Morphological changes in the digestive system of 322 necropsies of patients with acquired immune deficiency syndrome: comparison of findings pre- and post-HAART (Highly Active Antiretroviral Therapy).

Involvement of the digestive system in AIDS pathologies or injuries is frequent. Aiming at comparing the frequency, the importance that these lesions have for death and the survival time in patients using or not using HAART, we studied 322 necropsies classified as follows: Group A - without antiretroviral drugs (185 cases); B - one or two antiretroviral drugs or HAART for less than six months (83 cases); C - HAART for six months or longer (54 cases). In the overall analysis of the digestive system, changes were present in 73.6% of cases. The most frequent was Candida infection (22.7%), followed by cytomegalovirus (19.2%), Histoplasma capsulatum (6.5%), mycobacteria (5.6%), and Toxoplasma gondii (4.3%). T. gondii infection was more frequent in group A compared with group C, and cytomegalovirus (CMV) was more frequent in group A compared with groups B and C (p < 0.05); 2.2% of the deaths were due to gastrointestinal bleeding. Regarding the segments, only in the large intestine, and only cytomegalovirus, were more frequent in group A compared with group C. We conclude that digestive system infections are still frequent, even with the use of HAART. However, the average survival time in group C was more than three times greater than the one in group A and nearly double that of group B, demonstrating the clear benefit of this therapy.

In situ expression of regulatory cytokines by heart inflammatory cells in Chagas' disease patients with heart failure.

Chagas' disease is caused by the protozoan parasite Trypanosoma cruzi. The immune system plays an important role in the reduction of parasite load, but may also contribute to the development of lesions observed during the chronic phase of the disease. We analyzed cytokines produced by inflammatory heart cells in 21 autopsy samples obtained from patients with Chagas' disease divided according to the presence or absence of heart failure (HF). Left ventricular sections were analyzed by immunohistochemistry using antibodies against human IL-4, IFN-γ, TGF-ß, TNF-α, and NOS2. In situ mRNA expression was quantified by a Low Density Array. The number of IFN-γ-positive cells was significantly higher than IL-4 positive cells. TNF-α, TGF-ß and NOS2 were detected in 65%, 62% and 94% of samples respectively. There was an association between TNF-α-producing cells and the presence of HF. Subjects with HF presented higher levels of STAT4 mRNA, whereas FoxP3 and STAT6 levels were similar in the two groups. A Th1 cytokine pattern predominated in the cardiac inflammatory cell infiltrate of Chagas' disease patients associated with HF. High degree of fibrosis was associated with low NOS2 expression. These results support the idea that Th1 immune responses are involved in heart lesions of Chagas' disease patients.

Neuropathology of AIDS: An Autopsy Review of 284 Cases from Brazil Comparing the Findings Pre- and Post-HAART (Highly Active Antiretroviral Therapy) and Pre- and Postmortem Correlation.

A retrospective study of central nervous system (CNS) in 284 autopsy AIDS cases in Brazil (1989-2008) divided into 3 groups: A (without antiretroviral treatment: 163 cases); B (other antiretroviral therapies: 76 cases); C (HAART for 3 months or more: 45 cases). In 165 (58.1%) cases, relevant lesions were found, predominantly infections (54.2%); the most frequent was toxoplasmosis (29.9%) followed by cryptococcosis (15.8%), purulent bacterial infections (3.9%), and HIV encephalitis (2.8%); non-Hodgkin lymphomas occurred in 1.4% and vascular lesions in 1.1%. There was no difference when compared the frequency of lesion among the groups; however, toxoplasmosis was less common while HIV encephalitis was more frequent in group C related to A. CNS lesions remain a frequent cause of death in AIDS; however, the mean survival time was four times greater in group C than in A. In 91 (55.1%) of 165 cases with relevant brain lesions (or 32% of the total 284 cases), there was discordance between pre- and postmortem diagnosis; disagreement type 1 (important disease that if diagnosed in life could change the patient prognosis) occurred in 49 (53.8%) of 91 discordant cases (17.6% of the total 284) indicating the autopsy importance, even with HAART and advanced diagnostics technologies.

Fas/Fas-L expression, apoptosis and low proliferative response are associated with heart failure in patients with chronic Chagas' disease.

Chagas' disease affects 16-18 million patients in South America and heart involvement is the major cause of morbidity and mortality. Heart failure is the most severe clinical manifestation of the chronic phase of infection with Trypanosoma cruzi. The intensity and nature of the immune response is associated with the clinical outcome of the disease. In murine models, a low proliferative response and T-cell apoptosis have been observed during acute infection. In the present study the immune response of patients in the chronic phase of infection was analyzed. Patients were divided into: (a) asymptomatic, i.e., without involvement of the heart or digestive system; and (b) with heart failure. Patients with heart failure presented a significantly lower peripheral blood mononuclear cell (PBMC) proliferative response to T. cruzi antigens compared to asymptomatic patients. This low response was associated with antigen-induced apoptosis. Apoptosis of PBMC and a low proliferative response were also associated with double Fas/Fas-L expression and high production of TNF-alpha, a cytokine known to induce programmed cell death. These results suggest that apoptosis of PBMC, probably triggered by double expression of Fas/Fas-L and TNF-alpha, is implicated in the immune regulatory mechanism during the chronic phase of Chagas' disease.

Myocardiocyte apoptosis in heart failure in chronic Chagas' disease.

Chagas' disease is caused by the parasite Trypanosoma cruzi. The disease affects 16-18 million patients in South America and heart involvement is the major cause of morbidity and mortality of the disease. The myocarditis observed during the chronic phase affects patients independently of the clinical manifestation, although patients with heart failure present an intense degree of myocarditis and fibrosis. To address the pathogenesis of heart failure in Chagas' disease, we investigated the role of myocardial cell loss by apoptosis in patients in the chronic phase of Chagas' disease. Apoptosis was also evaluated in inflammatory cells. Twenty-two specimens of the left ventricle were obtained during autopsies. Eleven samples from patients with heart failure and equal number from patients without heart failure. The material was analyzed by TUNEL methods to identify early apoptotic events and fibrosis was evaluated on HE-stained slides. In patients with heart failure, the extent of fibrosis and the number of apoptotic myocardial and inflammatory cells were significantly higher than in specimens obtained from patients without heart failure. These results suggest that myocardial cell loss by apoptosis and fibrosis contribute to heart failure in the chronic phase of Chagas' disease.