IPINeT Ped-unPAD Study: Goals, Design, and Preliminary Results

Area of Science:

• Pediatric Immunology
• Clinical Genetics
• Infectious Diseases

Background:

• Unclassified primary antibody deficiency (unPAD) is a heterogeneous condition within Inborn Errors of Immunity (IEIs).
• Historically underestimated as mild, unPAD lacks extensive natural history studies.
• The Italian Primary Immunodeficiency Network (IPINet) Ped-unPAD study aims to characterize pediatric unPAD.

Purpose of the Study:

• To investigate the clinical characteristics and natural history of pediatric unPAD.
• To identify severe phenotypes and diagnostic evolution in unPAD patients.
• To inform optimal management strategies for pediatric unPAD.

Main Methods:

• Multi-center prospective study (IPINet Ped-unPAD).
• Data collection from 110 enrolled pediatric patients across three centers.
• Preliminary analysis of infectious phenotypes and diagnostic outcomes.

Main Results:

• A significant proportion of unPAD patients experienced severe infections requiring hospitalization (25%) and interventions (10%).
• After a median 5-year follow-up, 50% of patients maintained the unPAD diagnosis.
• The remaining 50% were reclassified into Transient Hypogammaglobulinemia of Infancy (25%) or other IEIs (25%).

Conclusions:

• UnPAD can present with severe infectious complications in pediatric populations.
• UnPAD is a dynamic condition, with a substantial percentage reclassifying to other IEIs over time.
• Comprehensive evaluation and long-term monitoring are essential for accurate diagnosis and treatment of pediatric unPAD.