Atypical lymphocytes in dengue: role in diagnosis and prognosis of disease. A systematic review of literature

Dengue is the arbovirus infection with the highest incidence in the world and a major cause of morbidity and mortality. Disease onset presents as a nonspecific febrile illness, and therefore, tools are required to identify and classify dengue patients at early stage. An useful parameter is the presence of atypical lymphocytes. Objective: to collect and analyze results from existing published studies on atypical lymphocytes and dengue infection, and its effect on diagnosis and prognosis of disease. Materials and methods: was conducted a PubMed and LILACS search under the terms: Dengue AND Atypical lymphocyte (OR Reactive lymphocyte, OR Turk cell), limiting the findings to human studies. The information was classified by its content. Only studies relevant to the topic were included in this study. Results: 68 references were identified using the search strategy, but only 12 met the inclusion criteria. All included studies reported the presence of atypical lymphocytes as particular hematologic finding in patients with dengue, and although it is not a classical specific finding of the disease, their concentrations were significantly higher in these patients, especially in severe forms of the disease. Conclusions: according to this evidence, there may be an association between the presence of atypical lymphocytes and dengue virus infection, but the intensity and usefulness of this finding requires further study and analysis.