29 July 2019 (Monday) - Pos or Neg?
At the weekend I had an interesting case. Two samples from the same patient which the analyser grouped both as “A”, but with an indeterminate Rh group. I performed the groups (both long groups and check groups) and made both A Rh(D) Negative. But I looked closely at the analyser plots. Was there something in there?
The standard operating procedure says that the anti-D reagent should be used macroscopically, but under the microscope was some very small agglutinates.
Reference to SPI-CE came up with the patient who had been tested from another hospital. They were known to have a weak Rh(D). A *very* weak Rh(D).
Now… had there been analyser failure and had I been working using manual techniques I would have called this patient Rh(D) negative. For a transfusion point of view this would have been fail-safe as I would have transfused Rh(D) negative blood. However if this had been an ante-natal patient I might have issued anti-D.
I’ve been fretting about this…
There’s more on weak D and D variants that you can read by clicking here…