When conducting diaskintest rate is estimated by the results of the skin reaction. Today it is the most modern and effective method for diagnosing tuberculosis. According to statistics, in the Russian Federation there is a significant decrease in the incidence of tuberculosis. Since 2010, there has been a federal program in our country that is aimed at preventing and fighting tuberculosis. But, despite the measures taken, the disease is quite a serious problem.
According to the federal program, modern research methods are used in the diagnosis of tuberculosis, in particular, diaskintest.
This diagnostic method was developed at the I.M. Sechenov in 2007. In 2008, it was approved by the Ministry of Health for use in children's institutions. The advantage of this study is that it absolutely does not respond to BCG, that is, the development of an allergic reaction to previously administered tuberculin in the first three days of a child’s life is excluded. At its core, it is an express method for diagnosing TB infection and the incidence of tuberculosis. The method passed with distinction all clinical studies and absolutely no contraindications.
This is a recombinant tuberculous allergen contained in a standard dilution. It consists of two antigens obtained from virulent Mycobacterium tuberculosis strains, which are completely absent in the BCG vaccine in children.
The mechanism of action of this method is based on the fact that in response to the introduction of antigens into the child’s body, cellular immunity (antibodies) is produced. That is, launching a delayed type of allergic reaction, the appearance of a specific skin reaction in the form of papules and hyperemia appears.
The indications for the study are as follows:
- detection of tuberculosis in all age groups;
- determination of the activity of the pathological process;
- identifying patients who are at high risk of developing tuberculosis;
- in order to diagnose with diseases of the bronchopulmonary system.
The test is carried out in a specially equipped vaccination room prescribed by a TB doctor.
This solution is intended only for intradermal injections using a tuberculin syringe. On the needles there must be an oblique cut at the top. Before the introduction of the drug, it is mandatory to check the date of manufacture and expiration date.
Under sterile conditions, a diaskintest is taken in a tuberculin syringe at a rate of 2 doses, and then carefully release one dose into a sterile cotton ball. In the region of the middle third of the forearm, after treatment with an antiseptic solution, a specially trained nurse performs a subcutaneous injection of a single dose of diaskintest. As a result of the injection, small papules form on the skin, the size of which is up to 7 mm in diameter in the form of an orange peel.
How is the evaluation of the results?
After the test, the results are evaluated after 72 hours by a TB doctor or a nurse in the treatment room. Using a special ticker that is completely transparent, determine the result. Evaluation of the results may be as follows:
- negative - the reaction to tuberculin is completely absent;
- mild (papule may be from 0 to 5 mm);
- moderately pronounced (from 6 mm to 10 mm);
- strongly pronounced (from 10 mm to 14 mm);
- hyperergic reaction (papule size more than 15 mm).
When a response to the introduction of tuberculin occurs, the reaction can be:
- positive;
- negative;
- doubtful.
If there are no reactions to the introduction of tuberculin in the body, this is the norm.
The reasons for the lack of reaction
A lack of response can be observed in patients who are not infected with Mycobacterium tuberculosis.
In addition, a negative reaction can be observed in patients who have already been ill with tuberculosis and successfully recovered. There is another group of patients in whom the reaction may be absent. These are persons who have previously been infected with Mycobacterium tuberculosis and currently have an inactive infection. A negative result in some cases can also be observed in patients with tuberculosis infection who are in the cure stage.
Therefore, it is imperative to remember that the absence of a reaction to the introduction of tuberculin does not mean that the patient can be healthy and not have a carrier of mycobacterium tuberculosis. In any case, the conclusion should be made by a qualified specialist who is well versed in this direction.
If a papule of any size is found in the individual being examined, then additional research methods are mandatory that can help in making a diagnosis. These include: chest radiography, computed tomography. It is mandatory to submit a complete blood count and blood test for biochemistry and gas composition. Repeatedly in 2-2.5 months, a new production of Diaskintest is being carried out.
Which method is more informative?
In children aged 12 months and older, doctors prescribe a test for Mantoux reaction. The test diaskintest has a high selectivity, which does not react to a BCG vaccine previously given to a child. This test is based as a method of allergic diagnosis, which helps to identify whether a child is infected with Mycobacterium tuberculosis or not. Unlike diaskintest, manta may show a reaction to previously administered tuberculin (BCG). Therefore, Diaskintest is considered to be more modern and highly informative.
Today, both methods are actively used. However, only a trained, qualified specialist can decipher the result obtained.
- Diaskintest characteristics
- Indications and Contraindications
- Conclusion, conclusions, recommendations
Today, diaskintest is used as a diagnosis of tuberculosis, the evaluation of the results of which is determined only by the attending physician. Currently, tuberculosis is of great social importance due to the high incidence and infection of the population, the difficulty of treatment and the possibility of spreading by airborne droplets. The method was introduced into medical practice only a few years ago, but has found wide application as a method for diagnosing tuberculosis infection. What is diaskintest and how to properly decode the results?
Diaskintest characteristics
Since 2009, new methods of detecting tuberculosis in the population have been introduced in Russia, such as Diaskintest and the quantiferon test. Until that time, one Mantoux test was used. It is a modern preparation for allergic diagnostics. He is appointed as an intracutaneous test. This procedure is performed for both adults and children. Using this technique, it is possible to detect the presence or absence of the disease in humans, to exclude the fact that there is a simple reaction to the introduction of BCG vaccine in children.
In some cases, Diaskintest is used to evaluate the effectiveness of anti-tuberculosis therapy. It must be remembered that this is not tuberculin diagnosis. This test does not cause a hypersensitivity reaction when administered. Diaskintest is a recombinant allergen containing 2 antigens. The latter are absent in the BCG vaccine, which is used as a specific prevention of tuberculosis. However, these antigens are isolated from virulent Mycobacterium tuberculosis. It is important that the results of Diaskintest do not depend on the previous vaccination.
In this preparation, there are no live mycobacteria, therefore a person cannot become infected with tuberculosis when a sample is administered. The sensitivity of diaskintest exceeds that for the Mantoux test, it is about 90%. The drug is injected in the same way as in the Mantoux test: intracutaneously for 72 hours in the area located on the border of the middle and upper third of the forearm. These two tests can be carried out at the same time, then injections are made on different hands. In this case, it is possible to determine the false results of the Mantoux test.
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Indications and Contraindications
Diaskintest, the results of which allow to detect human infection, is carried out according to strict indications. Consider the drug can be used starting from one year old. First, diaskintest is indicated in cases of suspected tuberculosis, if there are characteristic clinical symptoms of the disease. Secondly, it can be used to evaluate the activity of the infectious process. Thirdly, it is shown in case of doubts in the formulation of the correct diagnosis (for the differential diagnosis of tuberculosis with other diseases). Fourthly, when vaccinating children, very often there is a problem of correct evaluation of the obtained reaction. Diaskintest is used for mass screening, when it is necessary to distinguish the normal response to vaccination from infectious allergies.
It must be remembered that Diaskintest has contraindications for use. They include:
- exacerbation of acute and chronic diseases;
- some skin diseases;
- the presence of the examined epilepsy;
- the period of quarantine in institutions;
- exacerbation of somatic pathology;
- severe allergic diseases.
If a person has had a serious illness, then the diaskintest test can be prescribed no earlier than a month after recovery. This test should be carried out directly before the planned BCG vaccinations, otherwise it will take a whole month to wait.
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Interpretation of the data
After the expiration of 72 hours from the moment of the injection, the results are evaluated. The TB doctor or pediatrician must determine the size of the redness and the papule formed. The result of Diaskintest can be negative, questionable and positive.
A negative result is observed when there is one puncture reaction (bruise) in the area of drug administration.
This bruise should be less than 2 mm. A negative result indicates that the person being examined is not infected with Mycobacterium tuberculosis, or he is talking about a case of complete cure for a previously existing infection. In addition, this result may indicate the presence of an inactive form of tuberculosis.
If there is no infiltration, and only redness is present, then a dubious result takes place. Such people are subject to in-depth screening for tuberculosis. A positive reaction is put in the case of papules. At the same time its size does not matter. There are several degrees of positive reactions to the drug: weak, moderate, severe and strong (hyperergic). In any case, there is not only one bruise (puncture reaction). With a weak reaction, the size of the infiltrate area is less than 5 mm, with a moderate one - from 5 to 9 mm, with a pronounced one - from 10 to 14 mm, with a strong one - 15 and more. In the latter case, necrotic changes and lymphadenitis may occur.
Hello friends! In the previous article, we have already discussed the topic of diagnosis with these recombinant protein compounds, and here we will pay more attention to assessing the results of diagnosis and what the reaction rate of diaskintest is.
Recently, the information content and objectivity of the traditional tuberculin test is increasingly being questioned.
The mechanism of the drug's action is based on the cellular immune response that occurs after the introduction of antigens specific for tuberculous microbacteria.
Patients with a certain viral load develop special skin reactions that are manifestations of delayed hypersensitivity.
Diaskintest norm
The reaction to the introduction of the drug is considered positive (deviation from the norm) in the formation of papules or infiltrate of any size. At the same time, the degree of reaction is determined by the doctor or nurse, which gives an idea of the level of viral load.
The following response distribution is applied relative to the norm:
- Negative , which is characterized by the complete absence of traces of infiltration and hyperemic manifestations. In this case, only a puncture mark is visible on the skin at the injection site. This is the so-called "Diaskintest norm";
Of course, the first option can be considered an ideal option - normally, a person has no marks (except for the injection shot).
The result of the test is evaluated by the doctor not earlier than 72 hours after the administration of the drug by measuring the dimensions of the papule (infiltrate) with a transparent ruler.
The hyperemia is considered only in the absence of other reactionary manifestations. The papule itself also has a degree of severity:
- Weakly pronounced - the size of the infiltration spot does not exceed five millimeters;
- Moderate - papule size varies within 5-9 mm;
- Strongly expressed - the size of the infiltrate over 10 mm;
- Hyperergic is characterized by the size of the reaction zone of more than 15 mm, as well as vesicular-necrotic changes such as the formation of bubbles and areas of blackening of the skin.
Diaskintest reviews
The drug has been actively used in Russian medicine since 2009. During this time, a decent amount of feedback has accumulated, both from doctors and patients.
About the drug Diaskintest reviews in the majority say that this diagnostic method has an extremely high sensitivity to microbes of the tuberculosis series.
However, it can cause some side effects (headaches, general weakness, drowsiness, etc.). In addition, a large number of contraindications somewhat limits the possibilities of its use.
Unfortunately, at the moment, this technique is not able to become a full-fledged replacement for the tuberculin manta test, therefore, it is used only as an effective supplement to it.
Diaskintest and Manta simultaneously
Many TB doctors believe that without a tuberculin test, this tool has insufficient clinical information.
The drug is well allocated strains of the so-called "human" tuberculosis. However, it is rather weak in relation to many other species (there are 24 of them). Based on the norms of clinical practice, the treatment of only one type of tuberculosis seems impractical.
But applying diaskintest and manta can simultaneously form a more complete and objective picture of the disease. In addition, a graded tuberculin test provides more data on the patient's immune system.
Thus, these two similar diagnostic methods are very effective in complex application. It is important to remember that with the introduction of the drug diaskintest norm reactions are the absolute absence of infiltration, however, there are varieties of tuberculous microbacteria that this protein recombinant compound simply does not respond to.
“” - a recombinant tuberculosis allergen at standard dilution is a recombinant protein produced by a genetically modified culture EscherichiacoliBL21 (DE3) / pCFP-ESAT, diluted in sterile isotonic phosphate buffered saline, with preservative (phenol). Contains two antigens present in the virulent Mycobacterium tuberculosis strains and absent in the BCG vaccine strain.
Method of administration and dosage diaskintest . The drug is administered strictly intracutaneously. The skin test is carried out by a prescribed doctor trained nurse, who has access to the intradermal tests. For conducting the test, tuberculin syringes and thin short needles with an oblique cut are used. Before use, check their release date and expiration date.
The rubber stopper of the bottle with the preparation is treated with 70% ethyl alcohol and pierced with a separate needle for intramuscular injection, which after each sample of the drug in the syringe is left in the stopper of the bottle, covered with a sterile napkin. After opening, the bottle with the drug is allowed to be stored for no more than two hours. Using a syringe, take 0.2 ml (two doses) of DIASKINTEST, put a needle on it and release the solution to the 0.1 ml mark.
The test is carried out in a sitting position. After treatment of the skin area on the inner surface of the middle third of the forearm with 70% ethyl alcohol, 0.1 ml of the DIASKINEST preparation is injected into the upper layers of the stretched skin.
When testing, as a rule, a papule is formed in the skin in the form of a "lemon peel" measuring 7-10 mm in diameter whitish,
Persons with a history of manifestations of nonspecific allergy, it is recommended to test the background of taking desensitizing drugs for 7 days (5 days before the test and 2 days after it).
Profitability Analysis diaskintest . The result of the test is evaluated by the doctor or a trained nurse 72 hours after it was carried out by measuring the transverse (relative to the axis of the forearm) size of the hyperemia and infiltrate (papules) in millimeters with a transparent ruler. Hyperemia is taken into account only in the absence of infiltration.
The response to the sample is:
* negative - in the complete absence of infiltration and hyperemia, or in the presence of "prick reaction";
* doubtful - in the presence of hyperemia (of any size without infiltration) or infiltration of 2-4 mm in size;
* positive - in the presence of infiltration of 5 mm or more in size,
With an infiltrate size of 15 mm and more, with vesiculo-necrotic changes and (or) lymphangitis, lymphadenitis regardless of the size of infiltration, the reaction to the drug is considered hyperergic,
Persons with a dubious and positive reaction to DIASKINTEST are screened for tuberculosis.
In individuals in the early stages of the tuberculosis process, in patients with severe tuberculosis, as well as with co-morbidities (AIDS, viral hepatitis, etc.), the reaction to the test with the “DIASKINTEST” preparation may be negative. In contrast to the reaction of a delayed type, skin manifestations of nonspecific allergy (mainly hyperemia) to the drug, as a rule, are observed immediately after the test and in 48-72 hours usually disappear.
In the records note:
a) the name of the drug;
b) manufacturer, batch number, expiration date;
c) the date of the test;
g) the introduction of the drug in the left or right forearm;
d) the result of the test
Contraindications for the formulation of the sample:
- acute and chronic (in the period of exacerbation infectious diseases, with the exception of cases suspicious of tuberculosis;
* somatic and other diseases in the period of exacerbation;
* common skin diseases;
* allergic conditions;
* epilepsy.
In children's groups, where there is a quarantine for childhood infections, the test is carried out only after the removal of quarantine.
Side effect diaskintest. Individuals may experience short-term signs of a general reaction: malaise, headache, fever.
Interaction with other drugs. Prophylactic vaccinations (except for BCG) can be performed to healthy individuals with a negative test result immediately after evaluating and taking into account the test result. The formulation of the sample with the drug "DIASKINTEST *" should be planned before the prophylactic vaccinations. If prophylactic vaccinations are carried out, the test with the drug "DIASKINTEST *" is carried out no earlier than a month after the vaccination.
Release form
.
On In ml (30 doses) in glass vials, sealed with rubber stoppers with running-in aluminum caps with the control of the first opening,
1 or 5 bottles in a blister strip packaging made from PVC film,
] or 2 blister packs with 5 bottles or 1 blister pack with 1 bottle together with the instructions for use in a carton pack.
Shelf life : 2 years. The drug expired use is not subject to.
Transportation and storage conditions . The drug is transported and stored in accordance with SP 33.2L 24843 at a temperature of from 2 to 80 С. Do not freeze. Keep out of the reach of children.
Information provided for healthcare professionals. For complete information about the drug "DIASKINTEST *" you should read the instructions for use.
Diaskintest is highly sensitive:
A positive reaction is observed in 98-100% of patients with active tuberculosis and in individuals at high risk of its development (p.<0,05)
Diaskintest is highly specific:
The specificity of the test is 90-100% (p< 0,05)*.
The drug does not cause a reaction associated with BCG vaccination !.
Competitive advantages of Diaskintest
"DIASKINTEST" "- an allergen, is a combination of two recombinant proteinsESAT6 / CFP10. In the genome of M. tuberculosis, there is an RD1 region containing genes encoding the synthesis of ESAT6 and CFP10 proteins (the virulent properties of M. tuberculosis are determined).
The RD1 region is absent in the M.bovis BCG genome. This difference lies in the basis of the principle of action of the drug "DIASKINTEST *" and determines its high sensitivity and specificity in comparison with standard tuberculin PPD-L2.
* Skin test with the drug "Diaskintest *" - new opportunities to identify tuberculosis infection / Ed. Academician of the Russian Academy of Sciences and the Russian Academy of Medical Sciences M.A. Paltsev, - M .: OJSC "Medicine" Publishing House, 2010. - 176 p.
Major Medical Benefits drug "DIASKINTEST®":
allows you to clearly differentiate different types of allergic reactions: vaccine-free, infectious and non-specific, caused by non-tuberculous mycobacteria;
has high sensitivity
and specificity at the minimum frequency of excessively strong reactions;
does not cause an immune response associated with BCG vaccination;
The test is simple in formulation (identical to the Mantue PPD-L2 test technique, the results are evaluated after a similar period of time (72 hours)).
“DIASKINTEST®” is used in all age groups with the aim of:
diagnosis of tuberculosis and evaluation of the activity of the process;
differential diagnosis of tuberculosis;
differential diagnosis of post-vaccination and infectious allergies (delayed-type hypersensitivity);
monitoring the effectiveness of treatment in combination with other methods.
Comparative characteristics "DIASKINTEST®" and "Tuberculin 2TE PPD-L" *
* Skin test with the drug "Diaskintest®" - new opportunities for the identification of tuberculosis infection / Ed. Academician of the Russian Academy of Sciences and the Russian Academy of Medical Sciences M.A. Paltsev, - M .: OJSC "Medicine" Publishing House, 2010. - 176 p.
Sensitivity and specificity of Diaskintest® and 2TE PPD-L:
Sensitivity 
Specificity
Mantoux test with 2TE PPD-L does not reveal clear differences between active and inactive forms of the disease.
Mantoux test with 2TE PPD-L gives a positive result for BCG-vaccinated individuals.
The drug Diaskintest is positioned as a modernized analogue of the sample. His goal is to identify a child with tuberculosis. And although the composition of this pharmacological agent can indeed be considered more effective, the evaluation of the results of Diaskintest still occurs with the help of a conventional ruler.
Diaskintest - how to evaluate the result?
Evaluation of the results of Diaskintest in children is carried out 72 hours after the injection. As part of the drug recombinant tuberculosis allergen, diluted according to the standard scheme. Getting under the skin of the child, it interacts with internal fluids. As a result, it becomes possible to obtain a cellular immune response to specific mycobacterium tuberculosis antigens, which are contained in the preparation. This happens through the appearance of a delayed-type skin reaction. Most often, Diaskintest is prescribed after a conditionally positive Mantoux result, or in other situations that cause tuberculosis to be suspected in a child:
- to identify and differentiate the type of tuberculosis;
- to evaluate the results of anti-tuberculosis therapy;
- if it is impossible to conduct a tuberculin test.
- The child does not suffer from infectious diseases (not counting tuberculosis).
- Vaccination was carried out intracutaneously according to the rules. A qualified medical professional used a special syringe, scored 2 doses of the drug, one of which was released into a cotton ball, and only the second was given to a child. The injection site was chosen correctly - it should be the outer side of the forearm, approximately in the middle.
- The child has no somatic diseases in the phase of exacerbation and epilepsy.
Analyzing test data
Immediately after the vaccination, the child may experience redness, swelling and other skin reactions, but they should be considered allergic. Usually, all visible effects of the test pass within a day, a maximum of two. Sometimes a bruise appears after Diaskintest, this should not affect the results. It is possible to analyze the reaction of the child’s body to the introduction of a tuberculosis test only on the third day.
The negative result of Diaskintest indicates that the child is not sick, or the disease is in the final stage of treatment. Outwardly, it will look like the absence of redness and papules at the injection site. A slight reddening, no more than 2 mm in diameter, also makes it possible to speak of a negative test result.
The doubtful result of Diaskintest is if a red spot of more than 2 mm appeared on the injection site, or a papule with infiltration. This reaction is the reason for additional diagnostic procedures - X-rays, blood tests, ultrasound, and the like.
If the evaluation of the results of Diaskintest gave a positive result, it will manifest itself in the following way:
Without the formation of papules, seals, or infiltration, the result cannot be considered positive, it is considered doubtful and the child is sent to clarify the diagnosis.