Software Processes for the Antibody Screen

Based on the previous software post, I use the antiglobulin test algorithms to construct the antibody screen ABS, namely an INDIRECT antiglobulin test, i.e. incubate reagent red cells with the donor or patient’s plasma and then perform the DAT.  At HMC Doha and at NGHA in Riyadh, we mainly used three cell screens (no pooled cells for donors). The reactions could be machine-read (we had the interface) but the interpretation of the specificities found was done manually.

Donor ABS:

We screened all donors for irregular antibodies.  I disqualified most donor with non-negative screens from donation (my personal preference).  However, for nonspecific antibodies, I might elect to discard the current collection and then reassess the donor’s status at the next encounter.  Not everyone would agree with this most restrictive approach but I would not use the platelets or plasma in such situations.  I also did not use the donor RBCs, even though they were in SAGM—but I could elect to override this decision in Medinfo if there were a rare blood group (e.g. r’r’).

Example #1 (following) shows a sample donor ABS process:

Patient ABS:

Excluding emergency release, if the patient did not qualify for the electronic (computer) crossmatch, then the AHG crossmatch was required.  A three-cell antibody screen including R1R1, R2R2, and rr RBCs was used that usually included cells homozygous for the Kell, Duffy, Kidd, MNS antigens.  For any case with a non-negative antibody screen, either donor or patient, an antibody identification was performed.

Note that I did not use any other software to make antibody identifications.  I required my technologists to be proficient in identifying basic and intermediate-level testing.  The actual antigen makeup of each lot number of antibody screen or identification panel was NOT stored in Medinfo.  We scanned the antibody screen and panel workups and could store those in Medinfo.

Example #2 (following) shows a sample patient ABS process:

Patient ABS Fix for Interface Regression Caused by HIS:

Regretfully, with a software update from the hospital information system HIS vendor, a major regression occurred.  It would not discard results from Medinfo if more than one antibody result (e.g. anti-E and anti-c) was sent back.  We could see the results in Medinfo, but those outside Transfusion Medicine could not see antibody results.  The entire interface for antibody identification had to be rewritten so that the HIS would see each result uniquely and thus all results could be sent back to it.

Regression Example:

Anti-Kell sent from Medinfo:  one antibody result, HIS would store and show this result.

Anti-E and anti-c sent from Medinfo:  No antibody results shown, both results kicked out.

Regression Fix:

Anti-E sent as Method Type1-Antibody 1 and anti-c sent as Method Type 1-Antibody 2:  both results displayed in HIS.

Example #3 (following) shows the regression fix.

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