Circulating immune complexes (CIC)

The substance formed by the combination of the antigen and the corresponding antibody is called an immune complex. The immune complex is combined with complement and other immunoactive substances and deposited on the blood vessel wall, which can cause tissue damage and vasculitis, causing a series of diseases such as lupus erythematosus. Immune complexes can be detected in circulating blood, so they are called circulating immune complexes. Although the measurement of circulating immune complexes has no specific diagnostic significance, it has certain value for the activity judgment and guiding treatment of the disease. There are many methods for measuring circulating immune complexes. Only the commonly used polyethylene glycol method is introduced here. The circulating immune complex interacts with polyethylene glycol and exhibits turbidity changes, which can reflect the amount of immune complexes according to the size of the turbidity. If the turbidity is large, it indicates that the circulating immune complexes in the blood increase and the disease activity, but there is no specific value for the diagnosis. Basic Information Specialist classification: growth and development check classification: immunological examination Applicable gender: whether men and women apply fasting: not fasting Analysis results: Below normal: Normal value: no Above normal: negative: CIC was negative (anti-complement test, gelatin binding test). Positive: 4.3 ± 2.0, with ≥ 8.3 as positive for immune complexes (PEG precipitation test). Tips: After 8 pm on the day before the medical examination, you should start fasting for 12 hours, so as not to affect the test results. Normal value Anti-complement method is negative. The PEG precipitation method was 4.3 ± 2.0. The SPA sandwich enzyme-linked immunosorbent assay was less than 28.4 mg/L. Note that the normal reference values ​​of each laboratory are obtained according to different experimental methods and conditions. Clinical significance The circulating immune complex is formed by the reaction of antigen and antibody in the body. In most cases, it is beneficial to the body. In a few cases, the immune complex precipitates, causing tissue damage and causing disease. The antigens that form immune complexes can be classified into endogenous and exogenous. According to these differences, CIC diseases can be classified as follows: (1) Those related to endogenous antigens: 1 IgG antigen rheumatoid arthritis, mixed cryoglobulin disease, hypergammaglobulinemia purpura. 2 nuclear antigen systemic lupus erythematosus. 3 special cell antigen tumors, autoimmune diseases. (2) Those related to exogenous antigens: 1 iatrogenic antigen serum disease, drug allergy. 2 In the environment, antigen-inhalation antigen (exogenous allergic alveolitis), ingestion antigen (herpes-like dermatitis). 3 infectious biological antigens: A. Viral antigen hepatitis, dengue hemorrhagic fever. B. Glomerulonephritis and leprosy after infection with bacterial antigenic streptococcus. C. Protozoal antigen malaria, trypanosomiasis. D. Worm antigen schistosomiasis, onchocerciasis. (3) Unknown antigenic properties: Chronic immune complex glomerulonephritis with or without eosinophilic vasculitis. Positive results may be diseases: adult rheumatoid arthritis scleritis, vasculitis, acute glomerulonephritis, ankylosing spondylitis scleritis, Behcet's scleritis considerations First, the precautions before blood draw: 1, do not eat too greasy, high-protein food the day before the blood, to avoid heavy drinking. The alcohol content in the blood directly affects the test results. 2. After 8 pm on the day before the medical examination, you should start fasting for 12 hours to avoid affecting the test results. 3, should relax when taking blood, to avoid the contraction of blood vessels caused by fear, increase the difficulty of blood collection. Second, after blood draw should pay attention to: 1. After blood is drawn, local compression is required at the pinhole for 3-5 minutes to stop bleeding. Note: Do not rub, so as not to cause subcutaneous hematoma. 2, the pressing time should be sufficient. There is a difference in clotting time for each person, and some people need a little longer to clotting. Therefore, when the surface of the skin appears to be bleeding, the compression is stopped immediately, and the blood may be infiltrated into the skin due to incomplete hemostasis. Therefore, the compression time is longer to completely stop bleeding. If there is a tendency to bleed, the compression time should be extended. 3, after the blood draw symptoms of fainting such as: dizziness, vertigo, fatigue, etc. should immediately lie down, drink a small amount of syrup, and then undergo a physical examination after the symptoms are relieved. 4. If there is localized congestion, use a warm towel after 24 hours to promote absorption. 3. Please inform the doctor about the recent medication and special physiological changes before the test. Inspection process It is combined with anti-complement, gelatin, and PEG precipitation test. Not suitable for the crowd There are no special taboos. Adverse reactions and risks There are no related complications and hazards.