Unsatisfactory Detection of an in vivo Haemolytic Anti-Vel by the Gel Test

Abstract

Background and Objectives: A patient experienced a severe haemolytic transfusion reaction. Neither the haemolytic property nor the specificity of the causative antibody had been sufficiently recognised when performing a microcolumn gel test. Materials and Methods: Subsequent to the transfusion reaction, the serological property and specificity of the causative antibody were analysed. Tube and gel test methods were compared, as were various reagent red cell specimens and their constituents. Results: A haemolytic anti-Vel was detected in the tube test. In contrast, the particular commercial gel test kit used did not reveal the haemolytic property or specificity of the antibody. Our experiments suggest that this was apparently due to the presence of EDTA in the low ionic strength saline solution of the test kit. Conclusion: In rare cases life-threatening haemolytic activity of an irregular blood group antibody may be undetected by a commercial microcolumn gel test kit in which EDTA is a constituent.

A Newly Recognized Blood Group in Domestic Shorthair Cats: The Mik Red Cell Antigen

“…Although LISS may enhance antigen-antibody binding by decreasing stearic hindrance, its use in gel column methodology is not without controversy in human blood banking, and the potential for error in compatibility testing exists. 31,32 Increased blood compatibility testing will likely identify even more red cell antigens in cats. a,15 A non-AB, non-Mik alloantibody and corresponding antigen likely caused the incompatible tube crossmatch results seen with the 2 additional research cats.…”

Anti‐Vel reactivity diminished by adsorption with rabbit RBC stroma

“…Anti‐Vel has been noted in some published reports to be difficult to identify 9,10 . Storry and Mallory 9 described an anti‐Vel involved in a fatal hemolytic transfusion reaction that was misidentified due to inappropriate use of prewarming and adsorption techniques.…”

Disruption of SMIM1 causes the Vel− blood type

“…Anti‐Vel is well known for its aggressive haemolytic activity in vivo as well as for its notorious recalcitrance in vitro . Notably, anti‐Vel masquerades as a ‘high‐titer, low‐avidity’ antibody that can easily be missed when performing an antibody screen without appropriate methodology (Neppert et al, 1998; Storry & Mallory, 1994; Sweeney, 2006). Furthermore, some individuals appear to express very low levels of the Vel antigen that can be challenging to detect, especially since anti‐Vel does not work well in adsorption‐elution studies.…”