Today, in the first place in medicine, both prevention and timely diagnosis are important. Modern methods make it possible to accurately evaluate the results of tests and studies.
Along with the development of infectious pathology, methods such as enzyme-linked immunosorbent assay and polymerase chain reaction have proven themselves well. So PCR is the most modern and perhaps the most informative study in immunology, but often you have to resort to the use of simpler, cheaper, but no less significant methods. One of them is the ELISA of blood. Based on the antigen-antibody interaction mechanism, an enzyme-linked immunosorbent assay allows you to determine not only the presence or absence of antibodies, but also their number. Cerebrospinal fluid, vitreous puncture and amniotic fluid may be used for this study , but blood ELISA is most often performed. The sensitivity of this biochemical method reaches ninety percent, with a specificity of 95%. If we talk about the negative aspects of this study, then it is worth mentioning, perhaps, the only thing - the diagnosis is indirect. This means that with ELISA of blood, it is not the pathogen itself that is determined, but only the immune response that has formed on it, and due to the varying degree of activity of the immune system in people, it is not always possible to correctly interpret the results obtained from the study. Therefore, it is necessary to correlate the results with data on the immune activity in humans.
There are a large number of different modifications of the analysis, among which the competitive method and the double folding method are most often used.
What is ELISA based on blood based on?
By attaching specific enzyme labels to antibodies, reactions can be monitored. The start of the reaction indicates the presence of antibodies in human blood . There are special test systems that allow you to determine both specific antibodies and their number. Results can be taken into account either manually (by comparing the obtained reactions with the norm), or using special ELISA analyzers.
The enzyme immunoassay method allows you to determine not only the disease itself, but also its form (acute or chronic) and stage. This technique even allows the identification of clinically healthy carriers in which the infection does not develop and does not have any manifestations.
To increase the efficiency and accuracy of the diagnostic procedure, it is necessary to conduct a study in the initial period of the disease, as well as to identify antibodies of different classes (preferably M and G). The study of IgG levels is recommended in paired sera, this study is carried out with an interval of ten days. To determine the dynamics of the infectious process over time, a quantitative diagnosis is performed. In addition, it is worth considering that with reduced immune activity, as well as with protein starvation, antibodies to infectious agents may not be detected.
In case of doubtful results, a repeated study is recommended. Otherwise, you can resort to more modern and reliable methods such as polymerase chain reaction, which provides absolute results on the etiology of this disease.
Thus, an ELISA blood test today is a widely used method for the diagnosis of infectious diseases and allows you to obtain reliable research results on a number of issues (etiological agent, duration of the disease, manifestations and form of the disease), as well as gives insights on the development of the process and virulence of the strain of the viral agent.