Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (971 page)

   Therapy with steroids or androgens.

   Aplastic anemia (normal to very high).

   DM.

   Smoking.

   Aging.

   Red cell membrane or metabolic defects (G6PD deficiency, hereditary spherocytosis, paroxysmal nocturnal hemoglobinuria).

Decreased In

   Hemoglobinemia (related to the duration and severity of hemolysis) due to

   Intravascular hemolysis (e.g., hereditary spherocytosis with marked hemolysis, PK deficiency, autoimmune hemolytic anemia, some transfusion reactions)

   Extravascular hemolysis (e.g., large retroperitoneal hemorrhage)

   Intramedullary hemolysis (e.g., thalassemia, megaloblastic anemias, sideroblastic anemias)

   Genetically absent in 1% of white population and 4–10% of the US blacks.

   Parenchymatous liver disease (especially cirrhosis)

   Protein loss via the kidney, GI tract, skin