[Familial splenomegaly as a first clinical sign of autoimmune lymphoproliferative syndrome].

Background: The autoimmune lymphoproliferative syndrome (ALPS) is caused by genetic defect in lymphocyte apoptosis. Chronic lymphadenopathy and splenomegaly are the consequence of lymphoproliferation. The diagnosis is based on the assessment of the defective lymphocyte apoptosis and the identification of lymphocyte T subset that are double negative (CD4-CD8-). The susceptibility to lymphoma and autoimmune diseases, mainly blood cytopenias is increased.
Methods: We studied a 14 year-old boy with chronic splenomegaly and familial history of splenomegaly and lymphadenopathy. T lymphocyte phenotypes, and molecular defect of TNFRSF6 gene were studied in the child, his sister and his father. Lymphocyte apoptosis was also analysed in the child and his father.
Results: The boy and his father showed in vitro apoptosis defects, an increased number of double negative T lymphocytes (18% and 5%, respectively) and the same mutation in the TNFRSF6 gene. His sister had 16% of double negative T lymphocytes and the mutation in the TNFRSF6 gene.
Comments: Chronic familial splenomegaly can be the only clinical sign of autoimmune lymphoproliferative syndrome.
(2009 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.)