Fading D type

[John C. Staley]

We have a young lady (DOB 1978) we have typed 4 times in the last three years. The first D type was 3+, the second 2+ and the third 2+w, two days ago the ABS 2000 typed her as D negative and a manual repeat found a 1+w on IS and 2+ at AHG. The first three types were manual. All typing was done with either series 4 or series 5 monoclonal anti-D from Immucor and the ABS2000 uses both. The only diagnosis we've had on her is pregnant. We've seen no change in our daily QC for the reagents. Any one have any ideas what's going on here?

Thanks

John

[Dawn]

Wow John, that is really weird. We usually see the opposite. If you were using Novoclone for the first few types and are now using series 4 or 5 from Immucor this would be perfectly understandable. We used Novoclone a few years back and all the Rh positives were 4+. Our Rosys often misses weaker Rh positives. I would suspect that this patient is a partial D. If your transfusion service would alter transfusion recommendations based on such information then you might want to pursue a more detailed investigation.

[S.Hunt]

John,

Are you following the manufacturers package insert? We use ORTHO Bioclone and have noticed IMMEDIATE SPIN is not mix and read but the manufacturer recommends a minimal incubation before spinning. My other question would be - could she be using some herbal medicines not recorded. We have had some similar situations with transplanted 60's children up here in Maine and found in one case it was the result of an herbal mix a patient was taking recommended by her midwife.

Good Luck