Topic 4: Anemia Chronic Disease Flashcards
What is anemia of chronic disease?
Aka anemia of chronic inflammation
It’s a low RBC mass secondary to decreased RBC production in the setting of a chronic illness
What diseases can cause anemia of chronic disease?
- local and systemic infections (pneumonia and bacteremia)
- malignancies (leukemia, colon cancer)
- autoimmune disorders (rheumatoid arthritis, systemic lupus erythematosus)
What happens to transfused RBCs from a healthy patient to a patient with a chronic illness?
If RBCs from a healthy patient are transfused into another patient with a chronic illness, the transfused cells have a shorter lifespan than if they stayed in their donor
Normal RBC:120 days
ACD RBC: 10-20 days
Where is a big chunk of iron stored?
Macrophages and liver
Why can’t people with ACD just make more RBCs to replace old ones if they’re dying off quickly?
It’s not that they don’t have enough iron, it’s that they have a hard time using it
Iron is stored in liver and macrophages but when there’s chronic inflammation a person has higher levels of IL-6 cytokine
IL-6 increases hepcidin production which prevents macrophage and liver release of iron stores by decreasing the number of iron transporters on their cell surface
Without iron you can’t make RBCs
What protein prevents iron from leaving macrophages?
Hepcidin
What will a CBC in a patient with ACD show?
Low Hb
Low hematocrit
Low RBCs
MCV can be normal or low
How can you differentiate ACD from other anemias?
There’s decreased circulating iron
If you measure serum iron, it will be low but so will a patient with iron deficiency anemia
So further iron studies must be done to differentiate it like serum ferritin test, total iron binding capacity (TIBC), or % iron saturation
Will serum iron in ACD patients be low, normal or high?
Low
What is the serum ferritin test?
Ferritin measures the amount of iron stored in the body
Iron-deficient patients will have low ferritin but ACD patients will have normal or even high ferritin because there’s plenty of Fe being stored
Increased ferritin can be a marker of inflammation even if there’s no anemia
Will the TIBC in ACD patients be low, normal or high?
Normal
Total iron binding capacity will be normal because it can still bind just as much iron
What’s the difference between TIBC and % iron saturation?
Capacity vs. saturation
What is the TIBC and % saturation for a patient with iron deficiency?
Iron is typically transporter via transferrin
In Fe deficiency, there’s not a lot of total iron so transferrin will not be bound to iron
So transferring will have a lot of capacity to bind to iron = high TIBC and low % saturation
What is the TIBC and % saturation for ACD?
Total amount of Fe in the body is normal but there’s few transferrin molecules because this protein is downregulated in chronic inflammatory states
So normal Fe but fewer iron binding sites because of less transferring = TIBC will be low/normal and % saturation will be high/normal
Is transferring up or down regulated in ACD?
Down regulation in chronic inflammatory states
