Anemia and Disorders of Hemoglobin

Vocabulary flashcards for Anemia and Disorders of Hemoglobin to aid in exam preparation and review of lecture notes.

Hypoproliferative Anemia

Normocytic and normochromic red cells with low reticulocyte response.

Iron Deficiency Anemia

Most prevalent form of malnutrition caused by demand exceeding supply of iron.

Transferrin Saturation

Falls to 15-20% in iron-deficient erythropoiesis, and below 10-15% in iron-deficiency anemia.

Serum Ferritin

Decreases significantly in iron deficiency stages indicating reduced iron stores.

TIBC (Total Iron-Binding Capacity)

Increases in iron deficiency due to more transferrin being produced to bind iron.

Serum Iron (SI)

The amount of circulating iron bound to transferrin.

Transferrin Saturation Calculation

Serum Iron x 100 / TIBC

Ferritin function

Apoferritin binds to free ferrous iron and stores it in the ferric state.

Protoporphyrin

Increases when heme synthesis is impaired due to inadequate iron supply.

Oral Iron Therapy

Treatment option for asymptomatic patients with intact gastrointestinal tract, involving dietary changes and supplements.

Parenteral Iron Therapy

Used for patients unable to tolerate oral iron, those with acute needs, or who need ongoing iron.

Anemia of Inflammation

Associated with the release of proinflammatory cytokines, affecting EPO production and iron metabolism.

Hepcidin

Increased in inflammation, suppresses iron absorption and release from storage sites.

Anemia of Chronic Kidney Disease (CKD)

Primarily due to a failure of EPO production by the diseased kidney.

Hemoglobinopathies

Disorders of hemoglobin affecting the amino acid sequence.

Thalassemia

Disorder characterized by reduced hemoglobin synthesis.

Globin Gene Clusters

β-globin gene on chromosome 11, α-globin gene on chromosome 16.

P50

Partial pressure of oxygen at which hemoglobin is 50% saturated. Normal P50 is ~26 mmHg.

Sickle Cell Disease

Homozygosity for the sickle hemoglobin mutation (a2βS 2; glutamic acid 7 valine)

Acute Chest Syndrome

Pneumonia-like illness, frequent acute sickle cell-related event presenting with chest pain, cough, fever, and hypoxia.

Hydroxyurea

Recommended treatment for sickle cell disease for all ages, induces high levels of HbF.

Vasoocclusion

Unprovoked severe pain in extremities or torso that is often symmetrical, most common acute events in sickle cell disease

Unbalanced Globin Synthesis

Hallmark of thalassemia: reduced accumulation of either a- or β-globin chains.

Beta Thalassemia

Mediterranean anemia/ Cooley's anemia: mutation preventing accumulation of any globin from the affected gene.

Beta Thalassemia Major

Severe hemolytic anemias with hypochromia, microcytosis, reticulocytosis marked anisocytosis, and poikilocytosis variable numbers of circulating nucleated red cells.

Transfusion

Goal to maintain pretransfusion Hgb of 9-10.5 g/dL with oral iron chelation to prevent the accumulation of excess toxic iron

Alpha Thalassemia

Reduced accumulation of a-globin leaves non-a-globins unpaired and unable to participate in the formation of functional hemoglobin tetramers

M Hemoglobins

Oxidation of the heme iron from its ferrous (Fe++) to ferric (Fe+++) form.

Acquired Disorders of Hemoglobin

Carboxyhemoglobin - CO binds hemoglobin with high affinity forming carboxyhemoglobin

Carboxyhemoglobin

High-flow O2 via facemask is the preferred treatment

Megaloblastic Anemia

Group of disorders characterized by distinctive morphologic appearances of the developing red cells in the bone marrow. Defect in DNA synthesis affects rapidly dividing cells in the bone marrow.

Cobalamin

Synthesized solely by microorganisms

Active Cobalamin Absorption

Occurs through the ileum and is efficient for small doses, mediated by gastric intrinsic factor (IF).

Folate

Absorbed rapidly from the upper small intestine and reduced folate transporter (RFC, SLC19A1).

Peripheral Blood Finding in Megaloblastic Anemia

Oval macrocytes, usually with considerable anisocytosis and poikilocytosis.

Pernicious Anemia

Defined as a severe lack of IF due to gastric atrophy.

Hydroxocobalamin or cyanocobalamin

Initially six 1000-μg IM injections of hydroxocobalamin given at 3- to 7-day intervals

Folate Deficiency Treatment

Oral doses of 5-15 mg of folic acid daily x 4 months

Hemolytic Anemias

Overconsumption of red cells from the peripheral blood via destruction of red cells within the body.

Hereditary spherocytosis (HS)

Red cells were abnormally susceptible to lysis in hypotonic media

Hereditary elliptocytosis (HE)

Diagnosis of HE is generally incidental, because hemolysis may be compensated and there may be no anemia

Hereditary Pyropoikilocytosis (HPP)

Most severe HA in HE

Channelopathies/Stomatocytosis

Abnormal shape is related to abnormalities of channel molecules, the underlying disorders

ABNORMALITIES OF THE GLYCOLYTIC PATHWAY

Pyruvate Kinase Deficiency

ABNORMALITIES OF REDOX METABOLISM

Glucose-6-phosphate Dehydrogenase (G6PD) Deficiency

Immune Hemolytic Anemia

Innocent Bystander Mechanism

AUTOIMMUNE HEMOLYTIC ANEMIA WARM TYPE

abrupt onset

Evans syndrome

Can be associated with autoimmune thrombocytopenia: high risk

cold AIHA, PCH

rare form of AIHA occurring mostly in children

COLD AGGLUTININ DISEASE

chronic and more frequently indolent condition

RItuximab

First Line

Paroxysmal Nocturnal Hemoglobinuria (PNH)

acquired chronic HA characterized by persistent intravascular hemolysis with occasional or frequent recurrent exacerbations

Flow cytometry

Diagnosis: Gold Standard

Eculizumab:

blocks the complement component C5

Anemia due to Acute Blood Loss

posthemorrhagic anemia, which follows acute blood loss