A Multiplexed Human Papillomavirus 16 and 18 Diagnostic Chip for Cervical Cancer in Limited-Resource Settings

Abstract

Abstract 16 Purpose Despite being treatable, cervical cancer is responsible for 300,000 deaths annually and is the second most frequent cause of cancer-related death worldwide. The burden of cervical cancer disproportionately falls on developing countries, where 87% of deaths occur from limited or no resources for screening. Of cervical cancer cases, 99% are caused by human papillomavirus (HPV), with more than 70% of cases from HPV genotypes 16 and 18. We developed a low-cost cervical cancer diagnostic chip to detect HPV 16 and 18 DNA quickly and reliably in limited-resource settings (LRSs). Methods Unlike conventional HPV diagnostics that use polymerase chain reaction and resource-intensive equipment, our chip used isothermal—one temperature—amplification, specifically loop-mediated amplification, and required only a heat source, which made it suitable for LRSs. Amplified DNA was visually detected on a lateral flow strip, which is similar to a pregnancy test, providing a simple yes or no readout. Specific line patterns indicated the presence of HPV 16, 18, both, or neither. Each chip was single use and self-contained to be easily disposed of as biohazard waste, which reduced the risk of contamination and false positives. Results The loop-mediated amplification assay was optimized to detect HPV 16 and 18 simultaneously. Sensitive and specific amplification of cloned HPV 16 and 18 DNA was achieved and confirmed via specific restriction enzyme digests. The lower limit of detection was 104 and 103 copies for HPV 16 and 18, respectively. Clinical samples, namely discarded cervical swab samples, were also tested with the chip. Results were comparable with the gold standard of polymerase chain reaction, which proves that the chip is feasible for clinical samples. Time to result was less than 1 hour, making the chip appropriate for LRSs. Conclusion Our multiplexed HPV 16 and 18 diagnostic chip is clinically relevant and provides a much-needed screening method for LRSs. The chip will increase access to screening for a treatable cancer and provide a faster route to treatment as well as a decrease in deaths from cervical cancer. AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST No COIs from the authors.