Question about A subgroup

[AmyL86]

Hi, think this is my first post here. My name is Amy, just to share a tidbit with everyone.. 

 

I had a patient today that typed as such:

 

Forward type:

Anti-A = 2+

Anti-B = 4+

Anti-D = 4+

 

Reverse type:

Acell = 0

Bcell = 0

 

Anti-A1 = 0

 

87 y/o male, oncology patient. 

 

I was reviewing reports for the BB Supervisor, when I saw the weak Anti-A in forward, I investigated and got the aforementioned results.

The overnight tech released A+ blood on this patient, but no symptoms of transfusion reaction.

I notified my pathologist and switched the patient to O+ in light of the absence of A1 antigens.

 

my question:

I am surprised to see that the A cell in the reverse type is coming up negative. In my texbook, type discrepancies such as this are accompanied by the presence of anti-A1 in the patient's plasma. Here, I don't have a demostrable Anti-A1 and I am wondering if the antibody is naturally occuring, and in what frequency?

 

[SMW]

Hi Amy--thanks for sharing your case.  The results you report suggest the patient may be an A2B.  The overwhelming majority of A2B (and A2) individuals do NOT produce an anti-A1, which if present is generally naturally occurring as you noted.  Although anti-A1 is somewhat more frequent in A2B than A2 individuals, in the absence of a 37C reactive anti-A1, it is completely safe to transfuse group AB, A or B blood and is actually preferable to using group O units.  The use of group O Red Blood Cell units would not be expected to be harmful to the patient, however since group O units are generally in limited supply, their out-of-group use is judicially reserved for those patients that must receive group O units.

[David Saikin]

What SMW said . . .

[AmyL86]

Okay.

 

Why are we giving A type units? Can't an A₂ subtype form an allogeneic anti-A_1?  If so, should we continue to transfuse the patient with A type blood until they develop an antibody? 

[Sophie1210]

Anti-A1, natural or allogeneic, is not considered clinically significant unless it's reacting at 37C. The vast majority of patients with anti-A1 only react at IS.

 

In my opinion, this is just like any other patient. We don't worry about their phenotype and what antibodies they could form until they form one. If this were my blood bank, I would tell the techs to continue to transfuse AB or A blood to the patient.

[Yanxia]

Hi, think this is my first post here. My name is Amy, just to share a tidbit with everyone.. 

 

I had a patient today that typed as such:

 

Forward type:

Anti-A = 2+

Anti-B = 4+

Anti-D = 4+

 

Reverse type:

Acell = 0

Bcell = 0

 

Anti-A1 = 0

 

87 y/o male, oncology patient. 

 

I was reviewing reports for the BB Supervisor, when I saw the weak Anti-A in forward, I investigated and got the aforementioned results.

The overnight tech released A+ blood on this patient, but no symptoms of transfusion reaction.

I notified my pathologist and switched the patient to O+ in light of the absence of A1 antigens.

 

my question:

I am surprised to see that the A cell in the reverse type is coming up negative. In my texbook, type discrepancies such as this are accompanied by the presence of anti-A1 in the patient's plasma. Here, I don't have a demostrable Anti-A1 and I am wondering if the antibody is naturally occuring, and in what frequency?

I think it like AmB , AmB will not form anti-A1, and the reaction with anti-A is weak , but A2 type with anti-A reaction is4+or 3+stronger.

If this patient in my lab I will transe him with B or O type washed cells, and If AB type is compatible both in Is and IAT and poly, I will transfude AB cells.

There is one case of anti-A1  which is not react in gel IAT, but react in IS caused fetal hemolysis in our country , so I will pay more attention to it.