Autoimmune Lymphoproliferative Syndrome: A Rare Cause of Disappearing HDL Syndrome

الملخص EN

The term disappearing HDL syndrome refers to development of severe high density lipoprotein cholesterol (HDL-C) deficiency in noncritically ill patients with previously normal HDL-C and triglyceride levels.

Autoimmune lymphoproliferative syndrome (ALPS) is a disorder of the immune system due to an inability to regulate lymphocyte homeostasis resulting in lymphadenopathy and hepatosplenomegaly.

We describe a 17-year-old boy who was evaluated in the lipid clinic for history of undetectable or low HDL-C and low density lipoprotein cholesterol (LDL-C) levels.

Past medical history was significant for ALPS IA diagnosed at 10 years of age when he presented with bilateral cervical adenopathy.

He was known to have a missense mutation in one allele of the FAS protein extracellular domain consistent with ALPS type 1A.

HDL-C and LDL-C levels had been undetectable on multiple occasions, though lipids had not been measured prior to the diagnosis of ALPS.

He had been receiving sirolimus for immunosuppression.

The HDL-C and LDL-C levels correlated with disease activity and improved to normal levels during times when the activity of ALPS was controlled.

This case highlights the importance of considering ALPS as a cause of low HDL-C and LDL-C levels in a child with evidence of lymphoproliferation.