APDS (previously known as PASLI* Disease) is a rare, progressive, and underdiagnosed primary immunodeficiency that was first characterized in 2013.1-4 It is caused by genetic variants in either one of two identified genes known as PIK3CD or PIK3R1, which encode proteins that are vital to the normal development and function of immune cells.5-6
APDS is difficult to diagnose as symptoms vary even amongst family members with the same genetic variant.2 Since APDS was only recently fully characterized and shares many features of other immune disorders, patients with APDS may have been previously diagnosed with other conditions.5
Signs and symptoms of APDS start in childhood, and patients are vulnerable to repeat infections and immune dysregulation such as lymphadenopathy, splenomegaly, autoimmune cytopenias, and even lymphoma.12
Patients have often been previously diagnosed with other immunodeficiencies or autoimmune disorders and have a protracted course to obtain a correct diagnosis.7
Genetic testing can definitively diagnose APDS and many other primary immunodeficiencies, which may require targeted management.8-10
APDS is inherited in an autosomal dominant manner. Other family members may be affected, yet present with varying symptoms.2 Genetic testing of family members is recommended.
PI is also referred to as an Inborn Error of Immunity (IEI).
*PASLI, p110 delta activating mutation causing senescent T cells, lymphadenopathy, and immunodeficiency.
1. Angulo I, Vadas O, Garçon F, et al. Phosphoinositide 3-kinase δ gene mutation predisposes to respiratory infection and airway damage. Science. 2013;342(6160):866-871. doi:10.1126/science.1243292 2. Lucas CL, Kuehn HS, Zhao F, et al. Dominant-activating germline mutations in the gene encoding the PI(3)K catalytic subunit p110δ result in T cell senescence and human immunodeficiency. Nat Immunol. 2014;15(1):88-97. doi:10.1038/ni.2771 3. Deau MC, Heurtier L, Frange P, et al. A human immunodeficiency caused by mutations in the PIK3R1 gene [published correction appears in J Clin Invest. 2015 Apr;125(4):1764-5]. J Clin Invest. 2014;124(9):3923-3928. doi:10.1172/JCI75746 4. Lucas CL, Zhang Y, Venida A, et al. Heterozygous splice mutation in PIK3R1 causes human immunodeficiency with lymphoproliferation due to dominant activation of PI3K. J Exp Med. 2014;211(13):2537-2547. doi:10.1084/jem.20141759 5. Fruman DA, Chiu H, Hopkins BD, Bagrodia S, Cantley LC, Abraham RT. The PI3K Pathway in Human Disease. Cell. 2017;170(4):605-635. doi:10.1016/j.cell.2017.07.029 6. Okkenhaug K, Vanhaesebroeck B. PI3K in lymphocyte development, differentiation and activation. Nat Rev Immunol. 2003;3(4):317-330. doi:10.1038/nri1056 7. Jamee M, et al. Clin Rev Allergy Immunol. 2019;May 21. 8. Rotz, SJ, et al. Pediatr Blood Cancer. 2018; 65:e27260. 9. Kulm E, et al. Oral abstract presented at the 62nd Annual ASH Meeting; Dec 5-8, 2020 10. Chinn IK, et al. J Allergy Clin Immunol. 2020;145(1):46-69. 11. Maccari ME et al. Front. Immunol. 2018;9: Article 543. 12. Elkaim E et al. J Allergy Clin Immunol. 2016;138(1):210-218.
