Real-time PCR array for rapid detection of multiple viral pathogens should be highly useful in cases where the sample volume and the time of testing are limited, i.e. in the eligibility testing of tissue and organ donors.
Authors of this research work have developed a real-time PCR array capable of simultaneously detecting eight human viral pathogens: human immunodeficiency virus types 1 and 2 (HIV-1 and -2), hepatitis B virus (HBV), hepatitis C virus (HCV), human T-cell leukemia virus-1 and -2 (HTLV-1 and -2), vaccinia virus (VACV) and West Nile virus (WNV). Authors have designed using a combination of bioinformatics approaches one hundred twenty primers and, after experimental testing, 24 primer sets targeting eight viral pathogens were selected to set up the array with SYBR Green chemistry. Researchers test specificity and sensitivity of the virus-specific primer sets selected for the array using analytical panels with known amounts of viruses spiked into human plasma. The array detected: 10 genome equivalents (geq)/ml of HIV-2 and HCV, 50 geq of HIV-1 (subtype B), HBV (genotype A) and WNV. It detected 100–1,000 geq/ml of plasma of HIV-1 subtypes (A – G), group N and CRF (AE and AG) isolates. Further evaluation with a panel consisting of 28 HIV-1 and HIV-2 clinical isolates revealed no cross-reactivity of HIV-1 or HIV-2 specific primers with another type of HIV. All 28 viral isolates were identified with specific primer sets targeting the most conserved genome areas. The PCR array correctly identified viral infections in a panel of 17 previously quantified clinical plasma samples positive for HIV-1, HCV or HBV at as low as several geq per PCR reaction.
The viral array described here demonstrated adequate performance in the testing of donors’ clinical samples. Further improvement in its sensitivity for the broad spectrum of HIV-1 subtypes is under development and more extensive clinical validation will be necessary but shows a very interesting and promissing results.