Anti-T haemolysins: the effects of sialic acid removal and 2-aminoethylisothiouronium bromide treatment of erythrocytes on immune lysis.
OBJECTIVE
Intravascular haemolytic reactions are reported in red-cell T-activated patients after blood transfusion. The relationship between T antigen antibodies present in normal plasma and these reactions remains unclear. In this study, we assessed the haemolytic activity of T antibodies in vitro in comparison with anti-A/B antibodies.


METHODS
We established a haemolysis assay based on treating target red-blood-cells (RBCs) with 2-aminoethylisothiouronium bromide (AET). Two hundred and seven blood donor sera were analysed for anti-T, anti-A/B haemolysins and anti-T agglutinins.


RESULTS
Anti-T haemolysins were found in 4 (1·9%) blood donor sera using a standard haemolysis method and in 174 (84%) samples using AET-treated RBCs. Haemolysis correlated with agglutination titres (P<10(-7) ). With both methods, anti-T haemolysins were much weaker than anti-A and anti-B haemolysins. Gradual desialylation of RBCs showed a correlation between sialic acid level as indicated by agglutination with Sambucus nigra lectin and anti-T mediated haemolysis that was significantly increased (fold 2·4) independently of T antigen expression.


CONCLUSIONS
These data indicate that, in vitro, anti-T-mediated haemolysis depends primarily on the degree of desialylation of target RBCs. They suggest that the haemolytic activity of T antibodies-containing human sera is usually weak and may only become significant in the very rare setting of a profound desialylation of RBCs.
Etablissement Français du Sang Ile de France, Cochin Hospital, 33 rue du Faubourg Saint-Jacques, Paris, France. nicolas.burin-des-roziers@efs.sante.fr
N Burin
NB
des Roziers
G
G
Bodivit
P
P
Chadebech
R
R
Nzouakou
P
P
Bierling
F
F
Noizat-Pirenne
D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood / Q000276:immunology*; D001787:Blood Group Incompatibility / Q000097:blood / Q000276:immunology*; D004912:Erythrocytes / Q000276:immunology* / Q000378:metabolism; D005260:Female; D006461:Hemolysis / Q000187:drug effects / Q000276:immunology; D006801:Humans; D007518:Isoantibodies / Q000097:blood / Q000276:immunology*; D008297:Male; D019158:N-Acetylneuraminic Acid; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D000338:beta-Aminoethyl Isothiourea / Q000494:pharmacology*
D015295:Antigens, Tumor-Associated, Carbohydrate; D007518:Isoantibodies; D011837:Radiation-Protective Agents; D000338:beta-Aminoethyl Isothiourea; C016467:Thomsen-Friedenreich antigen; D019158:N-Acetylneuraminic Acid