TOTAL PSA ELISA

Features

• European Union: for in vitro diagnostic use
• rest of the world RUO
• the total assay time is less than 1.5 hours
• for quantitative determination of total PSA in human serum and plasma
• 0-5 calibrators are calibrated against the International Standard WHO 96/670
• calibrators and quality controls are ready to use
• limit of detection 0.216 ng/ml

Research topic

Immune Response, Infection and Inflammation, Oncology

Summary

PSA is a serine protease with chymotrypsin-like activity, whose primary function is seminal clot liquification. The production of PSA is regulated by androgens and occurs almost exclusively in the prostatic epithelial cells1. PSA is found in circulation in a number of different forms which can be classified into 2 general groups – complexed PSA (bound to serum protease inhibitors) and free PSA (unbound and inactive)2. The predominant form of PSA is that bound to the serum protease inhibitor alpha-1 anti-chymotrypsin and comprises 65 – 95% of the circulating level2 ; the remaining 5 – 35% of PSA in circulation is free PSA and that complexed with alpha-2 macroglobulin. PSA is produced by normal, as well as malignant, cells of the prostate gland and a number of benign (not cancerous) conditions can cause a man’s PSA level to rise. The most frequent benign prostate conditions that cause an elevation in PSA level are prostatitis (inflammation of the prostate) and benign prostatic hyperplasia (BPH) (enlargement of the prostate). However, prostate cancer is most commonly associated with elevated levels of PSA and since the correlation between PSA and prostate cancer volume was first published in 19873, PSA has become the most widely used tumour marker for prostate cancer4. Previously digital rectal examination (DRE) was frequently used as only diagnostic modality for the detection of early stages of prostate cancer. More recently assessment of serum PSA in conjunction with digital rectal examination (DRE) has been found to increase the chance of early detection of prostate cancer improving the diagnostic specificity of DRE. In male serum, the normal concentration of PSA is < 4 ng/mL with levels > 4 ng/mL indicative of carcinoma5. The determination of PSA serum levels is not only important for the screening of patients for prostate cancer, but also for monitoring patients that have been treated for this disease. Regular PSA measurements are an important tool to examine the potential and actual effectiveness of surgery or other therapies. An increase of PSA in patients after radical prostatectomy or radiotherapy may allow an earlier discoveryof residual or recurrent carcinoma6 - 8.