cold hemolysis test

Paroxysmal cold hemoglobinuria (PCH) is an autoimmune hemolysis syndrome in which a cold-reactive antibody (DL antibody) is produced in the patient, which is IgG and does not bind strongly to red blood cells at 37 °C. When the temperature drops below 20 ° C, DL antibodies can bind to the surface of red blood cells if complement is present. When the temperature is further increased to 37 ° C, hemolysis occurs due to the formation of voids in the erythrocyte membrane due to a series of complement involvement. Basic Information Specialist classification: cardiovascular examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Normal value: no Above normal: negative: normal. Positive: Paroxysmal cold hemoglobinuria was positive. Tips: Do not eat too greasy, high-protein foods the day before, and avoid heavy drinking. Normal value negative. Clinical significance Abnormal results: paroxysmal cold hemoglobinuria was positive. Some viral infections such as measles, mumps, varicella, infectious mononucleosis, etc. may also have a positive reaction. Need to check the crowd suspected of the above conditions. Positive result may be disease: measles precautions Inappropriate people: generally no special population. Forbidden before examination: Please inform the doctor about the recent medication and special physiological changes before the test. 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. Requirements for examination: When taking blood, you should relax your mind, avoid the contraction of blood vessels caused by fear, and increase the difficulty of blood collection. Inspection process This test is mainly used to check the degree of destruction of red blood cell walls by chemical substances such as cholate and soap in the injection, so as to limit the content during preparation to ensure safety. At present, the following methods can be used for traditional Chinese medicine injection: take 3 test tubes, add 2.0 ml of freshly prepared 2% rabbit blood physiological saline suspension, add 2.0 ml of normal saline as control tube, and dilute the second tube with test sample. The liquid (liquid A) was 2.0 ml, and the third tube was added with a test solution dilution (ethyl acetate) 2.0 ml, shaken, and allowed to stand at 37 ° C for 1 hour. If the whole blood sample of the second tube causes the red blood cells to completely rupture due to the liquid medicine, the red blood clearing solution is positive for the hemolysis test and is not suitable for injection. The third tube is also checked for the presence or absence of a sticky reaction, and should also be negative, otherwise it is not directly used for intravenous injection. The control tube should be free of hemolysis and adhesion. The liquid A is 0.5ml of the test solution, and diluted with physiological saline to 100ml, and it is obtained. Solution B is 1.0ml of the test solution for injection into the Hongyan vein, diluted with physiological saline to 10ml, shake well, that is. When 2% rabbit blood physiological saline suspension was prepared, take 2ml of rabbit whole blood without coagulation and hemolysis, and dilute with physiological saline to 100ml and shake well. Not suitable for the crowd Generally no taboos. Adverse reactions and risks Can be infected concurrently.