5 ms·

"some groups were "really, really rare" and there "might only be 10 people in the country" able to donate." oooof.... I knew some blood type was rare, but this

by pcurve 4y ago

"some groups were "really, really rare" and there "might only be 10 people in the country" able to donate." oooof.... I knew some blood type was rare, but this is another level.

d4mi3n 4y ago
What’s more is that the identities of those people need to be protected lest they be bombarded constantly for lab studies or requests for life saving donations. Many counties have laws about paying for blood donations and don’t allow donors to be compensated in any way, so they either need to take on the financial burden of flying to wherever their blood is needed or refusing to take on the financial burden and knowingly allowing someone to die. It’s not fair to them and while most of these laws prevent darker forms of abuse of vulnerable demographics, they don’t really account for cases like donation of rare blood types.
- tait 4y ago
  > so they either need to take on the financial burden of flying to wherever their blood is needed or refusing to take on the financial burden and knowingly allowing someone to die. Is that a real case or hypothetical? If real, I would like to explore further as it does seem rather inappropriate. In my experience, the blood can be drawn locally and then sent to the recipient. That's also true for bone marrow & peripheral blood stem cell donations. Source: I am a transfusion medicine physician.
beambot 4y ago
Always reminds me of this: > Harrison, known as the “Man With the Golden Arm,” has donated blood nearly every week for 60 years. After all those donations, the 81-year-old Australian man “retired” Friday. The occasion marked the end of a monumental chapter. According to the Australian Red Cross Blood Service, he has helped saved the lives of more than 2.4 million Australian babies. https://www.cnn.com/2018/05/11/health/james-harrison-blood-donor-retires-trnd https://www.cnn.com/2018/05/11/health/james-harrison-blood-d...
- pcurve 4y ago
  I wonder if they were able to find additional sources to replace him...
- gus_massa 4y ago
  It's a different case. The article you posted is about someone that has a high level of RH antibodies. In the main article, the rare blood type is because the the A, B, AB, 0 and RH+/RH- groups are due to 3 antigens (2^3=8). But there are like 20 or 25 more antigens that your blood may or may not have, so there are like 2^23 or 2^28 blood types. Some are very rare, some combinations are very rare. Most of the time the other 20 antigens don't produce a reaction that is so strong [1], so for most transfusions it's enough to classify using the A, B, and RH. [1] Why? I'd really like to know why, or if I'm oversimplifying too much.
  - tait 4y ago
    Ask and ye shall receive! To answer [1] Why?: it's complicated. There are more than 35 red blood cell groups (see https://www.science.org.au/curious/people-medicine/blood-types https://www.science.org.au/curious/people-medicine/blood-typ... for a nice writeup). For each of those blood groups, there is more than one possible configuration of some protein or carbohydrate (something like more than one possible genetic sequence leading to more than one kind of molecule on the surface of the RBCs). And, even with ABO, there can be infrequent variations that make things more complicated (see https://professionaleducation.blood.ca/en/transfusion/best-practices/serological-best-practices/abo-subgroups https://professionaleducation.blood.ca/en/transfusion/best-p... for more). For the other blood groups, I think every case the groups were identified because a patient somewhere made an antibody, causing either a transfusion reaction (if not tested ahead of time) or, more likely, a positive (incompatible) reaction on in compatibility testing. Each of those blood groups will have two or more versions. For example, there is the Kell blood group, which has two primary versions: you can express big K, little k, or both as Kell is a codominant system. Most people are homozygous little k (kk). When you are homozygous little k, you can make antibodies to big K (which is expressed on people who are Kk or KK). So, if you are homozygous little k, you are at risk of making antibodies on exposure to big K. Of course, not everyone is either big K or little k, that would be too simple. There are, I think, more than 20 variants of K out there... More or less, each of those blood groups can cause antibody formation if you lack an antigen on the surface of those antibodies. In practice, the likelihood of an antigen causing antibody formation varies by antigen (the term there is "antigenic"). Also, the immunologic status of the recipient matters - obviously, someone who is immunosuppressed from an organ transplant may be less likely to form antibodies (that's the point of of the immunosuppression). Conversely, some people are more likely than most to form antibodies. Also, it appears that the immune system is more likely to form antibodies in other blood groups if a person already has antibodies. In practice, there is a recommendation from NHLBI to match for C, E, and K in patients who are going to be transfused often to try to avoid forming new antibodies. People 'naturally' form antibodies to A and to B antigens that they lack (I am group O and have both anti-A and anti-B antibodies). This is because they are exposed to those antigens in everyday life (the A and B antigen is found on some gut bacteria). And Rh-D is very immunogenic and clinically significant. When we test blood prior to transfusion, we attempt to identify what antibodies the patient may have. If they have no unexpected antibodies, just honoring blood and Rh-D type is usually enough. If they have unexpected antibodies, we go through a complicated process to identify blood that lacks those antibodies to try to avoid a transfusion reaction. (Now to modify that testing point, we know some antibodies are not clinically significant - that is, they do not cause significant transfusion reactions. So, we can, if we have to, give blood that is incompatible for clinically insignificant antibodies. We still try to provide blood negative for those antigens because we wouldn't find out this patient is the first to have a clinically significant version of the antibody. Also, the blood tests as incompatible with clinically insignificant antibodies, and we would prefer to give blood that tests as compatible). Sorry this is rambling a bit - I have to take my daughter to school. Happy to expand/clarify/etc. when I can get back to it. Source: I am a practicing physician board certified in "Blood Banking/Transfusion Medicine". My statements in this are still likely inaccurate, but hopefully in a useful way. I am not your lawyer, and I am not your physician.
deleted 4y ago
[deleted]
nigerianbrince 4y ago
Don't people with such blood groups preserve their own blood for emergencies?
- tait 4y ago
  Some can and do, but there are some challenges for it being a general solution: - Some people don't know they need rare blood (because they didn't have the antibody at first, then found they had it later). - Some people may donate blood to have it available for a need, then a need comes up (either themselves or someone else). At that point, the blood gets used up - what happens when the need is greater than the number of stored units? - Some people may not be able to donate. We had a patient with something north of 9 antibodies who, due to sickle cell disease wasn't able to donate - (banking blood for long term storage requires freezing, which doesn't work with blood from patients with sickle cell disease).

by pcurve 4y ago

"some groups were "really, really rare" and there "might only be 10 people in the country" able to donate." oooof.... I knew some blood type was rare, but this is another level.

d4mi3n 4y ago

What’s more is that the identities of those people need to be protected lest they be bombarded constantly for lab studies or requests for life saving donations. Many counties have laws about paying for blood donations and don’t allow donors to be compensated in any way, so they either need to take on the financial burden of flying to wherever their blood is needed or refusing to take on the financial burden and knowingly allowing someone to die. It’s not fair to them and while most of these laws prevent darker forms of abuse of vulnerable demographics, they don’t really account for cases like donation of rare blood types.

tait 4y ago
> so they either need to take on the financial burden of flying to wherever their blood is needed or refusing to take on the financial burden and knowingly allowing someone to die. Is that a real case or hypothetical? If real, I would like to explore further as it does seem rather inappropriate. In my experience, the blood can be drawn locally and then sent to the recipient. That's also true for bone marrow & peripheral blood stem cell donations. Source: I am a transfusion medicine physician.

beambot 4y ago

Always reminds me of this: > Harrison, known as the “Man With the Golden Arm,” has donated blood nearly every week for 60 years. After all those donations, the 81-year-old Australian man “retired” Friday. The occasion marked the end of a monumental chapter. According to the Australian Red Cross Blood Service, he has helped saved the lives of more than 2.4 million Australian babies. https://www.cnn.com/2018/05/11/health/james-harrison-blood-donor-retires-trnd https://www.cnn.com/2018/05/11/health/james-harrison-blood-d...

pcurve 4y ago
I wonder if they were able to find additional sources to replace him...
gus_massa 4y ago
It's a different case. The article you posted is about someone that has a high level of RH antibodies. In the main article, the rare blood type is because the the A, B, AB, 0 and RH+/RH- groups are due to 3 antigens (2^3=8). But there are like 20 or 25 more antigens that your blood may or may not have, so there are like 2^23 or 2^28 blood types. Some are very rare, some combinations are very rare. Most of the time the other 20 antigens don't produce a reaction that is so strong [1], so for most transfusions it's enough to classify using the A, B, and RH. [1] Why? I'd really like to know why, or if I'm oversimplifying too much.
- tait 4y ago
  Ask and ye shall receive! To answer [1] Why?: it's complicated. There are more than 35 red blood cell groups (see https://www.science.org.au/curious/people-medicine/blood-types https://www.science.org.au/curious/people-medicine/blood-typ... for a nice writeup). For each of those blood groups, there is more than one possible configuration of some protein or carbohydrate (something like more than one possible genetic sequence leading to more than one kind of molecule on the surface of the RBCs). And, even with ABO, there can be infrequent variations that make things more complicated (see https://professionaleducation.blood.ca/en/transfusion/best-practices/serological-best-practices/abo-subgroups https://professionaleducation.blood.ca/en/transfusion/best-p... for more). For the other blood groups, I think every case the groups were identified because a patient somewhere made an antibody, causing either a transfusion reaction (if not tested ahead of time) or, more likely, a positive (incompatible) reaction on in compatibility testing. Each of those blood groups will have two or more versions. For example, there is the Kell blood group, which has two primary versions: you can express big K, little k, or both as Kell is a codominant system. Most people are homozygous little k (kk). When you are homozygous little k, you can make antibodies to big K (which is expressed on people who are Kk or KK). So, if you are homozygous little k, you are at risk of making antibodies on exposure to big K. Of course, not everyone is either big K or little k, that would be too simple. There are, I think, more than 20 variants of K out there... More or less, each of those blood groups can cause antibody formation if you lack an antigen on the surface of those antibodies. In practice, the likelihood of an antigen causing antibody formation varies by antigen (the term there is "antigenic"). Also, the immunologic status of the recipient matters - obviously, someone who is immunosuppressed from an organ transplant may be less likely to form antibodies (that's the point of of the immunosuppression). Conversely, some people are more likely than most to form antibodies. Also, it appears that the immune system is more likely to form antibodies in other blood groups if a person already has antibodies. In practice, there is a recommendation from NHLBI to match for C, E, and K in patients who are going to be transfused often to try to avoid forming new antibodies. People 'naturally' form antibodies to A and to B antigens that they lack (I am group O and have both anti-A and anti-B antibodies). This is because they are exposed to those antigens in everyday life (the A and B antigen is found on some gut bacteria). And Rh-D is very immunogenic and clinically significant. When we test blood prior to transfusion, we attempt to identify what antibodies the patient may have. If they have no unexpected antibodies, just honoring blood and Rh-D type is usually enough. If they have unexpected antibodies, we go through a complicated process to identify blood that lacks those antibodies to try to avoid a transfusion reaction. (Now to modify that testing point, we know some antibodies are not clinically significant - that is, they do not cause significant transfusion reactions. So, we can, if we have to, give blood that is incompatible for clinically insignificant antibodies. We still try to provide blood negative for those antigens because we wouldn't find out this patient is the first to have a clinically significant version of the antibody. Also, the blood tests as incompatible with clinically insignificant antibodies, and we would prefer to give blood that tests as compatible). Sorry this is rambling a bit - I have to take my daughter to school. Happy to expand/clarify/etc. when I can get back to it. Source: I am a practicing physician board certified in "Blood Banking/Transfusion Medicine". My statements in this are still likely inaccurate, but hopefully in a useful way. I am not your lawyer, and I am not your physician.

deleted 4y ago

[deleted]

nigerianbrince 4y ago

Don't people with such blood groups preserve their own blood for emergencies?

tait 4y ago
Some can and do, but there are some challenges for it being a general solution: - Some people don't know they need rare blood (because they didn't have the antibody at first, then found they had it later). - Some people may donate blood to have it available for a need, then a need comes up (either themselves or someone else). At that point, the blood gets used up - what happens when the need is greater than the number of stored units? - Some people may not be able to donate. We had a patient with something north of 9 antibodies who, due to sickle cell disease wasn't able to donate - (banking blood for long term storage requires freezing, which doesn't work with blood from patients with sickle cell disease).