RESUMO
The Doppler pseudonormal pattern of left ventricular (LV) diastolic function filling, characterized by apparent normal transmitral flow velocities, indicates advanced diastolic dysfunction with abnormal relaxation and compliance. Left ventricular diastolic dysfunction has been shown to occur in the early stages of the outcome of Chagas cardiopathy, and its identification may potentially contribute to the management of those patients. The aim of this study was to evaluate the usefulness of tissue Doppler imaging (TDI) in identifying LV diastolic dysfunction in patients with Chagas' disease with pseudonormal transmitral flow. For this purpose, 89 patients with Chagas' disease (48 men) who had no other pathology and showed normal (n = 79) or pseudonormal (n = 10) patterns of diastolic function by pulsed wave Doppler were submitted to TDI. A significant LV systolic impairment in terms of the dimensions (P = .00001), ejection fraction (P = .000001), and wall motion score (P = .000002) was observed in patients with diastolic dysfunction when compared with the group with normal LV diastolic function. Tissue Doppler imaging enabled the recognition of a pseudonormal type of transmitral flow velocity with high statistical significance through early (P = .000008) and late (P = .0003) expansion waves. The sensitivity and specificity in detecting LV diastolic dysfunction with TDI in the septal, anterior, inferior, posterior, and lateral walls were 90% and 87.3%, 87.3% and 90%, 87.3% and 90%, 84.8% and 90%, and 84.8 and 90%, respectively. In conclusion, TDI enabled the differentiation of patients with Chagas' disease with normal LV diastolic function and those with the pathologic LV pseudonormal pattern with high statistical significance. Moreover, this article shows the potential in demonstrating the occurrence of major alterations in the LV performance of patients with Chagas' disease with LV diastolic dysfunction, as well as the occurrence of signs of an increased LV filling pressure in those patients.
Assuntos
Cardiomiopatia Chagásica/fisiopatologia , Diástole/fisiologia , Ecocardiografia Doppler/métodos , Feminino , Humanos , Masculino , Sensibilidade e Especificidade , Disfunção Ventricular Esquerda/fisiopatologiaRESUMO
Two functionally distinct antibodies, categorized as conventional serology antibodies (CSA) and lytic antibodies (LA) have been described in Chagas' disease, based on their ability to bind to fixed epimastigotes (EPI) or live trypomastigotes (TRYPO), respectively. In this study, the profile of immunoglobulin G (IgG) subclasses of CSA and LA were analyzed by flow cytometry using serum samples from chronic chagasic patients with the indeterminate (IND), cardiac (CARD), and digestive (DIG) clinical forms of the disease. The results were expressed as percentage of positive fluorescent parasites (PPFP) for each sample. CSA showed a higher PPFP than LA for all samples. At serum dilutions between 1:256 and 1:2,048, IgG1 anti-EPI was able to distinguish chagasic from nonchagasic individuals. Different profiles of IgG subclasses were observed for CSA and LA. IgG1 and IgG2 were the main subclasses in CSA, whereas IgG1 and IgG3 were the predominant ones in LA. The reactivity of IgG2 anti-EPI was greater in IND and CARD than in DIG patients. Furthermore, a low level of IgG1 and IgG3 LA was associated with most of the CARD patients. On the other hand, a high level of IgG1 LA was associated with most of the IND patients. In summary, our findings indicate the potential of IgG1 anti-EPI for serological diagnosis of Chagas' disease, providing further evidence for a protective role of LA, and show that IgG1 anti-live Trypanosoma cruzi TRYPO may be used to predict the risk of cardiac damage in Chagas' disease.
Assuntos
Anticorpos Antiprotozoários/imunologia , Doença de Chagas/diagnóstico , Imunoglobulina G/imunologia , Trypanosoma cruzi/imunologia , Animais , Anticorpos Antiprotozoários/classificação , Linhagem Celular , Doença de Chagas/imunologia , Doença de Chagas/fisiopatologia , Humanos , Imunoglobulina G/classificação , Camundongos , PrognósticoRESUMO
Two families, comprising 11 individuals in the toxemic form of schistosomiasis mansoni, infected in Belo Horizonte, Brazil were treated. Parasitological cure was obtained in 5 (45%) of the patients after a single oral dose of oxamniquine (Mansil), 20 mg/kg body weight. No significant side effects were observed. To evaluate the possibility of resistance to the drug, cercariae collected from Biomphalaria glabrata infected with micracidia from eggs obtained from three of the individuals not cured were studied. Mice infected with these three strains were cured after a single dose of examniquine. It is suggested that research be continued with other therapeutic schedules and perhaps other, more potent, drugs.