Assessment of the possible inhibitory effect of carrageenan in human papillomavirus DNA testing by polymerase chain reaction amplification

• Published in: Journal of medical virology Vol. 93; no. 11; pp. 6408 - 6411
• Main Authors: Laurie, Cassandra, El‐Zein, Mariam, Franco, Eduardo L., Coutlée, François
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01-11-2021
• Subjects: Adult; Amplification; Carrageenan; Carrageenan - pharmacology; Carrageenans; Copy number; Deoxyribonucleic acid; Dilution; DNA; DNA testing; DNA, Viral - analysis; Experiments; Female; gels; Human papillomavirus; Human Papillomavirus DNA Tests - methods; Human Papillomavirus DNA Tests - standards; Humans; nucleic acid amplification techniques; Papillomaviridae - drug effects; Papillomaviridae - genetics; Papillomavirus Infections - diagnosis; Papillomavirus Infections - virology; Placebos; Polymerase chain reaction; Polymerase Chain Reaction - methods; Polymerase Chain Reaction - standards; Specimen Handling - methods; Vagina; Vagina - drug effects; Vagina - virology; Virology; Young Adult; female; carrageenan; gels; human papillomavirus; nucleic acid amplification techniques
• ISSN: 0146-6615; 1096-9071
• DOI: 10.1002/jmv.26963

We assessed carrageenan's potential to inhibit human papillomavirus (HPV) DNA extraction and amplification in vaginal swab samples collected in a trial, assessing the efficacy of a carrageenan‐based gel against HPV infections. Experiment #1 consisted of adding gel (carrageenan‐containing or placebo) to swabs and comparing HPV DNA detection by polymerase chain reaction (PCR) to unmanipulated samples collected from the same participants. For Experiments #2 and #3, we tested vaginal samples for inhibition by addition of an internal control and amplification by real‐time PCR. Experiment #4 investigated carrageenan's interference with the extraction process by assessing HPV45 detectability in undiluted and diluted HPV45 positive samples (n = 3) with carrageenan versus no gel. In Experiment #1, there was a loss of HPV positivity with the addition of carrageenan (n = 9), but none with placebo gel (n = 5). In Experiments #2 and #3, the absence of the amplified product was observed in samples from the carrageenan arm: 3.3% (1/30) and 0.5% (1/199) of samples. In Experiment #4, HPV45 was not detected in undiluted carrageenan‐containing samples, but after 1/50 dilution, the same HPV45 copy number was detected. Carrageenan does not affect the DNA extraction process, and inhibition of HPV DNA amplification by carrageenan occurs infrequently.