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Intestinal Chagas' disease in patients with AIDS

2000; Lippincott Williams & Wilkins; Volume: 14; Issue: 8 Linguagem: Inglês

10.1097/00002030-200005260-00027

1473-5571

Walter Oelemann, Jorge Néstor Velásquez, Silvana Carnevale, Horacio Besasso, Maria Gabriela Teixeira, José Mauro Peralta,

Parasitic Infections and Diagnostics

Chagas' disease or American trypanosomiasis is endemic throughout most parts of central and south America. As infection with HIV is increasing dramatically in areas endemic for Chagas' disease, it is possible that the presence of Trypanosoma cruzi in the gut can account for symptoms in T. cruzi/HIV-coinfected patients. In a cohort of 95 adult patients with AIDS who had been evaluated for chronic diarrhoea, stool samples were routinely examined for the presence of bacteria and parasites. Upper intestinal endoscopy and biopsy of the distal duodenum were carried out on all patients. In the present retrospective study, we re-examined duodenal biopsy specimens from 20 patients that showed structures potentially associated with protozoan infections. Duodenal biopsy specimens were processed for routine paraffin-embedding and stained with haematoxylin-eosin (H&E), Giemsa and Schiff's periodic acid. Formalin-fixed paraffin-embedded biopsy specimens from the 20 re-examined patients were used to obtain a DNA template for polymerase chain reaction (PCR) analysis. Standard protocols were performed for deparaffinization, proteolitic treatment and DNA extraction. Different PCR protocols were employed for specifically amplifying the variable regions of Leishmania ssp. and T. cruzi kinetoplast DNA [1], or other sequences specific for Toxoplasma gondii[2] and microsporidia [3]. T. cruzi could be detected in the intestinal tract of four individuals. The average age of these patients was 30 years and none of them used intravenous drugs or had received transfusions. Three patients were homosexual, and only one case had lived in an endemic area for Chagas' disease. The mean CD4 cell count was 52 cells/mm3. Endoscopy revealed changes in the mucosa in three cases, and duodenal histology revealed the presence of amastigotes and microsporidia in all four patients. T. cruzi amastigotes were microscopically identified by their size (3–5 μm in diameter) and their staining properties, revealing the presence of a prominent kinetoplast. In three of the four patients, the parasites were located in the cytoplasm of the enterocytes in the tip of the villi. In all patients, amastigotes also appeared in the lamina propria as free organisms or in the interior of macrophages (Fig. 1). The structures visualized could not be identified in Schiff's periodic acid-stained paraffin sections.Fig. 1.: Light micrograph (duodenal biopsy) showing an amastigote in the cytoplasm of a macrophage in lamina propria (H&E stain; magnification ×1000).Biopsies of the small bowel showed villus atrophy and unspecific inflammation of the lamina propria. Upon re-examination all slides revealed microsporidian spores refractive in H&E sections. PCR investigation of the four samples that showed light microscopic evidence of amastigotes resulted in all cases in the detection of a T. cruzi-specific amplicon of 330 base pairs (bp) and a Enterocytozoon bieneusi-specific amplicon of 210 bp. The four biopsy specimens were negative for Leishmania ssp. and T. gondii. T. cruzi, causing Chagas' disease in humans, should be added to the list of infectious agents capable of causing intestinal opportunistic infections in patients with AIDS. The classic syndromes associated with Chagas' disease and AIDS, namely meningoencephalitis, cardiomyopathy and megaoesophagus, are well known [4]. In contrast, the prevalence of small intestinal infections and clinical features are not described at present [5,6]. Diarrhoea was described in immunocompetent patients with acute Chagas' disease but not in individuals with AIDS [7,8]. The four patients investigated in this study presented with diarrhoea and the presence of E. bieneusi in association with T. cruzi could be detected. These data suggest that the intestinal localization of T. cruzi could be more frequent in HIV-infected individuals than previously described. Further work should be considered to determine whether the presence of T. cruzi amastigotes in the gut is associated with enteric symptoms in AIDS patients. Walter Oelemanna Jorge N. Velásquezb Silvana Carnevalec Horacio Besassod Maria G. M. Teixeiraa José M. Peraltaa