HAPTOGLOBIN - Haptoglobin is a protein that is produced by the liver. It normally binds free hemoglobin (that which is outside of red blood cells) in the plasma. Free hemoglobin concentrations increase in conditions where red blood cells are destroyed (e.g. hemolytic anemia). After the haptoglobin molecule has bound the hemoglobin, it is taken up by the liver where the components can be recycled. In conditions of hemolysis the haptoglobin concentration decreases (due to increased recycling in the liver). Normal values for haptoglobin are 27 to 139 mg/dl. Greater than normal values can indicate: acute rheumatic disease, ulcerative colitis, peptic ulcer disease, or biliary obstruction. Lower than normal values can indicate chronic liver disease, primary liver disease, hemolytic anemia, hematoma, erythroblastosis fetalis, or a transfusion reaction.