Anemia - Decreased RBC Production (complete) Flashcards
What are some of the major causes for anemia related to RBC underproduction?
1) Chronic infections
2) Chronic non-infectious, inflammatory disease
3) Malignant disease
4) Lead intoxication
5) Renal insufficiency
6) Endocrine disorders
What are the typical clinical findings for chronic infections as they relate to anemia w/ decreased RBC production?
Depends on underlying disease
Signs/symptoms: pain, cough, swelling
May include: fever, arthralgias, arthritis, fatigue
What are the typical lab findings for chronic infections as they relate to anemia w/ decreased RBC production?
- Mild/mod anemia
- May be normochromic/normocytic or microcytic w/ hypochromia
- decreased serum Fe
- decreased TIBC
- normal to ^ ferritin
- decreased EPO for Hct
- decreased retic count
What are the typical clinical findings for lead intoxication as it relates to anemia w/ decreased RBC production?
- Personality changes
- Irritability
- Headache
- Weakness
- Wt loss
- Abdom pain
- Vomiting
What are the typical lab findings for lead intoxication as it relates to anemia w/ decreased RBC production?
- Mild/mod anemia
- decreased retic count
- microcytosis/mild hypochromia
- Basophilic stippling
- ^ Zn protoporphyrin
What are the typical clinical findings for renal insufficiency as it relates to anemia w/ decreased RBC production?
- Fatigue
- Pallor
- Decreased exercise tolerance
- Dyspnea
- Tachypnea
What are the typical lab findings for renal insufficiency as it relates to anemia w/ decreased RBC production?
- Usually no anemia til creat clearance 2-2.5 mg/dL
- Mod/severe anemia
- Normochromic
- Normocytic
- Decreased retic count
- EPO deficiency — decreased production
What are the typical clinical findings for endocrine disorders as they relate to anemia w/ decreased RBC production?
- hyper- or hypoactivity
- weight gain/loss
- systemic symptoms
- skin/hair/nail changes (hypo- or hyperthyroidism)
- Nausea
- Vomiting
- Dehydration
- Weakness
- Circulatory collapse
What are the typical lab findings for endocrine disorders as they relate to anemia w/ decreased RBC production?
- Mild anemia
- Hypothyroidism: normochromic, normocytic (can be micro- or macrocytic)
- Hyperthyroidism: normocytic (may be micro)
- Adrenal: mild anemia, normocytic
ALL decreased RETIC COUNT
Describe the pathophysiology of anemia related to chronic disease for malignancies and sepsis
- TNF decreases Fe availability from stores
- Also, decreases production of EPO
- INF-beta inhibits erythropoiesis
overall, decreased RBC production
Describe the pathophysiology of anemia related to chronic disease for chronic infections/inflammation
- IL-1 decreases Fe metabolism
- Also, decreases EPO production
- INF-gamma inhibits erythropoiesis
Can’t use Fe stores —» decreased RBC production
Describe the rationale and indications for the use of erythropoietic in the management of underproduction anemia
Used when….
1) there is an absolute deficiency
2) EPO levels are decreased out of proportion to the degree of anemia
Explain the biochemical basis for B12 and folate deficiency leading to macrocytic anemia
- Both are critical cofactors for normal hematopoiesis (downstream product required for normal DNA synthesis)
- Deficiencies affect RBC precursor maturation process in BM
Cells increase in size, arrest in S phase of mitosis —»> destruction (ineffective erythropoiesis)
What are the dietary sources of B12?
1) Meat
2) Eggs
3) Milk
What are the dietary sources of folate?
Widespread
1) cereals, bread
2) fruits, veggies
3) meats, fish
4) breast milk (one of the reasons why breastfeeding is so important)
Describe the mechanisms for absorption, transport, and duration/location of storage for B12
Absorption:
- Intrinsic factor (IF) binds to B12 in the stomach
- In the ileum, B12 is absorbed and released by IF
Transport:
- Transcobalamin binding protein II (TcII) binds to B12
- Transport to the liver for storage
- Goes to tissues for use (e.g. BM)
Describe the mechanisms for absorption, transport, and duration/location of storage for folate
Absorption:
- in the jejunum
- hydrolyzed, reduced, methylated before distribution/storage
Transport:
- Tissues for use
- Liver for storage
Liver stores undergo turnover, secretion in the bile —» reabsorption
Describe the findings in peripheral blood and bone marrow in a pt w/ B12 or folate deficiency
BM:
- Megaloblastic changes in RBC and WBC precursors
- Erythroid hyperplasia
- Cytoplasmic maturation is normal
PB:
- Macrocytosis (MCV >97)
- Ovalocytes
- Hypersegmented nuclei of neutrophils
- Poikilocytes and fragmentation (as it progresses)
Severe cases
- neutropenia
- thrombocytopenia
- ^ bilirubin
- retic count <1
Describe the differences between the most common causes of B12 and folate deficiency
Both:
- Malabsorption
- Metabolic defects
B12:
- Autoimmune disease
- IF deficiency
- Defective transport/storage
Folate:
- Dietary insufficiency
- Drugs/toxins
- Increased demands
- Increased loss/metabolism
Describe the differences in the time to develop B12 and folate deficiency
B12:
- Slowly (YEARS)
Folate
- More quickly (WEEKS to MONTHS)
Describe the differences between the presence of neurologic abnormalities in B12 and folate deficiency
B12:
- Sensory losses first (numbness, tingling)
- Loss of proprioception
- Ataxia, spasticity, gait probs
- Cognitive/emotional changes
Folate
- infrequent
Describe the differences between the lab studies used to make a diagnosis for B12 and folate deficiency
Both:
- ^ MCV
- Low retic count/index
- ^ unconj. bilirubin and LDH
- Neutropenia/thrombocytopenia (in severe cases)
B12:
- normal/^ serum folate
- ^ serum methylmalonic acid
Folate:
- Decrease serum folate
- normal serum methylmalonic acid
Describe the appropriate therapies for B12 deficiency
- IM/SQ injections of B12
- Daily for 2 weeks
- then weekly until Hct is normal
- then monthly for life
Can be given orally if absorption isn’t an issue
For pernicious anemia, large oral doses can overcome absorption issue
Describe the appropriate therapies for folate deficiency
1mg/day orally or parentally
