For over 40 years, immunoassays have been used in hospitals, laboratory medicine, and research to improve health and well-being. Information gained by clinical immunoassay testing has shortened hospital stays and decreased the severity of illness by identifying and assessing the progression of disease, thereby leading to improved therapeutic choices.
The development of new immunoassays is proceeding more rapidly for some disease areas than for others as some pathogenic diseases, such as cancer and AIDS, present tough challenges to immunologists who are struggling to relate their fundamental research to the causes and cures of these and other devastating medical conditions. But the improved understanding of the immune system gained in research laboratories points the way to progress.
Keeping pace with emerging biomarkers and consolidating a broad test menu, are both important for developing new instruments and kits, or updating existing ones, with the aim of improving service and quality while decreasing costs. Manufacturers are designing new instruments to incorporate many additional capabilities and features. The design and functionality of new instruments are predominantly customer-driven. Factors like the available laboratory space for placing an instrument, throughput needs, and a range of workflows are considered in designing and including the components for providing a fully automated instrument. Manufacturers are also actively engaged in discovering and validating new biomarkers, creating assays for those biomarkers, and adding the assays to the menus of their instruments.
Increasing consolidation in laboratories and hospitals in the wake of healthcare reform to curb healthcare expenses is expected to stimulate market growth. Technological innovation for development of effective lab equipment along with new product launches with the ability to perform more than one test at a time are expected to drive the market globally.
India is expected to witness robust growth for automated instruments over the next sevenyears owing to increasing government focus toward development of healthcare infrastructure by encouraging public-private partnership to improve healthcare delivery into rural markets. Furthermore, increasing number of pathology laboratories and rising number of private and public hospitals is anticipated to fuel the market growth.
Since they were first utilized, immunoassays have witnessed phenomenal growth in the range and scope of their applications. A vast array of different labels and assay strategies has been developed to meet the requirements of sensitivity, accuracy, and convenience that have drastically improved the sensitivity of immunoassay systems, allowing an ever-increasing range of analytes to be measured accurately.
Of course, the menu of tests is at the heart of labs' needs, and strengthening the menu is always going to be a top priority for manufacturers. But today labs highly value workflow solutions that can quickly deliver reliable, trustworthy results at the best possible value to the hospital. It is not just instruments. A new development opportunity is any solution that drives reliability of results and operational efficiency in the lab. In the past, this looked like the consolidation of assay technologies onto integrated instrument platforms. Today, it looks like open workflow solutions that automate off-instrument operations, reduce total cost of ownership, and enhance the interoperability of the lab's equipment. Meeting these demands for automation, scalability, and openness is a key focus.
Immunoaffinity assays. These assays are the workhorse for measuring individual proteins but have been limited for proteomic applications by long development times, cross-reactivity preventing multiplexing, specificity issues, and incomplete sensitivity to detect proteins in the lower range of the abundance spectrum. Emerging technologies to address these issues include nucleotide-labeled immunoassays and aptamer reagents that can be automated for efficient multiplexing of thousands of proteins at high sample throughput, coupling of affinity capture methods to mass spectrometry for improved specificity, and ultrasensitive detection systems to measure low-abundance proteins.
iPCR. Immuno-PCR is an extremely powerful tool that combines the specificity of ELISA with the signal amplification of PCR.While rtPCR provides exponential signal amplification, it cannot be used directly for antigen detection, and while ELISA is adaptable to any protein, its sensitivity is not adequate for the detection of analytes of low abundance. iPCR therefore offers a number of key advantages by combining them both, such as extremely low limit of detection, compatible with complex samples such as serum, amenable to multiplexing,higher assay reproducibility, and rapid time to results.
Digital pathology. Another transformative development is the advent of digital pathology. Instead of viewing and analyzing slides under a microscope, digital pathology systems scan the stained slides in their entirety, storing the resulting whole-slide images in a digital format that can then be viewed and manipulated on a computer. Whole-slide imaging also simplifies sample storage and retrieval by providing an easily accessible record of the slide (as opposed to physical slides), and facilitates data analysis and subsequent reanalysis. Another benefit of digital pathology is the ability to perform sophisticated image analyses.
Chemiluminescence technology. Chemiluminescent immunoassay (CLIA) instruments steadily infiltrated the immunometric assay domain, eventually being used to measure serum concentrations of hormones, drugs, vitamins, tumor markers, infectious disease markers, myocardial damage markers and, finally, autoantibodies. Today, autoantibody detection in immunochemiluminescence can be carried out on instruments specifically dedicated to the autoimmunology laboratory as stand-alone instrumentation or as part of an automated analytical platform.
Regardless of its current optimal analytical performance, CLIA technology is destined for further development:
FICLIA technology. Flow-injection CLIA ensures a more efficient reagent mixture, reduces incubation time, increases temperature control, and is also able to improve the immunoreaction kinetics and therefore significantly reduce analysis time.
Multi-parametric CLIA. Current CLIA consists of discrete tests, i.e. measures one autoantibody at a time. However, the need for multi-parametric tests that can identify all the components of a complex immunological picture in a single analytical step, efficiently and at reasonable cost. Use of the 2D resolution for CL multiplex immunoassay could open doors for the setting up of multiparametric CLIA tests.
CL-MBs-nano-immunoassay. Ultrasensitive chemiluminescence magnetic nanoparticles immunoassay technology further increases the analytic sensitivity of the CLIA method. In this non-competitive and direct-type immunoassay, where the solid phase is made up of magnetic beads, gold nanoparticles with double labelling are used. This amplifies the luminescent signal derived from the immunoreaction and the associated enzymatic reaction in an exponential manner.
Diagnostic technology is rapidly evolving, and over the last decade substantial progress has been made for the identification of antibodies, increasingly approaching this type of diagnostic to that of automated clinical chemistry laboratory. The wide dynamic range, greater than that of immune-enzymatic methods, the high sensitivity and specificity of the results expressed in quantitative form, the high degree of automation and the clinical implications related to the reduction in the turnaround time, and the ability to run a large number of antibody tests, directed toward large antigenic panels in random access mode, make immunochemistry one of the most advanced segments in the clinical laboratory, with enormous repercussions on the workflow and on the auto-immunology laboratory organization.
The evolutionary process of the CLIA method is, in all likelihood, merely beginning. In the coming years, new and more efficient analytical methods based on the principle of chemiluminescence will be introduced into autoimmune diagnostics, at a steadily reduced cost, which will likely result in additional increases in the clinical efficacy of antibody tests. This transformation will align antibody diagnostics with already consolidated biochemistry and immunoassay methods, with noticeable advantages in terms of both diagnostic accuracy and expediency, to great clinical benefit.