Growing Alternative MDx Technologies

In the current diagnostics market, molecular diagnostics (MDx) for infectious disease testing offers one of the brightest areas for growth and innovation. The infectious disease space is the most dominant and profitable sector and is expected to continue to grow. Novel molecular technologies continue to evolve and improve significantly; reducing the time it takes to diagnose infectious diseases.

The market is growing because technology choices are growing. Manufacturers are currently involved in a diverse product offering designed to maximize efficiency and flexibility through broad menu and throughput capabilities, and to redefine staff productivity.

Nucleic acid amplification tests (NAATs) have shifted near entirely (in the clinical domain) from PCR-gel electrophoresis workflows to real-time PCR and other instrument-integrated workflows, such as array detection. The result has been the decentralization of NAATs, from specialized clinical labs to hospital labs and more recently near-patient settings such as urgent care clinics, physician offices, and field testing sites.

Indian Market Dynamics
The Indian MDx market is estimated at Rs. 111 crore in 2016. Reagents contributed 100 crore and the balance Rs. 11 crore is contributed by four units of high-throughput extraction analyzers and eight units of low-throughput extraction analyzers. Additionally six units of high-throughput and four units of low-throughput extraction analyzers were also placed. Although MDx tests are increasingly being preferred and new laboratories and diagnostic centers are being set up, the preference for placements, especially for high-throughput analyzers remains. Roche and Abbott have high-end, closed systems, whereas Qiagen is price competitive and offers open systems.

Reagents continue to be the mainstay and see an increase of about 12–15 percent every year. In India, they are majorly dominated by virology tests, with BBN and HBc reagent packs being the key drivers. Point-of-care (POC) is gaining momentum and is expected to be a key driver for next couple of years as the turnaround time for molecular diagnostic tests is critical in detecting infectious agents, in determining a patient’s ability to metabolize a drug or drug align, and in detecting minimal residual disease. These applications would benefit from the development of a POC device for nucleic acid extraction, amplification, and detection.

Technology Trends
As healthcare becomes more dependent on molecular diagnostic testing, suppliers are continually developing new molecular methods. These include improvements in PCR (polymerase chain reaction), as well as newer amplification methodologies. The rapid improvement in workflow and turnaround time for most molecular tests has thus provided promising results. The newly developed assays are more accurate than before and have the potential to replace many conventional assays. Advancements in technology have also resulted in more user-friendly testing platforms that are automated, have lower risks for contamination, and have the ability to deliver faster results.

Microfluidics. The emergence of microfluidics and nanotechnologies has enabled both new capabilities and instrument sizes practical for POC. They have introduced new functionality, enhanced the sensitivity, and reduced the time and cost involved in conventional molecular diagnostic techniques. Overall, microfluidic approaches to a wide variety of MDx applications are developing rapidly.

NGS. NGS technologies have now far exceeded previous DNA sequencing technologies, both in the breadth of genomic real estate that can be sequenced in a single experiment and in the depth of coverage for each genomic region sequenced, which allows for a superior limit of detection for low-level sequence variants. Labs are moving many molecular assays over to NGS – especially those involving large numbers of variants, whether for a single gene or multiple genes. Pyrosequencing is currently the variant of choice within NGS systems.

NAATs. NAATs are now considered as the gold standard method for diagnostic practices such as screening donated blood for transfusion-transmitted viruses. With recent NAATs, the turnaround time is reduced to 1–2.5 hours, resulting in improved clinical outcomes and reduced hospital cost. Multiplexed NAATs have been designed to detect multiple viruses or subtypes in a single run. Their detection platforms can comprise up to 20 viruses using diversified panels, for example, concurrent detection of HAV, HBV, and HCV infections, as well as co-infections.

PCR. The most widely used variants of conventional amplification are real-time PCR (quantitative PCR) and reverse transcription-PCR (RT-PCR). Both are nowadays becoming benchmarks in assessing the viral load. Among the latest enhancements in PCR systems, extraction, amplification, and detection steps have been combined within one unit. Digital PCR (dPCR) is an increasingly popular manifestation of PCR that offers a number of unique advantages and is a robust and reproducible approach that could lend itself to supporting accurate diagnostics in the future.

Road Ahead
In the upcoming years, MDx will continue to be of critical importance to public health. Molecular diagnostic offers physicians with critical information based on the early exploration of pathogens and subtle changes in patients’ genes and chromosomes, allowing for earlier diagnosis, selection of appropriate therapies, and monitoring of disease progression. Currently PCR-based testing outweigh others; however, alternative technologies aimed to explore genome complexity without PCR are anticipated to gain momentum in the coming years as sequencing devices are more costly at present. Thus the coming era will be revolutionary, it will not only change our diagnostic systems but also plan of treatment and therapy.