Síndrome linfoproliferativa autoimune

Introduction: Autoimmune lymphoproliferative syndrome (ALPS) is a rare, genetic disease caused by mutations in the genes of the Fas pathway and that cause defects in lymphocyte apoptosis, leading to autoimmune hemolytic anemia, lymphadenomegaly, splenomegaly, hypergammaglobulinemia, exaggerated elevation of vitamin B12 and propensity for lymphomatous transformation. Case report: A 5-month-old female, admitted to investigate anemia, splenomegaly and repetitive infections episodes. Laboratory tests showed anemia autoimmune hemolytic, hypergammaglobulinemia and serum elevation of vitamin B12. Flow acitometry showed a population of lymphocytes T anormal: TCR-αβ / C3 + / CD4- / CD8-. The histopathological study of the lymph node revealed hyperplasia paracortical with T-transformed cells, CD3 + / CD4- / CD8-. G-banding cytogenetic analysis in the bone marrow showed a normal karyotype (46, XX) and the FISH technique in the interphase nucleus removed the occurrence of chromosome 7. Sequencing of the Fas gene revealed the presence of thepathogenic variant of heterozygosis, at the intron 4 splicing site (IVS4 + 1G> A). The patient was diagnosed as ALPS and treated with corticosteroid; there was a significant  regression of splenomegaly and stabilization of hemolytic anemia, Coombs' test negative. She is currently stable, in use of low doses of corticosteroid. Comments: The authors draw attention for the need of the ALPS investigation in pediatric patients who have hemolytic anemia,  splenomegaly and repeat infections.