Advances in autoimmune lymphoproliferative syndromes

Area of Science:

• Immunology
• Genetics
• Hematology

Background:

• Autoimmune lymphoproliferative syndrome (ALPS) is a disorder of lymphocyte homeostasis.
• It is characterized by non-malignant lymphoproliferation, autoimmunity (primarily toward blood cells), and an increased risk of lymphoma.
• The majority of ALPS cases involve heterozygous germline mutations in the Fas (CD95) gene, inherited in an autosomal dominant manner.

Purpose of the Study:

• To review the clinical and laboratory manifestations of ALPS.
• To elucidate the molecular basis of the disease.
• To discuss recent advances in the diagnosis and targeted therapies for ALPS.

Main Methods:

• This review synthesizes current knowledge on ALPS pathophysiology.
• It incorporates findings from genetic studies identifying mutations in Fas, Fas-ligand, caspase 10, caspase 8, NRAS, and KRAS.
• The review also considers diagnostic criteria and therapeutic developments.

Main Results:

• Fas mutations are the most common genetic cause, followed by somatic Fas mutations.
• Mutations in FASLG, CASP10, CASP8, NRAS, and KRAS are identified in a smaller subset of patients.
• Approximately one-third of ALPS cases have an unidentified genetic defect, suggesting further research is needed.
• ALPS may be more common than previously recognized, warranting consideration in patients with unexplained lymphadenopathy, cytopenias, and hepatosplenomegaly.

Conclusions:

• Significant advances in understanding ALPS pathophysiology have led to refined diagnostic criteria and targeted therapies.
• The review underscores the importance of considering ALPS in patients presenting with characteristic symptoms.
• Continued research into the genetic underpinnings of ALPS is crucial for improving patient outcomes.