Guus Simons reveals where the molecular diagnostics sector in Europe is heading.
“Finally, multiparameter assays will also contribute to our understanding of the epidemiology of respiratory infections”
What are the current limitations of the classical assays for respiratory tract infections? How is your technology paving a new way to detect respiratory tract infections?
Guus Simons. Numerous viruses and bacteria are involved in acute respiratory tract infections (RTIs) and the clinical presentation is generally not indicative of a specific pathogen. Up to now, many laboratories still use classical assays to diagnose respiratory pathogens. These assays can be divided into cell culture, immunofluorescence/antigen detection and nucleic acid/PCR-based tests. Cell culture is still the golden standard for detection of respiratory pathogens. However, cell culture is time consuming and has a low sensitivity. Rapid antigen tests are available for some respiratory pathogens but have been shown to be less sensitive and less specific than cell culture-based approaches. Nucleic acid amplification tests have proven to be rapid, sensitive and specific alternatives that can be used in either a monoplex or a multiplex (up to five pathogens) format. PathoFinder's MultiFinder technology has overcome the limitations of conventional multiplex PCR. Detection and identification of up to 25 pathogens in a single assay is now possible, enabling the introduction of comprehensive molecular diagnostics in the daily clinical routine.
Can you explain the advantages of multiparameter tests compared to monoplex assays? Why are these advantages so important?
GS. The golden standard in nucleic acid based diagnostics is monoplex real-time PCR. However, multiparameter assays allow for the co-amplification of more than one target enabling the comprehensive detection of (multiple) infectious disease agents in a single assay. Up to now, multiplex real-time PCR assays have been suffering from a reduced sensitivity compared to monoplex assays. The sensitivity of PathoFinder's RespiFinder assay has been extensively compared to monoplex real-time PCR assays and an identical sensitivity was observed. This is also reflected in the good results obtained during independent quality control studies like the Quality Control for Molecular Diagnostics (QCMD) initiative. Multiparameter assays save time and reduce costs compared to sequentially performing multiple monoplex assays. Since diagnostics of infectious diseases is driven by costs and a fast turn around time, multiparameter tests have a great advantage on monoplex assays as long as sensitivity and specificity are not affected.
Why is it important to test all relevant pathogens for a certain disease in one assay?
GS. Multiparameter assays offer laboratories the ability to detect a wide range of pathogens in a single assay. Additionally, multiple infections (also know as co-infections) are poorly detected by classical assays whereas dual and triple infections are easily detected by multiparameter assays. The ability to detect multiple infections provides the possibility to investigate the clinical importance of these infections and to see whether they result in a poorer outcome of the patient. Finally, multiparameter assays will also contribute to our understanding of the epidemiology of respiratory infections and provide new information on seasonality, geographical distribution and risk groups.
Can you give an insight into the future development of the molecular diagnostics sector?
GS. Molecular testing has greatly improved the laboratory's ability to diagnose infectious diseases. I believe that the future of molecular diagnostics is comprehensive diagnostics. This means the molecular diagnostics of all relevant pathogens in a single assay. The increased sensitivity of molecular tests means that infected patients will be diagnosed more accurately and more often, especially at times when they are shedding low levels of pathogens that would be missed by non-molecular tests. Comprehensive diagnostics will set a new standard in diagnosis of panel diseases and will provide clinicians with important information to assist in better patient management decisions. RespiFinder was the first assay we launched and several RespiFinder products are now on the market in Europe. Currently we are validating multiparameter assays against viral meningitis and sexually transmitted diseases. We hope to launch these new products in the coming year.
After obtaining his PhD in molecular biology at the University of Nijmegen, The Netherlands, Guus Simons performed his post-doc period at the University of Ghent, Belgium. Before founding PathoFinder, he held several research and management positions at Dutch biotechnology companies. He has written over 50 scientific publications and 15 patent applications.