Neutrophils will help to identify asthma
A drop of blood for the diagnosis of asthma
Anatoly Kozlov, "Science and Life"
It is known that blood is a functionally very loaded element of the body. Therefore, it seems natural that the further away, the more different blood tests appear that allow you to diagnose a particular disease. So, recently it has already been reported about the appearance of a blood test, which can be used to diagnose Alzheimer's disease even before the symptoms appear. That analysis revealed a lack of certain metabolites in the blood, which was a signal of Alzheimer's disease.
In the article by Sackmann et al. Characterizing asthma from a drop of blood using neutrophil chemotaxis, published in one of the leading scientific journals PNAS, we are talking about a blood test that allows a person to diagnose asthma. (The press release The key to easy asthma diagnosis is in the blood is published on the UW-Madison – VM website.)
Asthma is a disease characterized by chronic inflammation of the respiratory tract, in which a person has attacks of suffocation, shortness of breath, cough. At the moment, there are more than 300 million patients with this disease in the world.
There are a number of tests aimed at diagnosing the disease, such as spirography or picfluometry. However, most of them are aimed at assessing the functional state of the lungs and bronchi - for example, they determine the volume and speed of inhaled air, its chemical composition. A significant disadvantage of these methods is their indirection. They do not allow to diagnose the disease "directly". An additional disadvantage is that such tests work if the symptoms of asthma appear in a person at the time of a doctor's visit.
Thus, the question of inventing a qualitative test capable of detecting bronchial asthma is more than relevant.
This is where the multifunctionality of blood comes to the fore. The process of any inflammation is associated with an increase in the number of immune cells of a certain type in the blood – neutrophils. These cells, circulating through the bloodstream, are able to leave the blood vessel and migrate to the source of infection in order to "swallow" and "digest" bacteria or those cells that have been infected (this process is called phagocytosis).
How does the neutrophil know where the inflammation is located in the tissue? There is a special chemotaxis mechanism for this. Neutrophil is able to sense special chemical signals – substances that are formed during inflammation. Thus, perceiving these signals, he, like a sniffer dog, moves along the gradient of these substances, that is, to where their concentration is as high as possible.
The method of diagnosing bronchial asthma proposed by specialists from the University of Wisconsin (Madison, USA) is based on testing the function of neutrophil chemotaxis.
The method was named by the authors KOALA (kit-on-a-lid-assay). At its core, it is quite simple and somewhat resembles a running sports competition. In a specially designed small chamber, only neutrophils are released from a drop of blood, which takes no more than 5 minutes. At the next stage, neutrophils begin to migrate using chemotaxis along paths from a chemoattractant applied to the surface – a substance that serves as a "bait" for the neutrophil. Then, with the help of special software on the computer, the migration rates of neutrophils are analyzed.
Using the described method, the authors conducted a study of 34 patients, in which they reliably managed to distinguish patients with asthma from patients with another inflammatory disease – allergic rhinitis ("hay fever").
The conducted study reliably showed a reduced rate of neutrophil migration in patients with asthmatic disease. It is this characteristic that may in the future turn out to be a marker in the diagnosis of this disease.
It is clear that in order to introduce such a test into widespread practice, it is still necessary to conduct a statistical study of a large number of patients, but its big advantages are already visible: simplicity – only a small amount of blood is needed, the analysis itself is not very long; low cost – the camera is made of pieces of ordinary plastic; accuracy – the analysis is carried out at the cellular level.
Portal "Eternal youth" http://vechnayamolodost.ru18.04.2014