Macrocytic Anemia

Learn about the mechanism behind the macrocytic anemias in this video.

For more information, look at Robbins and Cotran: Pathological Basis of Disease, Chapter 14.

[jameskingsley]

Thank you for your clear and concise presentation! The VitB12 pathway, however is a little over simplified with some clinical implications. So the R-binder produced in the mouth binds to B12 and travels into the stomach. Parietal cells in stomach produce IF and IF travels unbound B12-RBinder complex into the duodenum where pancreatic proteases break apart B12-RBinder complex in which case IF binds to B12 and is eventually absorbed in the terminal ileum like you mentioned by transcobalamin. This is important because the reason why short bowel syndrome (post small bowel resection) and pancreatic insufficiency are causes of macrocytic anemia/vitB12 deficiency is because the pancreatic enzymes are inactivated in the pathologically acidic environment of the duodenum (in the case of short short bowel syndrome) or are prematurely activated/blocked from getting to the duodenum. So two important causes of vitb12 deficiency and macrocytic anemia are pancreatic insufficiency and short bowel syndrome - which are more common than pernicious anemia and will be apart of more challenging board questions.

Also - don't forget chronic liver disease i.e. cirrhosis as being a cause of macrocytic anemia as well - because these patients if they have a slow variceal bleed their MCV will not necessarily be microcytic - it might be normocytic - in which case you depend on RDW for help.

[runswithwands]

I was recently diagnosed with megaloblastic macrocytic anemia. I'd been borderline anemic for a couple decades, but this seemed to come full bore recently. I had memory loss issues--both short and long term--and I could not figure out what happened. I decided the Minocycline I'd been on for 2+ years may have contributed somehow to all of this: long-term loss to good flora in the gut, vulnerability sets in, and here I am having to deal with macrocytic anemia. I recently dropped the Minocycline and am hoping that, once my body returns to a more normalized state, that the anemia goes away. In the meantime, supplements and my doctor are supportive and helping me figure this out.

Thank you for the video. While Minocycline may not be a common answer, I think it is the reason I have gone downhill with anemia, quite hard, in the past couple years. I just had to put two and two together. :)

[lisagonzalez]

It was excellent. The best video i could find on specifically megaloblastic anemia. you described everything in a simple way. thanks a lot

[Knuxsega]

Your information is very conceptual and thorough.. Thanks a bunch daf189!! :D

[AnotherBadyoga]

Great videos! As good or better than the Khan Academy (which I like but sometimes the lectures talk to slow).

[carrotgold]

I have the MTHFR mutation. The females in my family manifest with multiple miscarriages. I have never tried to conceive so even though I have the defect I wasn't sure how it would manifest. Unfortunately I metastasized endometrial cancer after surgical removal of all my reproductive organs. It was during chemotherapy that my RBC steadily declined and combined with my elevated RDW% created the megaloblastic anemia. I am now taking an OTC folate and B12 pill combo recommended by my niece's doctor. I believe the chemo did not cause the problem but it gave the MTHFR mutation the opportunity to manifest. 😥

[نقاءوردهالصادقه]

macrocytic anemia or megaloplastic anemia hyper cromic mcv 100-120 normality B12. folic acid disease liver faction thyroid disease thanke very much 🌹🌹

[mizmac]

Question, sir. You said that the body needs intrinsic factor in order to absorb the vit B12 in the gut. So how come the parenteral B12 itself treats the pernicius anemia that is caused by decreased intrinsic factor in the gut, knowing that there's only few intrinsic factor that will bind to B12?

[zSchreckensszene]

causes of
- folate deficiency: malnutrition (not enough green leafy FOLIAGE), treated by oral folic acid
- B12 deficiency: treated parenterally (anything that's not enterally, or GI wise): B12 also breaks down FAs, so if it's not there then myelin suffers --> peripheral neuropathy!
-- resection
-- tapeworm
-- decreased intrinsic factor: IF is released by the parietal cells. if they're being destroyed in autoimmunity, that's called "pernicious aniemia)

[luciamartin]

thank you so much for this wonderful explanation.

[Buttercup]

WHY DID U STOP MAKING THESE VIDEOS!! PLS COME BACK. WE NEEEED YOU GEEENIUSSSS!!!

[JEDDAHBOYS]

keep it up man you are very good, thank you

[nellyhoffman]

Wow amazing lectures brother !! :) thanks very much but if you can speak slowly ! :p
Good luck keep going

[drg]

What software and hardware have you used?

[otaribeldishevski]

Other causes of macrocytic anemia? Hypothyroidism? Liver disease? Acute bleeding?

[SmoDesign]

RBCs don’t have genetic materials, how come it goes through the check points cycle? or even why do we explain that macrocytic anaemia is due to “bad DNA”?

[fatimafernandes]

I'm on hiv aids drugs can this also cos this in my case

[mindheartandsoul]

hmmm... someone needs to fix this... info is incorrect.