Inverse expression of Pk and Luke blood group antigens on human RBCs

BACKGROUND: Luke (LKE) is a high-frequency RBC antigen, related to the P blood group system. A LKE-negative phenotype is found in 1 to 2 percent of donors and may be associated with increased P-k. Because P-k and similar glycolipids are receptors for shiga toxin on cell membranes, a LKE-negative phenotype could have implications for infections by Shigella dysenteriae and enterohemorrhagic Escherichia coli. STUDY DESIGN AND METHODS: Volunteer donors (n = 257) were serologically typed for LKE with a LKE MoAb, MC813-70. LKE-strong-positive, LKE-weak-positive and LKE-negative RBCs were analyzed for P-k, P, LKE, and shiga toxin binding by immunofluorescence flow cytometry, high-performance thin-layer chromatography, scanning densitometry, and high-performance thin-layer chromatography immunostaining. RESULTS: Among Iowa donors, 78.6 percent were LKE-strong-positive, 20.2 percent were LKE-weak-positive, and 1.2 percent were LKE-negative. There was an inverse expression of p(k) and LKE on RBCs. P-k expression was increased on LKE-negative RBCs and was associated with increased shiga toxin binding. A LKE-active glycolipid was identified in the ganglioside fraction of LKE-strong-positive RBCs. CONCLUSION: A LKE-negative phenotype is associated with increased expression of pk On RBCs. Differences in P-k and LKE expression may play a role in host susceptibility to infection with S. dysenteriae and E. coli