Protein Levels in Blood

Proteins are macromolecules that play a vital role in varied bodily processes. While the specialized proteins called antibodies help in fighting off pathogens or foreign invaders, some proteins act as carriers of molecules. Hemoglobin is an example of a carrier protein that transports oxygen through the blood, while ferritin is a storage protein that stores iron and releases it as and when required. Certain hormones, enzymes and clotting agents also contain proteins. The serum proteins, which are also called blood proteins, constitute about 6 to 8% of blood. The blood test that measures the protein levels in blood is referred to as total serum protein test. The total serum protein test is one of the 14 specific blood tests that are included in the Comprehensive Metabolic Panel.

The total serum protein test measures the levels of two major protein groups called albumin and globulin. Human serum albumin, which makes up about 50% of blood serum proteins, is responsible for preventing the leakage of blood from the blood vessels. It helps in promoting the growth of tissues and facilitates the healing process. Globulin refers to a protein group that consists of proteins known as the alpha, beta and the gamma types. Globulin proteins bind themselves to hemoglobin and transport iron in the blood. Under normal circumstances, the blood protein levels must be in the range of 6.0 to 8.3 gm/dL (grams per deciliter). If the levels of these blood proteins or albumin/globulin ratio is higher or lower than the normal reference range, it is usually indicative of certain ailments. So if the serum protein test results reveal abnormal blood protein levels, further testing may be required to ascertain the underlying cause of abnormal protein levels.

Reference Range for Blood Proteins

Before we look into the causes of high or low levels of blood proteins, let's take a look at the normal range for blood proteins.

Serum Protein	Normal Range
Total Protein	6.0-8.3 gm/dL
Albumin	3.8-5.0 gm/dL
Globulin	2.3-3.5 gm/dL
Alpha-1 globulin	0.1-0.3 gm/dL
Alpha-2 globulin	0.6-1.0 gm/dL
Beta globulin	0.7-1.1 gm/dL
Gamma globulin	0.7-1.6 gm/dL
Albumin/globulin ratio	1.1-1.4

High Blood Protein Levels

Wondering what causes high blood protein levels? Well, high blood protein levels could be indicative of a weakened immune system. When people have an abnormally high blood protein count, doctors may recommend them to get themselves tested for Hepatitis or HIV. Total blood protein levels may become elevated if one is suffering from a chronic infection. Liver dysfunction could also cause the serum protein levels to increase. High blood protein levels could also be caused due to chronic inflammation which is why people suffering from rheumatoid arthritis can have a high blood protein count. Sometimes abnormal levels of protein in blood could be caused due to certain bone marrow diseases such as multiple myeloma, amyloidosis or monoclonal gammopathy of undetermined significance.

Waldenstrom's disease is another medical condition which can be responsible for elevated blood protein levels. This is a type of cancer which can make the blood very viscous which in turn could impair the functioning of the brain. A person suffering from this disease could also experience symptoms such as fatigue, swollen lymph glands, nosebleeds or gum bleeding. Elevated levels of albumin could occur due to excess of glucocorticoids due to prolonged use of certain drugs. Albumin levels could also increase if adrenal glands produce larger amounts of cortisol. Albumin levels could also get elevated in people suffering from congestive heart failure or dehydration. Since most of the antibodies are gamma globulins, very high levels of globulins in blood could be indicative of an autoimmune condition, infection or an inflammatory disorder.

Low Blood Protein Levels

Total protein levels could become lower than the reference range due to malnutrition. A diet lacking in proteins and certain amino acids could be one of the factors responsible for causing low blood protein levels. Malabsorption of proteins could also be responsible for lowering blood protein levels. Such people must take the recommended daily protein intake. People suffering from nephrotic syndrome could also have a low blood protein count. Certain conditions that affect the kidneys can also cause a dip in the blood protein levels. Sometimes the level of proteins present in the urine could be high. If the kidneys are not working properly proteins might leak into urine. Besides kidney diseases, medical conditions such as Crohn's disease, celiac disease and Whipple's disease can also damage the intestines and affect their ability to absorb protein from food.

Since albumin and globulin are made in the liver, any damage to the liver can also be responsible for lowering blood protein levels. At times, there could be a dip in the blood protein levels due to retention of extra fluids within the vascular system. This could cause dilution of proteins and cause a dip in the blood protein levels. While low albumin levels may be seen in people suffering from malnutrition, albuminuria, loss of protein through gastrointestinal tract in diarrhea, liver dysfunction or hormonal imbalance, low levels of globulin may be seen in people who are suffering from liver dysfunction, nephrotic syndrome or acute hemolytic anemia.

This was some information on the causes of low or high protein levels in blood. While abnormal blood protein levels don't pinpoint any particular illness, these do indicate health problems. When the total serum protein test indicates abnormal blood protein levels, doctors usually order other tests to ascertain the underlying cause. Since people suffering from abnormal blood protein levels may have a weakened immune system, they must follow the dietary guidelines and make the right lifestyle choices to bring the blood protein levels within the normal range.