[xattt]

Neither article talks about whether this is a minor or a major antigen.

Blood for transfusion needs to be crossmatched against antigen types of the recipient. Many patients will tolerate several transfusions of a minor mismatched antigen before developing a sensitivity. Major antigens are what cause significant reactions that can be life-threatening.

Minor antigens come into play when crossmatching for infants and premies, but this is way beyond my scope.

[JackFr]

I recently had major surgery and got two units of blood in during the operation and two more post-op. Post-op before I got the blood, they typed my blood again, and a nurse stayed in the room while I got the blood and I wondered why. This comment makes it clear.

[xattt]

Close observation for 15 minutes is typical for any blood transfusion. You do a set of pre-transfusion vitals, vitals when the blood hits the vein, vitals every 5 minutes until 15 minutes is up, vitals every 15 minutes until the blood is done. Ask any nurse why they hate running blood.

Depending on the severity of the reaction, blood will either be stopped or the patient will be loaded up with Benadryl and Tylenol with the blood running at a slower rate.

[paulgerhardt]

> Minor antigens come into play when crossmatching for infants

I’m reminded of that American high schooler in Uganda running an orphanage and ran into this exact issue when doing a transfusion on a malnourished infant. [1]

She was skilled enough to perform a transfusion and knowledgeable enough to test for a ABO+/- match but not so knowledgeable as to be sensitive to this issue with disastrous results.

On the other hand her clinics metrics were on par or slightly above the local hospitals so it’s not clear to me they would have faired better getting care elsewhere there.

[1] https://stories.showmax.com/za/hbos-docuseries-savior-comple...

[leereeves]

I don't know anything about the case in Uganda, but transfusion reactions can happen to anyone, even in the United States.

We don't actually express antibodies to antigens until we're exposed to them, so crossmatching won't detect a minor antigen mismatch until the first transfusion containing the antigen is administered.

That first time causes a delayed hemolytic transfusion reaction, which is generally milder than the kind of reaction crossmatching will prevent, but can be serious or even fatal.

https://en.wikipedia.org/wiki/Delayed_hemolytic_transfusion_...

[yorwba]

With a single known case of somebody producing antibodies against the antigen, it might be a bit hard to say how many transfusions it typically takes to develop a sensitivity.

[mmazing]

Type O Negative here, they all kill me so luckily I don't have to guess!

[HarHarVeryFunny]

Does the concept of O -ve as a universal donor type apply at all outside of the ABO group, and am I understanding correctly from your comment that even within the APO group O -ve compatibility would still be subject to this antigen matching?

Don't we have synthetic blood, at least capable of transporting oxygen ?

[kadoban]

There's not really a synthetic oxygen-carrying blood substitute that's commonly used. Turns out it's actually pretty hard to get right. https://en.wikipedia.org/wiki/Blood_substitute has some info on different approaches and products that were/are sometimes used, but the short story is: not really.

[ajb]

That's interesting; I didn't know that to realize it was missing.