Chagas' disease: IgG isotypes against cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive antigens of Trypanosoma cruzi in chronic Chagasic patients

Abstract

The wide range of clinical Chagas' disease manifestations, of which heart involvement is the most significant, because of its characteristics, frequency and consequences, and lack of treatment and cure, justify research in this area. Specific immunoglobulin G (IgG) antibody subclasses have been associated with human Chagas' disease. Thus, in this study, the profile of IgG subclasses against cytoplasmic (CRA) and flagellar (FRA) recombinant repetitive T. cruzi-specific antigens was correlated with cardiac (CARD, n=33), cardiodigestive (CD, n=7), and indeterminate (IND, n=20) forms of Chagas' disease by indirect enzyme-linked immunosorbent assay (ELISA). IgG subclasses were detected in almost all Chagas patients studied. Nevertheless, only specific IgG2 isotype FRA was found with a significant statistical difference in CARD patients when compared to IND patients. This result suggests the potential use of this isotype for prognostic purposes, for monitoring the progression of chronic Chagas' disease, and for predicting the risk of CARD damage. This is important information, as it could help physicians to evaluate and manage the treatment of their patients. However, a follow-up study is necessary to confirm our result.

In-house ELISA method to analyze anti-Trypanosoma cruzi IgG reactivity for differential diagnosis and evaluation of Chagas disease morbidity

“…The evaluation of IgG2 did not reveal a direct association with cardiac involvement, in contrast to other authors, who reported higher reactivity of this IgG2 subclass in patients with different levels of cardiopathy [9][10]12 . On the other hand, high levels of IgG3 were detected, especially in the IND group as compared with the CARD and DIG/ Mix groups.…”

“…Additionally, other variables regarding the selected casuistry may be involved, such as the geographical origin of the patients and consequent predominant T. cruzi population, and the length of the infection [7][8][9][10][12][13]26 .…”

“…Several authors have already studied the relationship between the intensity of serological reactivity of different IgG subclasses and Chagas disease morbidity [7][8][9][10][11][12] . Morgan et al detected increased levels of IgG2 in CARD patients using an ELISA test based on epimastigotes of the Brazil strain.…”

Increased levels of IgA antibodies against CRA and FRA recombinant antigens of Trypanosoma cruzi differentiate digestive forms of Chagas disease

“…The specific production of immunoglobulin G (IgG) against the CRA and FRA antigens has already been demonstrated in chronic chagasic patients by VerÈosa et al [17]. These authors showed that the IgG2 isotype against the FRA antigen was able to distinguish patients with the CARD form from those with the IND form of Chagas disease.…”

Diagnosis of Chagas disease: what has been achieved? What remains to be done with regard to diagnosis and follow up studies?

“…Molecular testing using PCR combined with hybridization have shown promising results and may be used as a confirmatory test (MS 2005). There is, however, a need for other tests to identify CP soon after specific treatment, for a prognosis marker (Verçosa et al 2007, Lorena et al 2008) and for prediction of congenital transmission.…”