Immune system has 2 types of inherent and acquisitive part. This system evaluates by tests such as CBC and ESR. Aim of these tests are diagnosing Leukopenia, lymphopenia, neutropenia, neutrophilia and abnormal forms of peripheral blood cells.
Innate immune system includes physical and chemical barriers such as skin and mucus, floating proteins in plasma, such as complement proteins, alien ectopic cells such as neutrophils, macrophages, and natural lethal cells. Acquired or adaptive immunity has two important branches called cellular and humoral immunity. The most important cells are, T cell s in cellular immunity, and B cells in humoral immunity. The mechanisms of T cells are performed by themselves and partly by activated macrophages. B lymphocytes play a role in the production and secretion of immunoglobulins. Both of these cells are active against the antigen and give rise to specific responses.
Immunodeficiency means that immune system has inappropriate function, so that people are susceptible to a variety of infections. Immunodeficiency can be primary or secondary or be acquired. Most primary immunodeficiencies are due to genetic defects or immune function and have a genetic basis. In secondary immunodeficiencies, there are non-immune causes such as bacterial or viral infections, malnutrition or treatment. AIDS is the most famous secondary immunodeficiency disease.
Evaluation of immune system
Evaluation of immune system often begins with a CBC, peripheral blood platelet and ESR sedimentation test. The purpose of this study is to identify leukopenia, lymphopenia, neutropenia, neutrophilia and abnormal forms of peripheral blood cells and the probability of bacterial infection.
Function of B cells
Antibody deficiency is the most common type of immune defect, due to the lack of differentiation of B-lymphocytes in bone marrow or peripheral lymphatic encephalitis, and subsequently the inability of B-lymphocytes to secrete enough antibodies or to desirable quality. Patients with an initial deficiency of antibodies are susceptible to a variety of bacterial infections.
The first test to evaluate the function of Lymphocytes B is measuring serum immunoglobulins. Quantitative assays for IgA, IgG and IgM by ELISA or SRID methods are helpful in detecting the overall deficiency of immunoglobulins. It is also useful in identifying the deficiency of one or more immunoglobulin classes. In the study of B-lymphocytes, serum protein electrophoresis, immuno-electrophoresis and immunopharmation of electrophoresis have little or no quantitative sensitivity and capability.
Measuring serum immunoglobulins is the first test to evaluate the function of Lymphocytes B. Quantitative assays for IgA, IgG and IgM by ELISA or SRID methods are helpful in detecting the overall deficiency of immunoglobulins. It is also useful in identifying the deficiency of one or more immunoglobulin classes. In the study of B-lymphocytes, serum protein electrophoresis, immuno-electrophoresis and immunopharmation of electrophoresis have little or no quantitative sensitivity and capability.
- Patients with antibody deficiencies often have low serum antibodies, but sometimes amount of antibodies are normal, but their function is not normal.
- The most prevalent 88% deficiency is the IgA antibody deficiency.
- Common CVD is a syndrome characterized by decreasing antibodies in the bloodstream and the inability to produce antibodies with the normal number of peripheral B cells. Sexual distribution in CVID is roughly equal and affects men and women alike. The onset of recurrent infections in patients can begin at any age, but the first symptoms are more common in the age range of 1-5 and 16-20 years old.
Function of T cells
T lymphocytes have a more complex function than lymphocytes B. And so, their performance evaluation is more difficult. There are also simple, inexpensive, and reliable tests to check the function of T cells.
Delayed hypersensitivity reaction
This test is used with a set of antigens for screening in adults and children (with the exception of infants and infants). The positive result in delayed skin sensitivity testing in most cases is a sign of the normal functioning of T cells and cellular immunity. Of course, it should be noted that the positive result in the delayed skin sensitivity test performed with a group of antigens can not be a sign of the normal functioning of the immune system against other antigens. For example, in chronic mucosal-cardiovascular disease, immune function may be normal for all antigens other than Candida. In addition, the positive result of this test is the previous anti-human encounter. For example, people have received antigens through vaccine or infection, but in newborns they may still have not been exposed to some antigens. Thus, the test for skin allergy is negative, and this is a negative result of the disorder The immune system is not cellular.