Anemias Flashcards
What is Plummer-Vinson syndrome?
Triad of:
- iron-deficient anemia
- esophageal webs
- dysphagia (atrophic glossitis)
Lab findings in iron-deficient anemia:
- low iron
- low ferritin
- high TIBC
- high free erythrocyte protoporphyrin
Symptoms of iron deficient anemia:
- conjunctival pallor
- fatigue
- spoon nails (koilonychia)
- pica (eating non-food substances)
What is sideroblastic anemia caused by?
Defective protoporphyrin synthesis. Thus, the last step to produce heme cannot be completed.
–> Fe++ enters mitochondria and gets stuck because protoporphyrin unable to make heme
What are the histological findings for sideroblastic anemia?
BONE MARROW SMEAR: -Ringed sideroblasts -iron-laiden, Prussian blue stained mitochondria PERIPH SMEAR: -basophilic stippling of RBCs
What are causes of sideroblastic anemia?
CONGENITAL:
-ALA synthase defect (X-linked)
ACQUIRED:
- alcohol (mitochondrial poisoning)
- lead poisoning (inhibits ferrochelatase)
- Vit B6 deficiency (required as co-factor at beginning of heme synthesis)
What is anisocytosis?
Variance in size of RBC
What is poikilocytosis?
Variance in shape of RBC
What is anisopoikilocytosis?
Variance in size and shape of RBC
What is seen histologically with beta-thalassemia?
- target RBCs
- microcytic RBCs
- hypochromic RBCs
- increased anisopoikilocytosis
What does a lack of folate and vit B12 impair?
Synthesis of DNA precursors
What is megaloblastic anemia? Causes?
A type of macrocytic anemia (MC >100 fL) in which DNA synthesis is impaired.
- folate deficiency
- Vit B12 (cobalamine) deficiency
- Orotic aciduria
What are causes of folate deficiency?
- malnutrition (alcoholics)
- malabsorption
- drugs (methotrexate, trimethoprim, phenytoin)
- increased requirement i.e. hemolytic anemia, pregnancy
What are clinical findings in Vit B12 deficiency?
Neurological symptoms:
- reversible dementia
-
Time progression of symptoms in Vit B12 deficiency vs folate deficiency, and why?
Vit B12 deficiency
- can take up to years to show symptoms because liver is able to store B12
Folate deficiency
-symptoms occur much earlier because there are not many large stores of folate present in the body
What is Schilling test used for?
Determine whether VitB12 deficiency is due to dietary insufficiency or malabsorption
What causes non-megaloblastic anemia?
(Anemia where the DNA synthesis is not impaired)
- alcoholism
- liver disease
Laboratory findings of folate deficiency?
- low folate
- high homocysteine
- macrocytic RBCs
- hypersegmented neutrophils
What is the most common cause of Vit B12 deficiency?
Pernicious anemia
What is pernicious anemia?
Autoimmune destruction of parietal cells –> leading to a deficiency in the production of intrinsic factor (IF) –> which leads to deficiency of Vit B12 as it cannot be absorbed without IF
What can cause vit B12 deficiency?
- pernicious anemia
- Crohn’s disease –> damage to terminal ileum
-pancreatic insufficiency
(Intrinsic factor produced by parietal cells in stomach required for absorption of vit B12 in the ileum)
Clinical/lab findings in Vit B12 deficiency?
- macrocytic RBCs with hypersegmented neutrophils
- glossitis
- subcaute combined degeneration of spinal cord
- neurological symptoms ( reversible dementia)
- high serum homocysteine (increases risk for thrombosis)
Clinical and lab findings of extravascular hemolysis in normocytic anemia?
- splenomegaly
- jaundice (from high unconjugated bilirubin)
- risk for bilirubin gallstones
- marrow hyperplasia
Clinical and lab findings of intravascular hemolysis in normocytic anemia?
- decreased serum haptoglobin
- hemoglobinemia
- hemoglobinuria
- hemosiderinuria
- urobilinogen in urine
- schistocytes seen in blood smear
What are Howell-Jolly bodies and which condition do we find them?
Nuclear remnants within RBCs.
Found in:
- sickle cell anemia
- hereditary spherocytosis
