Titre for Anti A and Anti B

[khalidm3]

How to perform titre for Anti A and Anti B? Just titre serum and run with known reagent A and B cells or some special procedure? Please let know the reference like AABB Technical Manual or some else?

Thanks

[Malcolm Needs ☆]

It rather depends upon why you are doing the titre.

If you just want to know the titre as a matter of interest, then, yes, you just titre the plasma rom neat to, say, 512, and add the appropriate ABO red cells and get the titre like that.

If, on the other hand, you are performing the titre for reasons such as an ABOi renal transplant, then your renal surgeon may want to know both the IgM and the IgG titres, in which case you would need to perform the titre on untreated serum (as above), but also on serum that has been treated with a reducing agent, such as 0.01M dithiothritol, so that the IgM J chains are disrupted, and then perform the titre by IAT using a monospecific anti-IgG reagent.

[khalidm3]

Thanks! The physician's order is for a neonate.

[Malcolm Needs ☆]

In that case, I think you need to perform an ABO titre on the maternal sample, using DTT-treated serum, as the important thing in ABO HDFN is, of course, the maternal ABO IgG titre - although, having said that, there is little correlation between this titre and the severity of HDFN.

[att]

It rather depends upon why you are doing the titre.

If you just want to know the titre as a matter of interest, then, yes, you just titre the plasma rom neat to, say, 512, and add the appropriate ABO red cells and get the titre like that.

If, on the other hand, you are performing the titre for reasons such as an ABOi renal transplant, then your renal surgeon may want to know both the IgM and the IgG titres, in which case you would need to perform the titre on untreated serum (as above), but also on serum that has been treated with a reducing agent, such as 0.01M dithiothritol, so that the IgM J chains are disrupted, and then perform the titre by IAT using a monospecific anti-IgG reagent.

We recently titered 40 O plateletpheresis donors and found that the DTT treated samples correlated well with titers that were incubated at 37C for 60 minutes and testing at IAT using

anti-IgG. We are still reviewing all the data but that was one of our noted results.

[Malcolm Needs ☆]

We recently titered 40 O plateletpheresis donors and found that the DTT treated samples correlated well with titers that were incubated at 37C for 60 minutes and testing at IAT using

anti-IgG. We are still reviewing all the data but that was one of our noted results.

That is really useful to know att, as this shows good correlation of one method to another, but I think there you were probably looking for high-titre ABO antibodies, in case they were transfused to a patient of a different ABO group (e.g. giving group A platelets with the plasma containing anti-B to a group AB patient), and this would probably "work" for ABO HDFN and maternal ABO antibodies (although, it would not be diagnostic until there is proof of maternal IgG ABO antibodies - and evn then, not actually diagnostic, unless the same ABO antibody can be eluted from the baby's red cells and the baby is symptomatic.

In the case of an ABOi renal transplantation, however, we are looking at quite low titres of ABO antibodies, and there can be quite a big difference between the IgM titre and the IgG titre that is exacerbated by the fact that the titres are low.

[Mabel Adams]

I have been asked to titrate ABO antibodies as a cheap screening test for an immune deficiency due to lack or decrease of immunoglobulins (isohemagglutinin titer). This, of course, doesn't really work for neonates since they don't make normal amounts of ABO antibodies and any in their system would be the mom's but if someone was reading a textbook they might order it on a baby inappropriately. Malcolm's take is more likely but I thought I would throw this out there.

[K@The_Dresdeners]

When we have cases of AB0i renal transplantation we titre the patients plasma against known reagent red cells and against donor red cells by manual testing (gel-card,37°C IAT and 20°C NaCl) and Galileo (MTP for IgM and SC for IgG). Works fine. :-)

[Everett9239]

What is the difference between this test and a quantitative IgG or IgM.  We are looking to discontinue this test at our laboratory as we only get 1 every 2-3 months, but I want to make sure there is an alternative available for the physician that truly wants it.  At this time, we do not see transplant patients and do not do transplant surgeries.

[Auntie-D]

I don't understand why they request these tests for neonates - it doesn't affect the treatement. At the end of the day if the bilirubin is high they use UV, if the DCT is pos they use UV and IgG, if the bilirubin is REALLY high they exchange transfuse. All other testing is just out of interest and frankly, pointless for routine neonate workups.

[galvania]

I would be a bit careful if the baby has a really high bili.  It's too easy to assume that it's due to ABO just because the antibody screen is negative.  But I've seen a couple of cases where mum has had an antibody to an LFA present on her partner's cells, second baby etc etc