Qualitative multiplex RT-PCR for simultaneous detection of hepatitis C virus and human immunodeficiency virus in plasma samples

Mahfouz M, Zytouni DM. Detection of human bocavirus in Saudi healthy blood donors

Human bocavirus is associated with respiratory disease worldwide, mainly in children. There are conflicting results, however, regarding the existence of the HBoV in blood donors. Three hundred whole blood samples from non-immunodeficient healthy blood donors were screened for the presence of HBoV by polymerase chain reaction. The HBoV genotype of positive samples was determined using direct gene sequencing. Twenty-one out of the three hundred blood samples were found to be positive for HBoV. Sequence analysis of the positive samples revealed that all the strains were related to the HBoV-1 type with a low rate of variation among the detected sequences. It was concluded that there is a considerable risk of contracting HBoV from a blood transfusion from normal healthy individuals.

A novel multiplex real-time PCR assay for the concurrent detection of hepatitis A, B and C viruses in patients with acute hepatitis

A novel multiplex real-time PCR assay for concurrent detection of hepatitis viruses was evaluated for its clinical performance in screening patients with acute hepatitis. A total of 648 serum samples were collected from patients with acute symptoms of hepatitis. Concurrent detection of nucleic acids of HAV, HBV and HCV was performed using the Magicplex™ HepaTrio Real-time Detection test. Serum nucleic acid levels of HBV and HCV were also quantified by the Cobas® AmpliPrep/Cobas® TaqMan® (CAP/CTM) HBV and HCV tests. Patients’ medical records were also reviewed. Concordance rates between the results from the HepaTrio and the CAP/CTM tests for the detection of HBV and HCV were 94.9% (k = 0.88) and 99.2% (k = 0.98), respectively. The cycle threshold values with the HepaTrio test were also correlated well with the levels of HBV DNA (r = −0.9230) and HCV RNA (r = −0.8458). The sensitivity and specificity of the HepaTrio test were 93.8% and 98.2%, respectively, for detecting HBV infection, and 99.1% and 100.0%, respectively, for HCV infection. For the HepaTrio test, 21 (3.2%) cases were positive for both HBV and HCV. Among the positive cases, 6 (0.9%) were true coinfections. This test also detected 18 (2.8%) HAV positives. The HepaTrio test demonstrated good clinical performance and produced results that agreed well with those of the CAP/CTM assays, especially for the detection of HCV. This assay was also able to detect HAV RNA from anti-HAV IgM-positive individuals. Therefore, this new multiplex PCR assay could be useful for the concurrent detection of the three hepatitis viruses.

Design and development of an in-house multiplex RT-PCR assay for simultaneous detection of HIV-1 and HCV in plasma samples

BACKGROUND AND OBJECTIVES

HIV-1 and HCV infections are life threatening problems in patients who receive blood products. Serological methods have proven useful in detecting these infections, but there are setbacks that make it challenging to detect these infectious agents. By the advent of Nucleic Acid Testing (NAT) methods, especially in multiplex format, more precise detection is possible.

MATERIALS AND METHODS

We have developed a multiplex RT-PCR assay for simultaneous detection of HIV-1 and HCV. Primers were designed for highly conserved region of genome of each virus. Using these primers and standard plasmids, we determined the limit of detection, clinical and analytical specificity and sensitivity of the assay. Monoplex and multiplex RT-PCR were performed.

RESULTS

Analytical sensitivity was considered to be 100 and 200 copies/ml for HIV-1 and HCV, respectively. High concentration of one virus had no significant effect on the detection of the other one with low concentration. By analysis of 40 samples, clinical sensitivity of the assay was determined to be 97.5%. Using different viral and human genome samples, the specificity of the assay was evaluated to be 100%.

CONCLUSIONS

The aim of this study was to develop a reliable, rapid and cost effective method to detect HIV-1 and HCV simultaneously. Results showed that this simple and rapid method is perfectly capable of detecting two viruses in clinical samples.

A novel real-time multiplex reverse transcriptase-polymerase chain reaction for the detection of HIV-1 RNA by using dual-specific armored RNA as internal control

OBJECTIVE

Transmission of HIV-1 and diagnosis of infection in hospitals and public health settings remains a worldwide concern. HIV-1 detection is sometimes not possible using current commercial assays, probably due to mismatches between the selected primers and probes.

METHODS

By screening primers and probes, we developed a dual-specificity probe real-time reverse transcriptase-polymerase chain reaction (DSPrtRT-PCR) assay using dual-specific armored RNA as the internal control. The specificity and sensitivity were compared between the monospecificity probe real-time and DSPrtRT-PCR techniques.

RESULTS

The sensitivity of DSPrtRT-PCR improved significantly, with no effect on its specificity. The detection limit was 173 IU/ml. All the HIV-1 group M and group O could be detected. In clinical assays, 1,000 copies/ml of armored RNA was required as internal control. When applied to negative samples, 100% specificity was achieved. Among 60 samples from the tested patients, DSPrtRT-PCR demonstrated high sensitivity, accurately detecting 50 positives and 10 negatives that were confirmed by the COBAS AmpliScreen assay.

CONCLUSION

DSPrtRT-PCR is a more efficient and effective viral assay with high sensitivity and specificity as compared to monospecificity probe PCR. It can be widely applied in blood donor screening and qualitative individual detection of HIV-1 RNA.

Simultaneous detection of HCV and HIV-1 by SYBR Green real time multiplex RT-PCR technique in plasma samples

This paper describes the development of a SYBR Green-based multiplex real time RT-PCR for the simultaneous detection of HCV and HIV-1 genomes in plasma samples. Viral genomes were identified in the same sample by their distinctive melting temperature (Tm) which are 81.6 and 86.5 degrees C for HIV-1 gag 142 bp amplicon and HCV 5'-NCR region 226 bp amplicon, respectively. Analysis of known scalar concentrations of reference plasma indicated that the multiplex procedure detects at least 500 copies/ml of both HIV-1 and HCV. In addition, we also assayed HIV-1 and HCV viral load in 30 co-infected patients and in 15 blood donors, confirming the sensitivity and specificity of the assay. This method may represent a useful alternative method for the detection of HIV-1/HCV co-infection, reliable for a rapid and relatively inexpensive screening of blood donors.

Near-infrared spectroscopy: promising diagnostic tool for viral infections

Although several methods, including enzyme-linked immunosorbent assay, polymerase chain reaction, immunofluorescent assay, and Western blotting, have been used for the diagnosis of viral infections, none of them is ideal in terms of cost-effectiveness, speed, and accuracy. Currently, the rate of outbreak of emerging viruses is increasing and therefore the development and establishment of analytical methods for such viral infections are becoming more important. Near-infrared (NIR) spectroscopy is a fast, multicomponent assay that enables non-invasive, non-destructive analysis. Recently, the diagnosis of viral infections using NIR spectroscopy has been attempted. In this review, the potential of the NIR method in the medical and virological fields is discussed.