The Role of Interferon-γ in Autoimmune Polyendocrine Syndrome Type 1.

BACKGROUND: Autoimmune polyendocrine syndrome type 1 (APS-1) is a life-threatening, autosomal recessive syndrome caused by autoimmune regulator (AIRE) deficiency. In APS-1, self-reactive T cells escape thymic negative selection, infiltrate organs, and drive autoimmune injury. The effector mechanisms governing T-cell-mediated damage in APS-1 remain poorly understood. METHODS: We examined whether APS-1 could be classified as a disease mediated by interferon-γ. We first assessed patients with APS-1 who were participating in a prospective natural history study and evaluated mRNA and protein expression in blood and tissues. We then examined the pathogenic role of interferon-γ using Aire-/-Ifng-/- mice and Aire-/- mice treated with the Janus kinase (JAK) inhibitor ruxolitinib. On the basis of our findings, we used ruxolitinib to treat five patients with APS-1 and assessed clinical, immunologic, histologic, transcriptional, and autoantibody responses. RESULTS: Patients with APS-1 had enhanced interferon-γ responses in blood and in all examined autoimmunity-affected tissues. Aire-/- mice had selectively increased interferon-γ production by T cells and enhanced interferon-γ, phosphorylated signal transducer and activator of transcription 1 (pSTAT1), and CXCL9 signals in multiple organs. Ifng ablation or ruxolitinib-induced JAK-STAT blockade in Aire-/- mice normalized interferon-γ responses and averted T-cell infiltration and damage in organs. Ruxolitinib treatment of five patients with APS-1 led to decreased levels of T-cell-derived interferon-γ, normalized interferon-γ and CXCL9 levels, and remission of alopecia, oral candidiasis, nail dystrophy, gastritis, enteritis, arthritis, Sjögren's-like syndrome, urticaria, and thyroiditis. No serious adverse effects from ruxolitinib were identified in these patients. CONCLUSIONS: Our findings indicate that APS-1, which is caused by AIRE deficiency, is characterized by excessive, multiorgan interferon-γ-mediated responses. JAK inhibition with ruxolitinib in five patients showed promising results. (Funded by the National Institute of Allergy and Infectious Diseases and others.).

Lymphocyte-Directed Immunomodulation Remits Thymoma-Associated Autoimmune Pneumonitis.

BACKGROUND: Thymoma presents with several autoimmune manifestations and is associated with secondary autoimmune regulator (AIRE) deficiency. Pneumonitis has recently been described as an autoimmune manifestation associated with thymoma presenting with similar clinical, radiographic, histological, and autoantibody features as seen in patients with inherited AIRE deficiency who suffer from Autoimmune PolyEndocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED) syndrome. OBJECTIVES: To treat two patients with biopsy-proven thymoma-associated pneumonitis with lymphocyte-directed immunomodulation. METHODS: Two patients with thymoma were enrolled on IRB-approved protocols at the NIH Clinical Center. We performed history and physical examination; laboratory, radiographic, histologic and pulmonary function evaluations; and measurement of the lung-directed autoantibodies KCNRG and BPIFB1 prior to and at 1- and 6-months following initiation of lymphocyte-directed immunomodulation with azathioprine with or without rituximab. RESULTS: Combination T- and B-lymphocyte-directed immunomodulation resulted in improvement of clinical, functional, and radiographic parameters at 6-month follow-up evaluations in both patients with sustained remission up to 12-36 months following treatment initiation. CONCLUSION: Lymphocyte-directed immunomodulation remitted autoimmune pneumonitis in two patients with thymoma.

Early recognition of the APECED rash can accelerate the diagnosis of APECED.

Autoimmune-Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED) is a monogenic autoimmune disease most often resulting from biallelic loss-of-function variants in the autoimmune regulator (AIRE) gene. Although typically characterized by the classic triad of chronic mucocutaneous candidiasis, hypoparathyroidism, and adrenal insufficiency, we have recently reported that the clinical spectrum of the syndrome is far broader that previously described and that incorporation of an adjunct triad of APECED rash, autoimmune enteritis-associated intestinal dysfunction, and enamel hypoplasia in the classic triad manifestations could lead to earlier diagnosis. Among the adjunct triad manifestations, APECED rash occurs in 66% of American APECED patients by age 3, most often developing in the first year of life. Here, we describe the clinical and histological features of protracted APECED rash manifesting together with recurrent mucocutaneous candidiasis as the first two disease components of APECED in a 10-month-old girl.

Successful Treatment of Refractory Cutaneous Protothecosis With MAT2203, an Oral Lipid Nanocrystal Formulation of Amphotericin B.

Prototheca wickerhamii is a rare cause of cutaneous and systemic infection that requires long treatment courses with potentially toxic medications. We describe a patient with cutaneous protothecosis refractory to triazole monotherapy who experienced clinical and radiographic improvement with the novel oral lipid nanocrystal formulation of amphotericin B without experiencing toxicity.

Case Report: Dental Findings Can Aid in Early Diagnosis of APECED Syndrome.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), also known as autoimmune polyglandular syndrome type 1 (APS-1), is a rare genetic disorder caused most often by biallelic mutations in the AIRE gene. Classic clinical findings of the disease are chronic mucocutaneous candidiasis and autoimmunity that primarily targets endocrine tissues, such as hypoparathyroidism and adrenal insufficiency. Recently, however, it has been appreciated that enamel hypoplasia, together with intestinal malabsorption and a characteristic APECED rash, is a prominent early disease manifestation of APECED which can aid in the diagnosis of disease before other potentially life-threatening disease manifestations occur. To demonstrate this point, we present data from a cohort of APECED patients, approximately 70% of who present with enamel dysplasia at an early age. Importantly, early life presentation with enamel dysplasia was predictive of likelihood of development of a subsequent APECED diagnosis. Furthermore, we present a case of a patient with APECED and severe enamel defects and discuss the utility of medical-dental professional co-operation in the diagnosis and management of this complex disorder.