Antibody titers on Pregnant women

[PHYLLIS]

We are currently using Gel for our antibody titers with a diluent of 0.6% albumin on pregnant women. I recently read in the AABB Technical Manual that albumin should not be used when titering specimens from pregnant women. What does everyone else use?

[Joanne P. Scannell]

Titers are done using tube testing and NO enhancement medium. That is what is in the AABB Technical Manual and that is the method the literature had referred to when setting up 'guidance' for the obstetricians, eg. significant titer, two-fold changes, etc.

As far as I know, 'we' (the blood bankers of the world) are still in the validation stages of trying to correlate tube titers with gel titers with not much overwhelming success. Tube vs gel are very different mechanisms ... can we really expect to correlate? And are the MD"s really aware of the difference when looking at the report?

If you look at the CAP Surveys for titers, there is a vast difference in titers tube vs gel. Grading is different, titers are different ... is the 'two tube' significant difference really valid for gel?

So then, why are 'we' using gel when its not supported by the literature that was written based on tube testing with no enhancement? Until the literature catches up ... what is the real significance of gel titer reports?

[Trek Tech]

An article was published, and referenced in the CAP ABT-B 2008 Antibody Survey. A method was published in an effort to reduce the variation in performance of titers. It was published in the July 2008 Archives of Pathology and Laboratory Medicine. It is available, free of charge at the website for that publication. I have attached a copy of this article which I downloaded as a PDF.

Care must be taken when comparing from one laboratory to another due to widely discrepant methods which vary in diluent, incubation and strength of reaction.

It is an interesting read. Our laboratory is following the published method which is described in the article.

Reducing the Variation in Performance of Antibody Titrations.pdf