Activated PI3Kδ syndrome (APDS; sometimes referred-to as p110δ-activating mutation causing senescent T cells, lymphadenopathy, and immunodeficiency or PASLI ) is a recently described form of inborn error of immunity (IEI) that is characterised by a hyperactive PI3Kδ due to heterozygous mutations in PIK3CD or PIK3R1 genes.1 APDS presents with a variety of clinical manifestations such as recurrent sinopulmonary infections, non-neoplastic lymphoproliferation, and herpesvirus infections.2,3 Other significant complications related to immune dysregulation include lymphoproliferation, cytopenia, arthritis, inflammatory bowel disease, and lymphoma.2,3 Patients can wait a significant time without a diagnosis or are often incompletely diagnosed, as PID, CVID or CID patients.1 Untreated APDS may be associated with significantly increased morbidity and mortality,2-4 adversely affecting quality of life and may be life-threatening in some patients.

Genetic testing is the only way to confirm a diagnosis of APDS, and family testing is recommended to ensure early/accurate diagnosis and targeted treatment.

What is APDS?

The phosphatidylinositol 3-kinases are a family of lipid kinases that are activated by a variety of cellsurface receptors to regulate a wide range of downstream targets that affect cellular metabolism,
growth, survival, differentiation, adhesion and migration…

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APDS symptoms

APDS symptoms are caused by hyperactive PI3Kδ signalling due to specific mutations in either PIK3CD or PIK3R1...

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Diagnosing APDS

Genetic testing is the only way to confirm the diagnosis of APDS. As there is a 50% of chance of APDS being passed from parent to child, family members of patients with APDS should also be genetically tested…

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Managing APDS?

The management of APDS is mainly focussed on treatment of symptoms...

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APDS resources and links

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Patients, families & caregivers

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Find out about APDS

  1. Lougaris V, et al. Pediatr Allergy Immunol. 2022 Jan;33 Suppl 27:69-72.
  2. Elkaim E, et al. J Allergy Clin Immunol. 2016;138(1):210-218.
  3. Coulter TI, et al. J Allergy Clin Immunol. 2017;139(2):597-606.
  4. Maccari ME, et al. Front Immunol. 2018;9: Article 543.

APD-INT-2022-0039    Date of preparation: July 2022