Quantitative Detection of Weak D Antigen Variants in Blood Typing using SPR

Abstract

Modern techniques for quantifying blood group antibody-antigen interactions are very limited, especially for weaker interactions which result from low antigen expression and/or partial expression of the antigen structure. Surface plasmon resonance (SPR) detection is often used to monitor and quantify bio-interactions. Previously, a regenerable, multi-fucntional platform for quantitative RBC phenotyping of normal antigen expression using SPR detection was reported. However, detection of weaker variants were not explored. Here, this sensitivity study used anti-human IgG antibodies immobilized to a gold sensor surface to two clinically important types of weaker D variants using SPR; weak D and partial D. Positive pre-sensitised cells bind to the anti-human IgG monolayer, and the response unit (RU) is reported (>100 RU). Unbound negative cells are directly eluted (<100 RU). Weak D cells were detected between a range of 180–580 RU, due to a lower expression of antigens. Partial D cells, category D VI, were also positively identified (352–1147 RU), similar to that of normal D antigens. The detection of two classes of weaker D variants was achieved for the first time using this fully regenerable SPR platform, opening up a new avenue to replace the current subjective and arbitrary methods for quantifying blood group antibody-antigen interactions.

Recent Progress in Optical Biosensors Based on Smartphone Platforms

“…A SPR-based platform has been reported by Lepage et al for real-time detection of influenza virus [ 40 ]. Then et al presented an assay for quantitative detection of weak d antigen variants in blood by using the SPR technology [ 41 ]. SPR technology is also used in measuring the relative permittivity of a physiological solution [ 42 ], measuring antibodies binding to a functionalized sensing element [ 43 ], and quantitative determination of multiple tumor markers [ 44 ].…”

Modified stall‐side crossmatch for transfusions in horses

“…Change in sensitivity for the detection of antibodies could be due in part to the subjectivity of the reading (although less likely here because of the level of training and the fact that any trace of a positive reaction is considered positive). Inevitable changes over time in the panel of horses and donkeys used may have been associated with different levels of antigen expression, as it is recognized for dog erythrocyte antigen 1 in dogs19 or D antigens in humans,20 which could change the level of detection for some antibodies with weaker affinity.Finally, shipping conditions could affect the detection of less stable antibodies, and despite our best efforts to standardize the process for all research and hospital samples, blood and serum still had to be shipped across borders, which comes with potential delays.The detection of incompatible crossmatches predicted that compatible could either represent false positive results or a true increased sensitivity of gel-based crossmatching techniques. In either case, this would not have put the recipient at risk.…”

A multi‐centre study on the performance of the molecular genotyping platform ID RHD XT for resolving serological weak RhD phenotype in routine clinical practice

“…Some potentially immunogenic D variants such as DEL, partial D and some weak D types, which are very weakly expressed or only detectable by adsorption‐elution techniques, are frequently undetected by routine serological testing . In this regard, a considerable amount of literature has been published on the possible consequences arising from RhD typing errors.…”