Choroid plexus volume in multiple sclerosis vs neuromyelitis optica spectrum disorder: a retrospective, cross-sectional analysis

BACKGROUND AND OBJECTIVES: The choroid plexus has been shown to play a crucial role in CNS inflammation. Previous studies found larger choroid plexus in multiple sclerosis (MS) compared with healthy controls. However, it is not clear whether the choroid plexus is similarly involved in MS and in neuromyelitis optica spectrum disorder (NMOSD). Thus, the aim of this study was to compare the choroid plexus volume in MS and NMOSD. METHODS: In this retrospective, cross-sectional study, patients were included by convenience sampling from 4 international MS centers. The choroid plexus of the lateral ventricles was segmented fully automatically on T1-weighted MRI sequences using a deep learning algorithm (Multi-Dimensional Gated Recurrent Units). Uni- and multivariable linear models were applied to investigate associations between the choroid plexus volume, clinically meaningful disease characteristics, and MRI parameters. RESULTS: We studied 180 patients with MS and 98 patients with NMOSD. In total, 94 healthy individuals and 47 patients with migraine served as controls. The choroid plexus volume was larger in MS (median 1,690 µL, interquartile range [IQR] 648 µL) than in NMOSD (median 1,403 µL, IQR 510 µL), healthy individuals (median 1,533 µL, IQR 570 µL), and patients with migraine (median 1,404 µL, IQR 524 µL; all p < 0.001), whereas there was no difference between NMOSD, migraine, and healthy controls. This was also true when adjusted for age, sex, and the intracranial volume. In contrast to NMOSD, the choroid plexus volume in MS was associated with the number of T2-weighted lesions in a linear model adjusted for age, sex, total intracranial volume, disease duration, relapses in the year before MRI, disease course, Expanded Disability Status Scale score, disease-modifying treatment, and treatment duration (beta 4.4; 95% CI 0.78-8.1; p = 0.018). DISCUSSION: This study supports an involvement of the choroid plexus in MS in contrast to NMOSD and provides clues to better understand the respective pathogenesis

Skeletal Muscle Disorders: A Non-cardiac Source of Cardiac Troponin T.

Background: Cardiac troponin T (cTnT) and cTnI are considered cardiac-specific and equivalent in the diagnosis of acute myocardial infarction. Previous studies suggested rare skeletal myopathies as a non-cardiac source of cTnT. We aimed to confirm the reliability/cardiac specificity of cTnT in patients with various skeletal muscle disorders (SMD). Methods: We prospectively enrolled patients presenting with muscular complaints (≥2 weeks) for elective evaluation in four hospitals in two countries. After cardiac work-up, patients were adjudicated into three predefined cardiac disease categories. Concentrations of cTnT/I and resulting cTnT/I mismatches were assessed using high-sensitivity cTnT (hs-cTnT-Elecsys) and three hs-cTnI assays (hs-cTnI-Architect, hs-cTnI-Access, hs-cTnI-Vista), and compared to controls without SMD presenting with adjudicated non-cardiac chest pain to the emergency department (n=3508, mean age 55y, 37% female). In patients with available skeletal muscle biopsies, TNNT/I1-3 mRNA differential gene expression was compared to biopsies obtained in controls without SMD. Results: Among 211 patients (mean age 57y, 42% female), 108 (51%) were adjudicated to having no cardiac disease, 44 (21%) mild and 59 (28%) severe cardiac disease. hs-cTnT/I concentrations significantly increased from patients with no versus mild versus severe cardiac disease for all assays (all p<0.001). hs-cTnT-Elecsys concentrations were significantly higher in patients with SMD versus controls (median 16ng/L (IQR 7-32.5) versus 5ng/L (IQR 3-9), p<0.001) while hs-cTnI concentrations were mostly similar (hs-cTnI-Architect 2.5ng/L (IQR 1.2-6.2) versus 2.9ng/L (IQR 1.8-5.0), hs-cTnI-Access 3.3ng/L (IQR 2.4-6.1) versus 2.7ng/L (IQR 1.6-5.0) and hs-cTnI-Vista 7.4ng/L (IQR 5.2-13.4) versus 7.5ng/L (IQR 6-10)). hs-cTnT-Elecsys concentrations were above the upper-limit of normal (ULN) in 55% of patients with SMD vs 13% of controls (p<0.01). mRNA analyses in skeletal muscle biopsies (n=33), mostly (n=24) from non-inflammatory myopathy and myositis, showed 8-fold upregulation of TNNT2, encoding cTnT (but none for TNNI3, encoding cTnI); versus controls (n=16, pWald <0.001), the expression correlated with pathological disease activity (R=0.59, pt-statistic <0.001) and circulating hs-cTnT concentrations (R=0.26, pt-statistic =0.031). Conclusions: In patients with active chronic SMD, elevations in cTnT concentrations are common and not due to cardiac disease in the majority. This was not observed for cTnI, and may in part be explained by re-expression of cTnT in skeletal muscle

Skeletal Muscle Disorders: A Noncardiac Source of Cardiac Troponin T

BACKGROUND: Cardiac troponin (cTn) T and cTnI are considered cardiac specific and equivalent in the diagnosis of acute myocardial infarction. Previous studies suggested rare skeletal myopathies as a noncardiac source of cTnT. We aimed to confirm the reliability/cardiac specificity of cTnT in patients with various skeletal muscle disorders (SMDs). METHODS: We prospectively enrolled patients presenting with muscular complaints (≥2 weeks) for elective evaluation in 4 hospitals in 2 countries. After a cardiac workup, patients were adjudicated into 3 predefined cardiac disease categories. Concentrations of cTnT/I and resulting cTnT/I mismatches were assessed with high-sensitivity (hs-) cTnT (hs-cTnT-Elecsys) and 3 hs-cTnI assays (hs-cTnI-Architect, hs-cTnI-Access, hs-cTnI-Vista) and compared with those of control subjects without SMD presenting with adjudicated noncardiac chest pain to the emergency department (n=3508; mean age, 55 years; 37% female). In patients with available skeletal muscle biopsies, TNNT/I1-3 mRNA differential gene expression was compared with biopsies obtained in control subjects without SMD. RESULTS: Among 211 patients (mean age, 57 years; 42% female), 108 (51%) were adjudicated to having no cardiac disease, 44 (21%) to having mild disease, and 59 (28%) to having severe cardiac disease. hs-cTnT/I concentrations significantly increased from patients with no to those with mild and severe cardiac disease for all assays (all P<0.001). hs-cTnT-Elecsys concentrations were significantly higher in patients with SMD versus control subjects (median, 16 ng/L [interquartile range (IQR), 7-32.5 ng/L] versus 5 ng/L [IQR, 3-9 ng/L]; P<0.001), whereas hs-cTnI concentrations were mostly similar (hs-cTnI-Architect, 2.5 ng/L [IQR, 1.2-6.2 ng/L] versus 2.9 ng/L [IQR, 1.8-5.0 ng/L]; hs-cTnI-Access, 3.3 ng/L [IQR, 2.4-6.1 ng/L] versus 2.7 ng/L [IQR, 1.6-5.0 ng/L]; and hs-cTnI-Vista, 7.4 ng/L [IQR, 5.2-13.4 ng/L] versus 7.5 ng/L [IQR, 6-10 ng/L]). hs-cTnT-Elecsys concentrations were above the upper limit of normal in 55% of patients with SMD versus 13% of control subjects (P<0.01). mRNA analyses in skeletal muscle biopsies (n=33), mostly (n=24) from individuals with noninflammatory myopathy and myositis, showed 8-fold upregulation of TNNT2, encoding cTnT (but none for TNNI3, encoding cTnI) versus control subjects (n=16, P$_{Wald}$<0.001); the expression correlated with pathological disease activity (R=0.59, P$_{t-statistic}$<0.001) and circulating hs-cTnT concentrations (R=0.26, P$_{t-statistic}$=0.031). CONCLUSIONS: In patients with active chronic SMD, elevations in cTnT concentrations are common and not attributable to cardiac disease in the majority. This was not observed for cTnI and may be explained in part by re-expression of cTnT in skeletal muscle. CLINICALTRIALS: gov; Unique identifier: NCT03660969