It is exchanged chemically in the liver and excreted. Its accumulation leads to jaundice in many cases. Here it acts as a carrier molecule, and helps to maintain blood volume and pressure, preventing plasma loss from the capillaries. It can act as a source of rapid replacement of tissue proteins. Creatinine is a normal waste product of the kidneys.
Uric acid is another waste product removed from the blood by the kidneys.
People with gout have high levels of uric acid which forms crystals in the joints or tissues. Anti-nuclear antibodies react against components of the cell nucleus. Tests detect auto-antibodies often found in people with Lupus or Scleroderma. Immunoglobulin is one of a family of related proteins capable of acting as antibodies. All antibodies are immunoglobulins, but researchers have not yet determined if all immunoglobulins have antibody functions.