Articles on Medical Diseases and Conditions

Entries Tagged ‘Depletion Anemia’

Hemolytic Anemias Due to Extracorpuscular Agents

Anemias due to isoagglutinins (isoantibodies) These anemias are hemolytic reactions caused by antibodies within the various blood group systems. The classification, symptomatology, and diagnostic procedures necessary for detection of such reactions and identification of the etiology are discussed in Chapter 9 and Chapter 11. Anemias due to autoagglutinins (autoantibodies) Autoagglutinins are antibodies produced by an […]

Red Blood Cell Membrane Abnormalities

The major conditions in this category are congenital spherocytosis and hereditary elliptocytosis. Also included in this group are the uncommon condition abetalipoproteinemia and the extremely rare hereditary stomatocytosis. Congenital spherocytosis Congenital spherocytosis is one of the more common hereditary hemolytic anemias after the hemoglobinopathies and G-6-PD deficiency. Most patients are English or northern European. About […]

Red Blood Cell Enzyme Deficiencies

These conditions are sometimes called congenital nonspherocytic anemias. The RBC contains many enzymes involved in various metabolic activities. Theoretically any of these may be affected by congenital or possibly by acquired dysfunction. The most frequent congenital abnormalities are associated with enzymes that participate in metabolism of glucose. After glucose is phosphorylated to glucose-6-phosphate by hexokinase, […]

Hemoglobin Synthesis Abnormalities

Thalassemia Strictly speaking, there is no thalassemia hemoglobin. Thalassemia comprises a complex group of genetic abnormalities in globin chain synthesis. There are three major clinical categories: thalassemia major, associated with severe and often life-threatening clinical manifestations; thalassemia minor, with mild or minimal clinical manifestations; and a combination of the thalassemia gene with a gene for […]

The Unstable Hemoglobins

The unstable hemoglobins are characterized by a focal amino acid mutation that permits hemoglobin denaturation under certain conditions (e.g., heat or oxidation), with the formation of Heinz bodies. There are several different abnormalities, and either the alpha or beta hemoglobin chain may be affected. Unstable hemoglobin variants are rare; the best known are Hb-Kцln, Hb-Zurich, […]

The Hemoglobinopathies

At birth, approximately 80% of the infant’s hemoglobin is fetal-type hemoglobin (Hb F), which has a greater affinity for oxygen than the adult type. By age 6 months, all except 1%-2% is replaced by adult hemoglobin (Hb A). Persistence of large amounts of Hb F is abnormal. There are a considerable number of abnormal hemoglobins […]

Hemoglobin Structure Abnormalities

Hemoglobin consists of one heme unit (a complex of one iron atom within four protoporphyrin structures) plus one globin unit (consisting of two pairs of polypeptide chains, one pair known as alpha and the other pair called beta). The heme units are identical in each hemoglobin molecule; changes in amino acid sequence in the globin […]

Laboratory Tests in Hemolytic Anemias

Certain laboratory tests are extremely helpful in suggesting or demonstrating the presence of hemolytic anemia. Which tests give abnormal results, and to what degree, depends on the severity of the hemolytic process and possibly on its duration. Reticulocyte count. Reticulocyte counts are nearly always elevated in moderate or severe active hemolytic anemia, with the degree […]

Depletion Anemia

Two types of depletion anemia are possible: (1) abnormal loss of red blood cells (RBCs) from the circulation and (2) abnormal destruction of RBCs within the circulation. RBC loss due to hemorrhage has been covered elsewhere (blood volume, Chapter 10; iron deficiency anemia, Chapter 4). Intravascular or intrasplenic RBC destruction is called hemolytic anemia. There […]


Although anemia may be defined as a decrease in Hb concentration, it may result from a pathologic decrease in the RBC count. Since mature RBCs are fully saturated with Hb, such a decrease means that total blood Hb value will also be affected. Before commencing transfusion therapy or an extensive workup for the etiology of […]