Lessons learned from a muscle study in nail-patella syndrome.

Background: Nail-patella (NPS) syndrome is an autosomal dominant disorder caused by mutations in the LMX1B gene and manifests with involvement of kidneys, nails, eyes as well as skeletal musculature. NPS shows some clinical similarities with Emery-Dreifuss muscular dystrophy. However, thus far human muscle tissue has not been analysed in the context of NPS to precisely clarify the muscular involvement in this multi-systemic disease.

The potassium channel K2.1 shapes the morphology and function of brain endothelial cells via actin network remodeling.

K2.1 (gene: Kcnk2), a two-pore-domain potassium channel, regulates leukocyte transmigration across the blood-brain barrier by a yet unknown mechanism. We demonstrate that Kcnk2 mouse brain microvascular endothelial cells (MBMECs) exhibit an altered cytoskeletal structure and surface morphology with increased formation of membrane protrusions.

CD19xCD3 T cell engager blinatumomab effective in refractory generalized myasthenic syndromes.

In this case series, we report the first off-label use of the CD19xCD3 T cell engager blinatumomab in two patients with generalized myasthenia gravis (MG). Refractory MG remains a major therapeutic challenge, with patients experiencing severe disability and potentially life-threatening crises despite intensive immunotherapy. This study evaluates the clinical efficacy and safety of short-term blinatumomab treatment in two patients with severe, refractory generalized MG.

Co-occurrence of myositis and neuropathy after anti-CD30 therapy in a late-adolescent Hodgkin lymphoma patient.

Objective: Immune-related adverse events (irAEs) are recognized in oncology, particularly with immune checkpoint inhibitors and other targeted therapies. Brentuximab Vedotin (BV), is an anti-CD30 antibody-drug conjugate- its association with immune-mediated myositis remains unexplored. We report a case of an adolescent with Hodgkin lymphoma (HL) who developed neuropathy and myositis following BV therapy.

Activated Dendritic Cell Subsets Characterize Muscle of Inclusion Body Myositis Patients and Correlate with KLRG1+ and TBX21+ CD8+ T cells.

Inclusion body myositis (IBM) is an idiopathic inflammatory myopathy characterized by muscle-infiltrating KLRG1+ and TBX21+ cytotoxic T cells and type 1 inflammation. Myeloid dendritic cells (mDCs), including type 1 conventional dendritic (cDC1) cells, type 2 conventional dendritic (cDC2) cells, and mature immunoregulatory dendritic (mregDC) cells, have previously been reported in skeletal muscle of IBM patients and may activate these cytotoxic T cells. Here, we analyzed single-nucleus RNA-sequencing (snRNA-seq) and bulk RNA-sequencing (RNA-seq) data from skeletal muscle of IBM, other myositis, and control patients to identify and quantify these mDC subsets and characterize their contribution to IBM inflammation.

Lymphocyte signatures correspond to clinical phenotypes in autoimmune limbic encephalitis.

Autoimmune limbic encephalitis is an inflammatory condition confined to the limbic system of the brain that is deemed to be due to a dysregulated immune response. However, the exact pathophysiological mechanisms remain elusive. Diagnosis of autoimmune limbic encephalitis currently relies on clinical consensus criteria.

Risk factors and clinical significance of neurodegenerative co-pathologies in symptomatic cerebral small vessel disease.

Background: Cerebral small vessel disease (CSVD) often coexists with neurodegenerative pathologies, yet their role remains underexplored. This study aims to determine their prevalence, risk factors, and cognitive effects in patients with deep perforator arteriopathy (DPA) or cerebral amyloid angiopathy (CAA) using the biomarker-based ATN classification.

Methods: In this cross-sectional study 186 patients (median age 75 years, 41% females, 111 with probable CAA, 75 with DPA) underwent MRI for analysis of CSVD severity and etiology, and lumbar puncture for analysis of cerebrospinal fluid amyloid-β 42/40 ratio, phosphorylated-tau, total-tau and neurofilament light.

Mitochondrial damage is associated with an early immune response in inclusion body myositis.

Polymyositis with mitochondrial pathology (PM-Mito) was first identified in 1997 as a subtype of idiopathic inflammatory myopathy. Recent findings demonstrated significant molecular similarities between PM-Mito and inclusion body myositis (IBM), suggesting a trajectory from early to late IBM and prompting the inclusion of PM-Mito as an IBM precursor (early IBM) within the IBM spectrum. Both PM-Mito and IBM show mitochondrial abnormalities, suggesting that mitochondrial disturbance is a crucial element of IBM pathogenesis.

Differences in innate immune cell populations distinguish autoimmune from herpesvirus-associated encephalitis.

Background: Autoimmune encephalitis (AIE) is a disabling inflammatory condition of the brain deemed to be due to a dysregulated immune response. Viral infections and malignancies together with certain genetic polymorphisms are thought to contribute to the pathogenesis of AIE, yet the exact mechanisms remain insufficiently understood. Diagnosis of AIE currently relies on clinical consensus criteria.

C5 complement inhibition versus FcRn modulation in generalised myasthenia gravis.

Background: Myasthenia gravis (MG) is an autoimmune disorder affecting neuromuscular junctions, leading to fluctuating muscle weakness. While many patients respond well to standard immunosuppression, a substantial subgroup faces ongoing disease activity. Emerging treatments such as complement factor C5 inhibition (C5IT) and neonatal Fc receptor (FcRn) antagonism hold promise for these patients.

Abatacept Induces Long-Term Reconstitution of the B-Cell Niche in a Patient With CTLA-4 Haploinsufficiency: A Case Report.

Objectives: Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) haploinsufficiency is a rare genetic condition characterized by development of immune cytopenia, hypogammaglobulinemia, and/or lymphoproliferative disorder, as well as multiple autoimmunity. Treatment with abatacept was shown to alleviate autoimmune conditions, yet its long-lasting impact on bone marrow function remains undetermined.

Methods: We here present the case of a now 39-year-old woman with CTLA-4 haploinsufficiency with predominant CNS affection, yet multiorgan autoimmunity and lymphopenia.

Molecular composition of skeletal muscle in infants and adults: a comparative proteomic and transcriptomic study.

To gain a deeper understanding of skeletal muscle function in younger age and aging in elderly, identification of molecular signatures regulating these functions under physiological conditions is needed. Although molecular studies of healthy muscle have been conducted on adults and older subjects, there is a lack of research on infant muscle in terms of combined morphological, transcriptomic and proteomic profiles. To address this gap of knowledge, we performed RNA sequencing (RNA-seq), tandem mass spectrometry (LC-MS/MS), morphometric analysis and assays for mitochondrial maintenance in skeletal muscle biopsies from both, infants aged 4-28 months and adults aged 19-65 years.

Preventing long-term disability in CIDP: the role of timely diagnosis and treatment monitoring in a multicenter CIDP cohort.

Background: Chronic inflammatory demyelinating polyneuropathy (CIDP) is an inflammatory disease affecting the peripheral nerves and the most frequent autoimmune polyneuropathy. Given the lack of established biomarkers or risk factors for the development of CIDP and patients' treatment response, this research effort seeks to identify potential clinical factors that may influence disease progression and overall treatment efficacy.

Methods: In this multicenter, retrospective analysis, we have screened 197 CIDP patients who presented to the University Hospitals in Düsseldorf, Berlin, Cologne, Essen, Magdeburg and Munich between 2018 and 2022.

Identification of disease phenotypes in acetylcholine receptor-antibody myasthenia gravis using proteomics-based consensus clustering.

Background: The clinical heterogeneity of myasthenia gravis (MG), an autoimmune disease defined by antibodies (Ab) directed against the postsynaptic membrane, constitutes a challenge for patient stratification and treatment decision making. Novel strategies are needed to classify patients based on their biological phenotypes aiming to improve patient selection and treatment outcomes.

Methods: For this purpose, we assessed the serum proteome of a cohort of 140 patients with anti-acetylcholine receptor-Ab-positive MG and utilised consensus clustering as an unsupervised tool to assign patients to biological profiles.

Inter-alpha-trypsin inhibitor heavy chain H3 is a potential biomarker for disease activity in myasthenia gravis.

Myasthenia gravis is a chronic antibody-mediated autoimmune disease disrupting neuromuscular synaptic transmission. Informative biomarkers remain an unmet need to stratify patients with active disease requiring intensified monitoring and therapy; their identification is the primary objective of this study. We applied mass spectrometry-based proteomic serum profiling for biomarker discovery.

Cell-mediated cytotoxicity within CSF and brain parenchyma in spinal muscular atrophy unaltered by nusinersen treatment.

5q-associated spinal muscular atrophy (SMA) is a motoneuron disease caused by mutations in the survival motor neuron 1 (SMN1) gene. Adaptive immunity may contribute to SMA as described in other motoneuron diseases, yet mechanisms remain elusive. Nusinersen, an antisense treatment, enhances SMN2 expression, benefiting SMA patients.

Recombinant Acetylcholine Receptor Immunization Induces a Robust Model of Experimental Autoimmune Myasthenia Gravis in Mice.

Myasthenia gravis (MG) is a prototypical autoimmune disease of the neuromuscular junction (NMJ). The study of the underlying pathophysiology has provided novel insights into the interplay of autoantibodies and complement-mediated tissue damage. Experimental autoimmune myasthenia gravis (EAMG) emerged as a valuable animal model, designed to gain further insight and to test novel therapeutic approaches for MG.

The Use of Nitrosative Stress Molecules as Potential Diagnostic Biomarkers in Multiple Sclerosis.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) of still unclear etiology. In recent years, the search for biomarkers facilitating its diagnosis, prognosis, therapy response, and other parameters has gained increasing attention. In this regard, in a previous meta-analysis comprising 22 studies, we found that MS is associated with higher nitrite/nitrate (NOx) levels in the cerebrospinal fluid (CSF) compared to patients with non-inflammatory other neurological diseases (NIOND).

Right Brain: The Strangeness of a Good Diagnosis.

Coffee, black with a spritz of milk. I enjoyed routine, and today was no different. We were on the 12th floor of the "tower", as our hospital is lovingly called.

K2.1 is a regulator of inflammatory cell responses in idiopathic inflammatory myopathies.

K2.1 (TREK1), a two-pore domain potassium channel, has emerged as regulator of leukocyte transmigration into the central nervous system. In the context of skeletal muscle, immune cell infiltration constitutes the pathogenic hallmark of idiopathic inflammatory myopathies (IIMs).

Immune Checkpoint Inhibition-Related Myasthenia-Myositis-Myocarditis Responsive to Complement Blockade.

Objective: Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy but come with immune-related adverse events (irAEs) that provide a novel challenge for treating physicians. Neuromuscular irAEs, including myositis, myasthenia gravis (MG), and demyelinating polyradiculoneuropathy, lead to significant morbidity and mortality.

Methods: We present a case of severe myasthenia-myositis-myocarditis overlap in a patient receiving ICIs for breast cancer.