Diagnosis of diseases by saliva: details and comments
I don't care about the tests!Ekaterina Lyulchak, RBC daily
Every day, the technologies of laboratory and functional diagnostics are supplemented with alternative methods that can detect many diseases at an early stage and in a very short time. Perhaps in the future, people undergoing the examination will be tested not with blood, but with saliva. American doctors and biologists from the University of Rochester Medical Center, the University of Southern California, the Universities of California in San Francisco and Los Angeles and the Scripps Research Institute for the first time in the history of medicine have compiled the most complete map of saliva, which reflects all 1166 unique proteins that make up the secret of human salivary glands.
Such a diagnosis, from the point of view of physicians, is quite justified, because in addition to 99% of water, saliva contains dissolved anions of chlorides, phosphates, bicarbonates, rhodanides, iodides, bromides, fluorides, sulfates, Na+, K+, Ca2+, Mg2+ cations and trace elements Fe, Cu, Mn, Ni, Li, Zn, organic substances – protein and its fractions (albumin, globulins), amino acids, mucin; enzymes – amylase, lactase, lysozyme, kallikrein, parotin, as well as cholesterol, glucose, lactic acid and vitamins C, B1, B12, H, K. In addition, saliva compared with blood It is a dynamic environment reflecting daily changes in the body.
"Of course, the blood test has a higher accuracy than the saliva diagnosis. Nevertheless, as an express diagnosis, this method has the right to exist, - Nikolay Adrianov, Candidate of Medical Sciences, associate professor of the Department of Biochemistry of the Faculty of Medicine and Biology of the Russian State Medical University, told RBC daily. – After all, antibodies that are produced by the body in response to viruses get into saliva, and by their presence in the secret of the salivary gland, one can judge a particular disease. However, if saliva analysis reveals any pathological changes in the body, it is necessary to conduct more detailed analyses showing a holistic clinical picture." The fact is that the determination of deviations is possible only when the doctor considers the entire spectrum of substances contained in the analysis material.
Now biochemists have a reliable idea of the complete map of saliva proteins. To compile a detailed list of these proteins, scientists took samples of salivary gland secretions from 23 men and women of different ages and races, after which the samples were studied using mass spectrometry, which allows determining the elemental composition of the molecule.
About a fifth of all proteins found in saliva are present in the blood. Saliva tests already make it possible to detect the presence of diseases such as HIV or hepatitis, while the discovery of a complete protein map will significantly expand this framework. "To date, the detection of HIV infection is possible only by the results of a blood test, other methods will not be able to give an absolute guarantee, and the result will not correspond to the true state of things," the Moscow City Center for Prevention and Control of AIDS of the Moscow City Health Department told RBC daily. Meanwhile, saliva contains specific proteins that are a kind of indicators of the risk of various types of cancer – cancer of the digestive system, lungs, breast, as well as Alzheimer's, Parkinson's and diabetes. The study of the biochemical composition of saliva in patients with diabetes mellitus showed that in the saliva of both insulin-dependent and insulin-independent patients with diabetes mellitus, there is an increase in the level of glycosaminoglycans, which are part of the intercellular substance of connective tissue, by 32.2% and sialic acids, present in all tissues and body fluids, by 29.9%.
"The composition of saliva basically reflects the composition of blood plasma,– notes Nikolai Adrianov. – For example, with diabetes, the saliva content is sharply reduced and the sugar content is increased. You can measure the concentration and ratio of enzymes, the level of calcium and phosphorus. But it is almost impossible to diagnose oncology by saliva. Even a blood test should show the presence of a whole combination of cancer markers so that it is possible to judge the occurrence of oncology with a high probability. So it is unacceptable to rely on express methods in this matter."
Despite this, dentists from the University of Texas claim that they have developed a technique for determining breast cancer tumors by saliva, and this type of screening makes it possible to distinguish benign from malignant tumors. After analyzing the saliva of 30 patients with breast cancer, scientists found 49 marker proteins in their saliva, indicating the presence of cancerous tumors. For patients, such a diagnosis will be more convenient than the usual blood test. It will be possible to take saliva for analysis when visiting the dentist, which will save time, the patient will be insured against the risk of contracting AIDS or other dangerous diseases, and children will get rid of the fear of the doctor's office. In general, in the future, patients will literally spit on the tests.
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15.04.2008