I recently heard a radio show where two callers claimed that their blood types had changed. One caller claimed that he was born O-, but recent tests said he was A+. Another caller claimed to change from AB- to AB+. Both callers claim that they had multiple tests before and after the change.

What I noticed is that both cases claim a conversion from Rh- to Rh+, or from type O to some other type. These could potentially be explained by a person carrying a gene for Rh factor or some other blood type, but failing to express the protein. Then the gene starts expressing, changing their blood type.

Of course both stories could be false, intentionally or otherwise. This is purely anecdotal evidence, and one caller claimed that her blood type change was due to extraterrestrial interference. I couldn't find any better documented cases of blood type changes after a quick search on the internet, so I thought I'd ask here.

Are there any documented cases of a change in blood type?

  • $\begingroup$ This is highly unlikely. The only reason which comes to my mind would be a transfer of stem cells (aka bone marrow transplant). $\endgroup$ – Chris Apr 18 '17 at 13:14
  • $\begingroup$ @Chris And I doubt that aliens are transferring stem cells. $\endgroup$ – user137 Apr 18 '17 at 13:18
  • $\begingroup$ Embryonic bone marrow transplant, maybe...? But that wouldn't work since they'd tested blood group earlier too ;) $\endgroup$ – another 'Homo sapien' Apr 18 '17 at 13:46
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    $\begingroup$ @another'Homosapien' I would suspect that either the first test was wrong or somebody remembered something wrong. $\endgroup$ – Chris Apr 18 '17 at 14:04
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    $\begingroup$ @chris my first idea would be: "if your blood type has changed, then your body (immune system) will very soon kill you". It surely isn't easy at all...there has to be some misunderstanding here. $\endgroup$ – another 'Homo sapien' Apr 18 '17 at 14:06

Blood group antigens are either sugars or proteins found attached to the red blood cell membrane. ABO blood group antigens are the most clinically important antigens because they are the most immunogenic. As red blood cell antigens are inherited traits, they are usually not altered throughout the life of an individual. There have been occasional case reports of ABO blood group antigen change in malignant conditions,ABO antigen alteration associated with acute myeloid leukemia. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5242122/

https://www.ncbi.nlm.nih.gov/pubmed/15135601 ( B to O change)

https://www.ncbi.nlm.nih.gov/pubmed/22270426 (New laboratory procedures and Rh blood type changes in a pregnant woman.)

A bone marrow transplant will replace the cells which make your blood cells with cells from the donor. Over about 3-4 months (life span of a red cell), your blood will become your donors type.


protected by Chris Jan 7 at 8:24

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