ABC | Volume 113, Nº2, August 2019

Anatomopathological Correlation Pinesi et al. 26-year-old man with congenital chagas disease and heart transplantation Arq Bras Cardiol. 2019; 113(2):286-293 Chagas' disease reactivation can affect any individual with the chronic forms of the disease, especially when they are submitted to immunosuppression. In this context, the most important conditions are HIV coinfection and/or organ transplantation. 14 Among patients with Chagas cardiopathy submitted to heart transplantation, the incidence varies between 21 and 45% depending on the studied series. 15 Review studies show that mortality is low when appropriate treatment is implemented and, therefore, diagnosis is a crucial part of a favorable outcome. 16 The diagnosis of reactivation in the transplanted patient is based on the clinical picture and the routine screening for the parasite in endomyocardial biopsies, because often there are no symptoms, or the symptoms are non‑specific. Symptoms may be cardiac, such as congestive and low‑output symptoms in cases of myocarditis or changes in the electrocardiogram, such as cardiac rhythm disturbances or new blocks. The most frequent extracardiac symptoms are fever and skin lesions. Thus, a high degree of suspicion is necessary for diagnosis to be attained. When the endomyocardial biopsy is altered, the main differential diagnosis is acute cellular rejection, since there is lymphocyte/monocyte infiltration in both cases. The difference is that nests of Trypanosoma cruzi amastigotes may be present in the Chagas’ disease reactivation biopsy, observed by hematoxylin-eosin staining or by immunohistochemistry analysis. 15 When the reactivation diagnosis is made, the recommended treatment is benznidazole use, at the previously mentioned doses. It should be emphasized that this treatment does not result in the cure of the chronic infection, and the patient is subject to recurrent reactivations. As a consequence of this risk, it is recommended that the immunosuppression in these patients be as little as possible, aiming at an adequate balance between the risk of reactivation and rejection. 15 Azathioprine use should be preferred instead of mycophenolate in the Chagasic population, since it is associated with a lower reactivation rate, without worsening of other outcomes. 17 Thus, despite the drastic decrease in the disease transmission in the country, Chagas' cardiopathy continues to be very frequent in Brazil, both due to the number of patients with the chronic forms of the disease and to other forms of transmission that were not previously very relevant, such as vertical transmission. The care of pregnant women and the treatment of those infected at reproductive age should be improved. The active screening for infection in the children of infected mothers is essential, aiming at establishing the earliest possible antitrypanosomal treatment in infected children, thus achieving the cure and reducing the potential number of patients with the chronic forms of the disease. (Dr. Henrique Trombini Pinesi) Diagnostic hypothesis: Chagas disease reactivation in transplanted heart. (Dr. Henrique Trombini Pinesi) Infectious aspects The laboratory monitoring of Chagas' disease reactivation after cardiac transplantation is recommended. Due to the difficulty of attaining a clinical diagnosis of Chagas’ disease reactivation, with the exception of skin lesions, the laboratory monitoring of transplanted patients is recommended. 15 For this purpose, peripheral blood samples should be collected for direct detection of the parasite in the buffy coat, which increases the likelihood of its finding, and for parasite screening by molecular biology. This method seems to be more sensitive, detecting the increase of the parasitic load before the onset of clinical and/or histopathological manifestations. It can be qualitative or quantitative. Monthly or quarterly monitoring is recommended in the first year after cardiac transplantation, when the level of immunosuppression is higher and after the treatment of rejection episodes. (Prof. Dr. Tânia Mara Varejão Strabelli) Anatomopathological report The explanted heart weighed 332g. It had a globose shape and the external surface was covered by smooth serosa, with small white and prominent nodules being noticed, focally, in the trajectory of the coronary vessels. The opening showed dilatation of all chambers (Figure 6), predominantly of the ventricles. The endocardial surface was smooth, showing no thrombi. The left atrial endocardium was quite thick. The left ventricular tip showed a dilated lesion measuring 1.2 cm in diameter, where the wall was tapered and partially replaced by whitish tissue (Figure 7). The epicardial coronary arteries showed no macroscopic alterations, as well as the atrioventricular and arterial valves. Histological analysis showed chronic mononuclear myocarditis and diffuse fibrosis, of which intensity varied from one region to another. We did not find parasites in the histological sections of the explanted heart. The post-transplantation endomyocardial biopsy carried out in March 2017 showed good tissue representativeness, with a moderate inflammatory process and several cardiomyocyte aggression foci (Figure 8). As this was a patient with Chagas’ disease, an immunohistochemical reactionwas carried out for Trypanosoma cruzi parasites, which were positive in pseudocysts containing amastigotes (Figure 9). New sections of the same block stained with hematoxylin-eosin also showed the presence of pseudocysts (or nests) containing several amastigote forms (Figure 10). (Dr. Vera Demarchi Aiello) Anatomopathological diagnoses Explanted heart : Chronic myocarditis with diffuse fibrosis, compatible with cardiac involvement in chronic Chagasic cardiopathy. Post-transplantation endomyocardial biopsy : Chagas' disease reactivation, with moderate mononuclear myocarditis and presence of several parasite nests. (Dr. Vera Demarchi Aiello) Comments This case shows a young patient with chronic Chagasic cardiopathy who had clinical manifestations around the age of 20 years, after a diagnosis of congenital Chagas' disease. There was no clear history of childhood disease treatment. The explanted heart showed a typical picture of Chagas’ chronic heart disease. 290