Table of contents:
- The body's defense reaction: the production of antibodies to lamblia
- Antibodies to lamblia
- How to determine the amount of antibodies to lamblia antigens?
- Giardia antigen in feces, what does it mean?
Video: Antibodies To Lamblia - What Is It, The Norm And Decoding
The body's defense reaction: the production of antibodies to lamblia
- 1 Antibodies to lamblia
2 How to determine the amount of antibodies to lamblia antigens?
2.1 Decoding the result
- 2.1.1 IgA
- 2.1.2 IgG
- 2.1.3 IgM
- 2.2 What does a positive result say?
- 2.3 Negative result: no guarantee of absence of disease
- 3 Giardia antigen in feces, what does it mean?
Giardiasis is a fairly common disease of the small intestine caused by parasites. Despite this, there are still many problems in the qualitative diagnosis of this disease. The widespread test for detecting lamblia cysts in feces does not always bring the proper result, its effectiveness is 50%. This analysis is often complemented by blood tests for the presence of antibodies to lamblia antigens. It is quite effective and allows you to determine not only the presence of a parasite in the body, but also the severity of the course of the disease.
Antibodies to lamblia
The production of antibodies to lamblia is a protective reaction of the body to the penetration of parasites into it. Lymphocytes are responsible for the reproduction of protective cells. Giardia penetrate into the intestinal epithelium, in response, the body's immune system reacts with active production of antibodies, throwing them into the blood.
There are five types of antibodies:
- IgA is produced in infectious diseases of the respiratory system, in the case of chronic skin diseases, liver diseases such as hepatitis and cirrhosis, as well as alcoholism also lead to increased production of antibodies of this group;
- IgE begins to be actively reproduced by the body in the case of most infections, with the elimination of toxins, it is also produced in pregnant women during the development of fetal immunity;
- IgM signals that foreign bodies have entered the body (produced at the very beginning of the disease);
- IgGs are responsible for long-term immunity, providing lasting protection;
- IgD is a poorly understood class of antibodies, while experts find it difficult to give an exact answer for what exactly this immunoglobulin is responsible for.
When Giardia enters the body, the first thing to do is to actively reproduce antibodies of the IgM class. Their rise is the first sign that infection has occurred. It should be borne in mind that the body begins to secrete this immunoglobulin from the first day of infection. This takes some time. Therefore, if an analysis is made a day or two after infection, it will not determine the presence of this parasite in the body.
A month after the invasion, the body begins to actively produce antibodies of the IgA class. This suggests that the infection is progressing in full swing. In turn, within a couple of weeks after infection, the IgM antibodies change to IgG. Their presence signals that giardiasis has passed into an acute degree of the disease.
In the process of proper treatment, IgG antibodies gradually decline. It should be borne in mind that for another six months, and sometimes longer, after the parasites are completely eliminated from the body, this immunoglobulin may remain elevated, giving a positive reaction. This phenomenon is a consequence of the fact that even after the death of parasites, traces of its vital activity remain in the body. And during the entire time, while the body will get rid of toxins and poisons left by lamblia, IgG will be above normal.
How to determine the amount of antibodies to lamblia antigens?
Blood for analysis
To determine the content of antibodies to lamblia antigens in the body, it is required to take a blood test from a vein. To obtain an accurate result, you must follow the rules of preparation for this procedure.
- A few days before blood sampling, you need to give up spicy and salty foods, any alcohol and carbonated water is also prohibited;
- The day before the test, you should stop active sports, you can not carry out physiotherapy procedures;
- For several days, you need to refrain from taking antibiotics, if any;
- You need to donate blood in the morning on an empty stomach.
Decoding the result
After examining the analysis, the laboratory assistant makes a conclusion - a positive or negative result for this sample. Positive means there is a disease, negative means no antibodies were detected. The expert bases his conclusion on the basis of the norm of the content of antibodies to lamblia in the body, which varies not only depending on the age of the person, but also on the gender.
- For children under three months old, this figure corresponds to - 0.01-0.34 g / l;
- For children under one year old, the norm will be a content of 0.08-0.91 g / l;
- For a girl from 1-12 years old, the level of immunoglobulin A is 0.21-2.82 g / l;
- For a boy aged 1-12 years, this figure is 0.21-2.91 g / l;
- For a woman from 12-60 years old - 0.65-5.17 g / l, after 60 - 0.69-5.17 g / l;
- For a man from 12-60 years old - 0.63-4.84 g / l, after 60 - 1.01-6.45 g / l.
Deviations from these indicators upward indicate that a person is sick with tuberculosis, rheumatoid arthritis, cystic fibrosis. An increase in this antibody also indicates that some suppurative processes are taking place in the body in the stomach or intestines.
Decoding the analysis result
- For girls up to a month, the norm is 3.91-17.37 g / l;
- For boys under the age of one month, this indicator is 3.97-17.65 g / l;
- In girls, from a month to a year, 2.03-9.34 g / l is considered to be the norm;
- For boys from a month to a year, these figures are slightly higher - 2.05-9.48 g / l;
- For a girl from 1-2 years old, the indicators are 4.83-12.26 g / l;
- For a boy from 1-2 years old, the level of immunoglobulin G is 4.75-12.1 g / l;
- Starting at 2 years old, 5.52-16.31 g / l becomes the norm for women;
- For the male half, starting from 2 years old, the indicators should not go beyond 5.4-16.31 g / l.
It is the most abundant immunoglobulin in the body. Its deficiency is the first signal that serious health problems are occurring. It is possible that there are malignant diseases of the lymphatic system. A too high indicator signals infections, autoimmune diseases, and liver problems. Tuberculosis, rheumatoid arthritis, lupus, sarcoidosis and even HIV infection are not excluded.
- For newborns, the indicator should be kept within the range of 0.06-0.21 g / l;
- For girls from three months to one year, these indicators are 0.17-1.5 g / l;
- For boys from three months to a year - 0.17-1.43 g / l;
- In girls from one to 12 years old, the content of immunoglobulin M should be equal to 0.47-2.4 g / l;
- For boys from one to 12 years old, this indicator is 0.41-1.83 g / l;
- For women, the norm is a level of 0.33-2.93 g / l;
- In men, 0.22-2.4 g / l.
If the result of the analysis showed that antibodies of class M are slightly increased, but there is no IgG immunoglobulin, then lamblia are present in the body. In this case, it is noted that the test result is positive.
If the study reveals a significant increase in IgM - a sign of acute giardiasis.
If a slight excess of IgG is noted, but IgM is not recorded, it is a sign that there is a disease, but the number of multiplying parasites is not large.
What does a positive result say?
After passing the tests, did lamblia antibodies show a positive result? This is not a guarantee that giardiasis really develops in the body. A jump in IgM levels is likely during pregnancy; such a reaction can also manifest itself in any chronic disease in the acute stage.
It should be taken into account that total antibodies can detect abnormalities in the state of health in the human body, failures in the immune system. But with one hundred percent probability, it is impossible to say that these failures were caused by giardiasis. A blood test for the level of antibodies in it is just one of the methods for determining the diagnosis.
Negative result: not a guarantee of absence of disease
If the total antibodies to lamblia gave a negative result, there is no reason to rejoice. It is quite possible that too little time has passed since the moment of infection, and the body has not yet reacted with active production of antibodies to the invasion of foreign bodies. Especially if at the same time there are external signs of the manifestation of the disease. A second test is recommended in two weeks.
To obtain a more accurate result, in addition to taking blood to detect antibodies, an analysis is also performed to detect antigen in feces.
Giardia antigen in feces, what does it mean?
This analysis helps to determine the presence of parasites in the human body. Feces are handed over both during treatment and a week after the medication course is over. This procedure helps to determine the effectiveness of the therapy by detecting the antigen in the biomaterial.
What is Giardia Antigen in Feces? The human body perceives any foreign substance as an object against which it is necessary to fight. As a defense, the body begins to produce antibodies. The immune cell attracts the antigen, receiving information about the given body. If possible, the antibody kills the foreign cell; if not, it tries to neutralize it, preventing further reproduction.
There are no special requirements for the biomaterial for the analysis for antigens. Even a three-day feces are suitable for research. To determine the presence of antigen in the feces, antibodies of lamblia are injected. They, in turn, must attract the antigens of the parasites. After a while, reagents are introduced into the sample, which should free the biomaterial from the cells that have not reacted. Unbound enzymes are washed and a drug that inhibits the process is added. During the last procedure, the stool darkens with a positive response and remains the same color if the result is negative and no antigens are found.
This analysis was not without negative points, so it is very problematic to determine the presence of lamblia in the event that at least a small amount of E. coli is present in the test sample. A negative result can be even if the body has not yet had time to respond to the invasion of parasites. For a more accurate diagnosis, it is recommended to return the biomaterial in a week.
A blood test to detect Giardia antibodies and an analysis of feces, which allows you to determine whether it contains antigens or not, are the main studies that allow us to conclude whether a person is sick with giardiasis or not.