Alkaline Phosphatase / Enzymes Defenition. High and Low Levels

Alkaline Phosphatase is a type of enzyme which commonly found in our body. But large amounts of this enzyme are usually present in certain parts of the body such as liver, bile ducts, bones as well as placenta. It is primarily caused due to the rupture of cells related to the vital organs present in our body. It ultimately leads to an increase in the level of blood of Alkaline Phosphatase.

As per the ‘Harrison’s principle of internal medicine’, this enzyme is the root causes for both gastro intestinal and bone diseases. It is commonly found in the biliary system and is solely responsible for certain diseases such as Cholecystitis and gall stones. These enzymes are also present in our intestines which could lead to rupture of the bowel thereby increasing enzyme levels in the blood.

Alkaline Phosphatase

Alkaline phosphatase (or ALP) refers to an enzyme found in the bloodstream of humans.  It helps in the breaking down of proteins in the body.  ALP exists in some various forms, based on where it originates.  The liver is one of the primary sources of Alkaline Phosphate. However, human tissues including pancreas, intestines, bones, kidneys and white blood cells produce some amount too.  For women in pregnancy, the placenta secretes their ALP.  The release of alkaline phosphatase into the blood is prompted by the emergence of diseases that harm and destroy the cells of these organs, which then leads to a rise in the level of alkaline phosphatase in the bloodstream.

The role of enzymes in mediating a myriad of cellular activities in living organisms has been reiterated time and again. Their function as agents of catalysis at different cellular sites places a lot of importance on these seemingly-redundant proteins. Alkaline phosphatase is just one example from a large collection of proteins found in the body of living organisms with enzymatic functions. But what exactly are these proteins called enzymes?

What Are Enzymes?

In simple terms, enzymes are organic catalysts of protein origin secreted by living cells which are responsible for coordinating and regulating many bodily functions in all living organisms. Catalysts, generally, are substances which alter the rate of chemical reactions but are both quantitatively and qualitatively unchanged at the end the said chemical reaction. And what on earth is not chemistry? It might very helpful, at this juncture, to consider living systems as a complex interaction of chemical reactions happening in tandem towards the common goal of sustaining life through normal functioning of all parts of the system. While some of these chemical reactions can actually proceed without external interference, a good number of them require a slight nudge or some influence to spur them on. And this is where enzymatic action is key.

Enzymes are cellular protein molecules which function as catalysts; speeding up chemical reactions in living systems but nonetheless, remaining unchanged when the reaction is complete. Virtually all biochemical reactions in living things need enzymes. Enzyme-catalyzed reactions in living things proceed much faster than they would in the absence of enzymes. All enzymes act on specific substances. These substances are called substrates. Enzymes work on these substrates and turn them into products. Most enzymes are large molecules made from many amino acids. The amino acids are linked together in a large continuous chain, which is wound into a compact structure. Specific enzymes have a specific part which holds the substrate; a hollow, knob, cleft or claw to hold, stretch or bend the molecule as it acts on it, thereby changing the substrate and making it behave differently. This part of the enzyme that sort of ‘fits’ into the substrate is called the active site of the enzyme. Think of it as a key fitting perfectly into a lock and allowing for access.

Enzymes catalyze reactions by lowering the activation energy of these reactions. Activation energy is the minimum energy required for any reaction to occur. Apart from breaking large molecules into smaller molecules, some enzymes also take smaller chemicals and build them up into bigger chemicals and perform so many other chemical tasks. Some chemicals can help an enzyme perform even better; such chemicals are called activators. Others which retard enzymatic functions are called inhibitors or deactivators. Enzymes are also temperature and pH specific, they are denatured by extremes of these factors. Most enzymes perform best at optimum temperature and pH levels. A vast number of enzymes are in existence and they are classified based on the nature of the effects they have on substrates.

Functions of Enzymes

Enzymes are vital for life and serve a wide range of important purposes in living systems, some of which include;
1. They aid digestion
2. They regulate metabolism
3. Some help breakdown large molecules into smaller pieces that are more easily absorbed by the body.
4. They also function as binding agents, bringing two molecules together to produce another molecule that in many cases, is essential to the health of living organisms.

What is Alkaline Phosphatase?

Alkaline phosphatase is a homodimeric protein enzyme of 86 kilodaltons. Each monomer contains five cysteine residues, two zinc atoms, and one magnesium atom crucial to its catalytic function, and it is optimally active at alkaline pH environments. As its name indicates, ALP functions are usually best under alkaline pH environments, and have the physiological role of dephosphorylating compounds. The enzyme is found across a multitude of organisms, prokaryotes and eukaryotes alike, with the same general function but in different structural forms suitable to the environment they function in.

Functions of Alkaline Phosphatase

In humans for example, it is found in many forms depending on its origin within the body – it plays an integral role in metabolism within the liver and development within the skeleton. Due to its widespread prevalence in these areas, its concentration in the bloodstream is used by diagnosticians as a biomarker in helping determine diagnoses such as hepatitis or osteomalacia. The level of alkaline phosphatase in the blood is checked through the ALP test, which is often part of routine blood tests. The levels of this enzyme in the blood depend on factors such as age, gender, blood type and whether an individual is pregnant or not. Additionally, abnormal levels of alkaline phosphatase in the blood could indicate issues relating to the liver, gall bladder or bones. Kidney tumors, infections as well as malnutrition have also shown abnormal level of alkaline phosphatase in blood.

Additionally, alkaline phosphatase is an enzyme found in your bloodstream. ALP helps break down proteins in the body and exists in different forms, depending on where it originates. Your liver is one of the main sources of ALP, but some is also made in your bones, intestines, pancreas, and kidneys. In pregnant women, ALP is made in the placenta.

An alkaline phosphatase level test (ALP test) measures the amount of alkaline phosphatase enzyme in your bloodstream. The test requires a simple blood draw and is often a routine part of other blood tests.
Abnormal levels of ALP in your blood most often indicate a problem with your liver, gallbladder, or bones. However, they may also indicate malnutrition, kidney cancer tumors, intestinal issues, a pancreas problem, or a serious infection. The normal range of ALP varies from person to person and depends on your age, blood type, gender, and whether you are pregnant.

According to the University of California San Francisco (UCSF), the normal range for serum ALP level is 20–140 IU/L, but this can vary from laboratory to laboratory. The normal range runs higher in children and decreases with age. The best way to know what is normal or not is to discuss the results with your doctor, who will be able to interpret the lab’s specific result and reference ranges.

High Levels of Alkaline Phosphatase

Higher-than-normal levels of ALP in your blood may be indicative of a problem with your liver and gallbladder. If left untreated, it may regrettably degenerate to hepatitis (liver inflammation), cirrhosis (liver scarring), liver cancer, gallstones or a blockage in your bile ducts.

Bone-related issues such as rickets, Paget’s disease and bone cancer have also been found to be connected to abnormally-high ALP levels. In rarer cases, high ALP has also been found to be indicative of heart failure, kidney cancer amongst other cancers, mononucleosis and some bacterial infections.


Alkaline Phosphatase Low

Our bones also contain a large amount of this enzyme. Most of the diseases that affects the bone could lead to the rise of this type of enzyme. Some of the diseases include bone cancer, osteoporosis and metastatic bone cancer.

Infections associated with gall bladder such as Cholecystitis and Osteomylitis which is a infection related to bone could increase the risk of this type of enzyme.

It is present in some of the vital organs of our body such as liver, kidney, bones and placenta. A large amount of this enzyme in found in liver and bone. A regular blood test may be required in order to trace the amount of this enzyme present in the blood. This enzyme is often utilized to diagnose diseases related to liver and other bone disorders.

Low Alkaline Phosphatase Levels

It is found that the maximum quantity of ALP is present in those cells which are associated with bone and vital organs such as liver.

Low Alkaline Phosphatase Causes

A lower level of ALP occurs very occasionally. If it is reflected in the test results, it indicates that an individual is affected with malnutrition and it usually occurs due to celiac disease or deficiency of vitamins and minerals.

Normal Alkaline Phosphatase

There are certain blood tests which are conducted to help determine the quantity or level of this enzyme. The standard level of this enzyme range from 53 to 128 U/L for the menwho are aged between twenty and fifty. On the other hand, 42 to 98 U/L is the normal value for women who are aged between twenty and fifty.

The standard value of this type of enzyme is higher in pregnant women when compared to other groups of people. These standard values might fluctuate especially in people who have crossed the age of sixty.

Elevated Alkaline Phosphatase

It is commonly found in the tissues of our body. An elevated alkaline phosphatase means there are health issues with respect to kidney as well as liver. It could even affect the bile ducts and bones as well.

Alkaline Phosphatase (ALP)

It is a test which is performed to determine the level of enzymes present in an individual’s blood. During the initial stages, a sample blood is taken and later the concerned doctor or a physician monitors any health issues related to bones or gall bladder. These tests are also very helpful in tracking or detecting diseases such as kidney tumors, problems related to intestine as well as malnutrition.

The standard level of ALP often varies depending upon the age, gender and the blood group. A study conducted by the University of California San Francisco, they revealed that the standard value of an ALP range from 20-140 U/L. The test results submitted by each laboratory could change. The range is very high amongst the children but it gradually decreases as one gets older.

It is highly recommended to perform this test in order to determine any diseases such as hepatitis, inflammation of gall bladder and cirrhosis (discoloration of liver). It is very essential and helpful in detecting any diseases associated with bones such as rickets and osteomalacia.

ALP test is a combination of both liver as well as tests related to Kidney. An individual is required to fast about ten to twelve hours before performing this test. If the results are not satisfactory, the concerned doctor or physician may advise you to take another test. He/she must inform the doctor regarding the medications while appearing for the test. Consumption of food would definitely affect the test results.

The ALP test are usually handled or operated by a health care professional. The concerned health care professional who is accompanied by a nurse takes a sample of blood from an individual’s hand which is often conducted at the hospital or a clinic. Later, the nurse step forward to wash the skin thoroughly with an anti-septic. During the final stage, a plaster is applied over your arm to ensure proper supply of blood to your veins.

This test is performed by inserting a needle gently into your vein and transfers the sample blood to a tiny tube. Most of the people often experience discomfort while performing this type of test.

An individual may often come across small cuts or bruises around the spot. It might sometimes lead to the inflammation of your vein. This condition is known by the name ‘Phlebitis’. But it can be prevented by applying pressure on the spot for a certain period of time. If the problem persists, you may inform or consult the doctor as early as possible.

After performing the test, the doctor asks you to meet in person to discuss about the test results. If the results indicate a high level of ALP in an individual’s blood stream, it means that there are health issues with respect to either liver or gall bladder. Other diseases include liver cirrhosis, kidney tumor, liver cancer and gallstones.

A higher level of ALP is an indicator of health problems related to bones like rickets, bone cancer as well as Paget’s disease. In extreme cases, there are chances of heart diseases and mono nucleosis.

Alkaline Phosphate Level Test (ALP)

This is a medical test that measures the amount of alkaline phosphate present in your bloodstream.  The basic requirement for the test is a simple blood drawn from your body (from a vein located on the inside of the elbow or the back of the hand).  It is most times a routine part of other blood tests.  The test may be performed to detect problems with your bones or estimate how well your gallbladder and liver are working.

An ALP test may be performed to determine how well your liver and gallbladder are functioning or to identify problems with your bones.  For liver and gallbladder tests, verifying ALP levels is a routine.  The test can be helpful in identifying such conditions as blockage of bile ducts (from cancer, gallstone, or inflammation), hepatitis (inflammation of the liver caused by infectious or noninfectious media), cholecystitis (inflammation of the gallbladder) and cirrhosis (scarring of the liver).  For bones, on the other hand, the ALP test can assist in the diagnosis of such bone problems as vitamin D deficiency, unusual bone growth, and presence of cancer tumors.  Other problems include osteomalacia (a softening of the bones in adults due to inability to process vitamin D properly), rickets (weakening or softening of the bones in children due to high deficiency of calcium or Vitamin D), Paget’s disease of the bone (a disorder causing major problems with bone destruction and regrowth) and others.

Alkaline Phosphatase Range

The normal range of Alkaline Phosphatase in the bloodstream of humans is 44 to 147 international units per liter (IU/L) or 0.73 to 2.45 microkatal per liter (µkat/L) but is less than 350 U/L or less than 5.95 mckat/L in children.  However, standard values may be different slightly from laboratory to laboratory. They also can vary with gender and size, with high ALP levels normally observed in pregnant women and children experiencing growth spurts.

Symptoms of Elevated Levels of ATP

An elevated level of alkaline phosphatase suggests many possible health conditions, each with their own unique set of signs and symptoms.  One of those health conditions is the Biliary Obstruction, also known as bile obstruction, which is a blockage of the tubes responsible for the transportation of bile from the liver to the gallbladder and small intestine.  Bile obstruction is caused by inflammation of the bile ducts, the presence of cysts in the common bile duct, tumors of the pancreas, enlarged lymph nodes, gallstones, and others.  In addition to elevated alkaline phosphatase levels, other usual signs and symptoms associated with biliary obstruction include dark urine, fever, upper right side abdominal pain, itching, yellowing of your skin, nausea and vomiting, and pale-colored stools.

Another health condition is Rickets – a bone disorder that makes the bones to become soft and fracture easily and can cause increased alkaline phosphatase levels and many other signs and symptoms. Such signs and symptoms include abnormally curved spine, bowed legs, delayed growth, thick wrists and ankles, pain in your pelvis, spine, and legs and muscle weakness.

Liver Cirrhosis is another health condition suggested by an elevated level of alkaline phosphate.  It is a condition of the liver, which can lead to increasingly high levels of alkaline phosphatase in the blood thereby causing deterioration of the liver and eventually malfunctioning due to chronic injury. This tampers with the ability of the liver to fight infections, process nutrients and remove toxins from the blood.  Apart from elevated blood levels of ALP, common signs and symptoms associated with liver cirrhosis include nausea, weakness, vomiting, fatigue, decreased appetite, abdominal pain, spider-like blood vessels on the skin and itching.

Treatment of Elevated Levels of ALP

Treating elevated levels of Alkaline Phosphate can be done in many ways.  One is by removing the medication that is associated with elevated levels of ALP.  These medicines may be anti-inflammatory medication, narcotic medication, birth control pills, hormonal drug, steroid, antidepressant, and others.  Another is through dietary changes, i.e., including more foods rich in Vitamin D in the diets.  Also, another way is through a lifestyle change, by combining a healthy diet with proper physical exercise and by exposure to sunlight, which intern increases the production of vitamin D.

Alkaline Phosphatase Levels

The results of an Alkaline Phosphate Levels Test either shows a low, high or normal level of ALP in the bloodstream.

Normal Level

Normal ALP level means there is neither too much nor too little ALP in the bloodstream.  Normal level ranges differ from laboratory to laboratory.  The evaluation of the levels is done based on the health and other conditions of the individual.

Elevated levels

Elevated or higher than normal levels of Alkaline Phosphatase in the blood explains the situation where the levels of alkaline phosphatase (ALP) is above the reference range. This may indicate a problem related to the bones, such as Paget’s disease, rickets, bone cancer or an overactive parathyroid gland.  It may also indicate an issue with the liver or gallbladder. This could include liver cancer, gallstones, blockage of your bile ducts, hepatitis (inflammation of the liver) or cirrhosis (scarring of the liver).  In very rare cases, high Alkaline Phosphate levels can suggest kidney cancer, heart failure, mononucleosis, bacterial infection or other cancers.

Low levels

Low Level is the direct opposite of the elevated ALP level.  Though it is rare, it can indicate malnutrition, which could be as a result of a deficiency in certain minerals and vitamins or celiac disease.


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