[The unusual mimicker of a polymyositis]. / Der außergewöhnliche Nachahmer einer Polymyositis.

This article describes a hantavirus-associated pronounced myositis as a rare differential diagnosis to polymyositis. The literature on the pathogenesis of hantavirus disease discusses less a direct viral cytopathology but more a secondary immune dysregulation with induction of a capillary leak. This article describes for the first time a case of successful treatment of protracted hantavirus myositis using high-dose glucocorticoids and cyclophosphamide, followed by ciclosporin and MTX.

[Pathogenesis of large vessel vasculitides]. / Pathogenese der Großgefäßvaskulitiden.

Large vessel vasculitides comprise two distinct entities, giant cell arteritis (GCA) and Takayasu arteritis (TAK). GCA is the most common vasculitis in central Europe, becoming manifested at an age over 50 years. In contrast, the much rarer TAK affects almost exclusively young adults and mostly women. Both vasculitides are granulomatous arteritides affecting mainly the aorta and its major arterial branches. GCA and TAK are associated with different major histocompatibility complex genes. Infections possibly play a role in the initiation of large vessel vasculitides. Activation of dendritic cells in the adventitia induces chemokine and cytokine-mediated recruitment and maturation of T­helper (Th)1 and Th17 cells and macrophages producing cytokines, growth factors and matrix metalloproteinases. In GCA, CD4+ T­helper cells and macrophages are predominantly found in the inflammatory infiltrate. In TAK, the infiltrate also contains cytotoxic CD8+ T­cells and γδ T­cells. This could indicate different antigenic triggers in GCA and TAK. Inflammatory infiltration with T­cells and macrophages and activation of myofibroblasts and smooth muscular cells induce vascular remodeling with intimal hyperplasia and destruction of the media. Remodeling is histologically characterized by progressive arterial wall fibrosis, vascular stenosis and obstruction. In summary, GCA and TAK represent two different entities with a distinct human leukocyte antigen (HLA) and potentially etiopathogenetic background. Clinically, inflammation-related general symptoms and signs of ischemia are encountered, accompanied by increased levels of serological markers of inflammation.

[De-escalation of therapy in ANCA-associated vasculitides]. / Therapiedeeskalation bei ANCA-assoziierten Vaskulitiden.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) require a differentiated therapeutic approach depending on the degree of organ dysfunction and disease activity. In organ dysfunction and life-threatening AAV cyclophosphamide and rituximab are recommended for the induction of remission. For remission induction with a lack of organ dysfunction and non-life-threatening AAV, methotrexate or mycophenolate mofetil are recommended. For remission maintenance therapy azathioprine or methotrexate are used. In the case of contraindications, intolerance or previous failure of azathioprine and methotrexate treatment, rituximab, leflunomide or mycophenolate mofetil may be used as alternatives. Maintenance therapy is usually continued for at least 2 years. De-escalation of therapy requires continuous clinical monitoring while the glucocorticoid medication and immunosuppressive therapy is tapered; however, every de-escalation of therapy carries a risk of relapse.

Effector memory T­cells in the pathogenesis of ANCA-associated vasculitides.

Patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides (AAV) have an expansion of effector memory T­cells in peripheral blood. The enlarged effector memory cell population contains distinct cell subsets, including T­helper type 1 (Th1) CD4+ T­cells lacking co-stimulatory CD28 expression and Th17 cells in granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) and Th2 type and Th17 cells in eosinophilic granulomatosis with polyangiitis (EGPA). The cytokine response of autoreactive proteinase 3 (PR3)-specific effector memory T­cells is skewed towards an increase of Th2 type, Th17, and Th22 cell fractions in GPA. Anomalous effector memory CD4+ T­cell co-stimulation is suggested by the aberrant expression of P­selectin glycoprotein ligand-1, ß­2 integrin, chemokine receptors, natural-killer group 2 member D (NKG2D) and other activating receptors. The increased expression of these receptors is accompanied by T­cell activation and migration to inflamed tissues. T­cells are abundant and secrete proinflammatory cytokines in inflammatory lesions in AAV. The T­cell mediated tissue damage correlates with renal outcome, whereas B­cell infiltration does not. Activation of lesional CD4+NKG2D+ effector memory T­cells is independent of the antigen; moreover, CD4+NKG2D+ effector memory T­cells display NK-cell-like cytotoxicity towards microvascular endothelial cells in vitro. Thus, effector memory T­cells play an important role in tissue damage and disease progression in AAV. Sequentially administered or combined with B­cell depleting therapy, T­cell-directed therapies, especially those directed against effector memory CD4+ T­cells, may further improve the outcome and help to achieve long-term remissions in AAV.

[Clinical spectrum of IgG4-related diseases and the connection to rheumatology]. / Klinisches Spektrum der IgG-4-assoziierten Erkrankungen und der Bezug zur Rheumatologie.

Rheumatologist should be familiar with the concept of IgG4-related disease (IgG4-RD). Due to the clinical spectrum IgG4-RD can fall directly within the scope of rheumatology and are often diagnosed primarily by rheumatologists. Furthermore, IgG4RD are relevant differential diagnoses for many other rheumatic conditions. Finally, there are an increasing amount of data suggesting an important role of immunological processes observed in IgG4-RD for other rheumatic diseases.

[Effector memory T­cells in the pathogenesis of ANCA-associated vasculitides. German version]. / Effektor-Memory-T­Zellen in der Pathogenese von ANCA-assoziierten Vaskulitiden.

Patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides (AAV) have an expansion of effector memory T­cells in peripheral blood. The enlarged effector memory cell population contains distinct cell subsets, including T­helper type 1 (Th1) CD4+ T­cells lacking co-stimulatory CD28 expression and Th17 cells in granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) and Th2 type and Th17 cells in eosinophilic granulomatosis with polyangiitis (EGPA). The cytokine response of autoreactive proteinase 3 (PR3)-specific effector memory T­cells is skewed towards an increase of Th2 type, Th17 and Th22 cell fractions in GPA. Anomalous effector memory CD4+ T­cell co-stimulation is suggested by the aberrant expression of P­selectin glycoprotein ligand­1, beta­2 integrin, chemokine receptors, natural-killer group 2 member D (NKG2D) and other activating receptors. The increased expression of these receptors is accompanied by T­cell activation and migration to inflamed tissues. The T­cells are abundant and secrete proinflammatory cytokines in inflammatory lesions in AAV. The T­cell mediated tissue damage correlates with renal outcome, whereas B-cell infiltration does not. Activation of lesional CD4+NKG2D+ effector memory T­cells is independent of the antigen; moreover, CD4+NKG2D+ effector memory T­cells display NK-cell-like cytotoxicity towards microvascular endothelial cells in vitro. Thus, effector memory T­cells play an important role in tissue damage and disease progression in AAV. Sequentially administered or combined with B-cell depleting therapy, T­cell-directed therapies, especially those directed against effector memory CD4+ T­cells, may further improve the outcome and help to achieve long-term remission in AAV.

[Systemic vasculitides: revised nomenclature, new therapeutic strategies]. / Systemische Vaskulitiden: Revidierte Nomenklatur, neue Therapiestrategien.

Vasculitides comprise a heterogeneous group of inflammatory diseases of the blood vessels, which are characterized both by their diversity and an overlap of clinical and pathological findings and manifestations. The etiology of most vasculitides is not yet clear. Their nomenclature and classification is therefore a challenge for internists, immunologists, and pathologists. The revised Chapel Hill Consensus Conference (CHCC) 2012 nomenclature includes an update of the names and definitions of the CHCC 1994 nomenclature. In addition, four new categories were introduced to describe the spectrum of vasculitis comprehensively. Because of the side effects of cytotoxic immunosuppressive agents there is a need for safer and more effective targeted therapies. The first results from studies using biologicals in the treatment of vasculitides are promising.

[T-cells in ANCA-associated vasculitis]. / T-Zellen bei ANCA-assoziierten Vaskulitiden.

CD4+NKG2D+effector memory T-cell-mediated endothelial cell damage and a Th17 dominated cytokine profile of PR3-specific T-cells may play an important role in the pathogenesis of granulomatosis with polyangiitis (Wegener's). The anti-IL-5 antibody mepolizumab (anti-IL-5) induces remission in Churg-Strauss syndrome.

Preliminary classification criteria for the cryoglobulinaemic vasculitis.

BACKGROUND: To develop preliminary classification criteria for the cryoglobulinaemic syndrome or cryoglobulinaemic vasculitis (CV). METHODS: Study part I developed a questionnaire for CV to be included in the formal, second part (study part II). Positivity of serum cryoglobulins was defined by experts as an essential condition for CV classification. In study part II, a core set of classification items (questionnaire, clinical and laboratory items, as agreed) was tested in three groups of patients and controls-that is, group A (new patients with the CV), group B (controls with serum cryoglobulins but lacking CV) and group C (controls without serum cryoglobulins but with features which can be observed in CV). RESULTS: In study part I (188 cases, 284 controls), a positive response to at least two of three selected questions showed a sensitivity of 81.9% and a specificity of 83.5% for CV. This questionnaire was employed and validated in study part II, which included 272 patients in group A and 228 controls in group B. The final classification criteria for CV, by pooling data from group A and group B, required the positivity of questionnaire plus clinical, questionnaire plus laboratory, or clinical plus laboratory items, or all the three, providing a sensitivity of 88.5% and a specificity of 93.6% for CV. By comparing data in group A versus group C (425 controls), the same classification criteria showed a sensitivity 88.5% and a specificity 97.0% for CV. CONCLUSION: Classification criteria for CV were developed, and now need validation.

Molecular signatures of a disturbed nasal barrier function in the primary tissue of Wegener's granulomatosis.

Wegener's granulomatosis (WG) is a complex autoimmune disease of unknown etiology, frequently involving localized inflammation of the nasal mucosa as an early manifestation. The current hypothesis suggests that the disease is triggered by a disturbed interaction between genetic and environmental effects, such as an altered microflora at mucosal layers. In this study, a systematic assessment of 49 transcripts with potential pathophysiological relevance was performed using quantitative real-time PCR in nasal mucosa samples of more than 80 individuals, including normal control (NC) individuals and disease controls. In addition, colonization with Staphylococcus aureus was quantified in the same individuals to assess its impact on transcriptomic signatures. Transcription profiles show an increased heterogeneity in diseased individuals. In all, 10 transcripts were identified to be differentially expressed (P≤0.05, false discovery rate ≤0.05) between patients with WG and NC individuals. These transcripts include antimicrobial peptides (human ß-defensin (DEFB)1: fold-change WG vs. controls: +4.45, lysozyme: -3.4, DEFB4 and S100A7 (S100 calcium-binding protein A7): both "switched on" in WG), innate immune receptors (Toll-like receptor 4: -2.1, NOD-like receptor C3: -2.1, scavenger receptor CD36: +2.9), and cytokines (interferon-γ: -14, transforming growth factor-ß 1: -1.4, interleukin-17D: -2.7). These transcriptional profiles are independent of S. aureus colonization. This study for the first time describes that, on the basis of data obtained from the primary nasal tissue, WG exhibits molecular features that allow its differentiation from other inflammatory disorders with involvement of the nasal mucosa. Further studies based on these findings may enable the identification of subphenotypes, which are currently discussed as an important target for a personalized medicine approach, aiming to reduce side effects and the number of therapy non-responders.