Hemagglutination by Lectins in Friedreich's Ataxia

Abstract

Coded erythrocyte samples from ten individuals with Friedreich*š ataxia, from parents of five of these individuals, and from five unrelated control individuals were subjected to lecţin agglutination tests at three temperatures; before and after trypsinization; and before and after treatment with echinocyte-producing sodium salicylate and stornato^ cyte-pröducing tetracaine followed by shape-fixation with glutaraldehyde. The aġglutinins tested were the polycationic poly-L-lysirie (PLL) and four lectins with different saccharide specificities: soybean agglutinin, wheat germ agglutinin, Ufex europeus agglutinin (VEA) and concana-valin A. Altogether, over 45,000 individual test wells were scored, the status of each blood donor with respect to diagnosis being disclosed to the experimenters only after all results were tabulated. The majority of these tests revealed no significant difference among the three groups of blood samples. A few tests did reveal statistically valid (p<0.0l) differences between groups, the most significant of which were the following: Trypsin ized control RBC were more sensitive, on average, to agglutination by VEA (fucose-inhibited) than were RBC of ataxies or their parents. Non-trypsinized control “stomatocytes” were less sensitive, on average, to agglutination by PLL than were those of ataxies or their parents. Trypsinization appeared, on average, to sensitive control but not ataxia or parent RBC to PLL-agglutination. Other differences of borderline (p-0.01-0.025) or near borderline (p = 0.025-0.05) significance were also noted. None of the statistically significant, Friedreich's ataxia-telated differences in median agglutination titers were large, the greatest being about threefold, and in every case the ranges of individual titers within the differing groups overlapped. Thus, none of these tests at present offers a method of pre clinic al diagnosis or carrier detection, and only further tests can establish whether even the differences observed in the present series of tests are reproducible. © 1979, Canadian Neurological Sciences Federation. All rights reserved.