Urine 5-hydroxyindoleacetic acid

5-Hydroxyindoleacetic acid (5-HIAA) is a metabolite of human 5-HT. The chemical coloration method is generally used to determine the 5-HIAA content in urine for the diagnosis of carcinoid tumors. The basic principle is that 5-HIAA is coupled with 1-nitroso-2-naphthol and nitrous acid in a purple color. The color depth is proportional to the 5-HIAA content in urine, because normal human urine is generally not purple. Therefore, qualitative tests can meet the needs of clinical diagnosis. Basic Information Specialist classification: Oncology examination classification: urine / kidney function test Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Low levels can occur in patients with kidney disease. Normal value: Urine 5-hydroxyindoleacetic acid: 1.8-6.0mg/24h Above normal: Excessive secretion of 5-HIAA is the most specific biochemical indicator of carcinoid tumors. The amount of 5-HIAA excreted in the urine of patients with carcinoid tumors is generally 5 to 50 times the normal amount, and some even increase by more than 100 times. Generally, more than 25mg/24h in urine is suspicious. >50mg/24h can diagnose carcinoid. Mild elevation of 5-HIAA in the urine can occur in other gastrointestinal diseases such as oral inflammatory diarrhea, tropical stomatitis diarrhea, and bronchial oat cell cancer. negative: Positive: Tips: Yali, banana, eggplant, pineapple, plum and walnut are rich in 5-HT, which is easy to rise to 5-HIAA. These foods should be fasted 3 to 4 days before the examination. Acetanilide and related drugs, cough medicine, can be increased to false; phenothiazine, promethazine and other drugs can be hypothetically reduced, so the above drugs should be discontinued during the measurement. Normal value Qualitative test negative (light yellow). If the purple reaction is positive. Generally, 209 μmol (40 mg) of urine can be detected by 24 h of this method, and it is almost black if it reaches 15699 μmol (300 mg). Quantitative test 9.4 ~ 31.4 μmol / 24h (1.8 ~ 6.0mg / 24h). Clinical significance Excessive secretion of 5-HIAA is the most specific biochemical indicator of carcinoid tumors. The amount of 5-HIAA excreted in the urine of patients with carcinoid tumors is generally 5 to 50 times the normal amount, and some even increase by more than 100 times. Generally, more than 25mg/24h in urine is suspicious. >50mg/24h can diagnose carcinoid. The amount of 5-HIAA in urine is directly related to the frequency and severity of carcinoid syndrome. Urine 5-HIAA10～49mg/24h survival for 29 months; 50～149mg/24h, survival for 21 months;≥150mg/24h , survived for 13 months. Mild elevation of 5-HIAA in the urine can occur in other gastrointestinal diseases such as stomatitis diarrhea, tropical stomatitis diarrhea, and bronchial oat cell cancer; low levels can occur in patients with kidney disease. High results may be diseases: gastric carcinoid tumor, islet cell carcinoid, tropical stomatitis diarrhea precautions Randomly sampled urine samples can be screened. For 5-HIAA quantitative analysis, 24 h of urine was collected and contained in a 12 g boric acid or 10 ml 6 mol/L HCL bottle. Specimens can be stored at room temperature for one week and stored at 2 to 6 ° C for one month. (1) Yali, banana, eggplant, pineapple, plum and walnut are rich in 5-HT, which is easy to rise to 5-HIAA. These foods should be fasted 3 to 4 days before the examination. (2) Acetanilide and related drugs, cough medicine, can be increased to false; phenothiazine, promethazine and other drugs can be hypothetically reduced, so the above drugs should be discontinued during the measurement. (3) The application of fluorescence spectrophotometry and HPIC method can improve the sensitivity of the measurement, and can eliminate the interference of the above drugs, improve the specificity, and the qualified laboratory can be used. Inspection process 100 μl of sample (whole blood, plasma or tissue homogenate and body fluid) was mixed with 1.0 mol/L perchloric acid in an equal amount of ice bath, centrifuged at 20000 g for 20 min at 4 ° C, and centrifuged supernatant was added to the HPLC autosampler. 20 μl was injected into a C18 reverse phase column at a flow rate of 0.4 ml/min, 25 ° C, and the eluate was eluted. The isolated 5-HT and 5-HIAA were analyzed by an electrochemical or fluorescence analysis system and the results were calculated by setting internal or external standards. Not suitable for the crowd Generally no taboos. Adverse reactions and risks No.

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