Today, most immunoassays work on the basic principles of the antigen-antibody complex. In the late 1950s, the first immunoassays were developed. They were known as radioimmunoassay (RIA) and used radio isotopes for labeling, thus creating a challenge for waste management, disposal, storage, and lab tech safety training. In the 1970s new methodologies such as EIA (Enzyme Immunoassay) and ELISA (Enzyme Linked Immunoassay) were discovered that no longer required the radio isotope. In the 1980s, CEDIA (Cloned Enzyme Donor Immunoassay) and other homogeneous immunoassay technologies were developed.
One source, multiple solutions. Since not every analyte (drug) has the same features and characteristics, it is important to measure all accurately and precisely with one and the same technology. Thermo Scientific products use three different homogeneous immunoassay technologies to offer the best possible results. The CEDIA immunoassay, known for its low-end sensitivity, makes it possible to measure drugs in urine, serum (plasma) and now oral fluids. CEDIA is known worldwide for immunoassays in drugs-of-abuse screening, therapeutic drug monitoring (TDM), and specifically immunosuppressant drug (ISD) monitoring.
With advances in instrument connectivity and the introduction of laboratory middleware, automated real-time QC data submission is now a reality.
Immunoassays using the QMS (quantitative microparticle systems) technology are particularly suited for the measurement of blood levels of therapeutic drugs in the field of infection, epilepsy, cardiology (TDM) and organ transplant (ISD). Typically, one or more immunosuppressive drugs are used to prevent rejection of transplanted organs and tissues. Most common drugs are Cyclosporine A, Tacrolimus (FK-506), Everolimus, Sirolimus, and Mycophenolic Acid (Mycophenolate Mofetil). Periodic measurement of a drug concentration is performed to allow the physician to adjust the amount of a drug needed and to ensure long-term success of the transplantation. Immunosuppressant drug monitoring could be done by several methods, but the most common method is an immunoassay. Immunoassays, such as Thermo Scientific CEDIA Cyclosporine Plus Assay or Thermo Scientific QMS Everolimus Assay, provide laboratories with efficient solutions.
The DRI (G6PDH glucose-6-phosphate dehydrogenase) technology is a well-proven method for drugs-of-abuse screening, using liquid ready-to-use reagents that can be easily adapted to different clinical chemistry analyzers. The value of innovation with these stable technologies is moving toward the actual sample collected. Until recently, most drugs-of-abuse screening used a urine sample to complete the testing. With the recent FDA clearance of the CEDIA Oral Fluid immunoassays calibrators and controls, drug testing can now use saliva samples, which are a better indicator of recent drug use and is also a less invasive method.
Third-party quality controls (QC) are manufactured independently of the instrument, reagents, and calibrators to provide an unbiased assessment of instrument performance and the testing system as a whole. The inter-laboratory comparison program plays an integral part in the laboratory’s overall quality assurance strategy. Historically, QC data for peer comparison was mailed in monthly, with reports available for review a couple of weeks later. More recently, laboratories have preferred to submit QC data online while real-time inter-laboratory comparison programs offer the added advantage of immediate report generation following QC result submission.
With advances in instrument connectivity and the introduction of laboratory middleware, automated real-time QC data submission is now a reality. Enhanced web-based QC inter-laboratory programs offer not only peer-to-peer comparison but powerful QC statistical tools. These technological developments provide a laboratory manager with 24/7 online access to a total quality assurance solution that offers convenience and peace of mind. Programs such as LabLink xL provide a variety of reporting tools in real time with user-defined security with access rights established by the laboratory supervisor.
Kathy Ruzich serves as Marketing Communications Manager for Thermo Fisher Scientific-Clinical Diagnostics. She has been working in the areas of Drug Monitoring and Immunoassays for more than 15 years.
