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Concept: Autoimmune diseases

177

Genetic diversity across different human populations can enhance understanding of the genetic basis of disease. We calculated the genetic risk of 102 diseases in 1,043 unrelated individuals across 51 populations of the Human Genome Diversity Panel. We found that genetic risk for type 2 diabetes and pancreatic cancer decreased as humans migrated toward East Asia. In addition, biliary liver cirrhosis, alopecia areata, bladder cancer, inflammatory bowel disease, membranous nephropathy, systemic lupus erythematosus, systemic sclerosis, ulcerative colitis, and vitiligo have undergone genetic risk differentiation. This analysis represents a large-scale attempt to characterize genetic risk differentiation in the context of migration. We anticipate that our findings will enable detailed analysis pertaining to the driving forces behind genetic risk differentiation.

Concepts: Human Genome Project, Rheumatology, Ulcerative colitis, Corticosteroid, Systemic lupus erythematosus, Lupus erythematosus, Autoimmune diseases, Proteinuria

168

Behcet’s disease is a multisystem autoimmune disease with variable clinial manifestations. The diagnosis may pose a difficult challenge for the clinician, who has to be familiar with the wide spectrum and combination of the symptoms of Behcet’s disease. It is considered a rare disease in Hungary, and there are only few reports on Behcet’s disease in the Hungarian literature. However, the past history of Hungary, the worldwide growing incidence of the disease, and the authors' experience raise the possibility that the occurrence of the disease is higher than previously thought. In this review the authors present and discuss literature data on the pathogenesis and pathomechanism, as well as their own experience concerning the symptomatology of Behcet’s disease in order to promote diagnosis and offer adequate therapy for the patients. The authors presume that the importance of the disease is underestimated in Hungary due to a considerable number of unrecognized cases and they propose to establish a national registry for Behcets disease. Orv. Hetil., 2013, 154, 93-101.

Concepts: Epidemiology, Medical terms, Autoimmune diseases, Prevalence, Hungary, Behçet's disease, Hungarian language, Kingdom of Hungary

167

Alopecia areata (AA) is a common autoimmune disorder mostly presented as round patches of hair loss and subclassified into alopecia totalis/alopecia universalis (AT/AU) based on the area of alopecia. Although AA is relatively common, only 5% of AA patients progress to AT/AU, which affect the whole scalp and whole body respectively. To determine genetic determinants of this orphan disease, we undertook whole-exome sequencing of 6 samples from AU patients, and 26 variants in immune-related genes were selected as candidates. When an additional 14 AU samples were genotyped for these candidates, 6 of them remained at the level of significance in comparison with 155 Asian controls (p<1.92×10(-3)). Linkage disequilibrium was observed between some of the most significant SNPs, including rs41559420 of HLA-DRB5 (p<0.001, OR 44.57) and rs28362679 of BTNL2 (p<0.001, OR 30.21). While BTNL2 was reported as a general susceptibility gene of AA previously, HLA-DRB5 has not been implicated in AA. In addition, we found several genetic variants in novel genes (HLA-DMB, TLR1, and PMS2) and discovered an additional locus on HLA-A, a known susceptibility gene of AA. This study provides further evidence for the association of previously reported genes with AA and novel findings such as HLA-DRB5, which might represent a hidden culprit gene for AU.

Concepts: DNA, Gene, Genetics, Genetic linkage, Autoimmune diseases, Locus, Baldness, Alopecia areata

144

Over the last few years, dermoscopy has been shown to be a useful tool in assisting the noninvasive diagnosis of various general dermatological disorders. In this article, we sought to provide an up-to-date practical overview on the use of dermoscopy in general dermatology by analysing the dermoscopic differential diagnosis of relatively common dermatological disorders grouped according to their clinical presentation, i.e. dermatoses presenting with erythematous-desquamative patches/plaques (plaque psoriasis, eczematous dermatitis, pityriasis rosea, mycosis fungoides and subacute cutaneous lupus erythematosus), papulosquamous/papulokeratotic dermatoses (lichen planus, pityriasis rosea, papulosquamous sarcoidosis, guttate psoriasis, pityriasis lichenoides chronica, classical pityriasis rubra pilaris, porokeratosis, lymphomatoid papulosis, papulosquamous chronic GVHD, parakeratosis variegata, Grover disease, Darier disease and BRAF-inhibitor-induced acantholytic dyskeratosis), facial inflammatory skin diseases (rosacea, seborrheic dermatitis, discoid lupus erythematosus, sarcoidosis, cutaneous leishmaniasis, lupus vulgaris, granuloma faciale and demodicidosis), acquired keratodermas (chronic hand eczema, palmar psoriasis, keratoderma due to mycosis fungoides, keratoderma resulting from pityriasis rubra pilaris, tinea manuum, palmar lichen planus and aquagenic palmar keratoderma), sclero-atrophic dermatoses (necrobiosis lipoidica, morphea and cutaneous lichen sclerosus), hypopigmented macular diseases (extragenital guttate lichen sclerosus, achromic pityriasis versicolor, guttate vitiligo, idiopathic guttate hypomelanosis, progressive macular hypomelanosis and postinflammatory hypopigmentations), hyperpigmented maculopapular diseases (pityriasis versicolor, lichen planus pigmentosus, Gougerot-Carteaud syndrome, Dowling-Degos disease, erythema ab igne, macular amyloidosis, lichen amyloidosus, friction melanosis, terra firma-forme dermatosis, urticaria pigmentosa and telangiectasia macularis eruptiva perstans), itchy papulonodular dermatoses (hypertrophic lichen planus, prurigo nodularis, nodular scabies and acquired perforating dermatosis), erythrodermas (due to psoriasis, atopic dermatitis, mycosis fungoides, pityriasis rubra pilaris and scabies), noninfectious balanitis (Zoon’s plasma cell balanitis, psoriatic balanitis, seborrheic dermatitis and non-specific balanitis) and erythroplasia of Queyrat, inflammatory cicatricial alopecias (scalp discoid lupus erythematosus, lichen planopilaris, frontal fibrosing alopecia and folliculitis decalvans), nonscarring alopecias (alopecia areata, trichotillomania, androgenetic alopecia and telogen effluvium) and scaling disorders of the scalp (tinea capitis, scalp psoriasis, seborrheic dermatitis and pityriasis amiantacea).

Concepts: Systemic lupus erythematosus, Lupus erythematosus, Autoimmune diseases, Immunosuppressive drug, Eczema, Psoriasis, Conditions of the skin appendages, Discoid lupus erythematosus

65

Atopic eczema (AE) is characterized by skin barrier and immune dysfunction. Null mutations in filaggrin (FLG), a key epidermal barrier protein, strongly predispose to AE; however, the precise role of FLG deficiency in AE pathogenesis remains incompletely understood.

Concepts: Immune system, DNA, Proteins, Proteomics, Autoimmune diseases, Eczema, Psoriasis

31

B cells contribute to multiple aspects of autoimmune disorders and may play a role in triggering disease. Thus, targeting B cells may be a promising strategy for treating autoimmune disorders. Better understanding of the B cell subsets that are responsible for the development of autoimmunity will be critical for developing efficient therapies. Here we have reported that B cells expressing the transcription factor T-bet promote the rapid appearance of autoantibodies and germinal centers in spontaneous murine models of systemic lupus erythematosus (SLE). Conditional deletion of T-bet from B cells impaired the formation of germinal centers and mitigated the development of kidney damage and rapid mortality in SLE mice. B cell-specific deletion of T-bet was also associated with lower activation of both B cells and T cells. Taken together, our results suggest that targeting T-bet-expressing B cells may be a potential target for therapy for autoimmune diseases.

Concepts: Cell nucleus, Rheumatoid arthritis, Systemic lupus erythematosus, Lupus erythematosus, Glomerulonephritis, Autoimmune diseases, Sjögren's syndrome, Myasthenia gravis

31

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a severe condition encompassing two major syndromes: granulomatosis with polyangiitis (formerly known as Wegener’s granulomatosis) and microscopic polyangiitis. Its cause is unknown, and there is debate about whether it is a single disease entity and what role ANCA plays in its pathogenesis. We investigated its genetic basis.

Concepts: Vasculitis, Wegener's granulomatosis, Autoimmune diseases, Arthritis, Granuloma, Anti-neutrophil cytoplasmic antibody, Proteinase 3, Vascular-related cutaneous conditions

28

Celiac disease (CD) is an autoimmune disorder that occurs in genetically susceptible individuals of all ages and is triggered by immune response to gluten and related proteins. The disease is characterized by the presence of HLA-DQ2 and/or DQ8 haplotypes, diverse clinical manifestations, gluten-sensitive enteropathy and production of several autoantibodies of which endomysial, tissue transglutaminase and deamidated gliadin peptide antibodies are considered specific. Although anti-reticulin antibodies (ARA) have historically been used in the evaluation of CD, these assays lack optimal sensitivities and specificities for routine diagnostic use. This review highlights the advances in CD-specific serologic testing and the rationale for eliminating ARA from CD evaluation consistent with recommendations for diagnosis.

Concepts: Immune system, Antibody, Immunology, Autoimmune diseases, Autoimmunity, Coeliac disease, Gliadin, Triticeae glutens

28

Chronic leg ulcers in patients with rheumatological diseases can cause significant morbidity. We performed a retrospective case review to describe the epidemiology, clinical features and outcome of chronic leg ulcers in this group of patients. Twenty-nine patients with underlying rheumatological conditions, namely, rheumatoid arthritis (15 patients), systemic lupus erythematosus (8 patients), overlap syndromes (3 patients), systemic sclerosis (1 patient) and ankylosing spondylitis (1 patient) were included. The ulcers were mostly located around the ankle (55·2%) and calves (37·9%). The predominant aetiology of the ulcers, in decreasing order of frequency, was venous disease, multifactorial, vasculitis or vasculopathy, infective, pyoderma gangrenosum, ischaemic microangiopathy and iatrogenic. Treatment modalities included aggressive wound bed preparation, compression therapy (17 patients), changes in immunosuppressive therapy (15 patients), hyperbaric oxygen therapy (4 patients) and cellular skin grafting (2 patients). Management of chronic leg ulcers in rheumatological patients is challenging and the importance of careful clinicopathological correlation and treatment of the underlying cause cannot be overemphasised.

Concepts: Osteoporosis, Rheumatoid arthritis, Rheumatology, Systemic lupus erythematosus, Lupus erythematosus, Autoimmune diseases, Arthritis, Immunosuppressive drug

28

ABSTRACT:: Pyodermatitis-pyostomatitis vegetans (PPV) constitutes an inflammatory mucocutaneous dermatosis that is associated with inflammatory bowel disease. Clinically, PPV appears as pustules on mucosal surfaces and as vegetating exudative plaques on intertriginous surfaces. It is typically a clinical diagnosis supported by histological findings. Microscopic findings include epidermal hyperplasia, focal acantholysis, and a dense mixed inflammatory infiltrate with intraepithelial and subepithelial eosinophilic microabscesses. In the recent literature, immunofluorescence has been thought to be negative in PPV or, if positive, an aberrant finding. Herein, we report 2 cases of PPV associated with inflammatory bowel disease, which display intercellular IgA deposits. Although these cases may represent isolated epiphenomena, it is possible that the paucity of PPV cases with immunofluorescent studies hitherto has led to an oversight of an interesting association between intercellular IgA and PPV.

Concepts: Immune system, Inflammation, Anatomical pathology, Ulcerative colitis, Inflammatory bowel disease, Autoimmune diseases, Pemphigus, Pemphigus vegetans