SUMMARYThe P System antigens have been detected in numerous parasites, bacterias and viruses, nevertheless the clinical significance is still unknown. The aim was to study the presence of P 1 antigenic determiners in A. lumbricoides extracts by means of the use of 6 different monoclonal antibodies of well-known concentrations and Ig class. We worked with 14 A. lumbricoides extracts. Inhibition Agglutination Test was made in a bromelin enzymatic medium and 4 ºC temperature. Titre, Score and Sensitivity Parameter were determined for each monoclonal antibody against red cells suspension used as revealing system. Ten extracts inhibited the agglutination of all anti P 1 monoclonal antibodies. The 4 remaining extracts only inhibited the agglutination of some of them. It is demonstrated that the extracts have P 1 activity. This activity is independent of titre, Score, Sensitivity Parameter, concentration and Ig class and it depends on the epitope at which the monoclonal antibody is directed.
KEYWORDS: Ascaris lumbricoides; P SystemThe P blood group System was discovered by LANDSTEINER & LEVINE in 1927 4 in the course of a systematic attempt to identify new alloantigens by the immunization of rabbits with human erythrocytes.The new antigen was named P, but it was later designated P 1 when the antigen now known as P was identified 5,14 . The serology of this system has gradually increased in complexity, and the recognition of antibodies with compound specificities indicated a biochemical relation between P and other blood group systems.The currently recognized antigens of the P System include two common antigens, P 1 and P, and P k which has been considered a rare erythrocyte antigen. Approximately 75% of white individuals possess the P 1 antigen, and the P antigen is present on all normal red cells, the erythroblasts and endothelium cells 7 .Many blood group antigens have been found in numerous parasites, nevertheless the clinical significance of these antigenic similitudes between a parasite and its host is not very clear established yet 12 .The antigens of the P System have also been detected in various animal species: Taenia Echinococcus, Ascaris suum, Fasciola gigantica, Parogonimus westermani, Dicrocelium dentriticum . At the present time it is accepted that many microorganims and parasites carry blood group antigens which have become evident by Inhibition Agglutination Tests and Immune Fluorescence Techniques. Yet, the clinical significance of this fact is still unknown 13 .The aim was to study the presence of P 1 antigenic determiners in Ascaris lumbricoides extracts by means of the use of different monoclonal antibodies of well-known concentrations and Ig class.We worked with 14 A. lumbricoides extracts [AE]. In order to perform our experiments [AE] were prepared. Adult specimens were washed in physiological solution supplemented with 200 mg/ml of streptomycin and 200 mg/ml of penicillin. After that a refrigerated mechanical rupture was performed for 5 days. The supernatants were collected and kept at -20 ºC wit...