From autoimmune enteropathy to the IPEX (immune dysfunction, polyendocrinopathy, enteropathy, X-linked) syndrome

Area of Science:

• Immunology
• Genetics
• Gastroenterology

Background:

• Autoimmune enteropathy (AIE) was historically defined by intractable diarrhea, autoantibodies, and associated autoimmune conditions like type 1 diabetes.
• Early AIE cases exhibited male predominance, early onset, and poor response to nutritional support.

Purpose of the Study:

• To clarify the genetic and molecular basis of autoimmune enteropathy.
• To differentiate AIE from related immune dysregulation syndromes.

Main Methods:

• Genetic analysis focusing on the FOXP3 gene and its role in regulatory T cell (Treg) development.
• Clinical correlation of genetic findings with patient phenotypes, including immune dysfunction and enteropathy.

Main Results:

• Mutations in the FOXP3 gene cause Immune dysfunction, Polyendocrinopathy, Enteropathy, and X-linked inheritance (IPEX) syndrome, explaining many prior AIE cases.
• While FOXP3 is central, other molecules may also contribute to Treg function and related syndromes.
• The diagnostic significance of gut autoantibodies in AIE pathogenesis has diminished, now serving mainly as a screening tool.

Conclusions:

• IPEX syndrome, driven by FOXP3 mutations, is the primary diagnosis for most previously classified AIE cases.
• Understanding the genetic basis of IPEX/AIE refines diagnosis and management of rare immune-mediated enteropathies.
• Further research into Treg cell biology may reveal additional targets for treating these complex disorders.