Prevalence of selective inhibition of HPV-16 DNA amplification in cervicovaginal lavages

• Published in: Journal of medical virology Vol. 72; no. 1; pp. 132 - 137
• Main Authors: Lefevre, Jonas, Hankins, Catherine, Pourreaux, Karina, Voyer, Hélène, Coutlée, François
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.01.2004; Wiley-Liss
• Subjects: Biological and medical sciences; cervical cancer; Cervix Uteri - virology; DNA - analysis; DNA, Viral - analysis; Epidemiology; Female; Fundamental and applied biological sciences. Psychology; Globins - genetics; HPV-16; Human papillomavirus 16; Human viral diseases; Humans; Infectious diseases; Medical sciences; Microbiology; Miscellaneous; Papillomaviridae - genetics; Papillomaviridae - isolation & purification; Papillomavirus Infections - virology; PCR inhibitors; Polymerase Chain Reaction - methods; Polymerase Chain Reaction - standards; quantitative PCR; real-time PCR; Uterine Cervical Neoplasms - virology; Vagina - virology; Vaginal Douching; Viral diseases; Viral Load; Virology; Prevalence; quantitative PCR; HPV-16; Papovaviridae; Malignant tumor; real-time PCR; Real time; Epidemiology; Female genital diseases; Papillomavirus; Virus; Polymerase chain reaction; Human papillomavirus 16; Human papillomavirus; Gene amplification; PCR inhibitors; Inhibitor; Uterine cervix diseases; Cervical cancer; Quantitative analysis
• ISSN: 0146-6615; 1096-9071
• DOI: 10.1002/jmv.10539

HPV‐16 viral load has been assessed with real‐time PCR assays by measuring HPV‐16 DNA and a human gene in genital samples. HPV‐16 viral load measurements are thus based on the inference that inhibitors contained in samples will equally impede amplification of DNA sequences from HPV‐16 and human DNA. We have previously shown that sample lysates can inhibit amplification of HPV‐16 but not β‐globin DNA. In the current study, cervicovaginal lavages lysates considered adequate for PCR analysis by a qualitative β‐globin PCR test, were screened for the presence of inhibitors using internal controls (IC) for HPV‐16 DNA and β‐globin in real‐time PCR assays. Of 150 lysates screened with both ICs, 12 (8%) contained inhibitors. Inhibition of amplification of both ICs was demonstrated in four of these specimens. In eight lysates, amplification of HPV‐16 IC only was impeded. Six (50%) of these 12 lysates tested positive for HPV‐16 DNA despite the presence of PCR inhibitors. The HPV‐16 viral load increased significantly after dilution of 11 of 12 lysates, demonstrating the presence of inhibitors in the undiluted lysate. Nine (90%) of 10 samples with inhibitors that were tested after dilution did not demonstrate inhibitory activity. The use of internal controls in real‐time PCR is clearly essential to determine HPV viral loads since the effect of inhibitors on primer‐driven genomic amplification is variable. J. Med. Virol. 72:132–137, 2004. © 2004 Wiley‐Liss, Inc.