ACTIVATED PHOSPHOINOSITIDE 3-KINASE δ SYNDROME – A RARE FORM OF PRIMARY IMMUNODEFICIENCY

The activated phosphoinositide 3-kinase δ syndrome (APDS) refers to primary immunodeficiencies (PIDs) with autosomal dominant inheritance pattern and belongs to the PID group with immune dysregulation syndrome. APDS is caused by gain-of-function mutation in phosphoinositide 3-kinase δ (PI3Kδ) subunit coding genes which leads to PI3Kδ pathway overactivation, dysfunction of the adaptive T-cell and B-cell immunity. APDS is characterized by recurrent sinopulmonary infections leading to the progressive structural airway defects, herpesviral infections, lymphoproliferative syndrome with increased risk of B-cell lymphoma. We would like to present a late diagnostics APDS case in 5-years old female patient. The BCG-itis at 3 months was the first appeared symptom. Further, it was followed by recurrent bronchitis, severe and prolonged pneumonia, fibrous changes in the lungs with lymphoproliferation symptoms. Laboratory data: increased IgM with normal IgA and IgG levels, decreased CD3+, CD19+, and lymphocytes. Genetic analysis showed heterozygous PIK3CD gene mutation: c.3061G>A p.E1021K. In conclusion, children with early onset of prolonged respiratory tract infections especially if associated with the lymphoproliferative syndrome have to be administered with immunological and genetic tests for early diagnostics of the PID.