Anemias - Hertz - SRS Flashcards
An unbelievably skinny woman comes in with the attached CBC results. What do you think?
Severe anemia, high MCV indicates likely a B12 or folate deficiency
What are the most common/important anemias associated with red cell underproduction?
Top 3
- Nutritional deficiencies
- Renal failure
- Chronic inflammation
What do aplastic anemia, primary hematopoietic neoplasms, and infiltrative disorders have in common?
Lead to generalized marrow failure
What is the common theme among the megaloblastic anemias?
Impairment of DNA synthesis leading to ineffective hematopoiesis and distinctive morphological changes including abnormally large erythroid precursors and red cells.
What is a term we should associate with megaloblastic anemia?
Asynchrony
What are the major causes of megaloblastic anemia?
- B12 deficiency
- folic acid deficiency
What are examples of impaired absorption derived megaloblastic anemia?
- Intrinsif factor deficiency (pernicious anemia and gastrectomy)
- Malabsorption states
- Diffuse intestinal disease (lymphoma, systemic sclerosis
- Ileal resection, ileitis
- Bacterial overgrowth in blind loops and diverticula of bowel
What are the two causes of intrinsic factor deficiency Hertz talked about?
Which one did he emphasize?
Pernicious anemia
gastrectomy
Decreased intake can cause megaloblastic anemia, what are the big examples of this Hertz emphasized with big stars?
3
What are two other causes of decreased absorption of folic acid that were incorrectly formatted in the table hertz gave us?
- Inadequate diet
- Alcoholism
- infancy
- anticonvulsants
- oral contraceptives
What is an example of an impaired utilization megaloblastic anemia causitive agent?
Folic acid antagonists - methotrexate!
What does the presence of these nuclear hypersegmentation and macro-ovalocytes indicate?
B12 or foloate or myelodysplastic syndromes
What is pernicious anemia caused by?
Autoimmune gastritis that impairs the production of intrinsic factor
What is intrinsic factor important for?
B12 uptake from the gut
Your patient with anemia comes in for you to do endoscopy and gastric biopsy, this is what you find. What is going on?
On the left, the stomach should not be smooth like that. The histology image shows decreased glands and loss of normal villous structure.
These findings indicate that autoimmune gastritis is causing pernicious anemia in your patient.
How is the shillings test performed?
Radioactively tagged cobalamine given to patient will rule out intrinsic factor deficiencies.
Where does B12 come from?
Meat, specifically the bacteria in/on meat
What produces intrinsic factor?
Parietal cells of the fundic mucosa
What are B12 and folate needed for?
DNA synthesis
Pernicious anemia involves an autoimmune attack on the gastric mucosa. What do you find grossly/histologically?
Chronic atrophic gastritis
What are the three types of antibodies that can be involved in pernicious anemia?
Type I
Type II
Type III
Roughly 75% of pernicious anemia cases are due to type I antibodies. What does this antibody type do?
Blocks the binding of vitamin B12 to intrinsic factor
Where are type I antibodies found?
In both plasma and gastric juice
What do type II antibodies do?
Prevent binding of the intrinsic factor-vitamin B12 complex to its ileal receptor.
Type III antibodies are present in 85% to 90% of patients with pernicious anemia. What do these antibodies do?
Bind the alpha and beta subunits of the gastric proton pump, which is normally localized to the microvilli of the canalicular system of the gastric parietal cell.
Describe the findings shown, and identify what disease process they are associated with.
- Left: Fundic gland atrophy
- Right: Intestinalization (of the stomach, it now looks histologically like intestine)
- Pernicious anemia
Describe what is going on in the attached image and identify the disease process it is associated with.
- Silver stain reveals demyelination of the dorsal and lateral spinal tracts - leading to sensory deficits.
- Pernicious anemia