Ch. 9 Heme/Onc, Allergy, Immunology Flashcards
(289 cards)
What are 5 causes of microcytic anemia?
- Iron deficiency
- Thalassemia
- lead poisoning
- sideroblastic anemia
- chronic disease
What are 5 causes of normocytic anemia?
- hemorrhage
- hemolysis
- aplastic anemia
- sickle cell disease
- anemia of chronic disease/renal disease
What are 4 causes of macrocytic anemia?
- Vitamin B12 deficiency
- Folate deficiency
- Sulfa drugs
- EtOH abuse
What are normal fasting serum iron levels?
60-180 ug/dL
How will TIBC be changed in iron deficiency anemia?
increased, >400 ug/dL
What route causes lead poisoning in adults?
inhalation
(whereas in children, it is ingestion)
What causes sideroblastic anemia?
acquired or congenital defect in porphyrin synthesis.
Often related to toxins (like chloramphenicol,
isoniazid, cycloserine, lead); infections; malignancy; rheumatologic disease;
or hemolytic anemia.
What congenital disorder commonly causes aplastic anemia?
Fanconi anemia
What medications commonly cause aplastic anemia?
NSAIDs, chloramphenicol, sulfonamides, antiepileptics drugs, nifedipine
What viral infection most commonly causes aplastic anemia?
Parvovirus B19
(HIV and hepatitis also implicated)
Dark urine related to hemoglobinuria usually indicates ______ hemolysis
intravascular
Splenomegaly is more common in _______ hemolysis
extravascular
In _______ hemolysis, look for increased LDH, decreased haptoglobin,
hemoglobinuria, and schistocytes.
intravascular
In _______ hemolysis, look for indirect hyperbilirubinemia, increased
LDH, and spherocytes.
extravascular
Autosomal dominate disease caused by a defect in red cell membrane protein.
Hereditary spherocytosis
What is a risk factor for hereditary spherocytosis?
More common among persons of Northern European decent
What causes anemia in Hereditary Spherocytosis?
RBCs take on a microspherocytic shape that is unable to pass through the spleen leading to RBC destruction
How is Hereditary Spherocytosis diagnosed?
■ Peripheral smear with spherocytes.
■ Negative Coombs test (to rule out autoimmune hemolytic anemia).
■ Osmotic fragility test is confirmative.
What is the treatment for Hereditary Spherocytosis?
Folic acid supplementation in mild-moderate disease; splenectomy is curative
and indicated for severe anemia.
This X-linked recessive disorder results in RBCs that are more susceptible to oxidant stress.
G6PD Deficiency
What are risk factors for G6PD?
African, Asian, and Mediterranean descent
How does G6PD lead to anemia?
Oxidant stress leads to hemoglobin precipitation within the RBC and subsequently both intravascular cell lysis and removal of cell from circulation via spleen
What drugs/oxidizing agents commonly precipitate hemolysis in G6PD deficiency?
Dapsone, methylene blue, nitrofurantoin, phenazopyridine (Pyridium), primaquine sulfonamides, antimalarials
What are signs and symptoms of hemolytic crisis in G6PD deficiency?
severe hemolysis with dark urine (hemoglobinuria), jaundice, pallor, splenomegaly, dyspnea, and possible vascular collapse