Heme #1: Microcytic Anemias Flashcards
MCC of anemia worldwide is _________
Etiologies include…
Risk factors include
-Iron deficiency anemia
-Chronic blood loss MCC in US: menstruation, Colon cancer, hookworms in resource-poor countries
-decreased absorption (diet) MCC worldwide: Celiac, H. Pylori, bariatric surgery
-increased metabolic requirements: children, pregnant, lactating women
-cow milk ingestion in young children < 1 year old
Why does iron deficiency anemia occur (Patho)?
Symptoms of iron deficiency anemia
-Decreased RBC production due to lack of iron and decreased iron stories (ferritin).
-Pasophagia (craving for ice), Pica (craving for starch, clay), koilonychia (spooning of nails), angular chelitis, tachycardia, glossitis, pallor, poor concentration, irritability, restless legs syndrome
What do the labs for iron deficiency anemia show?
-CBC
-Iron studies
What is the definitive diagnostic for IDA?
-CBC: microcytic hypochromic anemia. Increased RDW.
-Iron studies: decreased ferritin***, increased TIBC (transferrin), decreased transferrin saturation, decreased serum iron.
Bone marrow biopsy: absent iron stores (definitive), but rarely done.
What is the treatment for iron deficiency anemia and what are some recommendations to taking the medication/supplement?
-Iron replacement (ferrous sulfate orally).
-Take with Vitamin C (ascorbic acid), with water or orange juice, and on an empty stomach. Give 2 hours before or 4 hours after ingestion of antacids.
-RBC transfusion if severe
What is microcytic?
What is normocytic?
What is macrocytic?
-Micro: < 80
-Normo: 80-100
-Macro: > 100
Lead Poisoning Anemia
-Patho
-Risk Factors (who MC in)
-Sources
-Patho: Lead poisons enzymes causing cell death. Shortens life span of RBCs, inhibits enzymes needed for heme synthesis.
-RF: MC in children (<6 years old)
-Sources: inhalation of environmental lead (paint chips or lead dust) especially if the house was built prior to the 1970’s.
Symptoms of lead poisoning anemia
-think specific symptoms
-Neuro: ataxia, fatigue, concentration, learning problems, peripheral neuropathy (wrist or foot drop), encephalopathy
-Intermittent abdominal pain, vomiting, loss of appetite, constipation.
-Burton’s line: thin, blue-black line at base of gums in adults
What do diagnostics for lead poisoning anemia show?
-Peripheral smear/CBC
-Lead
-Iron studies
-Radiographs
-Microcytic hypochromic anemia with basophilic stippling (dots of denatured RNA seen in RBCs). Ringed sideroblasts in bone marrow.
-Serum lead levels > 10 mcg/dL (capillary fingerstick)
-Normal/High serum iron, decreased TIBC
-Lead lines: linear hyperdensities at metaphyseal plates in children
Management for lead poisoning anemia
-Mainstay
-Mild (44 or lower)
-Moderate (45-69)
-Severe (70 or higher)
–without encephalopathy
–with encephalopathy
-Removal of source of lead
-Mild: outpatient follow up and lifestyle changes
-Mod: Succimer
-Severe w/o: Succimer + calcium disodium edetate
–with enceph: Dimercaprol + calcium disodium edetate
How does Succimer work for lead poisoning anemia?
-Forms water soluble chelates, and therefore, increases urinary excretion of lead.
What is thalassemia?
Normally after what age is adult Hgb the predominant Hgb produced?
When should you suspect a thalassemia?
decreased production of globin chains
After 6 months of age
Microcytic anemia with normal/increased serum iron or no response to Fe treatment
Alpha Thalassemia
-What is it?
-MC in what population?
-Explain 1-4 abnormal alleles and presentation
-Decreased alpha-globin chain production. 4 genes determine it.
-MC in SE Asians
-Alleles
–1 abnormal: silent carrier, asymptomatic
–2: Minor (trait)
–3: Intermedia (like B-Thalassemia Major)
–4: Hydrops Fetalis: stillbirth: Hgb Barts (gamma tetramers)
Diagnostics for Alpha Thalassemia and what do they show?
-Hemoglobin electrophoresis
–1 & 2 gene deletion: normal Hb ratios in adults
–3: HbH (beta chain tetramer) = Heinz bodies
–4: Hgb Barts (gamma tetramers)
-DNA analysis is definitive
What distinguishes alpha from beta thalassemia?
Alpha, in 1-2 gene deletions, has normal Hb ratios in adults. In Beta, HgbA is decreased, or little to none.
Explain why the thalassemias are seen as a hemolytic anemia
-Beta chain tetramers (Heinz bodies) are produced, which have no oxygen carrying capacity and therefore, the RBCs are destroyed by the spleen.