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Long time listener, first time caller (finally made a HN account).. Anyways, can someone please explain how positive/negative plays a factor here? Rh +/- is me

Long time listener, first time caller (finally made a HN account).. Anyways, can someone please explain how positive/negative plays a factor here? Rh +/- is mentioned once in the article but not discussed as far as being a donor. I was always told O- is the universal red cell donor [1]. Can anyone help explain is this enzyme fixes the +/- component in addition to the ABO component? Thanks! [1] https://www.redcrossblood.org/donate-blood/blood-types.html https://www.redcrossblood.org/donate-blood/blood-types.html

Terr_ 2y ago
That's probably a separate and harder problem from this: The A and B antigens refer to the presence of carbohydrates extending from the cell membrane, whereas Rh factor + refers to the presence of a protein. Since there are different classes of bio-molecules, proteins may need different techniques to remove, alter, or cover them up. If we do find such techniques, they may have much broader applications in immunology.
- XorNot 2y ago
  Rhesus factor is a lot more forgiving though: i.e. in a crisis you can transfuse rhesus positive blood to a rhesus negative person successfully since the sensitization doesn't emerge immediately.
HPsquared 2y ago
There are three components that can cause problems with transfusions: "A", "B" and "Rhesus". A person can have any combination of those three (8 combinations). The A/B/AB/O is basically having only A, only B, both, or neither. And the +/- is whether you have the "Rhesus" component. The basic rule is that you can't introduce new components to a person who doesn't have them in their system, and will be treated as foreign contaminants. So someone with all three components already (AB+) can take any blood because their system already is used to all three components. A person with none of the components in their system (O-) would have an allergic reaction to any of the three components being introduced. On the other hand their blood is safe to donate to anyone else as it won't introduce any "unexpected components" to a recipient. EDIT: ah, I see - article doesn't mention Rhesus. I guess it can convert AB- to O-, or AB+ to O+.
- wbl 2y ago
  Oh there are more. I think hundreds are known, but only a few populations have each one.
- Buttons840 2y ago
  I think O is recessive (if I remember from high school correctly). A is really AO (if we're being verbose). B is BO, AB is AB, O is OO. Each parent passes one of them on. So, a A dad and O mom would mix (being verbose again) AO and OO, and thus the child might be AO or OO, A or O. The + or - is for an independent "Rhesus" component, as you say. Not sure how this passes through the genes. This is all like high school level knowledge, so maybe someone can share more if they want. My dad had surgery and some paperwork we received said that he had AB blood. It became a family joke because me and my siblings are all O blood type. If my dad really did have AB blood then we are not his children. The hospital later confirmed it was a mistake.
  - deleted 2y ago
    [deleted]
  - blendergeek 2y ago
    You mostly remember correctly. One small nitpicko on the genetics (based on my high school biology) A can be either AA or AO and B can be either BB or BO. AB is always AB like you said and O is always OO.
  - linooma_ 2y ago
    > I think O is recessive Strangely, O is very common.
    - riffraff 2y ago
      I seem to remember the explanation is that A and B are somewhat recent mutations in evolutionary terms, they simply have not had time to cancel out 0 yet. Of course there's crackpot theories (aliens!) too.
    - thaumasiotes 2y ago

Terr_ 2y ago

That's probably a separate and harder problem from this: The A and B antigens refer to the presence of carbohydrates extending from the cell membrane, whereas Rh factor + refers to the presence of a protein. Since there are different classes of bio-molecules, proteins may need different techniques to remove, alter, or cover them up. If we do find such techniques, they may have much broader applications in immunology.

XorNot 2y ago
Rhesus factor is a lot more forgiving though: i.e. in a crisis you can transfuse rhesus positive blood to a rhesus negative person successfully since the sensitization doesn't emerge immediately.

HPsquared 2y ago

There are three components that can cause problems with transfusions: "A", "B" and "Rhesus". A person can have any combination of those three (8 combinations). The A/B/AB/O is basically having only A, only B, both, or neither. And the +/- is whether you have the "Rhesus" component. The basic rule is that you can't introduce new components to a person who doesn't have them in their system, and will be treated as foreign contaminants. So someone with all three components already (AB+) can take any blood because their system already is used to all three components. A person with none of the components in their system (O-) would have an allergic reaction to any of the three components being introduced. On the other hand their blood is safe to donate to anyone else as it won't introduce any "unexpected components" to a recipient. EDIT: ah, I see - article doesn't mention Rhesus. I guess it can convert AB- to O-, or AB+ to O+.

wbl 2y ago
Oh there are more. I think hundreds are known, but only a few populations have each one.
Buttons840 2y ago
I think O is recessive (if I remember from high school correctly). A is really AO (if we're being verbose). B is BO, AB is AB, O is OO. Each parent passes one of them on. So, a A dad and O mom would mix (being verbose again) AO and OO, and thus the child might be AO or OO, A or O. The + or - is for an independent "Rhesus" component, as you say. Not sure how this passes through the genes. This is all like high school level knowledge, so maybe someone can share more if they want. My dad had surgery and some paperwork we received said that he had AB blood. It became a family joke because me and my siblings are all O blood type. If my dad really did have AB blood then we are not his children. The hospital later confirmed it was a mistake.
- deleted 2y ago
  [deleted]
- blendergeek 2y ago
  You mostly remember correctly. One small nitpicko on the genetics (based on my high school biology) A can be either AA or AO and B can be either BB or BO. AB is always AB like you said and O is always OO.
- linooma_ 2y ago
  > I think O is recessive Strangely, O is very common.
  - riffraff 2y ago
    I seem to remember the explanation is that A and B are somewhat recent mutations in evolutionary terms, they simply have not had time to cancel out 0 yet. Of course there's crackpot theories (aliens!) too.
  - thaumasiotes 2y ago