Rapid diagnosis of human herpesvirus 6 infection by a novel DNA amplification method, loop-mediated isothermal amplification.
A novel nucleic acid amplification method, termed loop-mediated isothermal amplification (LAMP), which amplifies DNA with high specificity, efficiency, and rapidity under isothermal conditions, may be a valuable tool for the rapid detection of infectious agents. LAMP was developed for human herpesvirus 6 (HHV-6), and its reliability was evaluated in this study. Although LAMP products were detected in HHV-6 B and HHV-6 A DNA, they were not detected in HHV-7 and human cytomegalovirus DNA. The sensitivity of the original HHV-6 LAMP protocol was 50 copies/tube. In order to increase the method's sensitivity, HHV-6 LAMP was modified by increasing the primer concentration. As a result of the modification, sensitivity increased to 25 copies/tube. After these initial validation studies, 13 patients with fever were tested for HHV-6 by viral isolation, serological analysis, and HHV-6 LAMP. In three of the eight patients with primary HHV-6 infection, HHV-6 DNA was detected in whole blood by the original HHV-6 LAMP protocol in not only the acute phase but also the convalescent phase. HHV-6 DNA was detected by modified HHV-6 LAMP in all eight plasma samples collected in the acute phase; however, no HHV-6 DNA was detected in plasma samples collected in the convalescent phase. Although HHV-6 DNA was detected in both the acute and convalescent phases of whole-blood samples in patients with past HHV-6 infection, it was not detected in plasma samples that did not contain latent viral DNA. Thus, detection of HHV-6 DNA in plasma by using this modified HHV-6 LAMP protocol is appropriate for diagnosis of active HHV-6 infection.
Ihira
Masaru
M
Department of Medical Information Technology, Fujita Health University College, Konan, Aichi, Japan.
Yoshikawa
Tetsushi
T
Enomoto
Yoshihiko
Y
Akimoto
Shiho
S
Ohashi
Masahiro
M
Suga
Sadao
S
Nishimura
Naoko
N
Ozaki
Takao
T
Nishiyama
Yukihiro
Y
Notomi
Tsugunori
T
Ohta
Yoshinori
Y
Asano
Yoshizo
Y
D001483:Base Sequence; D004279:DNA, Viral / Q000032:analysis; D005077:Exanthema Subitum / Q000175:diagnosis*; D015654:Herpesvirus 6, Human / Q000235:genetics*; D008969:Molecular Sequence Data; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity
D004279:DNA, Viral