A comparison of the Aplysia lectin anti-I specificity with human anti-I and several other I-detecting lectins

BACKGROUND: Lectins displaying blood group specificity are important for bl ood group typing and antigen recognition;Their use in blood banks is especi ally widespread in situations where there is a shortage of specific antiser a. This report describes the efficiency of Aplysia gonad lectin as reliable reagent for the detection of I antigen, which is common on adult human cel ls but reduced in fetal, newborn, and rare adult red cells. STUDY DESIGN AND METHODS: The selective hemagglutinating activity of the Ap lysia lectin was compared with that of human anti-I and several I-reactive lectins, including two plant lectins, one galactophilic microbial lectin, a nd bovine spleen galectin. RESULTS: The comparison has revealed that Aplysia gonad lectin, like human anti-I, strongly agglutinates and adsorbs to adult I-positive red cells, di fferentiating between them and fetal or rare I-negative adult red cells (al though with less of a difference). In contrast to the plant and microbial l ectins examined, its I-affinity does not depend on the presence of ABH or P system antigens and it clearly detects higher I antigen expression in O-h red cells. The hemagglutinating activity of Aplysia lectin as that of all t he I-detecting proteins is enhanced at 4 degrees C, but unlike the human an ti-I Aplysia lectin-induced hemagglutination is stable at room temperature. CONCLUSIONS: The Aplysia lectin is a reliable anti-I reagent, which strongl y agglutinates I-positive adult human red cells irrespective of their ABH o r P system antigens. This lectin is usable at room temperature.