Kim
Department of Internal Medicine, Institute of Gastroenterology, Yonsei University College of Medicine, Seoul, Korea. ; Liver Cirrhosis Clinical Research Center, Seoul, Korea. ; Brain Korea 21 Project for Medical Science, Seoul, Korea.
Kwang-Hyub
KH
Han
D000328:Adult; D000998:Antiviral Agents / Q000627:therapeutic use*; D003429:Cross Reactions; D004279:DNA, Viral / Q000097:blood / Q000592:standards; D024882:Drug Resistance, Viral / Q000235:genetics*; D005838:Genotype; D006147:Guanine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D006515:Hepatitis B virus / Q000235:genetics; D019694:Hepatitis B, Chronic / Q000188:drug therapy* / Q000235:genetics; D006801:Humans; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000592:standards; D011933:Reagent Kits, Diagnostic / Q000592:standards*; D012015:Reference Standards; D017422:Sequence Analysis, DNA; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000592:standards
D000998:Antiviral Agents; D004279:DNA, Viral; D011933:Reagent Kits, Diagnostic; C413685:entecavir; D006147:Guanine
Drug; Entecavir; HBV; MALDI-TOF; Resistance mutation