Inflammation of the temporalis muscle and adjacent nerve tissue in giant cell arteritis: expanding the spectrum of inflammatory lesions.

OBJECTIVES: To investigate the histopathological features of the temporalis muscle (TM) and adjacent nerve tissue in active cranial giant cell arteritis (C-GCA). METHODS: Temporal artery biopsy (TAB) specimens containing fragments of the TM from patients with active C-GCA fulfilling the 2022 ACR/EULAR classification criteria (n = 11) were assessed by conventional histology and immunohistochemistry in comparison with non-GCA controls (n = 3). Clinical, laboratory and imaging features based on patient charts at time of biopsy were retrospectively recorded. RESULTS: The majority of the studied TAB specimens showed inflammation of the TM (10/11) and adjacent nerve fascicles (7/11) that was characterized by prominent endomysial lymphomonocytic infiltrates, whereas controls showed no inflammatory lesions and no disruption of the local architecture. Association of active C-GCA with sarcolemmal MHC class I (8/8) and MHC class II (6/11) upregulation suggests primary inflammation of the TM in a subset of patients. αB-Crystallin positivity (10/11) highlights areas of pre-necrotic myofibres within the TM. The presence of endomysial fibrosis, signs of atrophy and variations of muscle fibre size suggest a rather longstanding and potentially subclinical process of myoinflammation. CONCLUSION: Our results expand the spectrum of inflammatory lesions known to be associated with active C-GCA. Specifically, inflammatory infiltration of the TM and adjacent nerve structures could contribute to localized symptoms of the temporomandibular region and may be included in future concepts of pathophysiology.

Anti-Ku + myositis: an acquired inflammatory protein-aggregate myopathy.

Myositis with anti-Ku-autoantibodies is a rare inflammatory myopathy associated with various connective tissue diseases. Histopathological studies have identified inflammatory and necrotizing aspects, but a precise morphological analysis and pathomechanistic disease model are lacking. We therefore aimed to carry out an in-depth morpho-molecular analysis to uncover possible pathomechanisms. Muscle biopsy specimens from 26 patients with anti-Ku-antibodies and unequivocal myositis were analyzed by immunohistochemistry, immunofluorescence, transcriptomics, and proteomics and compared to biopsy specimens of non-disease controls, immune-mediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM). Clinical findings and laboratory parameters were evaluated retrospectively and correlated with morphological and molecular features. Patients were mainly female (92%) with a median age of 56.5 years. Isolated myositis and overlap with systemic sclerosis were reported in 31%, respectively. Isolated myositis presented with higher creatine kinase levels and cardiac involvement (83%), whereas systemic sclerosis-overlap patients often had interstitial lung disease (57%). Histopathology showed a wide spectrum from mild to pronounced myositis with diffuse sarcolemmal MHC-class I (100%) and -II (69%) immunoreactivity, myofiber necrosis (88%), endomysial inflammation (85%), thickened capillaries (84%), and vacuoles (60%). Conspicuous sarcoplasmic protein aggregates were p62, BAG3, myotilin, or immunoproteasomal beta5i-positive. Proteomic and transcriptomic analysis identified prominent up-regulation of autophagy, proteasome, and hnRNP-related cell stress. To conclude, Ku + myositis is morphologically characterized by myofiber necrosis, MHC-class I and II positivity, variable endomysial inflammation, and distinct protein aggregation varying from IBM and IMNM, and it can be placed in the spectrum of scleromyositis and overlap myositis. It features characteristic sarcoplasmic protein aggregation on an acquired basis being functionally associated with altered chaperone, proteasome, and autophagy function indicating that Ku + myositis exhibit aspects of an acquired inflammatory protein-aggregate myopathy.

The value of non-enhanced MRI in the evaluation of patients with suspected idiopathic inflammatory myopathy.

INTRODUCTION/AIMS: The performance of magnetic resonance imaging (MRI) for diagnosing suspected idiopathic inflammatory myopathy (IIM) remains controversial. Furthermore, the role of contrast-enhanced magnetic resonance imaging (CE-MRI) sequences is unclear. The aim of this study was to evaluate the sensitivity and specificity of a non-enhanced magnetic resonance imaging (NE-MRI) protocol compared to a CE-MRI protocol in adult patients with confirmed IIM. METHODS: This study retrospectively enrolled patients with suspected IIM who underwent MRI of the upper thigh between 2008 and 2020. The protocol consisted of a T1-weighted (T1w) sequence, a turbo inversion recovery magnitude (TIRM) sequence and a contrast-enhanced T1-weighted sequence (CE-T1w). After randomly stratifying patients into a group with only the T1w and TIRM sequences available and another group with additional availability of CE-T1w, three blinded readers assessed the presence of IIM based on characteristic imaging features. Confirmation of the diagnosis was determined based on the 2017 ACR/EULAR criteria. RESULTS: Of the 80 patients (mean age 49.0 ± 21.1 years; 42 female, 38 male) included, 54 (67.5%) had a positive diagnosis of IIM. Cumulated sensitivity and specificity for MRI to detect IIM was 87.1% and 83.3% in the NE-MRI group versus 87.0% and 63.0% in the CE-MRI group. The group differences for sensitivity and specificity were non-significant for each of the three readers, respectively (p ≥ .081). DISCUSSION: NE-MRI detects suspected IIM with high diagnostic accuracy and performs equivalently to CE-MRI. Therefore, it may be appropriate to omit the use of contrast agents in MRI scans performed for suspected IIM.

The Joint Vasculitis Registry in German-speaking countries (GeVas): subgroup analysis of 195 GCA patients.

OBJECTIVES: Giant cell arteritis (GCA) is one of the most common forms of vasculitis. There is an abundance of studies which are conducted in a randomised controlled trial setting but limited with respect to cohort size and follow-up time. GeVas is the first large-scale registry for vasculitides in German-speaking countries that enables to evaluate this rare disease. Herein we focus on the subgroup of GCA patients including follow-up data up to one year. METHODS: GeVas is a prospective, web-based, multicentre registry for the documentation of organ manifestations, outcomes, and therapy regimens in vasculitides. Recruitment started in June 2019. By April 2023, 15 centres were initiated and have started to enrol patients. RESULTS: After 4 years, 195 GCA-patients were included in the registry, of which 64% were female and 36% were male. The average age was 76 years at the time of recruitment (IQR=69-82). Seventy-nine percent were included in the registry because of a newly diagnosed GCA and 21% because of a relapse. At the first assessment most of the patients (89%) described general symptoms. Thirty-one percent stated ocular symptoms. Cranial symptoms were documented in 78% of the cases. All patients were documented with immunosuppressive treatment at start, of whom 95% received prednisolone, 16% cyclophosphamide, 20% methotrexate, and 48% tocilizumab. After three months 62% and after one year 91% of the patients achieved remission. CONCLUSIONS: Regarding demographics, clinical manifestations and diagnostics, our study showed a similar composition compared to other studies. However, our data differed in terms of treatment regimens.

The Joint Vasculitis Registry in German-speaking countries (GeVas): subgroup analysis of 266 AAV patients.

OBJECTIVES: Prospective long-term observational data on the disease course of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) were missing in Germany to date. Therefore, the Joint Vasculitis Registry in German-speaking countries (GeVas) has been established to follow the course of patients with AAV. The aim of this study is to present baseline data of patients with newly diagnosed and relapsing AAV enrolled in the GeVas registry. METHODS: GeVas is a prospective, web-based, multicentre, clinician-driven registry for the documentation of organ manifestations, damage, long-term outcomes, and therapy regimens in various types of vasculitis. Recruitment started in June 2019. RESULTS: Between June 2019 and October 2022, 266 patients with AAV were included in the GeVas registry: 173 (65%) with new-onset and 93 (35%) with relapsing AAV. One hundred and sixty-two (61%) patients were classified as granulomatosis with polyangiitis (GPA), 66 (25%) as microscopic polyangiitis (MPA), 36 (13%) as eosinophilic granulomatosis with polyangiitis (EGPA), and 2 (1%) as renal limited AAV. The median age was 59 years (51-70 years, IQR), 130 (51%) patients were female. Most patients were ANCA positive (177; 67%) and affected by general symptoms, pulmonary, ear nose throat (ENT), renal and neurological involvement. For induction of remission, the majority of patients received glucocorticoids (247, 93%) in combination with either rituximab (118, 45%) or cyclophosphamide (112, 42%). CONCLUSIONS: Demographic characteristics are comparable to those in other European countries. Differences were found regarding ANCA status, frequencies of organ manifestations, and therapeutic regimens. The GeVas registry will allow longitudinal observations and prospective outcome measures in AAV.

Diagnostic accuracy of a large language model in rheumatology: comparison of physician and ChatGPT-4.

Pre-clinical studies suggest that large language models (i.e., ChatGPT) could be used in the diagnostic process to distinguish inflammatory rheumatic (IRD) from other diseases. We therefore aimed to assess the diagnostic accuracy of ChatGPT-4 in comparison to rheumatologists. For the analysis, the data set of Gräf et al. (2022) was used. Previous patient assessments were analyzed using ChatGPT-4 and compared to rheumatologists' assessments. ChatGPT-4 listed the correct diagnosis comparable often to rheumatologists as the top diagnosis 35% vs 39% (p = 0.30); as well as among the top 3 diagnoses, 60% vs 55%, (p = 0.38). In IRD-positive cases, ChatGPT-4 provided the top diagnosis in 71% vs 62% in the rheumatologists' analysis. Correct diagnosis was among the top 3 in 86% (ChatGPT-4) vs 74% (rheumatologists). In non-IRD cases, ChatGPT-4 provided the correct top diagnosis in 15% vs 27% in the rheumatologists' analysis. Correct diagnosis was among the top 3 in non-IRD cases in 46% of the ChatGPT-4 group vs 45% in the rheumatologists group. If only the first suggestion for diagnosis was considered, ChatGPT-4 correctly classified 58% of cases as IRD compared to 56% of the rheumatologists (p = 0.52). ChatGPT-4 showed a slightly higher accuracy for the top 3 overall diagnoses compared to rheumatologist's assessment. ChatGPT-4 was able to provide the correct differential diagnosis in a relevant number of cases and achieved better sensitivity to detect IRDs than rheumatologist, at the cost of lower specificity. The pilot results highlight the potential of this new technology as a triage tool for the diagnosis of IRD.

Clinical presentation and genetic variants in patients with autoinflammatory diseases: results from the German GARROD registry.

To investigate clinical symptoms and genetic variants in patients from the German anti-IL-1 registry for autoinflammatory orphan diseases (GARROD) between 2013 and 2022. Multicentre, retrospective analysis of demographic, clinical and genetic data of patients with autoinflammatory diseases (AID) who received anti-IL-1 targeted therapy. The cohort comprised 152 patients with familial Mediterranean fever (FMF; n = 71), cryopyrin-associated periodic syndromes (CAPS; n = 43), TNF-receptor associated periodic syndrome (TRAPS; n = 19), mevalonate kinase deficiency (MKD; n = 3) and unclassified AID (uAID; n = 16). Inflammatory attacks started in 61.2% of the patients before the age of 18 years. The delay between the first AID attack and anti-IL-1 therapy was 17.8 years. Monogenetic AIDs were diagnosed by clinical symptoms. Genetic analyses confirmed the diagnosis in 87.3% of patients with FMF, 65.2% with CAPS and 94.8% with TRAPS. Among this group, heterozygous MEFV variants and variants of unknown significance (VUS) were detected in 22.5% of patients with FMF, 51.2% with CAPS and 47.4% with TRAPS. Patients with VUS were older at disease onset which is consistent with a milder phenotype. Twenty-four patients had secondary AA amyloidosis (AA) at initiation of anti-IL-1 therapy. The mean age of these patients was 16.4 years at their first attack and 44.9 years at the time of AA diagnosis. Turkish-Armenian ancestry correlated with MEFV variants and higher FMF disease activity compared to German ancestry. Molecular genetic analyses should substantiate the clinical diagnosis of a monogenetic AID. Our data support the concept of variable penetrance of VUS which can be associated with late-onset AID.

Vignette-based comparative analysis of ChatGPT and specialist treatment decisions for rheumatic patients: results of the Rheum2Guide study.

BACKGROUND: The complex nature of rheumatic diseases poses considerable challenges for clinicians when developing individualized treatment plans. Large language models (LLMs) such as ChatGPT could enable treatment decision support. OBJECTIVE: To compare treatment plans generated by ChatGPT-3.5 and GPT-4 to those of a clinical rheumatology board (RB). DESIGN/METHODS: Fictional patient vignettes were created and GPT-3.5, GPT-4, and the RB were queried to provide respective first- and second-line treatment plans with underlying justifications. Four rheumatologists from different centers, blinded to the origin of treatment plans, selected the overall preferred treatment concept and assessed treatment plans' safety, EULAR guideline adherence, medical adequacy, overall quality, justification of the treatment plans and their completeness as well as patient vignette difficulty using a 5-point Likert scale. RESULTS: 20 fictional vignettes covering various rheumatic diseases and varying difficulty levels were assembled and a total of 160 ratings were assessed. In 68.8% (110/160) of cases, raters preferred the RB's treatment plans over those generated by GPT-4 (16.3%; 26/160) and GPT-3.5 (15.0%; 24/160). GPT-4's plans were chosen more frequently for first-line treatments compared to GPT-3.5. No significant safety differences were observed between RB and GPT-4's first-line treatment plans. Rheumatologists' plans received significantly higher ratings in guideline adherence, medical appropriateness, completeness and overall quality. Ratings did not correlate with the vignette difficulty. LLM-generated plans were notably longer and more detailed. CONCLUSION: GPT-4 and GPT-3.5 generated safe, high-quality treatment plans for rheumatic diseases, demonstrating promise in clinical decision support. Future research should investigate detailed standardized prompts and the impact of LLM usage on clinical decisions.

[Wearables in rheumatology]. / Wearables in der Rheumatologie.

As a result of digitalization in medicine wearable computing devices (wearables) are becoming increasingly more important. Wearables are small portable electronic devices with which the user can record data relevant to health, such as number of steps, activity profile, electrocardiogram (ECG), heart and breathing frequency or oxygen saturation. Initial studies on the use of wearables in patients with rheumatological diseases show the opening up of new possibilities for prevention, disease monitoring and treatment. This study provides the current data situation and the implementation of wearables in the discipline of rheumatology. Additionally, future potential fields of application as well as challenges and limits of the implementation of wearables are illustrated.

[The most frequent febrile syndromes and autoinflammatory diseases in adulthood]. / Die häufigsten Fiebersyndrome und autoinflammatorischen Erkrankungen im Erwachsenenalter.

Autoinflammatory diseases are characterized by inflammatory manifestations in various organ systems, whereby recurrent febrile episodes, musculoskeletal complaints, gastrointestinal and cutaneous symptoms frequently occur accompanied by serological signs of inflammation. Autoinflammatory diseases include rare monogenic entities and multifactorial or polygenic diseases, which can manifest as a variety of symptoms in the course of time. Examples of monogenic autoinflammatory diseases are familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) and the recently described VEXAS (vacuoles, E1 enzyme, X­linked, autoinflammatory and somatic) syndrome. For non-monogenically determined autoinflammatory diseases, the most important representatives in adulthood are adult-onset Still's disease (AOSD) and the Schnitzler syndrome, in which a polygenic susceptibility and epigenetic factors are more likely to play a role.

[Fever in rheumatological diseases]. / Fieber bei rheumatologischen Erkrankungen.

Fever is a frequent and important symptom in patients with rheumatological diseases and can be an expression of activity of the underlying rheumatological disease. There is great variability in the incidence of fever as a symptom of the disease between individual diseases. The growing understanding of the molecular signatures of the diseases can help to explain these discrepancies: A genetic overactivation of potently pyrogenic cytokines is the reason why fever is nearly always present in autoinflammatory syndromes. In contrast, fever is less common in polyarthritis and myositis and mostly limited to severe courses of disease. In the diagnostic work-up of fever, frequent differential diagnoses, such as infections, malignancies, side effects of drugs and hypersensitivity reactions should be considered. This article provides an overview of the physiology of the development of fever, describes the relevance of fever in individual rheumatological diseases and proposes a workflow for the clinical clarification of rheumatological patients who present with fever.

[Update on Behçet syndrome]. / Neues zum Behçet-Syndrom.

BACKGROUND: Behçet syndrome (BS) is a vasculitis of variable vessels with multiple organ manifestations. OBJECTIVE: This article gives an overview of innovations in the last 2 years. MATERIAL AND METHODS: A literature search was carried out using the keyword "Behcet" in 2022-2024 in PubMed. The selection of suitable articles was based on the relevance. RESULTS AND CONCLUSION: With respect to the pathophysiology it is now clear that BS occupies an intermediate position between autoinflammatory and autoimmune clinical pictures. It is now classified as MHC-I-opathy, i.e., a disease that has a strong association with HLA class I antigens, which also play a prominent role in the pathogenesis. The diagnostic international criteria for Behcet's disease (ICBD) from 2014 with a score of 4 points or more that makes the diagnosis of BS probable have become established; however, in countries with a low prevalence of BS, the differential diagnosis of BS from other diseases is difficult and a higher point limit in the diagnostic score seems to make sense in order to avoid incorrect diagnoses. Clusters or phenotypes of the disease have now been described in various countries in which different symptom complexes frequently occur together; however, the clusters differ between the different countries of origin and depending on the age of the patients. Sonography of the common femoral vein with specific wall thickening in BS patients has been established as an additional tool for the differential diagnosis. Typical characteristics of oral aphthae in BS were also described and the frequency of positivity in the pathergy test could be significantly increased using pneumococcal antigens as the reagent. The treatment recommendations of the EULAR from 2018 still apply; in treatment-refractory cases, tocilizumab, secukinumab, Janus kinase inhibitors (JAKi) and ustekinumab have now also been successfully used. The new EULAR treatment recommendations are expected in 2025.

[Hemophagocytic lymphohistiocytosis and macrophage activation syndrome : A multidisciplinary challenge]. / Hämophagozytische Lymphohistiozytose und Makrophagenaktivierungssyndrom : Eine multidisziplinäre Herausforderung.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening hyperinflammatory syndrome that is characterized by hyperferritinemia, cytopenia, disseminated intravascular coagulopathy and functional disorders of the liver and the central nervous system. The term macrophage activation syndrome is predominantly used for secondary HLH in the context of autoimmune diseases (e.g., systemic juvenile idiopathic arthritis). In addition, malignancies and genetic inborn errors of immunity can predispose to the development of HLH. Infections (e.g., Epstein-Barr virus) in turn represent possible triggers of an acute episode. Due to the unspecific manifestation of the disease, a systematic evaluation of the organ systems is recommended in the clinical and laboratory analytical clarification of hyperinflammatory syndromes. In general, the treatment should be carried out by a multidisciplinary team with expertise in rheumatology, hematological oncology, infectious diseases and intensive care medicine. The primary treatment of HLH usually consists of glucocorticoids and in cases of a rapid deterioration of the condition anakinra (interleukin 1 block) and intravenous immunoglobulins can be employed. Treatment of the underlying disease should be consequently carried out in parallel, together with antimicrobial treatment.

[Digital health applications-What we should know as rheumatologists]. / Digitale Gesundheitsanwendungen ­ was sollten wir als Rheumatolog:innen wissen.

Digital health applications (DHAs) are revolutionising patient care by improving access to evidence-based therapy and promoting active self-management. The continuously growing number of DHAs enables patients to act more independently through digital support. The budget-neutral prescription and cost coverage by statutory health insurance companies reduce financial barriers for practitioners and patients. Initial studies show that DHAs can be used successfully to treat comorbidities and rheumatic diseases. Several DHAs for inflammatory rheumatic diseases are at an advanced stage of development. The identification of suitable patients and support through shared decision making are crucial for successful implementation. Challenges remain in adherence and acceptance of the applications. This article provides an overview of prescription in clinical routine, initial data and experiences from the reality of rheumatology care, and reports on current developments.

[Vasculitic involvement of the skeletal muscle and the peripheral nervous system: clinical and neuropathologic perspective]. / Vaskulitische Beteiligung der Skelettmuskulatur und des peripheren Nervensystems: Klinische und neuropathologische Perspektive.

The peripheral nervous system is a classic target organ in systemic vasculitis. In addition, the skeletal muscle can also be affected. Myalgia, muscle weakness and sensory deficits are typical signs, which can lead to severe functional limitations and impaired of quality of life. Vasculitic involvement of the skeletal muscle (vasculitic myopathy [VM]) and peripheral nerves (vasculitic neuropathy [VN]) occurs predominantly in polyarteritis nodosa and small-vessel vasculitis. VM presents with elevated markers of inflammation and is typically characterized by immobilizing myalgia with normal creatine kinase activity and diffuse or patchy areas of hyperintensity on T2-weighted MRI ("MRI myositis without myositis"). In VN, sensor motor deficits predominantly affect the lower extremity in the area supplied by several peripheral nerves (e.g., mononeuritis multiplex) with acute to subacute history. The histopathological examination of nerve and muscle biopsies is the gold standard for the diagnosis of vasculitic manifestations and has a significant impact on the therapeutic approach.

Survey on the working, training, and research conditions of resident physicians in internistic and rheumatological continuing education-BEWUSST.

BACKGROUND: Data on the training and continuing education situation of residents in the field of internal medicine and rheumatology are not available for Germany. For this reason, the Commission for Education and Training of the German Society of Rheumatology (DGRh) initiated the BEWUSST survey on the working, training and research conditions of residents in rheumatology. METHODS: A total of 102 questions on the topics of working conditions in everyday professional life, continuing medical education and training, compatibility of career and family, compatibility of work and research, perspectives as a rheumatologist and practical activities were included in an online questionnaire. RESULTS: A total of 102 participants took part in the survey. Of the respondents 48.1% were satisfied with their professional situation, 40.2% of the participants were supervised by a specialist mentor and 54.9% were working as scientists during their work as a physician. A compatibility of family and career was possible for 34.7%. After completion of the residency 52.9% of the respondents aspired to a combined clinical and outpatient activity. CONCLUSION: Half of the trainee rheumatologists are satisfied with their professional activities, although mentoring of the assistants in training should be further improved. With respect to the desired combined clinical and outpatient activity, the existing options should be expanded or new professional fields of activity should be established, so that the specialty remains attractive for the upcoming generations.

How to treat VEXAS syndrome: a systematic review on effectiveness and safety of current treatment strategies.

OBJECTIVES: To evaluate the effectiveness and safety of current treatment strategies for the vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome. METHODS: A protocolized systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was performed. Three databases were searched for reports on treatment strategies for VEXAS. Data from the included publications was extracted and a narrative synthesis was performed. Treatment response was recorded as complete (CR), partial (PR) or none (NR) depending on changes in clinical symptoms and laboratory parameters. Patient characteristics, safety data and previous treatments were analysed. RESULTS: We identified 36 publications with a total of 116 patients; 113 (98.3%) were male. The identified reports included azacytidine (CR 9/36, 25%; PR 14/36, 38.9%), Janus kinase inhibitors (JAKi) (CR 11/33, 33%; PR 9/33, 27.3%), tocilizumab (CR 3/15, 20%; PR 6/15, 40%), allogeneic stem cell transplantation (CR 6/7, 85.7%; one patient died), anakinra (CR 4/5, 80%; NR 1/5, 20%), canakinumab (CR 1/2, 50%; PR 1/2, 50%) and glucocorticoid monotherapy (CR 1/6, 16.7%; PR 4/6, 66.7%). Individual reports were available for TNF inhibitors, rituximab and MTX. Data on adverse events were available for 67 patients (67/116, 57.8%) and included: pneumonia (12/67, 17.9%), other infections (9/67, 13.4%), venous thromboembolisms (6/67, 8.9%), cytopenias (4/67, 5.9%), and acute (4/67, 5.9%) and chronic graft-vs-host-disease (2/67, 2.9%). CONCLUSION: Current data on VEXAS treatment are limited and inhomogeneous. Treatment decisions should be individualized. For the devolvement of treatment algorithms clinical trials are needed. Adverse events remain a challenge, especially an elevated risk for venous thromboembolism associated to JAKi treatment should be carefully considered.

When it looks like Behçet's syndrome but is something else: differential diagnosis of Behçet's syndrome: a two-centre retrospective analysis.

OBJECTIVE: To investigate the differential diagnostic spectrum in patients with suspected Behçet's syndrome (BS) in low prevalence regions. In addition, the number of patients fulfilling the ICBD criteria despite not having BS was evaluated. METHODS: This retrospective analysis was performed in two referral centres for BS. Patients with confirmed BS (clinical diagnosis with fulfilment of ISG criteria or a score of ≥5 points in the ICBD criteria) were excluded. The remaining patients were divided into 11 differential diagnosis categories. If no definitive alternative diagnosis could be established, patients were termed 'probable BS' in case of (i) relapsing orogenital aphthosis in the absence of other causes and either HLA-B51 positivity, or origin from an endemic area or presence of an additional typical BS symptom that is not part of the classification criteria, or (ii) with 3-4 points scored in the ICBD criteria. RESULTS: In total 202 patients were included and categorized as follows: 58 patients (28.7%) as 'probable BS', 57 (28.2%) skin disease, 26 (12.9%) chronic pain syndrome, 14 (6.9%) eye disease, 11 (5.4%) spondyloarthropathy, 9 (4.5%) gastrointestinal disease, 7 (3.5%) neurological disease, 4 (2%) arthritis, 3 (1.5%) auto-inflammation, 3 (1.5%) connective tissue disease and 10 (5.0%) miscellaneous disease. HLA-B51 was positive in 55/132 (41.7%); 75/202 (37.1%) of the patients fulfilled the ICBD criteria. CONCLUSION: In a low disease prevalence setting, the straightforward application of the ICBD criteria may lead to overdiagnosis of BS. The differential diagnosis of BS is enormously broad. Clinicians should be aware that HLA-B51 positivity is still not considered as a diagnostic feature in BS.

Secondary immune-mediated thrombotic thrombocytopenic purpura in idiopathic inflammatory myopathy: a case-based review.

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a potentially fatal acquired thrombotic microangiopathy syndrome that frequently develops in the context of infectious diseases or systemic autoimmune conditions including connective tissue diseases. We report the case of a 42-year-old female suffering from severe iTTP associated with anti-Jo-1 positive antisynthetase syndrome, which was successfully treated with combination therapy of intravenous immune globulin, rituximab and plasma exchange. Based on a systematic review of the literature, two additional cases of idiopathic inflammatory myopathy-associated iTTP (secondary iTTP) were identified. In conclusion, iTTP may be a rare complication of IIM that clinicians should consider in cases of marked thrombocytopenia. Further work-up of this finding should include a peripheral blood smear (schistocyte count) and ADAMTS13 activity. The concomitant manifestation of these autoimmune conditions may require intensive immunosuppressive therapy.

Digital health information on autoinflammatory diseases: a YouTube quality analysis.

Getting access to specialists for autoinflammatory diseases (AID) can be challenging. Therefore, an increasing number of patients and healthcare professionals are seeking information on AID via the Internet, using the video platform YouTube, for example. However, the quality of such videos has not yet been evaluated. A YouTube search was conducted to assess videos about AID to evaluate the quality and usefulness from both the patient's and healthcare professional´s perspectives. Video duration, number of views, likes, dislikes, comments, and uploading source on various AID were extracted. Video quality was evaluated by the modified global quality scale (GQS). The reliability was assessed by the modified five-point DISCERN score. In total, 140 videos were screened of which 105 videos met the inclusion criteria for further analysis. Based on the GQS, the overall quality of videos for patients was found to be low in 64.8%, intermediate in 27.6%, and high in 7.6% of videos. The quality of videos for professionals was similar (54.3% low, 23.8% intermediate, and 21.9% of high quality). Videos were more often targeting medical professionals (65.7%) and less often patients (34.3%). This analysis demonstrates that the majority of videos regarding AIDs are of limited quality. Available videos more often address users with a professional medical background. Only a small proportion of existing videos provide understandable and useful information for AID patients. Thus, there is a strong need to develop high-quality and audience-oriented videos in the context of educational campaigns for these rare disease groups.