An explanation and the clinical significance of the failure of microcolumn tests to detect weak ABO and other antibodies

Abstract

Shear forces are proposed to explain the failure of antiglobulin and 'neutral' (no antiglobulin) microcolumn tests at 37 degrees C to detect weak ABO incompatibilities and other weak antibodies, clearly detectable by spin-tube methods. These shear forces can be minimized in a microcolumn test using a biphasic centrifugation phase. Although this biphasic test is not suitable for routine use, it may be of use as an investigational method for reference laboratories. This failure of microcolumn test to detect weak ABO incompatibilities is of little clinical significance as the antibodies are dubiously active at 37 degrees C.

A new approach to detection of incomplete antibodies using hydrogel chromatography medium

“…In addition, the expense of the MGIA assay is cost prohibitive for mainstream clinical use. In the solidphase red cell adherence test, the short viability span of indicator cells is the key factor prohibiting this method from being widely used [5,[8][9][10][11].…”

K, Fya, and Jka phenotyping of donor RBCs on microplates

“…For K phenotyping, agreement was achieved in all cases, except with the DiaMed‐ID gel test, which gave 3 (/1031; 0.3%) indeterminate results and 1 (/1031; 0.1%) false‐negative result (Table 1). It has been proposed that, because of disruptive shear forces, weak agglutinates may be broken down as they are driven through the gel matrix by centrifugal forces, 22 and low K site density of these four samples may explain the outcome, although it was not seen with the other two methods. Other explanations that must be considered are the possibility of technician error or a batch‐to‐batch variation in the gel cards.…”

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

“…An additional benefit of this system over the conventional tube test is the improved detection of drug-dependent, low-avidity autoantibodies against red blood cells without the need of any drugs being added to the washing solution [3]. Some problems with the gel test have been reported [1, 2]suggesting that it may lack sensitivity for demonstrating AB0 incompatible crossmatches [4, 5]. We report here a failure of the gel test to detect and identify a clinically relevant complement activating anti-Vel, probably due to the inclusion of EDTA in the medium of a commercial test kit.…”