The future of molecular diagnostics lies with NAATs and NGS that can rapidly provide definitive and actionable results for the detection of bacterial diseases with better sensitivity.
Molecular diagnostics as a whole is revolutionizing healthcare and changing the way people are treated. It represents almost a tenth of the in-vitro diagnostics (IVD) market, yet most of it promises revenue growth. Once esoteric, molecular diagnostics has earned its place in routine medical practice and has expanded to all levels of healthcare – from the pathology lab to the doctor’s office and clinics. Still, as they occupy routine spaces, their growth trajectory is secured through platform innovation in lower-cost nucleic acid amplification tests (NAATs) and clinical next-generation sequencing (NGS).
Over the past 20 years, clinical molecular diagnostic technology has made rapid development, and became the most promising field in clinical laboratory medicine. New technologies and applications are being continually added, making it a rapidly advancing area of research and medicine.
PCR. It is continuously evolving. Modern target amplification platforms, for example, provide greater sensitivity from a smaller sample size; they do so by using Frster resonance energy transfer (FRET) to deliver a larger number of PCR cycles on almost any open qPCR platform with virtually no background.
Digital PCR (dPCR) is an increasingly popular manifestation of PCR that offers a number of distinctive advantages when applied to preclinical research. As is common with many new research methods, the application of dPCR to potential clinical scenarios is also being increasingly described. dPCR could have an important role in advancing molecular diagnostics either by supporting qPCR calibration or as a diagnostic method in its own right.
NGS. It is one of the greatest achievements of the modern era and has revolutionized molecular diagnostic testing. Not since the advent of the PCR has there been such a dramatic transformation in the capabilities of molecular analysis of DNA and RNA for clinical diagnostic testing. As the cost, speed, and ease of use of NGS continue to improve, this technology has the potential to replace many of the current molecular testing modalities. Although it is unlikely to replace many of the common molecular technologies in current use in the near future, the day may come when almost all molecular testing incorporates NGS technology.
NAATs. They have frequently been the standard diagnostic approach when specific infectious agents are sought in a clinic specimen. NAATs are both rapid and sensitive. Given their accuracy, rapidity, and ease of use, they should replace antigen detection and culture for the detection of bacterial diseases.
The advent of CLIA-waived rapid NAATs provides new opportunities for disease diagnosis. They are better in sensitivity and can rapidly provide definitive and actionable results. With the availability of CLIA-waived rapid NAATs, we are now entering the next frontier in molecular diagnostics. These tests are easy to perform and can be used in many settings, including, but not limited to, outpatient clinics, urgent-care centers, and hospital laboratories. These state-of-the-art diagnostics will provide new opportunities to streamline the testing and treatment of patients in a myriad of settings, including traditional health care settings and nontraditional locales.
Microfluidics. Advances in molecular biology are enabling rapid and efficient analyses for effective intervention. The emergence of microfluidics and nanotechnologies has enabled both new capabilities and instrument sizes and also introduced new functionality, enhanced sensitivity, and reduced the time and cost involved in conventional molecular diagnostic techniques.
Microfluidic technology is regarded with optimism for the management of infectious diseases by allowing timely therapy. It provides a key potential solution for remote areas and near-patients facilities by avoiding turnaround trips of the patients between the clinic and the laboratory. Their use is also beneficial where time is crucial, or when physical spaces do not allow setting up of conventional methods.
Mass spectrometry. MS is nowadays a benchmark of laboratory qualitative and quantitative investigation, particularly in bacteriology. Mass spectrometric-based methods are versatile, sensitive, rapid, and cost-effective, and do not require interpretation software for data analysis. The automated machinery necessitates easy sample preparation and fewer operators. The analysis capacity can reach up to 960 specimens per day, which makes it suitable for routine diagnosis in high-volume laboratories and large-scale studies. Tests can also be performed efficiently on archived specimen.
Molecular diagnostic tests have been widely used to detect and quantify biomarkers, such as nucleic acids and proteins, associated with specific health conditions or diseases to obtain critical information for health care providers and patients to make correct medical decisions. However, existing diagnostic instruments usually require costly reagents, long analysis time, established lab infrastructure, and trained professionals to operate, which limits their availability for large-scale screening applications. There is a strong demand for robust, cost-effective, and simple-to-operate instruments for molecular diagnostics. The features of microfluidics, such as short analysis time, reduction in fabrication costs, and low sample/reagent consumption, make it a natural fit for the development of new diagnostic instruments.
The future of the molecular diagnostics market lies with NAATs and sequencing-based tests. Time to results for qPCR and isothermal amplification are crucial for several infectious disease testing applications including respiratory testing, hospital-acquired infections, bloodstream infections, and molecular point-of-care tests. Superior sensitivity and noninvasive sampling will make qPCR and NGS the future methods of choice for cancer testing and prenatal screening. The accuracy of molecular diagnostics as well as its high sensitivity, its fast turnaround time and increasingly easy workflow, as well as recent improvements in the cost-effectiveness of molecular testing are the key benefits that will drive growth in the coming years. The contribution of molecular testing to modern medicine is not finished yet.
Diagnostics- The Way Forward
The Indian diagnostic sector is rapidly growing and extremely versatile. The top companies are constantly churning out state-of-the art technologies and novel players are emerging at a fleeting rate. In the recent past, corporates, including multinational pharma companies, have added to this whirlwind because of the mirage of lucrativeness. This trend has been further expanded after diagnostic chains have gone public.
Several international brands have dominated the bulk of the top diagnostic equipment in the market, but the approach while choosing a suitable module must be multi-faceted. These should take into account not only the sample load but also other key factors such as levels of automation, ease of operation, turnaround time, space requirement, and cost; and most importantly the report should be interpretable by the physician since this has a direct effect on patient care. To achieve this, physician sensitization is absolutely indispensable whether it is through regular CME’s or conferences.
Diagnosis is not the end but the beginning of practice. This quote is quintessential since the right diagnosis is the start of the management of the patient and any compromise in quality can render the entire effort that follows completely futile. Some like to call it hyposkillemia but the lack of training of new doctors to make a sound diagnosis exclusively by clinical examination has led to numerous additions to prescribed tests. Easy availability of literature on the internet also has played a role in the rapid growth of demands of the patient along with new centres in Tier II and Tier III cities making up for the vacuum in the past.
The big challenge in the market currently is to boost made in India equipment so costs can be brought down; thus reducing GST and abolishing import duties, while maintaining excellent quality that is affordable for the common man. Accreditation must be made mandatory for the entire scope of tests to ensure quality of lab services. Regardless of other factors, quality still remains the best business model with the current cut throat competition that exists.
Special care must also be taken to avoid pre-analytical errors, such as barcoding of samples since majority of incorrect reports are due to wrong labelling and patient identification. With the trend shifting to point of care equipment, it might be appropriate in the future to say that a smart mother makes often a better diagnosis than a poorly trained doctor.
Dr Arjun Dang
Clinical Head, Consultant Histopathology,
Dr Dangs Lab