Unexplained lymphadenopathies: autoimmune lymphoproliferative syndrome in an adult patient.

Autoimmune lymphoproliferative syndrome (ALPS) is characterised by massive enlargement of the lymphoid organs, autoimmune cytopenias and a predisposition to develop lymphoid malignancies. The basic defect is a disturbance of the lymphocyte apoptosis, and a high number of circulating TCRab CD3+CD4-CD8- T-cells (double-negative T cells (DNT cells)). We describe a case of a 41-year-old man with fever, hepatosplenomegaly, multiple lymphadenopathy, autoimmune haemolytic anaemia and severe thrombocytopenia. Peripheral blood immunophenotyping revealed elevation of the characteristic DNT cells in 8% and high levels of interleukin 10. Histopathological analysis of lymph nodes showed lymphadenitis with paracortical hyperplasia. It was assumed as a probable diagnosis of ALPS, and the procedure was to medicate the patient with steroids. As a result, a significant clinical improvement was achieved, and he has been in remission for 2 years. To our knowledge, this is the first case reported in a Portuguese adult patient.