24 research outputs found
Autoantibody to MOG suggests two distinct clinical subtypes of NMOSD
We characterized a unique group of patients with neuromyelitis optica spectrum disorder (NMOSD) who carried autoantibodies of aquaporin-4 (AQP4) and myelin-oligodendrocyte glycoprotein (MOG). Among the 125 NMOSD patients, 10 (8.0%) were AQP4- and MOG-ab double positive, and 14 (11.2%) were MOG-ab single positive. The double-positive patients had a multiphase disease course with a high annual relapse rate (P=0.0431), and severe residual disability (P<0.0001). Of the double-positive patients, 70% had MS-like brain lesions, more severe edematous, multifocal regions on spinal magnetic resonance imaging (MRI), pronounced decreases of retinal nerve fiber layer thickness and atrophy of optic nerves. In contrast, patients with only MOG-ab had a higher ratio of monophasic disease course and mild residual disability. Spinal cord MRI illustrated multifocal cord lesions with mild edema, and brain MRIs showed more lesions around lateral ventricles. NMOSD patients carrying both autoantibodies to AQP4 and MOG existed and exhibited combined features of prototypic NMO and relapsing-remitting form of MS, whereas NMOSD with antibodies to MOG only exhibited an “intermediate” phenotype between NMOSD and MS. Our study suggests that antibodies against MOG might be pathogenic in NMOSD patients and that determination of anti-MOG antibodies maybe instructive for management of NMOSD patients
Investigating the relationship between multi-scale perfusion and white matter microstructural integrity in patients with relapsing-remitting MS
Background: Multiple sclerosis is characterized by the formation of central nervous system demyelinating lesions with microvasculature inflammation. Objective: Evaluate how lesion cerebral perfusion relates to white matter microstructural integrity in patients with RRMS using perfusion MRI and myelin-related T1-weighted to T2-weighted (T1w/T2w) ratios. Methods: Forty-eight patients with RRMS were imaged with dynamic susceptibility contrast imaging using SAGE (spin- and gradient-echo) to calculate global and capillary-sized perfusion parameters, including cerebral blood flow (CBF), volume (CBV), and mean transit time (MTT). T1w/T2w ratios were used to indirectly assess white matter microstructural integrity. Results: For global perfusion metrics, CBF was reduced 28.4% in lesion regions of interest (ROIs) compared to normal appearing white matter (NAWM), CBV was reduced 25.9% in lesion ROIs compared to NAWM, and MTT increased 12.9%. For capillary perfusion metrics (via spin-echo (SE)), CBF-SE was reduced 35.7% in lesion ROIs compared to NAWM, CBV-SE was reduced 35.2% in lesion ROIs compared to NAWM, and MTT-SE increased 9.1%. Capillary-level CBF was correlated (ρ = 0.34, p = 0.024) with white matter microstructural integrity in lesion ROIs. Conclusion: This study demonstrates that lesion perfusion is reduced at both the global and capillary level and capillary-associated hypoperfusion is associated with reduced white matter microstructural integrity in RRMS
Investigating the relationship between multi-scale perfusion and white matter microstructural integrity in patients with relapsing-remitting MS
Background Multiple sclerosis is characterized by the formation of central nervous system demyelinating lesions with microvasculature inflammation. Objective Evaluate how lesion cerebral perfusion relates to white matter microstructural integrity in patients with RRMS using perfusion MRI and myelin-related T1-weighted to T2-weighted (T1w/T2w) ratios. Methods Forty-eight patients with RRMS were imaged with dynamic susceptibility contrast imaging using SAGE (spin- and gradient-echo) to calculate global and capillary-sized perfusion parameters, including cerebral blood flow (CBF), volume (CBV), and mean transit time (MTT). T1w/T2w ratios were used to indirectly assess white matter microstructural integrity. Results For global perfusion metrics, CBF was reduced 28.4% in lesion regions of interest (ROIs) compared to normal appearing white matter (NAWM), CBV was reduced 25.9% in lesion ROIs compared to NAWM, and MTT increased 12.9%. For capillary perfusion metrics (via spin-echo (SE)), CBF-SE was reduced 35.7% in lesion ROIs compared to NAWM, CBV-SE was reduced 35.2% in lesion ROIs compared to NAWM, and MTT-SE increased 9.1%. Capillary-level CBF was correlated (ρ = 0.34, p = 0.024) with white matter microstructural integrity in lesion ROIs. Conclusion This study demonstrates that lesion perfusion is reduced at both the global and capillary level and capillary-associated hypoperfusion is associated with reduced white matter microstructural integrity in RRMS. </jats:sec
Rapid whole-brain myelin imaging with selective inversion recovery and compressed SENSE
PURPOSE: Quantitative magnetization transfer (QMT) using selective inversion recovery (SIR) can quantify the macromolecular-to-free proton pool size ratio (PSR), which has been shown to relate closely with myelin content. Currently clinical applications of SIR have been hampered by long scan times. In this work, the acceleration of SIR-QMT using CS-SENSE (compressed sensing SENSE) was systematically studied. THEORY AND METHODS: Phantoms of varied concentrations of bovine serum albumin and human scans were first conducted to evaluate the SNR, precision of SIR-QMT parameters, and scan time. Based on these results, an optimized CS-SENSE factor of 8 was determined and the test-retest repeatability was further investigated. RESULTS: A whole-brain SIR imaging of 6 min can be achieved. Bland-Altman analyses indicated excellent agreement between the test and retest sessions with a difference in mean PSR of 0.06% (and a difference in mean R of -0.001 s ). In addition, the assessment of the intraclass correlation coefficient (ICC) revealed high reliability in nearly all the white matter and gray matter regions. In white matter regions, the ICC was 0.93 (95% confidence interval [CI]: 0.88-0.96, p \u3c 0.001) for PSR, and 0.90 (95% CI: 0.83-0.94, p \u3c 0.001) for R . In gray matter, ICC was 0.84 (95% CI: 0.66-0.93, p \u3c 0.001) in PSR, and 0.98 (95% CI: 0.95-0.99, p \u3c 0.001) for R . The method also showed excellent capability to detect focal lesions in multiple sclerosis. CONCLUSION: Rapid, reliable, and sensitive whole-brain SIR imaging can be achieved using CS-SENSE, which is expected to significantly promote widespread clinical translation
Interleukin-7 Expression and its Effect on Natural Killer Cells in Patients With Multiple Sclerosis
Decreased NK cell numbers and impairment of NK cell function are reported in patients with multiple sclerosis (MS). Interleukin-7 (IL-7) is a member of the common gamma-chain (γc) cytokine superfamily that has well documented roles in lymphocyte development and homeostasis. The interleukin-7 receptor α chain (IL-7Rα) gene was identified as a top non-major histocompatibility complex-linked risk locus for MS. The objective of this study was to test biological function of IL-7/IL-7Rα on NK cells in MS patients. We observed markedly lower IL-7 levels in MS sera, and relatively higher IL-7Rα expression in NK cells of MS. Upon IL-7 stimulation, IL-7Rα on NK cells from MS patients was significantly down-regulated compared with healthy controls (HCs). IL-7 induced a higher increase of IFN-γ production in CD56bright NK cells and a pronounced enhancement of cytotoxicity in NK cells from MS. IL-7 did not impact the proliferation of NK cells differently in MS and HC. In contrast, IL-7 promoted a higher survival of CD56bright NK cells in MS and inhibited their apoptosis by increasing Bcl-2 expression, but had no effect on CD56dim NK cell survival in MS. In conclusion, MS patients have lower serum IL-7 and a higher membrane IL-7Rα expression on CD56bright NK cells. The skew at the IL-7 and IL-7Rα level influences functional responsiveness of NK cells in MS
Rapid simultaneous estimation of relaxation rates using multi-echo, multi-contrast MRI.
PURPOSE: Multi-echo, multi-contrast methods are increasingly used in dynamic imaging studies to simultaneously quantify R
METHODS: Spin- and gradient-echo (SAGE) data were simulated across T
RESULTS: Across all fitting methods, T
CONCLUSIONS: LLSQ reliably fit for
