Laser incubation for the rapid detection of red cell alloantibodies in human blood samples.

Abstract

Pre-transfusion antibody screening requires the detection and identification of immunoglobulin G (IgG) antibodies against red blood cells (RBCs). Using the indirect antiglobulin test (IAT), plasma-RBC solutions are incubated at 37°C in gel cards, typically by heating block technology. Here, we apply the newly developed laser incubation method to detect RBC alloantibodies in the plasma from human donors. Donated human plasma samples (N=128) containing clinically significant IgG antibodies directed against Rh (D, C, c, Cw and E), Kell (K and Kpa ), Duffy (Fya and Fyb ), Kidd (Jka ) and MNS (S) blood group system antigens were tested by the indirect antiglobulin test (IAT). Samples were heated to 37°C by infrared laser (980 nm) for incubations of up to 5min. Samples were also incubated in a heating block for comparison. When heating by laser, the presence of an alloantibody is detected after only a 1-min incubation for 96% of samples. No samples required longer than 3min of laser incubation in order to detect the antibody. For all samples, incubation by laser gave the same or stronger result within 5min. No samples required longer than 5min to achieve an equivalent result to that of the 5-min heating block incubation. The laser was not found to damage cells or antibodies. Laser incubation provides comparable results in shorter time frames than the heating block. Laser incubation can rapidly detect even very weak antibodies.