Biannual/annual quality checks

[Zana R]

Hello,

What does everyone do for biannual/annual checks, besides carryovers and manual vs automated correlations? We only do prenatal testing (blood typing, antibody screen, ID and titer), no transfusions. 

Thanks in advance!

[Cliff]

Can you give us more background?  Is this for a particular accrediting agency?  We are accredited by AABB and TJC and inspected by FDA.  Every 6 months we do a method comparison.  ABO, RH, ABS between tube and the instrument.  All ABS methods in use.  Molecular Ag typing and serologic.  Is that what you are asking?

Thanks, and welcome to the site!

[Malcolm Needs ☆]

4 hours ago, Cliff said:

Molecular Ag typing and serologic.

Sorry Cliff, but this is wrong terminology, and so it is completely impossible to compare one with the other.

There is no such thing as "molecular antigen typing".  At the molecular level, what is being examined is not an antigen, but the gene, or part of gene, that predicts what antigens may or may not be expressed on, in this case, red cells.  This prediction may not always be accurate.  For example, foetal RHD genotyping looks at certain parts of the RHD gene, rather than a full RHD gene sequencing, and so, if a mutation is not within the areas of the RHD gene probed, there may be either a false positive or, much worse, a false negative, where the foetus is predicted to be D Negative, but is actually D Positive.

On the other hand, no serological technique can be regarded as 100% "accurate".  For example, not all polyclonal anti-Fyb reagents will detect the Fyx antigen, and I have been asking for ages now, with no definitive answer, whether the newer monoclonal anti-Fyb reagents will detect the Fyx antigen.  Not all antigen typing reagents will detect all antigens by all techniques, which is why it is so important to follow the insert instructions for the particular grouping reagents.

The above is a very long winded way of saying that it is IMPOSSIBLE to compare some things, because it is like comparing apples to oranges.  Sadly, I don't believe that all of the accrediting inspectors understand this.  Even worse, I have had experience where such inspectors will ignore these truths, even when presented with chapter, verse and citations as to why it is true, and blindly go ahead with their own views, and "ping" people, thus causing excessive amounts of work for everyone to defend themselves against rank stupidity on their behalf.

RANT OVER!

[Cliff]

I feared the wrath of Malcom when I posted this. 

In the US, it is expected that we compare different methods to ensure the clinician is receiving the same result regardless of how we choose to get there.

In our case, we perform molecular genotyping and serologic phenotyping.  We select a few antigens to compare, keeping in mind the shortfalls you describe.  

Often, tasks must be performed for no other reason than to satisfy an inspector, and we do the best we can to ensure we add value to everything we do.