Autoimmune Lymphoproliferative Syndrome

Background: Autoimmune lymphoproliferative syndrome (ALPS) is a rare disorder of the immune system caused by a mutation in the FAS gene. In ALPS, the body stores too many germ-fighting cells called lymphocytes. This can lead to an enlarged spleen and lymph nodes. Current treatments for ALPS can have many adverse effects. Better treatments for ALPS are needed. Objective: To test a study drug (soquelitinib) in people with ALPS. Eligibility: People aged 16 years and older with ALPS. Design: Participants will have 8 clinic visits and 6 remote visits within 1 year. Participants will be screened. They will have a physical exam with blood and urine tests. Some may have tests of their lung function. Soquelitinib is a tablet taken by mouth twice a day. Participants will record their doses and any symptoms on a paper or online form. Blood tests and other procedures will be repeated during study visits. Three visits will include imaging scans. Participants will lie on a table that slides through a doughnut-shaped machine while X-rays capture pictures of the inside of their body. Some participants may be able to remain in the study for a second year.

The main objective of this study is to generate diagnosis and therapeutic-decision tools through the identification of molecular causes of PIDs with autoimmunity/inflammation and the variability in disease outcome at the transcriptional level using a combination of omics signatures (transcriptomics, epigenomics, proteomics, metagenomics, metabolomics and lipidomics).