RBC Decreased Synthesis Flashcards
Important blood findings in Vit B12, Folate deficiency
Macrocytosis, Normochronic, anisocytosis
Low Retic Count
Large, hypersegmented PMNs
Large megakaryocytes
Erythroid:Myeloid ratio in Vit B12, Folate deficiency
1:1
Probably cause of Vit B12, Folate deficiency
Folic – Dietary insufficiency
B12 - malabsorption (pernicious anemia)
Vit B12, Folate deficiency – which one has neuro probs
B12
What might cause an increased B12 requirement?
Pregnancy, Hyperthyroid, Ca
Where does B12 come from
animal products
get ya 2-3 gm/day
Describe B12 handling
IF secreted in fundus parietal cells
Peptic digestion + rapid binders (cobalophilins)
IF+B12 in duodenum
Absorbed in ileum
B12 is required for…
- Homocysteins –> Methionine
2. Methylmalonyl coenzyme A –> Succinyl coenzyme A
Problem with elevated methylmalonyl coenzyme A
Forms abnormal fatty acids that incorporate into lipids
Neurological complications
How does pernicious anemia happen
Autoimmune destruction –> Chronic atrophic gastritis
Loss of Parietal cells
Clinical findings of pernicious anemia?
- Atrophic glossitis (Glazed, beefy tongue)
- Chronic gastritis w/ fundic atrophy –> Intestinalization + Gastric Cancer
- CNS lesions (Subacute combined degeneration)
- Hemosiderosis of liver, spleen, BM
What is a schilling test?
a test of ability to absorb radioactive cobalamin
Causes of diminished folate
Diet, Diffuse interstitial disease/resection, anticonvulsant therapy, oral contraceptives
Name three folate antagonists
Methotrexate
6-mercaptopurines
Cyclophosphamide
Folate deficiency is most commonly seen in what populations?
alcoholics, indigent, elderly
Metabolic processes that use folate
- Purine synth
- Methionine –> homocysteine
- Synth of dTMP
Unique test for folate deficiency
FIGlu in urine after histidine admin
Most common nutritional disorder in the world
Iron deficiency anemia
Most common causes of iron deficiency
In US – chronic blood loss (Colon Cancer)
In world – nutritional deficiency
Why do infants get iron deficiency?
Low iron in breast milk
Cows milk has poor iron bioavailability
Pathogenesis of iron deficiency
- Iron reserves (ferritin and hemosiderin) are consumed to maintain hematopoesis
- Eventually, serum iron, plasma ferritin, and transferrin sat drop. TIBC rises
On peripheral smear, iron deficiency anemia shows
Microcytic, hypochromic
Three clinical associations of anemia of chronic disease
Chronic microbial infections (osteomye., endocardi.)
Chronic Immune disorders (RA, regional enteritis)
Neoplasms (Hodgkin’s disease, carcinoma of lung/breast)
Clinical features of anemia of chronic disease
Low iron, reduced TIBC, high ferritin
____ may cause decreased utilization of iron by erythroid precursors in anemia of chronic disease
IL-1
Describe hematocrit changes surrounding blood loss
Immediately after normal (equal loss of cells+Fluid)
Then, fluid retention to compensate drops Hct
Low Hct will trigger erythropoesis to return to normal
Important physiological difference in external and internal hemorrhage
Internal hemorrhage will not cause loss of iron stores
DJ and I. What is absorbed where?
D - Iron
J - Folate
I - B12
anemia of chronic disease. maco, normo, or microcytic?
Micro or Normo
Other work from chromatin clumping
Pkynosis
What is achlorhydria (like in B12)
Lack of hydrochloric acid in gastric secretions
How does she explain ferritin and hemosiderin
Ferritin – Storage form of iron
Hemosiderin – Garbage dump of iron (not really coming back)
Predictable dose dependent causes of Aplastic Anemia
Benzene, Chloramphenicol, Alkylating Agents, Antimetabolites
Idiosyncratic reactions that trigger Aplastic Anemia
Phenylbutazone, Chlorpromazine
Streptomycin, Carbamazepine (TEGRETOL)
Non-drug related causes of Aplastic Anemia
Whole Body Radiation
HIV, Hep C
Inherited (Fanconi)
Aplastic Anemia can transform into
Acute leukemia
Pathology associated with Aplastic Anemia
Hypocellular marrow with increased fat cells, fibrous stroma
If multiple transfusions, can cause iron overload and hemosiderosis
Other than Aplastic Anemia, what are the four important forms of marrow failure
- Pure Red Cell Aplasia
- Diffuse Liver Disease
- Chronic Renal Failure – EPO loss + uremic suppression
- Chronic Infections (via IL-1)
Difference btw primary and secondary polycythemia
1 – Intrinsic stem cell abnormality
2 – RBC progenitors normal, but high EPO pushes production
What is a polycythemia
RBC overproduction
