Prostatic acid phosphatase
Encyclopedia
Prostatic acid phosphatase (PAP), also prostatic specific acid phosphatase (PSAP), is an enzyme
produced by the prostate
. It may be found in increased amounts in men who have 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 hyperparathyroidism
, diseases of blood cell
s, such as sickle-cell disease
or multiple myeloma
or lysosomal storage disease
s, such as Gaucher's disease
, will show moderately increased levels.
Certain medication
s can cause temporary increases or decreases in acid phosphatase levels. Manipulation of the prostate gland through massage, biopsy
or rectal exam before a test may increase the level.
Its physiological function may be associated with the liquefaction process of semen
.
until the introduction of 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.
s. For example, poorly differentiated prostate adenocarcinoma (prostate cancer
) and urothelial carcinoma (bladder cancer
) may appear similar under the microscope
, but PSAP and PSA
staining can help differentiate them; prostate adenocarcinoma often stains with PSA and/or PSAP, while urothelial carcinoma does not.
and its presence can be used as a presumptive test
for semen. Other acid phosphatase
s are present in other bodily fluids, but the high concentration of PAP in semen gives a strong indication that semen is present.
. Researchers at the University of Ulm
in Germany
found that PAP forms fibers made of amyloid
. They called the fibers 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.
and University of Helsinki
suggested that PAP could have potent antinociceptive, antihyperalgesic, and antiallodynic effects that last longer than 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 adenosine triphosphate
(ATP) which in turn invokes a painful sensation. ATP is broken down into AMP which PAP converts into adenosine, a molecule known to suppress pain.
tumour marker and emerged in the 1940s and 1950s.
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
produced by the prostate
Prostate
The prostate is a compound tubuloalveolar exocrine gland of the male reproductive system in most mammals....
. It may be found in increased amounts in men who have prostate cancer
Prostate cancer
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...
or other diseases.
The highest levels of acid phosphatase are found in metastasized prostate cancer. Diseases of the bone, such as Paget's disease
Paget's disease
Sir James Paget, a surgeon and pathologist, described several diseases, including:* Paget's disease of bone * Paget's disease of the breast* Paget-Schroetter disease* Extramammary Paget's disease...
or hyperparathyroidism
Hyperparathyroidism
Hyperparathyroidism is overactivity of the parathyroid glands resulting in excess production of parathyroid hormone . The parathyroid hormone regulates calcium and phosphate levels and helps to maintain these levels...
, diseases of blood cell
Blood cell
A blood cell, also called a hematocyte, is a cell normally found in blood. In mammals, these fall into three general categories:* red blood cells — Erythrocytes* white blood cells — Leukocytes* platelets — Thrombocytes...
s, such as sickle-cell disease
Sickle-cell disease
Sickle-cell disease , or sickle-cell anaemia or drepanocytosis, is an autosomal recessive genetic blood disorder with overdominance, characterized by red blood cells that assume an abnormal, rigid, sickle shape. Sickling decreases the cells' flexibility and results in a risk of various...
or multiple myeloma
Multiple myeloma
Multiple myeloma , also known as plasma cell myeloma or Kahler's disease , is a cancer of plasma cells, a type of white blood cell normally responsible for the production of antibodies...
or lysosomal storage disease
Lysosomal storage disease
Lysosomal storage diseases are a group of approximately 50 rare inherited metabolic disorders that result from defects in lysosomal function...
s, such as Gaucher's disease
Gaucher's disease
Gaucher's disease is a genetic disease in which a fatty substance accumulates in cells and certain organs.Gaucher's disease is the most common of the lysosomal storage diseases. It is caused by a hereditary deficiency of the enzyme glucosylceramidase. The enzyme acts on the fatty acid...
, will show moderately increased levels.
Certain medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
s can cause temporary increases or decreases in acid phosphatase levels. Manipulation of the prostate gland through massage, biopsy
Biopsy
A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
or rectal exam before a test may increase the level.
Its physiological function may be associated with the liquefaction process of semen
Semen
Semen is an organic fluid, also known as seminal fluid, that may contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize female ova...
.
Serum marker
PSAP was used to monitor and assess progression of prostate cancerProstate cancer
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...
until the introduction of prostate specific antigen
Prostate specific antigen
Prostate-specific antigen also known as gamma-seminoprotein or kallikrein-3 is a glycoprotein that in humans is encoded by the KLK3 gene. KLK3 is a member of the kallikrein-related peptidase family that are secreted by the epithelial cells of the prostate gland...
(PSA), which has now largely displaced it. Recent work, suggesting it has a role in prognosticating
Prognosis
Prognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...
intermediate and high-risk prostate cancer, has led to renewed interest in this marker.
Immunohistochemistry
PSAP immunohistochemical staining is often used with PSA (staining), by pathologists, to help distinguish poorly differentiated carcinomaCarcinoma
Carcinoma is the medical term for the most common type of cancer occurring in humans. Put simply, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that generally arises from cells originating in the endodermal or ectodermal germ layer during...
s. For example, poorly differentiated prostate adenocarcinoma (prostate cancer
Prostate cancer
Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...
) and urothelial carcinoma (bladder cancer
Bladder cancer
Bladder cancer is any of several types of malignant growths of the urinary bladder. It is a disease in which abnormal cells multiply without control in the bladder. The bladder is a hollow, muscular organ that stores urine; it is located in the pelvis...
) may appear similar under the microscope
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...
, but PSAP and PSA
Prostate specific antigen
Prostate-specific antigen also known as gamma-seminoprotein or kallikrein-3 is a glycoprotein that in humans is encoded by the KLK3 gene. KLK3 is a member of the kallikrein-related peptidase family that are secreted by the epithelial cells of the prostate gland...
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 semenSemen
Semen is an organic fluid, also known as seminal fluid, that may contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize female ova...
and its presence can be used as a presumptive test
Presumptive test
In medical and forensic science, a presumptive test is an analysis of a sample which establishes either:#The sample is definitely not a certain substance#The sample probably is the substance....
for semen. Other acid phosphatase
Acid phosphatase
Acid phosphatase is a phosphatase, a type of enzyme, used to free attached phosphate groups from other molecules during digestion. It is basically a phosphomonoesterase...
s 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 HIVHIV
Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...
. Researchers at the University of Ulm
University of Ulm
The University of Ulm is a public university in the city of Ulm, in the South German state of Baden-Württemberg. The university was founded in 1967 and focuses on natural sciences, medicine, engineering sciences, mathematics, economics and computer science...
in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
found that PAP forms fibers made of amyloid
Amyloid
Amyloids are insoluble fibrous protein aggregates sharing specific structural traits. Abnormal accumulation of amyloid in organs may lead to amyloidosis, and may play a role in various neurodegenerative diseases.-Definition:...
. They called the fibers 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 University of North CarolinaUniversity of North Carolina
Chartered in 1789, the University of North Carolina was one of the first public universities in the United States and the only one to graduate students in the eighteenth century...
and University of Helsinki
University of Helsinki
The University of Helsinki is a university located in Helsinki, Finland since 1829, but was founded in the city of Turku in 1640 as The Royal Academy of Turku, at that time part of the Swedish Empire. It is the oldest and largest university in Finland with the widest range of disciplines available...
suggested that PAP could have potent antinociceptive, antihyperalgesic, and antiallodynic effects that last longer than morphine
Morphine
Morphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...
. 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 adenosine triphosphate
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
(ATP) which in turn invokes a painful sensation. ATP is broken down into AMP which PAP converts into adenosine, a molecule known to suppress pain.
History
PSAP was the first useful serumBlood serum
In blood, the serum is the component that is neither a blood cell nor a clotting factor; it is the blood plasma with the fibrinogens removed...
tumour marker and emerged in the 1940s and 1950s.