R1R1 patient with anti-G?

[Beth Eades]

I have a sample from a patient with a previous history of warm auto antibodies. He is Opos and his phenotype is C+ c- E-; K-; Fy(a-b+); Jk(a+b+); S- s+. The screen (gel )this time is 1+, w+, 0 and AC is 3+. The DAT is 2+ with Poly and IgG, neg with C' and saline. The eluate is a 4+ panagglutinin. The panel (gel) shows all D+C+ and D-C+ cells as 1+ and D+ C- cells as vw+. All D-C- cells are negative. Phenotypically matched cells are 1+. Our policy is to give Rh and K matched for warm autos but if he has an allo anti-G, couldn't this cause a severe hemolytic reaction? I know I can differentiate using adsorbtion/elution studies. If it's an anti-D, -C, then it's auto and I can give R1R1 K-. If it's an anti-G, it could be auto or allo, right?

[Malcolm Needs ☆]

I have a sample from a patient with a previous history of warm auto antibodies. He is Opos and his phenotype is C+ c- E-; K-; Fy(a-b+); Jk(a+b+); S- s+. The screen (gel )this time is 1+, w+, 0 and AC is 3+. The DAT is 2+ with Poly and IgG, neg with C' and saline. The eluate is a 4+ panagglutinin. The panel (gel) shows all D+C+ and D-C+ cells as 1+ and D+ C- cells as vw+. All D-C- cells are negative. Phenotypically matched cells are 1+. Our policy is to give Rh and K matched for warm autos but if he has an allo anti-G, couldn't this cause a severe hemolytic reaction? I know I can differentiate using adsorbtion/elution studies. If it's an anti-D, -C, then it's auto and I can give R1R1 K-. If it's an anti-G, it could be auto or allo, right?

Wrong, I'm afraid; it's got to be an auto.

All C+ and D+ red cells, with very few rare exceptions, are G+. Even if this patient has the amazingly rare genotype of DCe/---, the DCe haplotype will automatically mean that he or she is also G positive.

That having been said, auto-anti-G, in itself, is very rare, and I would suspect that it is a specificity that is mimicking auto-anti-G, rather than a true anti-G (from the results you have obtained with your eluate).

Have you tried testing group O, rr, DAT negative cord red cells against the patient's plasma by IAT? These results may or may not give a clue to the true specificity.

I do not think that there is any danger of R1R1 causing a severe haemolytic transfusion reaction, as the antibody, whatever the specificity appears very, very weak, but if you are worried, you could cover the patient with IVIG prior to transfusion.

:blowkiss::blowkiss:

[Beth Eades]

Thank you for the info. Unfortunately, I do not have access to cord blood since I work in a blood manufacturing facility instead of a hospital blood bank. Because of privacy issues, local hospitals cannot share these with us anymore. I did, however, use papain treated group O rr donor cells to perform one adsorption and the antibody was significantly reduced. After the adsorption, I had only very weak reactions with D+C+ cells. I sent R1R1 units which were 1+ reactive with the unaltered plasma (vw+ with adsorbed plasma) as compared to a 3+ auto control. Thanks again. I appreciate your input.

[Yanxia]

Have you tried testing group O, rr, DAT negative cord red cells against the patient's plasma by IAT? These results may or may not give a clue to the true specificity.

:blowkiss::blowkiss:

Malcolm, would you tell us what is the meaning of use this type of cord cells?

[Malcolm Needs ☆]

Cord rr DAT- red cells have a high expression of the LW antigen.