Primary immunodeficiency diseases worldwide: more common than generally thought

Area of Science:

• Immunology and Genetics
• Epidemiology
• Public Health

Background:

• Primary immunodeficiency diseases (PIDs) encompass over 176 rare hereditary disorders.
• The true prevalence and incidence of PIDs are largely unknown.
• Recent studies suggest PIDs are more common than generally believed.

Purpose of the Study:

• To estimate the global prevalence and incidence of PIDs.
• To highlight the discrepancy between estimated and identified PID cases.
• To underscore the underrepresentation of adult PID patients in registries.

Main Methods:

• Extrapolating PID frequencies from national registries and epidemiologic surveys.
• Applying reported frequencies to continental and global populations.
• Analyzing data from national registries and the Jeffrey Modell Centers Network.

Main Results:

• An estimated six million individuals worldwide may have a PID.
• Identified PID cases range from 27,000 to 60,000 globally.
• Significant underreporting exists, with only 2.27% of estimated European cases registered and even fewer in Africa.

Conclusions:

• Dedicated epidemiologic studies are essential for accurate PID statistics.
• Increased physician and public health awareness of PIDs is crucial.
• The evolving definition of PIDs may increase estimated population impact in adults and children.