Automated Nucleic Acid Extraction Systems for Detecting Cytomegalovirus and Epstein-Barr Virus Using Real-Time PCR: A Comparison Study Between the QIAsymphony RGQ and QIAcube Systems

EBV Viral Loads in Diagnosis, Monitoring, and Response Assessment

The quantification of circulating Epstein Barr virus (EBV) DNA loads has played an important role in the diagnosis and management of EBV-associated lymphoid malignancies. Viral load measurement is particularly useful for monitoring EBV-DNA in hematopoietic stem cell transplant patients, and for assessing the prognosis or response to therapy of EBV-associated intractable lymphomas like extranodal NK/T-cell lymphoma, nasal type. Cell-free EBV-DNA in plasma can be used as a biomarker for estimating the severity or prognosis of these lymphomas. In addition to plasma, whole blood has been used for the management of transplant patients. Although measuring EBV-DNA has been useful, there is a lack of standardization and the optimal specimens for measuring viral loads are unknown. This can be attributed to the different forms of EBV-DNA that exist in peripheral blood and the different pathologies that result from diverse EBV disease states. As a result, guidelines for EBV diagnosis or the initiation of treatment are unclear. However, the newly established World Health Organization standard for EBV quantification will encourage collaborative studies across institutions and countries to establish proper guidelines for EBV diagnosis and the initiation of treatment.

Diagnosis and drug resistance of human soil-transmitted helminth infections: A public health perspective

Soil-transmitted helminth (STH) infections represent a major public health problem globally, particularly among socio-economically disadvantaged populations. Detection of STH infections is often challenging, requiring a combination of diagnostic techniques to achieve acceptable sensitivity and specificity, particularly in low infection-intensity situations. The microscopy-based Kato-Katz remains the most widely used method but has low sensitivity in the detection of, for instance, Strongyloides spp. infections, among others. Antigen/antibody assays can be more sensitive but are parasite species-specific. Highly sensitive PCR methods have been developed to be multiplexed to allow multi-species detection. Novel diagnostic tests for all STH species are needed for effective monitoring, evaluation of chemotherapy programmes, and to assess the potential emergence of parasite resistance. This review discusses available diagnostic methods for the different stages of STH control programmes, which vary in sensitivity and spectrum of detection requirements, and tools to evaluate drug efficacy and resistance.

Performance Evaluation of the Beckman Coulter DxN VERIS Hepatitis B Virus (HBV) Assay in Comparison With the Abbott RealTime HBV Assay

The detection and quantification of hepatitis B virus (HBV) DNA plays an important role in diagnosing and monitoring HBV infection as well as in assessing the therapeutic response. We compared the analytical performance of a random access, fully automated HBV assay—DxN VERIS Molecular Diagnostics System (Beckman Coulter, Brea, CA, USA)—with that of Abbott RealTime HBV assay (Abbott Laboratories, Des Plaines, IL, USA). The between-day precision of the VERIS assay ranged from 0.92% (mean 4.68 log IU/mL) to 4.15% (mean 2.09 log IU/mL) for pooled sera from HBV patients. HBV DNA levels measured by the VERIS HBV assay correlated with the calculated HBV DNA levels (r²=0.9994; P<0.0001). The lower limit of quantification was estimated as 8.76 IU/mL (Probit analysis, 95% confidence interval: 7.32–12.00 IU/mL). Passing-Bablok regression analysis showed good concordance between the VERIS and RealTime assays for 187 chronic HBV samples (y=−0.2397+0.9712x; r=0.981), as well as for 20 drug-resistant HBV genotype C positive samples (y=−0.5415+0.9954x; r=0.961). The VERIS assay demonstrated performance similar to the RealTime assay and is suitable for high-throughput HBV DNA monitoring in large hospital laboratories.