Develop a solid-phase red cell adherence reagent kit for IgG unexpected alloantibody identification

Objective To develop a solid-phase red cell adherence(SPRCA) reagent kit for unexpected alloantibody identification. Methods A solid-phase carrier for bounding red blood cell(RBC) was prepared by coating microstrip with succinimide, then panel cell suspensions were dispensed to microwells to produce RBC monolayers, after that, 1×PBS(pH7.40) was used to lysis the RBC monolayer to form stroma monolayer. Prior to the drying procedure, drying medium suspension was added to microwell to protect stroma monolayer. The solid-phase microplate was successfully produced after the stroma had been dried in refrigerator at 4℃. IgG anti-E and anti-Fya with low titer were tested every two months with the reagent kit to observe its stability. Seventy-two plasma samples containing unexpected antibodies and 152 normal plasma samples were determined with SPRCA reagent kit and column agglutination technique(CAT). Performances including sensitivity and specificity of the two reagents were compared by paired chi-square test. Results RBC stroma monolayer could be attached well on microwell bottom coated with succinimide. Drying medium suspension could provide effective protection for stroma monolayer. Both IgG anti-E and anti-Fya with low titer were determined well by the reagent kit during the storage period. Of the 72 positive samples, 70 were identified correctly by SPRCA kit and 71 by CAT [Sensitivity:97.22%(70/72) vs 98.61%(71/72)]. Of the 152 negative plasma samples, 149 were correctly detected by SPRCA kit and 152 by CAT [Specificity:98.02%(149/152) vs 100%(152/152)]. Paired chi-square test showed no significant differences between the two reagents (P>0.05). Conclusion A SPRCA reagent kit for IgG unexpected antibody identification had been developed successfully.