Antibodies to Trypanosoma cruzi express idiotypic patterns that can differentiate between patients with asymptomatic or severe Chagas' disease
Reis, D.D.; Gazzinelli, R.T.; Gazzinelli, G.; Colley, D.G.
Journal of Immunology 150(4): 1611-1618
1993
ISSN/ISBN: 0022-1767 PMID: 8432996 Document Number: 410753
Immunization of rabbits with pools of immunoaffinity-purified anti-T. cruzi epimastigote antibodies derived from patients from endemic areas in Minas Gerais, Brazil, with different clinical forms of Chagas' disease induced anti-idiotypic sera that could distinguish between anti-epimastigote antibodies from patients with asymptomatic (indeterminate (IND)) or severe (cardiac (CARD)) Chagas' disease. These idiotypically different anti-EPI antibodies from patients with the different clinical forms did not differ in their anti-epimastigote activities or isotypes. Analysis of immunoaffinity purified antibodies from individual chagasic patients by specific competitive ELISA generally confirmed that idiotype-specific rabbit antisera could differentiate the clinical forms of the source of the antibodies. It is suggested that immunoaffinity-purified antibodies from patients share many idiotypes with those from IND patients, although antibodies from IND patients express much lower levels of the distinctive idiotype characteristic of CARD patients. Reduction and alkylation of antibodies from IND patients reduced somewhat, but did not abolish, the ability of their idiotype to be recognized, and to effectively inhibit in competitive ELISA. In contrast, reduction and alkylation of antibodies from CARD patients almost completely eliminated the ability of their predominant idiotype to be either recognized by, or inhibit, the appropriate systems. It is implied that the expression of the major idiotypes that define CARD patients by these serologic anti-idiotype systems is largely dependent on the tertiary conformation of the Ig molecule. It is concluded that this agrees with earlier studies on the respective differential abilities of CARD vs IND idiotypes to stimulate anti-idiotype cells by direct stimulation vs processing and presentation mechanisms.