Nucleic Acid Testing - Diagnostic solutions for the 21st century
Over the last decade Nucleic Acid Testing (NAT) has become the gold standard for HLA typing and infectious disease screening. NAT is particularly useful in HLA typing as it offers sequence information at the basic genetic level to the highest resolution possible therefore aiding clinicians in their determination of suitable HLA matches for transfusions and transplants. TBG utilises the SSP method whereby HLA typing is acheived through the PCR process.
With regard to infectious disease, NAT has major advantages over the sole use of serology. NAT is a more sensitive method allowing detection of lower amounts of infectious agents and therefore giving the ability to detect infections earlier than was previously possible. This ability is especially significant in blood screening. Prior to the advent of NAT being applied to blood screening, antibodies or antigens were solely used to detect contaminated blood samples. Due to the delay in production of antibodies (seroconversion) or the generation of significant amount of antigens, the window period, the time between infection and ability to detect infection, was significantly longer for serology only testing methods. With the addition of NAT methodology to traditional serology methods, the HCV window period has been cut from 66 days to 19 days. Advanced NAT methods can even detect HIV infection within 16 days of the initial infection event.
NAT is now being applied in a wider array of diagnostic tests than ever before. It is the gold standard method for detection of viral load for HIV-positive and HCV-positive patients. Viral load can be an important determinant in the treatment dosage and choice of drug therapy for patients. It may also indicate the severity of infection. Real-Time PCR provides an effective tool to establish efficacy of therapy and modify treatment when appropriate. Various PCR techniques are also used to not only identify viruses but to further identify the individual strains. This is commonly known as genotyping. This is important in the case of infection by viruses such as HPV, whereby some strains are associated with a non-malignant outcome whereas others have a high correlation with the development of cervical cancer.
At TBG, we apply PCR and Real-Time PCR techniques in our wide array of diagnostic kits and services. Nucleic acid testing is at the core of what we do as we continue to push for more accurate, more sensitive and more useful diagnostic tests for HLA typing, infectious disease detection, treatment modification and genotyping.