b-type nAtriuretic peptide: B-type natriuretic peptide (BNP) is found only in the ventricles of the heart. Increased levels may indicate heart failure. There is strong correlation between the degree of heart failure and the BNP level. Studies suggest the BNP may have important prognostic significance in people with acute coronary syndrome (ACS).
bAsophil count: A basophil is a type of white blood cell that is primarily involved in the body’s response to allergens. Basophil levels become elevated in response to allergic stimuli. Levels may also be elevated in myxedema, parasitic infections, and alterations in bone marrow function, such as leukemia or Hodgkin’s disease. Corticosteroid drugs, allergic reactions, and acute infections may cause basophil levels to decrease. Basophils do not respond to either bacterial or viral infections.
bAsophil percentAge: Basophil, a type of white blood cell, makes up only 0.5-1.0 % of the total number of white blood cells. The basophil percentage goes up in response to allergens, myxedema, parasitic infections, and alterations in bone marrow function, such as leukemia or Hodgkin’s disease. Corticosteroid drugs, allergic reactions, and acute infections may cause basophil percentages to decrease.
betA-2-glycoprotein Antibody (b2gp Ab): Beta-2 glycoprotein antibodies (B2GP Ab) are found in conditions such as the antiphospholipid syndrome, a clotting disorder which can cause recurrent miscarriage. Beta-2 glycoprotein antibodies are also associated with an increased risk of venous and arterial blood clotting.
betA-2-Microglobulin (b2M): Beta-2-microglobulin (B2M) is a protein found on the surface of most cells. High levels are seen in kidney failure, kidney transplant rejection and chronic severe inflammatory diseases. B2M levels are also increased in certain cancers, especially lymphoma, leukemia and multiple myeloma.
bilirubin, total: Bilirubin is a yellow breakdown product of hemoglobin, the oxygen-carrying molecule in red blood cells (RBCs). Bilirubin levels may be elevated in people with liver disease or a blocked bile duct, as seen with gallstones. The total bilirubin value includes both conjugated and unconjugated bilirubin. High unconjugated bilirubin levels are most commonly seen in newborns. Elevated conjugated bilirubin levels may occur when any portion of the biliary tree becomes blocked or abnormally permeable, retarding the passage of bilirubin and other bile components normally to the intestinal tract.
blood ureA nitrogen (bun): This test measures the amount of urea nitrogen in the blood. Urea is the major breakdown product of bodily protein and contains nitrogen. Urea and other nitrogen-rich waste products are normally eliminated from the bloodstream by the kidneys, so an increased blood urea nitrogen (BUN) level may indicate impaired renal (kidney) function. However, many other conditions other than renal disease can cause BUN alterations. An elevated BUN level may also be caused by congestive heart failure, dehydration, shock, hemorrhage into the gastrointestinal tract, acute myocardial infarction, stress, or excessive protein intake or protein breakdown. A decreased level may be seen in liver failure, malnutrition, anabolic steroid use, or impaired nutrient absorption. In patients with liver disease, the BUN level may be low even if the kidneys are normal.
blood ureA nitrogen/creAtinine rAtio: Unlike urea, blood creatinine is relatively insensitive to body hydration and the presence of blood or meat in the intestinal tract; therefore, the blood urea nitrogen (BUN) to creatinine ratio may help to distinguish impaired kidney function due to dehydration from other kinds of kidney damage. The ratio of BUN:creatinine is normally 10:1, but can increase to 20:1 or even higher with dehydration. An increased BUN:creatinine ratio may also be due to certain types of kidney disease, breakdown of blood in the intestinal tract, increased dietary protein, or any clinical circumstance resulting in reduced blood flow to the kidneys (such as heart failure or renal artery disease). The BUN:creatinine ratio is decreased in other renal conditions, liver disease, malnutrition and sickle cell anemia.
bordetella pertussis antibody (b. pertussis Ab): Bordetella pertussis (B. pertussis) antibody is evidence of recent infection with, exposure to, or vaccination with B. pertussis, the bacterium causing whooping cough.
brain-derived neurotrophic factor(bdnf): Brain-derived neurotrophic factor (BDNF) is a protein found in the central nervous system, which is important to the survival of existing brain cells and the growth of new brain cells. BDNF levels may be abnormally low in certain nervous system condition such as depression and Alzheimer’s disease, as well as other mood disorders. Research has shown that persistent exposure to stress and the stress hormone corticosterone decreases the expression of BDNF and leads to atrophy of part of the brain, specifically the hippocampus. Physical activity has been reported to increase BDNF expression.
