Immune Defect in Adults With Down Syndrome: Insights Into a Complex Issue

Area of Science:

• Immunology
• Genetics
• Clinical Medicine

Background:

• Down syndrome (DS) is associated with recurrent respiratory infections, a leading cause of childhood mortality.
• This susceptibility is multifactorial, involving impaired immune function and non-immunological factors.
• Infections are also a major cause of death in adults with DS, leading some to classify it as a syndromic immunodeficiency.

Purpose of the Study:

• To investigate the clinical and immune phenotype of adults with Down syndrome.
• To correlate immune status with infectious history in this population.
• To understand the immune profile of adult DS patients, an understudied area.

Main Methods:

• Studied 44 adults with Down syndrome.
• Assessed clinical and immune phenotypes.
• Correlated findings with the patients' infectious history.

Main Results:

• Adults with DS exhibited an aberrant lymphocyte phenotype.
• Observed decreased naïve/memory T cell ratios and reduced switched memory B cells.
• Found a lower incidence of infectious events in adulthood compared to other inborn errors of immunity.

Conclusions:

• Primary immunodeficiency-related features in DS may contribute to increased risks of autoimmunity, malignancies, and infections.
• Immune dysfunction in DS might be compensated for in mid-adulthood.
• Infection-related mortality in older DS adults could be influenced by neurological impairment and nosocomial antigen exposure.