Hypoproteinemia is a condition where there is an abnormally low level of
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
in the
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the c ...
. There are several causes that all result in edema once serum protein levels fall below a certain threshold.
Causes
# Nutritional hypoproteinemia is due to severe limitation of protein intake in the diet. An example of nutritional hypoproteinemia is
Kwashiorkor
Kwashiorkor ( , ) is a form of severe protein malnutrition characterized by edema and an enlarged liver with fatty infiltrates. It is thought to be caused by sufficient calorie intake, but with insufficient protein consumption (or lack of goo ...
, a type of protein energy malnutrition affecting young children.
#
Malabsorption
Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal (GI) tract. Impairment can be of single or multiple nutrients depending on the abnormality. This may lead to malnutrition and a variety ...
# Liver disease can also cause hypoproteinemia by decreasing synthesis of plasma proteins like albumin.
# Renal disease like
nephrotic syndrome
Nephrotic syndrome is a collection of symptoms due to kidney damage. This includes protein in the urine, low blood albumin levels, high blood lipids, and significant swelling. Other symptoms may include weight gain, feeling tired, and foamy ...
can also result in hypoproteinemia because plasma proteins are lost in the urine.
# Sepsis (whole body infection) –
macrophages
Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer ce ...
activated in the liver and spleen secrete
TNF-alpha
Tumor necrosis factor (TNF, cachexin, or cachectin; formerly known as tumor necrosis factor alpha or TNF-α) is an adipokine and a cytokine. TNF is a member of the TNF superfamily, which consists of various transmembrane proteins with a homolog ...
into the bloodstream resulting in hypoproteinemia.
Pathophysiology
Decreased serum protein reduces the oncotic pressure of the blood, leading to loss of fluid from the intravascular compartment, or the blood vessels, to the interstitial tissues, resulting in edema. This is termed as hypoproteinemia.
Diagnosis
Hypoproteinemia is often confirmed by testing for
serum albumin
Serum albumin, often referred to simply as blood albumin, is an albumin (a type of globular protein) found in vertebrate blood. Human serum albumin is encoded by the ''ALB'' gene. Other mammalian forms, such as bovine serum albumin, are chemical ...
and total protein levels.
References
External links
Abnormal clinical and laboratory findings for blood
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