Complement-binding anti-Jka not detectable by DiaMed gels.
BACKGROUND
An anti-Jka was not detectable by the DiaMed-ID Micro Typing System but was strongly reactive when tested using other indirect antiglobulin test (IAT) methods. However, it was detectable in the DiaMed-ID system when the recommended diluent ID-Diluent 2, was replaced by other low ionic Strength saline (LISS) solutions. This led us to believe that the problem lay with the ID-Diluent 2.


METHODS
The anti-Jka was investigated using various low ionic strength diluents in the IAT against both polyspecific and monospecific antiglobulin reagents. We tested the ID-Diluent 2 for its ability to inhibit complement activation, and bind calcium.


RESULTS
The anti-Jka was shown to be a 'complement-only' binding antibody that reacted in all IATs performed except when tested with ID-Diluent 2. The ID-Diluent was shown to prevent haemolysis of ABO lytic antibodies, and further testing shows that it binds calcium.


CONCLUSIONS
The use of a diluent which prevents haemolysis and binds calcium in an IAT system that contains anti-complement as well as anti-IgG must be questioned.
O'Brien
P
P
Department of Haematology and Blood Transfusion, St. Vincent's Hospital, Dublin, Ireland.
Hopkins
L
L
McCarthy
D
D
Murphy
S
S
D000368:Aged; D000369:Aged, 80 and over; D001787:Blood Group Incompatibility; D001788:Blood Grouping and Crossmatching / Q000379:methods; D003298:Coombs Test / Q000379:methods; D005188:False Negative Reactions; D005782:Gels; D006801:Humans; D007518:Isoantibodies / Q000097:blood / Q000378:metabolism; D007667:Kidd Blood-Group System / Q000276:immunology*; D008297:Male; D011951:Receptors, Complement / Q000097:blood*
D005782:Gels; D007518:Isoantibodies; D007667:Kidd Blood-Group System; D011951:Receptors, Complement