Prostate-specific antigen (PSA) is a single-chain glycoprotein secreted by prostate, which exists in epithelial cells of prostate duct. The serum PSA level of patients with prostate cancer is significantly increased. 80% of total serum PSA(t-PSA) exists in the form of binding, which is called compound PSA (C-PSA). 20% exists in free form, which is called free PSA(f-PSA). T-PSA and f-PSA increased, while f-PSA/t-PSA ratio decreased, suggesting prostate cancer.
Clinical significance:
If serum tPSA and fPSA increase, but tPSA/fPSA decreases, the diagnosis of prostate cancer should be considered to improve the specificity and accuracy of diagnosis. The slight increase of serum tPSA and fPSA can also be seen in prostatitis, prostatic hypertrophy, nephritis, prostatic polyp and urogenital diseases. When using tPSA or fPSA alone to diagnose prostate cancer, the influence of benign prostate diseases cannot be ruled out.
Normal reference range:
Total prostate specific antigen (TPSA):
Precautions:
1. Prostate massage, prostate biopsy, digital rectal examination, indwelling catheter and cystoscopy should be avoided before blood collection.
2. The PSA values measured by different methods are different and cannot be mixed with each other.
3.PSA should be determined 8 weeks after the symptoms of prostatitis disappear.
4. Cycling for a long time can easily lead to the increase of serum PSA level.
5. Hormone therapy can affect the expression of PSA, thus reducing PSA level.
6. Blood samples should be centrifuged within 3 hours after collection, and serum should be refrigerated for no more than 24 hours.
7. Age has an effect on serum PSA level, which shows an upward trend with age.
Check the crowd:
1.50 male with lower urinary tract symptoms.
2. Male population with family history of prostate cancer.
3. Male rectal digital examination is abnormal, with clinical manifestations (such as fracture and bone pain). ) or abnormal imaging.
4. Patients who have been diagnosed with prostate cancer also need to regularly detect serum PSA in the follow-up after treatment.
Prostate specific antigen (PSA) is an amino acid of single-stranded polypeptide, which can dilute semen.
Prostate-specific antigen is an important index to check prostate diseases. This antigen can decompose collagen in semen, thus achieving the effect of diluting semen. If the serum prostate-specific antigen is less than 4.0 ng/ml, it belongs to the normal state, while it is greater than 10ng/ml, which may be caused by inflammation, hyperplasia and tumor in the prostate.
If the prostate specific antigen is abnormal, it is necessary to communicate with a professional doctor in time, do further examination, clarify the cause, and then cooperate with the doctor for treatment.