Immune Dysregulation, Polyendocrinopathy, Enteropathy, X-linked (IPEX) Syndrome

Key Clinical and Laboratory Features

Common clinical features: Typical triad is early-onset enteropathy (watery diarrhea, onset typically before 6 months of age), endocrinopathy (Type 1 diabetes or thyroiditis) and dermatitis (eczema, psoriasiform dermatitis, pemphigoid, etc.).
Other clinical features: Autoimmune hemolytic anemia (AIHA), idiopathic thrombocytopenic purpura (ITP), autoimmune neutropenia, autoimmune hepatitis, autoimmune nephropathy, etc.
Physical exam: Dermatitis (eczema) is common. Sometimes lymphadenopathy and splenomegaly are present.
Common laboratory features: Highly elevated IgE in almost all patients. Other immunoglobulin subsets are typically normal. Eosinophilia is common. Markedly decreased or absent FOXP3+ regulatory T cells.

	TEST	COMMENTS
GENE	FOXP3 Gene Sequencing	The gold standard for confirming a diagnosis of IPEX in a patient with suggestive symptoms.
PROTEIN	FOXP3/CD25 Protein Flow/TREGFlow	FOXP3 expressing regulatory T cells are absent or markedly decreased in more than 75% of patients with IPEX syndrome. There are however some patients with missense mutations in FOXP3 that express near-normal levels of FOXP3 protein. This test does not provide any information about the regulatory function of the FOXP3 expressing cells.
FUNCTION	N/A	There are currently no available clinical tests to evaluate FOXP3 protein function.
OTHER		Immunoglobulin levels: IgE typically highly elevated. IgA may also be elevated. IgM/IgG are typically normal. Complete blood count with differential: Eosinophilia is common. Hematocrit and platelets may be low.