Diacylglycerol Kinase ζ Regulates Macrophage Responses in Juvenile Arthritis and Cytokine Storm Syndrome Mouse Models.

Dysregulation of monocyte and macrophage responses are often observed in children with systemic juvenile idiopathic arthritis (sJIA) and cytokine storm syndrome (CSS), a potentially fatal complication of chronic rheumatic diseases. Both conditions are associated with activation of TLR signaling in monocyte and macrophage lineage cells, leading to overwhelming inflammatory responses. Despite the importance of TLR engagement in activating proinflammatory macrophages, relatively little is known about activation of intrinsic negative regulatory pathways to attenuate excessive inflammatory responses. In this study, we demonstrate that loss of diacylglycerol (DAG) kinase (Dgk) ζ, an enzyme which converts DAG into phosphatidic acid, limits inflammatory cytokine production in an arthritic mouse model dependent on TLR2 signaling and in a CSS mouse model dependent on TLR9 signaling. In vitro, Dgkζ deficiency results in reduced production of TNF-α, IL-6, and IL-1ß and in limited M1 macrophage polarization. Mechanistically, Dgkζ deficiency decreases STAT1 and STAT3 phosphorylation. Moreover, Dgkζ levels are increased in macrophages derived from mice with CSS or exposed to plasma from sJIA patients with active disease. Our data suggest that Dgkζ induction in arthritic conditions perpetuates systemic inflammatory responses mediated by macrophages and highlight a potential role of Dgkζ-DAG/phosphatidic acid axis as a modulator of inflammatory cytokine production in sJIA and CSS.

NRF2 Augments Epidermal Antioxidant Defenses and Promotes Atopy.

Atopic dermatitis is a chronic form of allergic contact dermatitis that is closely associated with a compromised epidermal barrier. Immunogenicity of a given electrophilic hapten after penetration of this barrier depends directly on biochemical reactions in the thiol-rich layer in the stratum granulosum. In response to electrophilic hapten, NF-erythroid 2-related factor 2 (NRF2) in keratinocytes efficiently induces the production of antioxidants. In this study, we show that the immunogenicity of a given hapten depends directly on the extent to which it induces antioxidant host defenses within the epidermal tissue. We found that allergic contact dermatitis did not develop in NRF2-deficient mice because of compromise of the epidermal innate immune responses that upregulate IL-1α. We also analyzed epidermal NRF2 in association with congenital disorders with features similar to atopic dermatitis in humans. Epidermal samples from patients with Netherton syndrome and peeling skin syndrome exhibited elevated levels of NRF2 and also elevated levels of its downstream target, small proline-rich protein 2. Taken together, these results suggest that the thiol-mediated biochemical responses in the stratum granulosum provide a critical link between defective epidermal barrier function and the development of atopy. Likewise, our results suggested that NRF2 may have a profound impact on the generation of cutaneous immunological memory.

The systemic autoinflammatory disorders for dermatologists. Part 2: disease examples.

The systemic autoinflammatory disorders (SAIDS) or periodic fever syndromes are disorders of innate immunity, which can be inherited or acquired. They are almost all very rare and easily overlooked; typically, patients will have seen multiple specialities prior to diagnosis, so a high level of clinical suspicion is key. It is important to note that these are 'high-value' diagnoses as the majority of these syndromes can be very effectively controlled, dramatically improving quality of life and providing protection against the development of irreversible complications such as AA amyloidosis. In Part 1 of this review, we took an overview of SAIDS and described the common features; in this article, we take a more in-depth look at the better recognized or more dermatologically relevant conditions.

Integrin-modulating therapy prevents fibrosis and autoimmunity in mouse models of scleroderma.

In systemic sclerosis (SSc), a common and aetiologically mysterious form of scleroderma (defined as pathological fibrosis of the skin), previously healthy adults acquire fibrosis of the skin and viscera in association with autoantibodies. Familial recurrence is extremely rare and causal genes have not been identified. Although the onset of fibrosis in SSc typically correlates with the production of autoantibodies, whether they contribute to disease pathogenesis or simply serve as a marker of disease remains controversial and the mechanism for their induction is largely unknown. The study of SSc is hindered by a lack of animal models that recapitulate the aetiology of this complex disease. To gain a foothold in the pathogenesis of pathological skin fibrosis, we studied stiff skin syndrome (SSS), a rare but tractable Mendelian disorder leading to childhood onset of diffuse skin fibrosis with autosomal dominant inheritance and complete penetrance. We showed previously that SSS is caused by heterozygous missense mutations in the gene (FBN1) encoding fibrillin-1, the main constituent of extracellular microfibrils. SSS mutations all localize to the only domain in fibrillin-1 that harbours an Arg-Gly-Asp (RGD) motif needed to mediate cell-matrix interactions by binding to cell-surface integrins. Here we show that mouse lines harbouring analogous amino acid substitutions in fibrillin-1 recapitulate aggressive skin fibrosis that is prevented by integrin-modulating therapies and reversed by antagonism of the pro-fibrotic cytokine transforming growth factor ß (TGF-ß). Mutant mice show skin infiltration of pro-inflammatory immune cells including plasmacytoid dendritic cells, T helper cells and plasma cells, and also autoantibody production; these findings are normalized by integrin-modulating therapies or TGF-ß antagonism. These results show that alterations in cell-matrix interactions are sufficient to initiate and sustain inflammatory and pro-fibrotic programmes and highlight new therapeutic strategies.

Autoinflammatory Diseases in Pediatric Dermatology-Part 1: Urticaria-like Syndromes, Pustular Syndromes, and Mucocutaneous Ulceration Syndromes. / Enfermedades autoinflamatorias en dermatología pediátrica. Parte 1: síndromes urticariformes, síndromes pustulosos y síndromes con ulceraciones cutáneo-mucosas.

Monogenic autoinflammatory diseases are a heterogeneous emergent group of conditions that are currently under intensive study. We review the etiopathogenesis of these syndromes and their principal manifestations. Our aim is to propose a classification system based on the clinicopathologic features of typical skin lesions for routine clinical use in dermatology. Our focus is on diagnosis in pediatric practice given that this is the period when the signs and symptoms of these syndromes first appear. In Part 1 we discuss the course of urticaria-like syndromes, which include cryopyrin-associated periodic conditions and hereditary periodic fever syndromes. Pustular syndromes are also covered in this part. Finally, we review the range of therapies available as well as the genetic mutations associated with these autoinflammatory diseases.

Autoinflammatory Diseases in Pediatric Dermatology-Part 2: Histiocytic, Macrophage Activation, and Vasculitis Syndromes. / Enfermedades autoinflamatorias en dermatología pediátrica. Parte 2: síndromes histiocítico-macrofágicos y síndromes vasculopáticos.

The discovery of new autoinflammatory syndromes and novel mutations has advanced at breakneck speed in recent years. Part 2 of this review focuses on vasculitis syndromes and the group of histiocytic and macrophage activation syndromes. We also include a table showing the mutations associated with these autoinflammatory syndromes and treatment alternatives.

Successful Short Desensitization Treatment Protocol with Narrowband UVB Phototherapy (TL-01) in Polymorphic Light Eruption.

INTRODUCTION: Polymorphic light eruption (PLE) is a common idiopathic photodermatosis that typically presents with pruritic papular or papulovesicular lesions on sun-exposed skin between spring and autumn. In many subjects PLE is mild, and can usually be prevented by the use of broad-spectrum topical sunscreens and a gradual increase in sunlight exposure. However, in some individuals, sunlight exposure results in florid PLE and they often benefit from prophylactic desensitization treatment using phototherapy in early spring, an artificial method that induces a "hardening" phenomenon. OBJECTIVE: To describe and evaluate the efficacy of a short desensitization protocol, based on a one-month-treatment, administered twice a week with narrow band UVB in subjects with severe polymorphic light eruption (PLE). METHODS: A retrospective, open planned and non-randomized study to assess the efficacy of UVB phototherapy in prevention of polymorphic light eruption. RESULTS: Fifteen subjects diagnosed with severe PLE were treated with the standard protocol in our Photobiology Unit between 2014 and 2015. The effect of hardening was sustained during follow up in 87.5% of desensitization treatments. A statistically significant association (p<0.05) between the years of duration of the PLE and the response to treatment was found. CONCLUSIONS: The effect of hardening was maintained in the vast majority of subjects, obtaining a good benefit with no PLE episodes during all the summer. We demonstrate that our standard protocol is effective, and produces a successful outcome for the majority of PLE subjects. Our protocol is shorter than those currently applied, being favourable both for the patient and the physician.

Cutaneous amyloidosis associated with autoimmune hepatitis-primary biliary cirrhosis overlap syndrome.

Cutaneous amyloidosis is a rare disease characterized by the deposition of amyloid in the dermis. It can be primary or secondary, depending on associated diseases. It has been linked to various autoimmune diseases, including primary biliary cirrhosis. We present the case of a patient with an autoimmune hepatitis-primary biliary cirrhosis overlap syndrome with concomitant cutaneous amyloidosis, a very unusual association, and discuss similar cases and possible pathophysiological implications.

Annular erythema in primary Sjogren's syndrome: description of 43 non-Asian cases.

OBJECTIVE: The objective of this paper is to evaluate the prevalence and characterize the main epidemiological, clinical and immunological features of annular erythema (AE) in non-Asian patients with primary Sjögren's syndrome (SS). METHODS: We carried out a retrospective study searching for AE in 377 Spanish patients with primary SS fulfilling the 2002 American-European criteria. In addition, we searched PubMed (1994-2012) using the MeSH terms "annular erythema" and "primary Sjögren's syndrome" for additional cases. All cases with AE reported in patients with SS associated with systemic lupus erythematosus were excluded. RESULTS: In our Spanish cohort, we found 35 (9%) patients diagnosed with AE. All were white females, with a mean age of 47 years at diagnosis of AE. AE preceded diagnosis of SS in 27 (77%) patients. Cutaneous AE lesions involved principally the face and upper extremities. All patients reported photosensitivity, with cutaneous flares being reported during the warmest months in 93% of patients. Immunological markers consisted of anti-Ro/La antibodies in 31 (89%) patients. In the literature search, we identified eight additional non-Asian patients with primary SS diagnosed with AE. In comparison with 52 Asian patients, the 43 non-Asian patients with AE related to primary SS were more frequently women (100% vs 78%, p=0.008), and cutaneous lesions were less frequently reported in the face (55% vs 81%, p=0.045) and more frequently in the neck (40% vs 14%, p=0.041). Immunologically, non-Asian patients had a lower frequency of anti-Ro antibodies and a higher frequency of negative Ro/La antibodies, although the differences were not statistically significant. CONCLUSION: AE is not an exclusive cutaneous feature of Asian patients with primary SS. In addition to the characteristic cutaneous expression, AE has a very specific clinical and immunological profile: often presenting before the fulfillment of SS criteria, overwhelmingly associated with anti-Ro antibodies but weakly associated with other immunological markers and the main systemic SS-related features.

[Effect of proteflazid on TLRs expression by mononuclear leukocytes of peripheral blood and epithelial cells of mucous membranes and skin in patients with herpes-associated erythema multiforme and erythema annulare centrifugum].

The article reports survey data on 23 patients with erythemas, including 19 patients with herpes-associated erythema multiforme (HAEM) and 4 patients with Darier's erythema annulare centrifugum (DEAC). Patients in the initial state (baseline) and after two weeks of therapy with proteflazid were characterized by measuring the levels of Toll-like receptor (TLR) expression in peripheral blood mononuclear cells (PBMC) and in epithelial cells of the throat and the skin. The TLR expression in PBMC and skin was assessed by flow cytometry with monoclonal antibodies (ICA) (Caltag Laboratories, USA; Hycult Biotech, Netherlands) against relevant antigens. In addition, patients were also characterized by the content of subpopulations of lymphocytes expressing surface markers CD3, CD4, CD8, CD16, CD21, CD23, CD72, CD25, and HLA-DR in the peripheral blood, which was measured by flow cytometry. The therapy with proteflazid in patients with both HAEM and DEAC led to normalization of the level of both T-cell and B-cell immunity, which was manifested by an increase in the total number of lymphocytes, CD3+, CD4+, CD21+, and CD72+. Measurements of the dynamics of TLR expression in the course of immunotherapy showed an increase in the number of TLR 2, 3, 4, 7, 8, and 9 in PBMC (which was especially pronounced for TLR2) and in epithelium of the pharyngeal mucosa and skin (increased expression of TLR3, 7, and 9).

Monogenic causes of inflammatory disease in rheumatology.

PURPOSE OF REVIEW: To review the single-gene defects that can mimic rheumatologic diseases. RECENT FINDINGS: Monogenic disorders can cause a variety of diseases that may be seen by a rheumatologist. Many of these illnesses present with recurrent episodes of arthritis, rash, fever and inflammation, and serositis. Recent discoveries have defined inflammatory diseases due to mutations in the IL-1 and IL-36 receptor antagonists, as well as the immunoproteosome. Further study of well defined monogenic causes of inflammatory diseases, such as FMF, PAPA, TRAPS, and HIDS, has elucidated the pathophysiology of these diseases leading to targeted immunotherapy with anticytokine biological medications. SUMMARY: A rheumatologist should be aware of the genetic causes of inflammatory disease mimics. This will not only help with the prognosis of these diseases, but also help to guide therapy to prevent long-term complications associated with these disorders.

A case of H syndrome showing immunophenotye similarities to Rosai-Dorfman disease.

H syndrome (OMIM 612391) is a recently described autosomal recessive genodermatosis characterized by indurated, hyperpigmented, and hypertrichotic skin and systemic manifestations including hepatosplenomegaly, cardiac anomalies, hearing loss, hypogonadism, low height, hypertriglyceridemia, hallux valgus, and flexion contractures. H syndrome results from mutations in the SLC29A3 gene, which encodes the human equilibrative nucleoside transporter hENT3. The cutaneous histopathology is characterized by a striking mononuclear cell infiltrate in the dermis consisting of CD68+ monocyte-derived cells and CD34+ and factor XIIIa+ dendrocytes. We describe a case of H syndrome in which the infiltrating mononuclear cells were CD68+, CD163+, S-100+, and CD1a-, thus simulating the immunophenotype observed in Rosai-Dorfman disease (RDD). The immunostaining for CD21, fascin, and CD34 were negative, and there were also many factor XIIIa+ dendrocytes interspersed within the dense mononuclear cell infiltrate. Recent findings of biallelic mutations in SLC29A3 in 2 families reported to have familial RDD and in a kindred with Faisalabad histiocytosis (OMIM 602782), which is an autosomal inherited form of histiocytosis with similarities to RDD, may explain the RDD-like immunophenotype in our H syndrome case.

Localized unilateral basaloid follicular hamartoma along Blaschko's lines on face.

Basaloid follicular hamartoma (BFH) is a rare hamartoma of hair follicle. Clinical presentations may vary but are united by the same histopathological features in the form of folliculocentric basaloid or squamoid cell proliferation in the superficial dermis, which represents malformed and distorted hair follicles. It is important to recognize this entity as its simulant is basal cell carcinoma, a low-grade malignancy. Here, we report a case of localized unilateral BFH in a Blaschkoid distribution on the face of a 14-year-old female.