Autoimmune lymphoproliferative syndrome (ALPS)

Autoimmune lymphoproliferative syndrome is a rare inherited condition in which the body cannot properly clear out old immune cells through normal programmed cell death, a process called apoptosis, most often because of changes in the FAS gene. As a result, lymphocytes build up in the lymph nodes and spleen, and the immune system becomes prone to attacking the body's own blood cells.

Research attributes roughly 60 to 70 percent of ALPS cases to FAS gene mutations, with a smaller share linked to changes in the FAS ligand or caspase 10 genes, and it usually appears in childhood with persistent swollen lymph nodes and an enlarged spleen. Because normal apoptosis fails, the excess immune cells produce characteristic laboratory findings, including elevated interleukin-10, elevated IgG, and a distinctive population of double-negative T cells that clinicians use to help confirm the diagnosis. Along with autoimmune destruction of blood cells that can cause anemia, low platelets, and easy bruising or fatigue, people with ALPS carry a higher lifetime risk of certain lymphomas, so ongoing monitoring matters.

Common signs

The swollen lymph nodes and enlarged spleen are usually painless and persist for months or years, unlike the swelling that comes with a typical infection. A subset of people develop Evans syndrome, meaning autoimmune anemia and low platelets occurring together, which along with easy bruising and fatigue can be an early clue to the diagnosis.

This is a plain-language summary for orientation, not a diagnosis. Mechanisms are described as current understanding, not settled fact. Work with your own clinician for your care.