RESUMO
We studied five fatal cases of dengue haemorrhagic fever (DHF), confirmed using the reverse transcriptase-polymerase chain reaction (RT-PCR) method, in Vietnamese children. The liver seems to be a target for dengue virus, so postmortem examinations were performed to investigate elementary lesions, local recruitment of inflammatory cells and whether the virus was present in target cells of the liver. We detected severe, diffuse hepatitis with midzonal necrosis and steatosis in two patients, focal areas of necrosis in two patients, and normal histology in one patient. Dengue virus antigen was detected using immunohistochemistry in hepatocytes from necrotic areas in four cases. There was no recruitment of polymorphonuclear cells, and no lymphocytes were detected in the liver lesions of patients who died from DHF. Lymphocytic infiltration occurred in only one hepatitis B virus-positive patient, with no signs of chronic hepatitis. Kupffer cells had mostly been destroyed in cases with focal or severe necrosis. TUNEL tests were positive in necrotic areas, with positive cells forming clusters, suggesting that an apoptotic mechanism was involved. Thus, we suggest that the hepatocyte and Kupffer cells may be target cells supporting virus replication and that the councilman body is an apoptotic cell, as in the pathogenesis of yellow fever.