prostate specific antigen

Prostatespecific antigen (PSA) is a single-chain glycoprotein produced by vesicles in prostate epithelial cells containing 237 amino acid residues. Its molecular weight is about 34kD, which is functionally related to kallikrein. Serine protease. PSA is present in the prostatic endoplasmic reticulum and prostatic epithelial cells and secretions. PSA is contained in both normal prostate tissue and diseased prostate tissue, and the PSA content in a single cell is relatively constant. PSA can be α1-antichymotrypsin and α2-megasphere. Protein binding is inactivated, usually with little or no trace of PSA in the blood. Basic Information Specialist classification: male examination inspection classification: blood examination Applicable gender: whether men and women apply fasting: not fasting Analysis results: Below normal: normal. Normal value: Prostate specific antigen: 0-4μg/L Above normal: Can be seen in patients with prostate cancer, prostatitis, benign prostatic hyperplasia. negative: Positive: 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 <4 μg/L. Clinical significance Abnormal result (1) The serum free PSA (F-PSA) and total PSA (T-PSA) values ​​of prostate cancer patients were significantly increased, and the increase of T-PSA was more obvious, so the ratio of free PSA to total PSA (F/T ratio) decline. The F/T ratio can be used to distinguish between prostate cancer and benign prostatic hyperplasia. Especially when the PSA level is limited to the range of 4 to 10 μg/L, the application F/T ratio is superior to PSA. (2) PSA has important clinical significance for early diagnosis, clinical staging, postoperative efficacy observation and follow-up of prostate cancer. (3) In the prostate hyperplasia (BPH), prostate infarction, acute bacterial prostatitis, acute urinary tract obstruction, etc. can also cause elevated serum PSA levels. The people who need to be examined have frequent urination, urgency, urinary retention, dysuria, and difficulty in forming symptoms such as urinary flow, hematuria, and bone pain. High results may be diseases: seminal vesicle malignancy, prostate cancer, bladder adenocarcinoma Before inspection: 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. After inspection: 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. Inspection process The examination process: the blood volume is about 5 mL, and after the blood is drawn, the antigen is examined with a specific antibody. Not suitable for the crowd Have a coagulopathy such as hemophilia. Adverse reactions and risks Risk of infection: If you use an unclean needle, you may be at risk of infection.