[Peripheral neuroimmunological diseases - Neuropathological insights and clinical perspectives]. / Periphere neuroimmunologische Erkrankungen ­ neuropathologische Einsichten und klinische Perspektiven.

This article deals with peripheral neuroimmunological diseases and briefly outlines the currently most important aspects and treatment developments. Idiopathic inflammatory myopathies have different mechanisms of development, manifestations and prognoses. New classification systems and more specific treatment concepts have been developed. The IIMs include different subgroups. These entities can have specific autoantibodies. Diagnostically, a muscle biopsy is generally desirable for a precise diagnosis and is essential in unclear cases. Primary systemic vasculitides can be divided into different groups based on the predominant pattern of involvement, while secondary vasculitides and single organ vasculitides are also differentiated. Vasculitic myopathy cannot be equated with myositis and a reliable distinction is currently only possible by a muscle biopsy. Treatment concepts should be developed on an interdisciplinary basis. Chronic inflammatory demyelinating polyneuropathy is the most frequent immune-mediated neuropathy and is characterized by a predominant demyelination of the motor and sensory nerves. The disease course runs in phases or is progressive and leads to significant disability and reduction in quality of life, despite current standard treatment. Novel treatment approaches are currently undergoing clinical trials. Myasthenia gravis, with the leading symptom of exercise-induced muscle weakness, is caused by autoantibodies against structures of the neuromuscular endplate. Autoantibody testing is the most important pillar in the diagnosis and is now also increasingly guiding treatment decisions. Overall, peripheral neuroimmunological diseases represent a heterogeneous group. Increasing knowledge of the pathophysiology is the key to numerous developments in diagnostics and treatment, which could lead to far-reaching practical changes in the future.

Pulmonary embolism versus pulmonary vasculitis in Hughes-Stovin syndrome: Characteristic computed tomography pulmonary angiographic findings and diagnostic and therapeutic implications. HSS International Study Group.

BACKGROUND AND AIM: Hughes-Stovin syndrome (HSS) is a rare systemic vasculitis with widespread venous/arterial thrombosis and pulmonary vasculitis. Distinguishing between pulmonary embolism (PE) and in-situ thrombosis in the early stages of HSS is challenging. The aim of the study is to compare clinical, laboratory, and computed tomography pulmonary angiography (CTPA) characteristics in patients diagnosed with PE versus those with HSS. METHODS: This retrospective study included 40 HSS patients with complete CTPA studies available, previously published by the HSS study group, and 50 patients diagnosed with PE from a single center. Demographics, clinical and laboratory findings, vascular thrombotic events, were compared between both groups. The CTPA findings were reviewed, with emphasis on the distribution, adherence to the mural wall, pulmonary infarction, ground glass opacification, and intra-alveolar hemorrhage. Pulmonary artery aneurysms (PAAs) in HSS were assessed and classified. RESULTS: The mean age of HSS patients was 35 ± 12.3 years, in PE 58.4 ± 17 (p < 0.0001). Among PE 39(78 %) had co-morbidities, among HSS none. In contrast to PE, in HSS both major venous and arterial thrombotic events are seen.. Various patterns of PAAs were observed in the HSS group, which were entirely absent in PE. Parenchymal hemorrhage was also more frequent in HSS compared to PE (P < 0.001). CONCLUSION: Major vascular thrombosis with arterial aneurysms formation are characteristic of HSS. PE typically appear loosely-adherent and mobile whereas "in-situ thrombosis" seen in HSS is tightly-adherent to the mural wall. Mural wall enhancement and PAAs are distinctive pulmonary findings in HSS. The latter findings have significant therapeutic ramifications.

[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.

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.

Daratumumab for autoimmune diseases: a systematic review.

OBJECTIVE: Refractory autoimmune diseases remain a significant challenge in clinical practice and new therapeutic options are needed. This systematic review evaluates the existing reported data on the CD38-targeting antibody daratumumab as a new therapeutic approach in autoantibody-mediated autoimmune diseases. METHODS: A protocolised systematic literature review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. Two databases (Medline and Embase) were searched for suitable studies. Usage of daratumumab in non-oncological or non-transplantation associated diseases with autoimmune pathophysiology was analysed including patient characteristics, therapeutic regimen, adverse events and patient outcome. RESULTS: 38 publications reporting the clinical course of 83 patients met the inclusion criteria. Daratumumab usage was reported in therapy-refractory cases (median of 5 different previous therapies) in 24 different autoimmune diseases. The median number of applications of daratumumab was 4, mainly via intravenous applications (87%). Concomitant treatment included glucocorticoids in 64% of patients, intravenous immunoglobulins (33%) and rituximab (17%). Remission or improvement of disease was reported in 81% of patients. Autoantibody depletion or reduction was stated in 52% of patients. Death occurred in three patients (3%). Adverse events were reported in 45% of patients including application-associated reaction (20%), infection (19%) and hypogammaglobulinaemia (33%). CONCLUSION: Targeting CD38 via daratumumab is a new promising therapeutic option in therapy refractory autoimmune diseases. Efficacy as well as optimal therapeutic regimen and management or prevention of adverse events require further investigation. Therefore, systematic clinical trials of this therapeutic approach are needed.

VEXAS syndrome: a diagnostic puzzle.

The VEXAS syndrome (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) is an adult-onset systemic autoinflammatory condition that is caused by an acquired deficiency of the UBA1 gene in hematopoietic progenitor cells. The clinical spectrum of the VEXAS syndrome currently comprises a broad range of phenotypes such as vasculitis, relapsing polychondritis and Sweet's syndrome. In the past, VEXAS patients have left clinicians puzzled and the true nature of this disease has not been captured until late 2020. This viewpoint describes the relevant clinical features of the VEXAS syndrome and reviews different approaches to establish the diagnosis. Finally, future directions within the field of systemic inflammatory diseases caused by somatic mutations are being discussed.

[Hughes-Stovin syndrome: a life-threatening manifestation of Behçet's syndrome]. / Hughes-Stovin-Syndrom: eine lebensbedrohliche Manifestation des Behçet-Syndroms.

Hughes-Stovin syndrome (HSS) is a systemic inflammatory condition of unknown origin that is considered to be part of the Behçet's syndrome (BS) spectrum. Recurrent venous thrombosis and superficial thrombophlebitis in combination with bilateral pulmonary artery aneurysms (PAA) represent the hallmark of HSS. The diagnostic evaluation includes computed tomography pulmonary angiography to detect signs of pulmonary vasculitis. The management of HSS is based on the European Alliance of Associations for Rheumatology (EULAR) recommendations for BS and mainly comprises immunosuppressive therapy with glucocorticoids and cyclophosphamide. In addition to drug therapy, PAA should be evaluated for interventional treatment. Spontaneous PAA rupture due to fragile vessel architecture can occur even in cases of remission and/or PAA regression.

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.

[Cocaine-induced vasculitis and mimics of vasculitis]. / Kokain-induzierte Vaskulitiden und Vaskulitis-Mimics.

Cocaine is a psychotropic tropane alkaloid and stimulant drug. Nasal insufflation of cocaine powder is a common route of administration. In Germany, cocaine is frequently adulterated with levamisole, an anthelminthic drug with immunomodulatory effects. Both substances are linked to various autoimmune conditions. Cocaine-induced midline destructive lesions cause a progressive destruction of osteocartilaginous structures within the upper respiratory tract and can mimic localized granulomatosis with polyangiitis. In addition, systemic vasculitis due to cocaine and levamisole has been reported. Differentiation of these conditions from primary vasculitis can be challenging because antineutrophil cytoplasmic antibodies (ANCA) are commonly detected. Early diagnosis of these conditions is crucial as clinical improvement is closely related to drug cessation.

[Chronic Tropheryma whipplei infection: an important differential diagnosis of refractory polyarthritis]. / Chronische Tropheryma-whipplei-Infektion: Eine wichtige Differentialdiagnose der therapierefraktären Polyarthritis.

BACKGROUND: Refractory arthritis is a common problem in routine rheumatology practice, and can be a diagnostic challenge. In these cases, chronic Tropheryma whipplei (T. whipplei) infection is an important differential diagnosis that should be considered. OBJECTIVE: Based on five clinical cases, this case-based review describes the diagnostic and therapeutic principles in the management of chronic T. whipplei infection. RESULTS: Whipple's disease is a multisystemic infectious disease caused by the bacterium T. whipplei. The disease typically manifests with arthralgia, weight loss and diarrhoea. Joint involvement often develops years before gastrointestinal symptoms occur. In addition to systemic manifestations ("classic Whipple's disease"), T. whipplei can also lead to localized joint infections without gastrointestinal involvement. Articular manifestations of systemic and localized T. whipplei infections are commonly misdiagnosed as a sign of various forms of autoimmmune arthritis. DISCUSSION: Whipple's disease and localized T. whipplei joint infection should be considered in the diagnostic work-up of refractory arthritis. Synovial fluid analysis by means of specific polymerase chain reaction-based testing for T. whipplei is diagnostically ground-breaking.

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.

New-onset dermatomyositis following SARS-CoV-2 infection and vaccination: a case-based review.

Dermatomyositis is a rare, type I interferon-driven autoimmune disease, which can affect muscle, skin and internal organs (especially the pulmonary system). In 2021, we have noted an increase in new-onset dermatomyositis compared to the years before the SARS-CoV-2 pandemic in our center. We present four cases of new-onset NXP2 and/or MDA5 positive dermatomyositis shortly after SARS-CoV-2 infection or vaccination. Three cases occurred within days after vaccination with Comirnaty and one case after SARS-CoV-2 infection. All patients required intensive immunosuppressive treatment. MDA5 antibodies could be detected in three patients and NXP2 antibodies were found in two patients (one patient was positive for both antibodies). In this case-based systematic review, we further analyze and discuss the literature on SARS-CoV-2 and associated dermatomyositis. In the literature, sixteen reports (with a total of seventeen patients) of new-onset dermatomyositis in association with a SARS-CoV-2 infection or vaccination were identified. Ten cases occurred after infection and seven after vaccination. All vaccination-associated cases were seen in mRNA vaccines. The reported antibodies included for instance MDA5, NXP2, Mi-2 and TIF1γ. The reviewed literature and our cases suggest that SARS-CoV-2 infection and vaccination may be considered as a potential trigger of interferon-pathway. Consequently, this might serve as a stimulus for the production of dermatomyositis-specific autoantibodies like MDA5 and NXP2 which are closely related to viral defense or viral RNA interaction supporting the concept of infection and vaccination associated dermatomyositis.

[Sarcoidosis as prime example of a granulomatous disease]. / Sarkoidose als Paradebeispiel einer granulomatösen Erkrankung.

Sarcoidosis is the most frequent immunologically related granulomatous disease and can serve as a model for understanding diseases within this category. The evidence on the diagnostics and treatment is so far limited. It is therefore all the more important that two new and significant guidelines on diagnosis and treatment of sarcoidosis were published during the last 2 years. Additionally, there were more new publications, which were considered for this review article. In this context, this review article provides a current update and overview of sarcoidosis. Pathophysiologically, there is an increasing understanding of the complex processes and interactions involved in the inflammatory processes and granuloma formation. The probability of a diagnosis of sarcoidosis is determined by compatible histology, the exclusion of differential diagnoses and if possible evidence of a multiorgan manifestation. The clinical course is variable and ranges from an asymptomatic manifestation to severe life-threatening organ failure. The most frequently affected organ are the lungs. Pulmonary fibrosis is the most severe form and is also decisive for mortality. An increasing focus is on the extrapulmonary organ manifestations, in particular, cardiac, hepatosplenic, gastrointestinal, renal, ocular and neurological involvement. Treatment, which consists primarily of immunosuppression, should be initiated in cases of organ-threatening or quality of life-impairing activity of the disease. Additional organ-specific management must also be evaluated. In cases of organ failure transplantation should be considered. Due to the limited evidence especially for the treatment of multiorgan sarcoidosis, when possible, patients with this disease should be included in clinical trials.

Effectiveness and Safety of JAK Inhibitors in Autoinflammatory Diseases: A Systematic Review.

Introduction: Autoinflammatory diseases (AID) are rare diseases presenting with episodes of sterile inflammation. These involve multiple organs and can cause both acute organ damage and serious long-term effects, like amyloidosis. Disease-specific anti-inflammatory therapeutic strategies are established for some AID. However, their clinical course frequently includes relapsing, uncontrolled conditions. Therefore, new therapeutic approaches are needed. Janus Kinase inhibitors (JAKi) block key cytokines of AID pathogenesis and can be a potential option. Methods: A systematic review of the literature in accordance with the PRISMA guidelines was conducted. Three databases (MEDLINE, Embase and Cochrane Central Register of Controlled Trials) were searched for publications regarding the use of JAKi for AID. Data from the included publications was extracted and a narrative synthesis was performed. Criteria for defining treatment response were defined and applied. Results: We report data from 38 publications with a total of 101 patients describing the effects of JAKi in AID. Data on Type I Interferonopathies, Adult-Onset Still's Disease (AOSD), Systemic Juvenile Idiopathic Arthritis (sJIA), Familial Mediterranean Fever (FMF), and Behçet's Syndrome (BS) was identified. From a total of 52 patients with type I interferonopathies, in seven patients (7/52, 13.5%) a complete response was achieved, most (35/52, 67.3%) showed a partial response and a minority (10/52, 19.2%) showed no treatment response. For AOSD, a complete or a partial response was achieved by eleven (11/26, 42.3%) patients each. Two sJIA patients achieved complete response (2/4, 50%) and in two cases (2/4, 50%) a partial response was reported. Half of FMF patients showed a complete response and the other half had a partial one (3/6, 50.0%). Amongst BS patients most achieved a partial response (8/13, 61.5%). Five patients showed no response to therapy (5/13, 38.5%). Overall, the most frequent AEs were upper respiratory tract infections (17), pneumonia (10), BK virus viremia (10) and viruria (4), herpes zoster infection (5), viral gastroenteritis (2) and other infections (4). Conclusion: The results from this systematic review show that JAKi can be beneficial in certain AID. The risk of AEs, especially viral infections, should be considered. To accurately assess the risk benefit ratio of JAKi for AID, clinical trials should be conducted.