tailieunhanh - Chapter 098. Iron Deficiency and Other Hypoproliferative Anemias (Part 5)

Clinical Presentation of Iron Deficiency Certain clinical conditions carry an increased likelihood of iron deficiency. Pregnancy, adolescence, periods of rapid growth, and an intermittent history of blood loss of any kind should alert the clinician to possible iron deficiency. A cardinal rule is that the appearance of iron deficiency in an adult male means gastrointestinal blood loss until proven otherwise. Signs related to iron deficiency depend on the severity and chronicity of the anemia in addition to the usual signs of anemia—fatigue, pallor, and reduced exercise capacity. Cheilosis (fissures at the corners of the mouth) and koilonychia (spooning of. | Chapter 098. Iron Deficiency and Other Hypoproliferative Anemias Part 5 Clinical Presentation of Iron Deficiency Certain clinical conditions carry an increased likelihood of iron deficiency. Pregnancy adolescence periods of rapid growth and an intermittent history of blood loss of any kind should alert the clinician to possible iron deficiency. A cardinal rule is that the appearance of iron deficiency in an adult male means gastrointestinal blood loss until proven otherwise. Signs related to iron deficiency depend on the severity and chronicity of the anemia in addition to the usual signs of anemia fatigue pallor and reduced exercise capacity. Cheilosis fissures at the corners of the mouth and koilonychia spooning of the fingernails are signs of advanced tissue iron deficiency. The diagnosis of iron deficiency is typically based on laboratory results. Laboratory Iron Studies Serum Iron and Total Iron-Binding Capacity The serum iron level represents the amount of circulating iron bound to transferrin. The TIBC is an indirect measure of the circulating transferrin. The normal range for the serum iron is 50-150 pg dL the normal range for TIBC is 300-360 pg dL. Transferrin saturation which is normally 25-50 is obtained by the following formula serum iron x 100 TIBC. Iron-deficiency states are associated with saturation levels below 18 . In evaluating the serum iron the clinician should be aware that there is a diurnal variation in the value. A transferrin saturation 50 indicates that a disproportionate amount of the iron bound to transferrin is being delivered to nonerythroid tissues. If this persists for an extended time tissue iron overload may occur. Serum Ferritin Free iron is toxic to cells and the body has established an elaborate set of protective mechanisms to bind iron in various tissue compartments. Within cells iron is stored complexed to protein as ferritin or hemosiderin. Apoferritin binds to free ferrous iron and stores it in the ferric state. As ferritin