Missing Insight Into T and B Cell Responses in Dermatitis Herpetiformis

Gluten Intolerance and Its Association With Skin Disorders: A Narrative Review

Gluten sensitivity is defined as a chronic intolerance to gluten ingestion in genetically predisposed individuals. The etiology is thought to be immune-mediated and has a variable dermatologic presentation. Celiac disease (CD) is one of the most common forms of gluten intolerance and encompasses a wide range of extra-intestinal pathology, including cutaneous, endocrine, nervous, and hematologic systems. Psoriasis, another long-term inflammatory skin condition, has been linked to significant symptomatic improvement with a gluten-free diet (GFD). Palmoplantar pustulosis (PP), a variant of psoriasis, and aphthous stomatitis, which causes recurrent oral ulcers, have also exhibited beneficial results after the dietary elimination of gluten. In addition to this, dermatitis herpetiformis (DH), another immune-mediated skin disorder, is genetically similar to CD and has, therefore, shown tremendous improvement with a GFD. Another highly prevalent long-term skin condition called atopic dermatitis (AD), however, has revealed inconsistent results with gluten elimination and would require further research in the future to yield concrete results. Hereditary angioedema (HA) has shown an association with gluten intolerance in some patients who had symptomatic benefits with a GFD. Similarly, vitiligo and linear IgA bullous dermatosis have also shown some clinical evidence of reversal with a GFD. On the contrary, rosacea enhances the risk of developing CD. This narrative review emphasizes the potential impact of gluten intolerance on different cutaneous conditions and the potential therapeutic effect of a GFD on various symptomatic manifestations. There is a need for additional clinical and observational trials to further expand on the underlying pathophysiology and provide conclusive and comprehensive recommendations for possible dietary interventions.

The risk of renal comorbidities in celiac disease patients depends on the phenotype of celiac disease

BACKGROUND

An increased risk of kidney disease in patients with celiac disease has been reported, but the association has remained obscure. Only few studies have investigated the association between renal comorbidities and dermatitis herpetiformis, a cutaneous manifestation of celiac disease.

OBJECTIVES

We investigated whether patients with different phenotypes of celiac disease are at higher risk of kidney diseases than age- and sex-matched references.

METHODS

The diagnoses of glomerulonephritis, diabetic nephropathy, interstitial nephritis, and end-stage renal disease obtained from the National Hospital Discharge Register between 1970 and 2015 were identified in celiac disease (Marsh III, n = 1072) and dermatitis herpetiformis (n = 368) patients diagnosed at Tampere University Hospital catchment region and in 4296 reference subjects. Using the Cox proportional hazards model, we compared the risk of kidney diseases between patients and references. The study protocol was approved by the Regional Ethics Committee of Tampere University Hospital (R16090). As the study was register based, no consent from patients was required.

RESULTS

Even after adjusting for type 1 diabetes, celiac disease was associated with an elevated risk of kidney disease (hazard ratio [HR] 1.85, 95% confidence interval [CI] 1.12-3.03), glomerulonephritis (HR 3.37, 95% CI 1.64-6.95), and IgA nephropathy (IgAN) (HR 18.98, 95% CI 2.29-157.63). No similarly elevated risk was found among dermatitis herpetiformis patients (HR 1.50, 95% CI 0.63-3.55; HR 2.21, 95% CI 0.77-6.38; and HR 5.87, 95% CI 0.53-64.79, respectively).

CONCLUSION

Celiac disease patients were at increased risk of kidney diseases, notably IgAN. The risk was dependent on the celiac disease phenotype and was not seen in patients with dermatitis herpetiformis. Awareness of possible renal manifestations is recommended when treating celiac disease patients.

Antibody Responses to Transglutaminase 3 in Dermatitis Herpetiformis: Lessons from Celiac Disease

Dermatitis herpetiformis (DH) is the skin manifestation of celiac disease, presenting with a blistering rash typically on the knees, elbows, buttocks and scalp. In both DH and celiac disease, exposure to dietary gluten triggers a cascade of events resulting in the production of autoantibodies against the transglutaminase (TG) enzyme, mainly TG2 but often also TG3. The latter is considered to be the primary autoantigen in DH. The dynamics of the development of the TG2-targeted autoimmune response have been studied in depth in celiac disease, but the immunological process underlying DH pathophysiology is incompletely understood. Part of this process is the occurrence of granular deposits of IgA and TG3 in the perilesional skin. While this serves as the primary diagnostic finding in DH, the role of these immunocomplexes in the pathogenesis is unknown. Intriguingly, even though gluten-intolerance likely develops initially in a similar manner in both DH and celiac disease, after the onset of the disease, its manifestations differ widely.