Prostatic acid phosphatase

Prostatic acid phosphatase (PAP), also prostatic specific acid phosphatase (PSAP), is an is_associated_with::enzyme produced by the is_associated_with::prostate. It may be found in increased amounts in men who have is_associated_with::prostate cancer or other diseases.

The highest levels of acid phosphatase are found in metastasized prostate cancer. Diseases of the bone, such as Paget's disease or is_associated_with::hyperparathyroidism, diseases of is_associated_with::blood cells, such as is_associated_with::sickle-cell disease or is_associated_with::multiple myeloma or is_associated_with::lysosomal storage diseases, such as is_associated_with::Gaucher's disease, will show moderately increased levels.

Certain is_associated_with::medications can cause temporary increases or decreases in acid phosphatase levels. Manipulation of the prostate gland through massage, is_associated_with::biopsy or is_associated_with::rectal exam before a test may increase the level.

Its physiological function may be associated with the liquefaction process of is_associated_with::semen.

Serum marker
PSAP was used to monitor and assess progression of is_associated_with::prostate cancer until the introduction of is_associated_with::prostate specific antigen (PSA), which has now largely displaced it. Recent work, suggesting it has a role in prognosticating intermediate and high-risk prostate cancer, has led to renewed interest in this marker.

Immunohistochemistry
PSAP is_associated_with::immunohistochemical staining is often used with PSA (staining), by is_associated_with::pathologists, to help distinguish poorly differentiated is_associated_with::carcinomas. For example, poorly differentiated prostate adenocarcinoma (is_associated_with::prostate cancer) and is_associated_with::urothelial carcinoma (is_associated_with::bladder cancer) may appear similar under the is_associated_with::microscope, but PSAP and PSA staining can help differentiate them; prostate adenocarcinoma often stains with PSA and/or PSAP, while urothelial carcinoma does not.

Presumptive test for semen
Prostatic acid phosphatase is present in is_associated_with::semen and its presence can be used as a is_associated_with::presumptive test for semen. Other is_associated_with::acid phosphatases are present in other bodily fluids, but the high concentration of PAP in semen gives a strong indication that semen is present.

HIV
PAP may play an important role in the transmission of is_associated_with::HIV. Researchers at the is_associated_with::University of Ulm in is_associated_with::Germany found that PAP forms fibers made of is_associated_with::amyloid. They called the fibers is_associated_with::Semen-derived Enhancer of Virus Infection (SEVI) and showed that they capture HIV virions promoting their attachment to target cells. The association of PAP with HIV may increase the ability of the virus to infect human cells "by several orders of magnitude." PAP may be a future target of efforts to combat the spread of HIV infection.

Pain suppression
A study at the is_associated_with::University of North Carolina and is_associated_with::University of Helsinki suggested that PAP could have potent antinociceptive, antihyperalgesic, and antiallodynic effects that last longer than is_associated_with::morphine. One dose of PAP lasted for up to three days, much longer than the five hours gained with a single dose of morphine. When in distress, nerve cells release a chemical known as is_associated_with::adenosine triphosphate (ATP) which in turn invokes a painful sensation. ATP is broken down into AMP which PAP converts into is_associated_with::adenosine, a molecule known to suppress pain.

History
PSAP was the first useful serum is_associated_with::tumour marker and emerged in the 1940s and 1950s.