Impaired salivary gland activity in patients with autoimmune polyendocrine syndrome type I

Oral manifestations of autoimmune polyglandular syndrome type 1

AIMS

Autoimmune polyglandular syndrome type I (APS-I) is a rare condition of autosomal recessive and monogenic inheritance, which is characterized clinically by at least two signs of the classic triad: mucocutaneous candidosis, hypoparathyroidism, and Addison's disease. This study aims to report the oral manifestations of APS-I in a 42-year-old woman, who attended the Special Care Dentistry Center.

METHODS AND RESULTS

The patient presented with hypoparathyroidism, diabetes mellitus, and autoimmune hepatitis. Chronic hyperplastic candidosis (CHC) was the main oral manifestation and it was diagnosed based on clinical and cytologic characteristics. Microstomia, angular cheilitis, xerostomia, enamel hypoplasia, and microdontia were also present.

CONCLUSIONS

CHC was treated with topical nystatin and oral fluconazole, resulting in a significant improvement of the lesions.

Infections in the monogenic autoimmune syndrome APECED

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is caused by mutations in the Autoimmune Regulator (AIRE) gene, which impair the thymic negative selection of self-reactive T-cells and underlie the development of autoimmunity that targets multiple endocrine and non-endocrine tissues. Beyond autoimmunity, APECED features heightened susceptibility to certain specific infections, which is mediated by anti-cytokine autoantibodies and/or T-cell driven autoimmune tissue injury. These include the 'signature' APECED infection chronic mucocutaneous candidiasis (CMC), but also life-threatening coronavirus disease 2019 (COVID-19) pneumonia, bronchiectasis-associated bacterial pneumonia, and sepsis by encapsulated bacteria. Here we discuss the expanding understanding of the immunological mechanisms that contribute to infection susceptibility in this prototypic syndrome of impaired central tolerance, which provide the foundation for devising improved diagnostic and therapeutic strategies for affected patients.

Response to Comments on "Aberrant type 1 immunity drives susceptibility to mucosal fungal infections"

Puel and Casanova and Kisand et al. challenge our conclusions that interferonopathy and not IL-17/IL-22 autoantibodies promote candidiasis in autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy. We acknowledge that conclusive evidence for causation is difficult to obtain in complex human diseases. However, our studies clearly document interferonopathy driving mucosal candidiasis with intact IL-17/IL-22 responses in Aire-deficient mice, with strong corroborative evidence in patients.

Comment on "Aberrant type 1 immunity drives susceptibility to mucosal fungal infections"

[Figure: see text].

IL-22 Paucity in APECED Is Associated With Mucosal and Microbial Alterations in Oral Cavity

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is caused by recessive mutations in the AIRE gene. The hallmark of the disease is the production of highly neutralizing autoantibodies against type I interferons and IL-22. Considering the importance of IL-22 in maintaining mucosal barrier integrity and shaping its microbial community, we sought to study potential changes in the oral cavity in this model of human IL-22 paucity. We found that besides known Th22 cell deficiency, APECED patients have significantly fewer circulating MAIT cells with potential IL-22 secreting capacity. Saliva samples from APECED patients revealed local inflammation, the presence of autoantibodies against IFN-α and IL-22, and alterations in the oral microbiota. Moreover, gene expression data of buccal biopsy samples suggested impaired antimicrobial response and cell proliferation, both of which are processes regulated by IL-22. Our data complement the knowledge gained from mouse models and support the concept of IL-22 being a critical homeostatic cytokine in human mucosal sites.

Profiling Autoantibodies against Salivary Proteins in Sicca Conditions

Salivary gland dysfunction occurs in several autoimmune and immune-related conditions, including Sjögren syndrome (SS); immune checkpoint inhibitor-induced sicca (ICIS) that develops in some cancer patients and is characterized by severe, sudden-onset dry mouth; and autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). Although subjects with these conditions present with oral dryness and often exhibit inflammatory infiltration of the salivary gland, little is known about the B-cell humoral responses directed against salivary gland protein targets. In this study, autoantibodies were evaluated against Ro52, Ro60, and La, as well as against a panel of 22 proteins derived from the salivary proteome. The tested cohort included healthy volunteers and subjects with SS, ICIS, and APECED without and with sicca. As expected, a high percentage of autoantibody seropositivity was detected against Ro52, Ro60, and La in SS, but only a few ICIS patients were seropositive for these autoantigens. A few APECED subjects also harbored autoantibodies to Ro52 and La, but only Ro60 autoantibodies were weakly associated with a small subset of APECED patients with sicca. Additional testing of the salivary panel failed to detect seropositive autoantibodies against any of the salivary-enriched proteins in the SS and ICIS subjects. However, APECED subjects selectively demonstrated seropositivity against BPI fold containing family A member 1 (BPIFA1), BPI fold containing family A member 2 (BPIFA2)/parotid salivary protein (PSP), and lactoperoxidase, 3 salivary-enriched proteins. Moreover, high levels of serum autoantibodies against BPIFA1 and BPIFA2/PSP occurred in 30% and 67% of the APECED patients with sicca symptoms, respectively, and were associated with an earlier age onset of oral dryness (P = 0.001). These findings highlight the complexity of humoral responses in different sicca diseases and provide new insights and biomarkers for APECED-associated sicca (ClinicalTrials.gov: NCT00001196; NCT00001390; NCT01425892; NCT01386437).

A rare case of autoimmune polyglandular syndrome with Sjögren’s syndrome and primary hypoparathyroidism

A 31-year-old woman experienced tetany and was diagnosed with Hashimoto thyroiditis and hypoparathyroidism. At 33 years of age, her renal function gradually decreased. At 39 years of age, she moved to our hospital and was diagnosed with tubulointerstitial nephritis by renal biopsy. Simultaneously, she was diagnosed with Sjögren’s syndrome by autoantibodies and salivary gland biopsy. At 40 years of age, based on hypoglycaemia and eosinophilia, she was suspected of adrenal insufficiency, and was diagnosed with primary adrenal insufficiency by both corticotropin stimulation and corticotropin-releasing hormone stimulation test. She was diagnosed as autoimmune polyglandular syndrome (APS) (Hashimoto thyroiditis and possible primary adrenal insufficiency) as well as primary hypoparathyroidism and Sjögren’s syndrome, which are very rarely complicated in APS-2. Therefore, in this patient, it was helpful to pay attention for new onset of other autoimmune diseases.

Oral microbiota in autoimmune polyendocrine syndrome type 1

Background: Autoimmune polyendocrine syndrome type-1 (APS-1) is a rare, childhood onset disease caused by mutations in the Autoimmune Regulator gene. The phenotypic expression is highly variable and includes disease manifestations in the oral cavity, including mucocutaneous candidiasis. Increasing evidence suggests a potential role of the skin, oral and gut microbiotas in the pathogenesis of autoimmunity. To date, no information exists regarding the oral microbiota in APS-1. Objective: To assess the bacterial microbiota of whole saliva in APS-1 patients by using high throughput sequencing. Design: Whole unstimulated saliva was collected from 10 APS-1 patients and 17 healthy controls and examined by high throughput sequencing of the hypervariable region V1-V2 of 16S rRNA using the 454 GS Junior system. Metastats (http://cbcb.umd.edu/software/metastats) was used to analyse the pyrosequencing reads. Results: A reduction in the total number of bacterial genera and species was detected in APS-1 compared to healthy controls. The proportion of the major phyla Firmicutes was higher (60% vs 41%, p = 0.002) and Bacteroidetes lower (15% vs 28%, p = 0.007) in APS-1 compared to healthy controls. On the genus level, Streptococcus and Gemella were prevalent in APS-1. Conclusion: Our findings indicate a significantly altered oral microbiota in APS-1.