L30: Anemias, Pt. 1 Flashcards
What is anemia? What is it due to?
Anemia is a decrease in O2 carrying capacity of blood
Due to a decrease in absolute # of RBCs or decrease in hemoglobin or its ability to carry oxygen
At what hemoglobin levels is anemia classified in males and females?
Less than the following levels
Male: 13.0 - 13.5 g/dL
Female (non-pregnant): 12 g/dL
Female (pregnant): 10.5 - 11 g/dL
What can persistent, severe anemia lead to?
Arrhythmias and/or heart failure
What is observed in initial assessment of anemia?
General symptoms: fatigue, dyspnea, vertigo
History: age, diet, mediations, family history, travel, etc.
Physical exam: pallor, jaundice, cardiac arrhythmias, evidence of bleeding, hepato- or splenomegaly, lymphadenopathy, neurologic manifestations
What information does reticulocyte count provide?
Increased means BM is responding to anemia
Decreased means BM is not resonding to anemia
What would peripheral blood smear examination show in initial assessment of anemia?
Abnormal RBC morphology (volume, shape, hemoglobin content)
Immature forms: nucleated RBCs
Abnormalities in #, maturity, or morphology of WBCs and PLTs
What information does serum ferritin provide in microcytic anemias?
Low serum ferritin: iron deficiency anemia
High or normal serum ferritin: anemia of chronic disease, sideroblastic anemia, thalassemias (or Hb E disease/trait)
What are the causes for the types of microcytic anemias?
Iron deficiency anemia: quantitative iron deficiency
Anemia of chronic disease: iron sequestration and decreased iron availability
Sideroblastic anemias: deficiency or inhibition of enzymes for synthesis
Thalassemas, Hb E disease or trait: absence or inhibition of synthesis
What are the causes of iron deficiency anemia (IDA)?
Inadequate intake - dietary deficiency: malnutrition, dieting
Increased iron requirements: pregnancy, lactaton, infancy, toddlers, adolescent growth periods
Decreased absorption: celiac disease, gastrectomy, bariatric surgery
Excessive loss - chronic bleeding: gastrointestinal blood loss (colon cancer, gastritis, Chron’s disease, ulcer, etc.), genitourinary blood loss, miscellaneous
What are some symptoms of IDA?
Fatigue, lethargy, shortness of breath, pallor, dizzness, poor exercise tolerance
Pica (severe IDA): craving for and consumption of unusual substances (dirt, clay, glass)
Epithelial cell changes (stomatitis, glossitis)
Gastritis
Spoon shaped nails (koilonychia) rare; brittle or ridged nails
Plummer-Vinson syndrome
Triad of IDA, esophageal webs, glossitis
Dysphagia
How is iron deficiency diagnosed?
Serum ferritin: reflects iron storage in bone marrow; early indicator of iron deficiency when ↓; acute phase reactant - will ↑
in inflammation due to ↑ hepcidin
Serum iron: ↓ only after storage iron is depleted; ↓ in infection, inflammation, neoplasms; recent ingestion of iron supplements falsely increases serum levels
Total iron binding capacity (TIBC): a measure of the amount of transferrin; ↑ in iron deficiency (upregulated to transport more iron); ↓ in inflammation, infections, malignancies and liver disease (site of transferrin synthesis)
% Transferrin saturation: normally 1/3 saturated; IDA < 16 - 20%
What is the treatment for iron deficiency anemia?
Determine and treat underlying disorder
Oral iron therapy, ↑ retics ~1 week post-therapy
Oral iron not effective if deficiency due to malabsorption; intravenous iron needed
What occurs in anemia of chronic disease/inflammation?
Iron maldistribution
↑Hepcidin: traps iron in enterocytes and macrophages and inhibits iron absorption
How can IDA and ACD be differentiated? Why is it important to differentiate them?
In IDA, would have severe decreases in hemoglobin whereas in ACD the decrease is mild to moderate
TIBC is ↑ in IDA and normal or ↓ in ACD
Serum ferrtin is ↓ in IDA and normal or ↑ in ACD
It is important to differentiate them bc the treatments are different; iron therapy for IDA and EPO for ACD
What occurs in sideroblastic anemia?
Defect in heme biosynthesis
Hereditary X-linked sideroblastic anemia
Mutation in ALAS-2 (enzyme needed for the first step of protopophyrin synthesis)
Treated w/ pyridoxine (vitamin B6), a cofactor for ALAS
Acquired sideroblastic anemia
Idopathic: refractory anemia w/ ring sideroblasts (type of MDS)
Secondary due to drugs/toxins (reversible): lead, alcohol, isoniazd, chloramphenicol
How does lead poisoning lead to microcytic anemia?
Inhibition of ALA dehydrase and ferrochetalase in protoporphyrin synthesis
Inhibits rRNA degradation (caorse basophilic stippling)
What is the etiology, findings, labs and treatment for lead poisoning?
Etiology: infants and children exposed to lead-based chipped pain; adults with occupational exposure
Findings: anemia, neuropathy, memory and motor problems, abdominal colic, kidney damage, wrist and foot drop, Burton’s lines on gingivae
Lab: ↑ in serum δ-amino levulinic acid (ALA) and ↑ in blood lead levels
Treatment: EDTA, dimercaprol (chelation therapy; binds with lead; excreted in urine)
What are some findings of sideroblastic anemia?
↑ serum ferritin and bone marrow iron
Ring sideroblasts in bone marrow (non-heme iron granules in RBC precursors)
Basophilic stippling (abnormal rRNA aggregates in RBCs; may be very coarse)
Pappenheimer bodies (non-heme iron aggregates in RBCs)
Iron deposits in other organs
How can microcytic anemias be differentiated?
By looking at serum ferritin and TIBC
What are porphyrias causes by?
Due to mutation or inhibition of an enzyme in heme synthesis
Accumulation of heme precursors damage cells
What are the most common porphyrias? What are their features?
Prophyria cutanea tarda (PCT): chronic, blistering photosensitivity, red/brown “tea-colored” urine, most are acquired & in adults
Acute intermittent porphyria (AIP): acute, polyneuropathy, abdominal pain, psychological symptoms, red urine
Erythropoietic protoporphyria (EPP): acute, non-blistering, photosensitivity, mainly affects RBC precursors, mild anemia