Do common infections trigger disease-onset or -severity in CTLA-4 insufficiency?

Area of Science:

• Immunology
• Genetics

Background:

• CTLA-4 insufficiency, caused by heterozygous mutations in CTLA4, is an inborn error of immunity.
• Variable disease expressivity and reduced penetrance in CTLA-4 mutation carriers suggest modifying factors influence disease onset and severity.
• Infections are known to trigger autoimmunity, particularly in genetically predisposed individuals.

Purpose of the Study:

• To investigate the association between specific infections and disease onset or severity in CTLA-4 insufficiency.
• To examine the humoral immune response and immunoglobulin function in CTLA-4 mutation carriers with and without autoimmune manifestations.

Main Methods:

• Studied humoral immune response to cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus 1/2 (HSV 1/2), parvovirus B19, and Toxoplasma gondii in 13 CTLA-4 mutation carriers.
• Assessed FcγRIII/CD16A activation by EBV-specific IgG antibodies to evaluate immunoglobulin function.
• Compared seroprevalence and immunoglobulin function between affected and unaffected carriers.

Main Results:

• No significant difference in seroprevalence for the examined pathogens between affected and unaffected CTLA-4 mutation carriers.
• CTLA-4 mutation carriers produce EBV-specific IgG antibodies with unimpaired FcγRIII/CD16A activation capabilities.
• The presence or prevalence of these pathogens did not correlate with disease severity or expressivity.

Conclusions:

• The investigated pathogens are unlikely to be triggers for disease onset in CTLA-4 insufficiency.
• Infections do not appear to be a significant modifying factor for disease severity or expressivity in CTLA-4 insufficiency.