Thread by @TransfusionWM

I’m spending a lot of time thinking about O D neg this week. R0 is something that often causes difficulties – for #haemSpRs and transfusion labs! So what is R0?

(also tempted to add a poll for how you say it! Will stick to "R oh" personally....)

and we have the correct answer! Capital R = D pos, then 0 means (to my mind) no C or E. R0 = cDe; R1 = CDe; R2 = cDE. r = cde which is of course D neg

R0 is the rh phenotype where c, D and e are expressed. These patients are D positive. 44% African Caribbean people will have this phenotype, but only 4% Caucasian people do.

Patients with sickle cell anaemia require blood that is fully Rh matched. Most patients with sickle cell anaemia are African Caribbean but 96% of UK blood donors are Caucasian.

The most common “C neg E neg” phenotype in Caucasians is cde (r). These donors are D negative (obviously). Hence to find Rh matched blood for pts with sickle cell anaemia can mean giving cde (r) blood to cDe (R0) pts, i.e. substituting D neg when there is no other indication!

*question time* #blooducation
Additional pressures are brought by the additional requirements for blood for patients with sickle cell anaemia. Q for #haemSpRs: what are these?

How to reduce the need to substitute D neg for D pos:
1. Clinicians: request blood for pts with SCD in good time
2. BMSs: only subst D neg when necessary, only give O when no other ABO compatible RBC available
3. Everyone: encourage people of BAME backgrounds to donate