Interleukin-2 receptors in experimental Chagas' disease

Chronic Chagas' heart disease: a disease on its way to becoming a worldwide health problem: epidemiology, etiopathology, treatment, pathogenesis and laboratory medicine

Chagas' disease, caused by Trypanosoma cruzi infection, is ranked as the most serious parasitic disease in Latin America. Nearly 30% of infected patients develop life-threatening complications, and with a latency of 10-30 years, mostly Chagas' heart disease which is currently the major cause of morbidity and mortality in Latin America, enormously burdening economic resources and dramatically affecting patients' social and labor situations. Because of increasing migration, international tourism and parasite transfer by blood contact, intrauterine transfer and organ transplantation, Chagas' heart disease could potentially become a worldwide problem. To raise awareness of this problem, we reflect on the epidemiology and etiopathology of Chagas' disease, particularly Chagas' heart disease. To counteract Chagas' heart disease, in addition to the general interruption of the infection cycle and chemotherapeutic elimination of the infection agent, early and effective causal or symptomatic therapies would be indispensable. Prerequisites for this are improved knowledge of the pathogenesis and optimized patient management. From economic and logistics viewpoints, this last prerequisite should be performed using laboratory medicine tools. Consequently, we first summarize the mechanisms that have been suggested as driving Chagas' heart disease, mainly those associated with the presence of autoantibodies against G-protein-coupled receptors; secondly, we indicate new treatment strategies involving autoantibody apheresis and in vivo autoantibody neutralization; thirdly, we present laboratory medicine tools such as autoantibody estimation and heart marker measurement, proposed for diagnosis, risk assessment and patient guidance and lastly, we critically reflect upon the increase in inflammation and oxidative stress markers in Chagas' heart disease.

Cell-mediated immunity in experimental Trypanosoma cruzi infection

Infection of humans with the protozoan Trypanosoma cruzi leads to Chagas disease, or American trypanosomiasis, a disease that affects nearly 20 million people, and constitutes one of the largest socioeconomic burdens in Latin America. Much of the present knowledge on pathogenic mechanisms underlying T. cruzi infection comes from experimental murine models. Here, George A. DosReis reviews recent findings about the features of host cell-mediated immunity against the parasite and possible mechanisms leading to chronic infection.

Mechanisms of development of immunosuppression during Trypanosoma infections

Acute infection with Trypanosoma cruzi or its African relatives, including T. brucei rhodesiense, T. b. gambiense, T. b. brucei and T. congolense, is frequently accompanied by manifestations of immunological dysfunction. Initially investigators catalogued the ensuing immunologic alterations and identified a number of modifications in lymphoid or accessory cell properties. More recently, the emphasis has switched towards the molecular underpinnings of immunosuppression in these infections. In this article, Marcelo Sztein and Felipe Kierszenboum focus on recent progress made in the quest to delineate the mechanisms behind altered lymphocyte functions in tryponosomal infections, point out particular and common features of immunosuppression induced by T. cruzi and African trypanosomes, and outline possible directions for future research.