Light diffraction of suspended particles method (light scattering) applicable to inhibitory capacity in relation to ABO epithopes in Ascaris lumbricoides

Previous experiences have shown ABO epithopes presence in Ascaris lumbricoides. The aim of this work was to determine the inhibitory capacity of A. lumbricoides in relation to ABO epithopes by light diffraction of suspended particles method (Light Scattering). Eight parasite extracts (AE) from B Group patients and 4 AE from A Group patients (AE with and without ABO epithopes) were selected. The AE were faced against dilutions of monoclonal antibody (anti A or anti B). The exceeding antibody was neutralized with isogroup erythrocytes. The optical extinction of the agglutinates was measured. The agglutination percentage versus antibody dilution was graficated. Titre-50 (T-50) was calculated. Inhibitory Power (IP) was defined as the relation between T-50 of the studied extract and T-50 of the control extract The protein concentration of the AE was determined to express IP/ protein gram. IP values for the AE with ABO epithopes were greater than 1. The IP/ protein gram made it possible to obtain representative values of the ABO epithopes amount in each extract I. The utilization of this method enabled corroboration of the ABO epithopes presence and comparison of the inhibitory capacity for these epithopes between different extracts.