Valid blood type

[illinoisbloodbanker]

Do you require a reverse type be 2+ or greater to be considered a valid type?  I am not aware of any requirement for a specific grade of reaction for a reverse to be valid.  If the reaction is macroscopic I have proceeded with my interpretation without further enhancement.  There is a hospital within our affiliation that has more stringent rules and I want to make sure I am not missing something. 

[Kelly Guenthner]

Nope.  Positive is positive.

 

[R1R2]

Agree with Kelly

 

[yan xia]

We require the reverse type to be 2+ or stronger in tube, because weaker reaction can mean subgroup or weak immunoglobulin.

[John C. Staley]

That's a new one to me.  I'm with Kelly, positive is positive as long as it matches the forward type.  If not, let the investigation begin!

[galvania]

I would just be a bit suspicious if say there was a + reaction with A1 cells and 4+ with B cells in an apparent group O - or vice versa; or very weak reactions in a young healthy adult.....a bit of common sense required, that's all

Edited May 2, 2021 by galvania
clarification

[yan xia]

I'm with galvania, we have identified a lot of subgroup patients based on the weaker reverse reactions.

Such as A2,A3, Ax, Ael, Aend, and the same the Bsubgroup

Edited May 3, 2021 by yan xia

[yan xia]

"2.7.6 Ael

Under usual conditions Ael cells are not agglutinated

by anti-A or -A,B, although they do bind these anti

bodies, as demonstrated by adsorption and elution

[298,337–339]. Saliva from Ael

secretors contains

H, but no A substance. Serum from Ael individuals

usually contains anti-A1 and may also contain an anti

body that agglutinates A2

cells [337,339]. No A

transferase has been detected in Ael serum or red cell

membranes [232,287–289]. Serum H-transferase is

weaker than that found in A1 or A2 serum [289]. No

example of Ael was found in testing 150000 French

blood donors [283], but fifive were found among

400000 Chinese from Taiwan [328]. Ael appears to be

inherited as a rare gene at the ABO locus [337–339].

As a result of allelic enhancement (Section 2.10.2),

AelB cells may be weakly agglutinated by some mono

clonal anti-A and may resemble B(A) phenotype [340]"

The text above comes from Danels' HUMAN BLOOD GROUPS the second edition, page 36

If we just look at the forward group , we may identify it as type O, but because it has weaker anti-A, we do think it is not a normal reaction ,so we will do further  investigation ,and then find out it has weak A antigens. It is important for transfusion and organ transplantation.

 

 

Edited May 3, 2021 by yan xia
typo