Type I interferons (IFNs) are essential mediators of antiviral responses. These cytokines have been implicated in the pathogenesis of autoimmunity, most notably systemic lupus erythematosus (SLE), diabetes mellitus, and dermatomyositis, as well as monogenic type I interferonopathies. Despite a fundamental role in health and disease, the direct quantification of type I IFNs has been challenging. Using single-molecule array (Simoa) digital ELISA technology, we recorded attomolar concentrations of IFNα in healthy donors, viral infection, and complex and monogenic interferonopathies. IFNα protein correlated well with functional activity and IFN-stimulated gene expression. High circulating IFNα levels were associated with increased clinical severity in SLE patients, and a study of the cellular source of IFNα protein indicated disease-specific mechanisms. Measurement of IFNα attomolar concentrations by digital ELISA will enhance our understanding of IFN biology and potentially improve the diagnosis and stratification of pathologies associated with IFN dysregulation.

Monoclonal antibodies acting on the calcitonin gene-related peptide or on its receptor are new drugs to prevent migraine. Four monoclonal antibodies have been developed: one targeting the calcitonin gene-related peptide receptor (erenumab) and three targeting the calcitonin gene-related peptide (eptinezumab, fremanezumab, and galcanezumab). The aim of this document by the European Headache Federation (EHF) is to provide an evidence-based and expert-based guideline on the use of the monoclonal antibodies acting on the calcitonin gene-related peptide for migraine prevention. The guideline was developed following the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach. The working group identified relevant questions, performed systematic review and analysis of the literature, assessed the quality of available evidence, and wrote recommendations. Where the GRADE approach was not applicable, expert opinion was provided. We found low to high quality of evidence to recommend eptinezumab, erenumab, fremanezumab, and galcanezumab in patients with episodic migraine and medium to high quality of evidence to recommend erenumab, fremanezumab, and galcanezumab in patients with chronic migraine. For several clinical questions, there was not enough evidence to provide recommendations using the GRADE approach and recommendations relied on experts’ opinion. Monoclonal antibodies acting on the calcitonin gene-related peptide are new drugs which can be recommended for migraine prevention. Real life data will be useful to improve the use of those drugs in clinical practice.

See Charidimou (doi:10.1093/aww253) for a scientific commentary on this article. Cerebroretinal vasculopathy, hereditary vascular retinopathy, and hereditary endotheliopathy, retinopathy, nephropathy and stroke are neurovascular syndromes initially described as distinct entities. Recently they were shown to be one disease caused by C-terminal frame-shift mutations in TREX1, which was termed ‘retinal vasculopathy with cerebral leukodystrophy’. Here we defined the genetic and clinicopathologic spectrum of this clinically and pathophysiologically poorly characterized and frequently misdiagnosed fatal neurovascular disorder. We identified five different TREX1 mutations in 78 members from 11 unrelated families and by using a standardized study protocol we retrospectively reviewed and aggregated the associated clinical, neuroimaging, and pathology data. Findings were similar across mutations and families. Sixty-four mutation carriers had vascular retinopathy. Neuroimaging revealed (i) punctate, hyperintense, white matter lesions with or without nodular enhancement in 97% of them; (ii) rim-enhancing mass lesions in 84%; and (iii) calcifications in the white matter in 52%. Ninety per cent had clinical manifestations of brain disease, including focal neurological deficits (68%), migraine (59%), cognitive impairment (56%), psychiatric disturbances (42%), and seizures (17%). One mutation carrier had enhancing brain lesions and neurological features but unknown retinopathy status. Additional systemic features included liver disease (78%), anaemia (74%), nephropathy (61%), hypertension (60%), mild Raynaud’s phenomenon (40%), and gastro-intestinal bleeding (27%). Mean (± standard deviation) age at diagnosis was 42.9 ± 8.3 years and at death 53.1 ± 9.6 years. Pathological examination revealed systemic vasculopathy with luminal narrowing and multi-laminated basement membranes. The 13 mutation carriers without retinopathy or brain lesions were on average 8 years younger (mean age: 35.1 ± 10.6 years). Of them, 54% had mild Raynaud’s phenomenon, 42% had migraine, and 23% had psychiatric disturbances. Retinal vasculopathy with cerebral leukodystrophy is an autosomal dominant systemic small-vessel disease due to specific TREX1 mutations and clinically primarily characterized by (i) visual impairment from vascular retinopathy; and (ii) neurological decline and premature death due to progressive enhancing cerebral white matter lesions. Impaired liver and kidney function, anaemia sometimes associated with gastrointestinal bleeding, hypertension, migraine, and Raynaud’s phenomenon appear to be part of the clinical spectrum as well. Penetrance seems high. Because of the pathogenetic basis and the emerging clinical picture with systemic manifestations and conspicuous absence of leukodystrophy, we renamed the disease ‘retinal vasculopathy with cerebral leukoencephalopathy and systemic manifestations’. We propose diagnostic criteria to facilitate clinical recognition and future studies.

Background: The blood metabolome incorporates cues from the environment and the host’s genetic background, potentially offering a holistic view of an individual’s health status. Methods: We have compiled a vast resource of proton nuclear magnetic resonance metabolomics and phenotypic data encompassing over 25 000 samples derived from 26 community and hospital-based cohorts. Results: Using this resource, we constructed a metabolomics-based age predictor (metaboAge) to calculate an individual’s biological age. Exploration in independent cohorts demonstrates that being judged older by one’s metabolome, as compared with one’s chronological age, confers an increased risk on future cardiovascular disease, mortality, and functionality in older individuals. A web-based tool for calculating metaboAge ( metaboage.researchlumc.nl ) allows easy incorporation in other epidemiological studies. Access to data can be requested at bbmri.nl/samples-images-data . Conclusions: In summary, we present a vast resource of metabolomics data and illustrate its merit by constructing a metabolomics-based score for biological age that captures aspects of current and future cardiometabolic health.

Cortical hyperexcitability due to enhanced glutamatergic activity has been implicated in migraine pathophysiology but direct evidence is lacking. Here we assessed glutamate levels and intracellular mobility of glutamate in the visual cortex of migraineurs in-between attacks. We included 50 migraineurs (23 with aura and 27 without aura) and 24 age- and gender-matched non-headache controls. We used proton magnetic resonance spectroscopy (¹H-MRS) and diffusion weighted spectroscopy at 7 T with a single volume of interest (2 × 2 × 3 cm) located in the primary and secondary visual cortex. For ¹H-MRS we used a semi-LASER sequence with water referencing for absolute quantification. For diffusion weighted spectroscopy we used an adapted PRESS sequence with gradients applied in three directions and two different gradient amplitudes. Between-group differences were evaluated using analysis of covariance with the grey matter fraction in the volume of interest as covariate and post hoc comparisons with Bonferroni correction. Glutamate concentrations differed between groups (P = 0.047) and were higher in migraineurs without aura (mean ± standard deviation: 7.02 ± 0.50 mM) compared to controls (mean ± standard deviation: 6.40 ± 0.78 mM, P = 0.042). The apparent diffusion coefficient of glutamate was similar among groups (P = 0.129) suggesting similar inter- and intracellular mobility of glutamate in all three study groups. No differences were observed for concentrations and diffusion constants of other metabolites. The present study suggests that interictal glutamate levels are increased in the visual cortex of migraineurs without aura, supporting the hypothesis of cortical hyperexcitability in migraine.