Weak Anti-B

[nancanne]

What do you do when you have a very weak Anti-B on the reverse type? We have seen this recently in 2 elderly patients. We are using the gel system now, but still had some cells and were able to do a tube type and get microscopic agglutination. We also had documentation that showed these patients as A in the past. But what do we do in the future when we no longer have cells? I would appreciate any help.

[L106]

Just curious..... You commented that in the future you would no longer have commercial Reverse Grouping Cells. Will you be using gel and not have any type of "back-up" method available?

[Malcolm Needs ☆]

Just curious..... You commented that in the future you would no longer have commercial Reverse Grouping Cells. Will you be using gel and not have any type of "back-up" method available?

Yes, I'd like to know that too, and what are you using for the reverse grouping in your gels?

:confused::confused:

[DAWNA1983]

Recommendation: Using the B cells for reverse grouping for gel, change the concentration from 0.8% to 3% and use the tube method to confirm the backtype.

Dawn Arnett, MT

[Deny Morlino]

Will you be using gel and not have any type of "back-up" method available?

This was how we operated once switching to gel for a few years as we were led to believe we would not need a back-up method when first beginning with gel. Shortly after I took over in blood bank we had a situation that would not allow us to provide cross match compatible units for a patient utilizing gel. We added tube method as a backup back into our protocol. I think a backup is a very good idea for the gel system.

Our use of the 0.8% solutions was such that we were very close to needing another set just prior to expiration. The change was made to 3% solutions. We dilute to 0.8% an aliquot of each solution daily. This limits the chances for contamination of the reagents, allows the primary vials to be returned to the refrigerator quickly limiting the time they spend at room temp thus reducing the chance for bacterial growth, etc., and saves us money compared to purchasing another set of 0.8% solutions. It also provides reagents for the tube backup when necessary. Just something to think about.

[leema]

What do you do when you have a very weak Anti-B on the reverse type? We have seen this recently in 2 elderly patients. We are using the gel system now, but still had some cells and were able to do a tube type and get microscopic agglutination. We also had documentation that showed these patients as A in the past. But what do we do in the future when we no longer have cells? I would appreciate any help.

Well, personally I would repeat the reverse group at 4C including an auto control using neutral card, most of the time the reaction is really enhanced :redface:

[Yanxia]

I noticed you mention they are elderly people, we think people elderly than 60 years old can get weaker reverse reaction, it is common.

[KE4JC]

I have seen this several times in elderly or immunocompromised patients - usually in type O and usually the anti-B drops first. Incubating either the gel card or the tube at 4C for 5-10 minutes before spinning will enhance the reaction.

Kathy E

MT(ASCP)SBB

:rolleyes: