Background: Diffusion kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI) provide more comprehensive and informative perspective on microstructural alterations of cerebral white matter (WM) than single-shell diffusion tensor imaging (DTI), especially in the detection of crossing fiber. However, studies on systemic lupus erythematosus patients without neuropsychiatric symptoms (non-NPSLE patients) using multi-shell diffusion imaging remain scarce.
Methods: Totally 49 non-NPSLE patients and 41 age-, sex-, and education-matched healthy controls underwent multi-shell diffusion magnetic resonance imaging. Totally 10 diffusion metrics based on DKI (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity, mean kurtosis, axial kurtosis and radial kurtosis) and NODDI (neurite density index, orientation dispersion index and volume fraction of the isotropic diffusion compartment) were evaluated. Tract-based spatial statistics (TBSS) and atlas-based region-of-interest (ROI) analyses were performed to determine group differences in brain WM microstructure. The associations of multi-shell diffusion metrics with clinical indicators were determined for further investigation.
Results: TBSS analysis revealed reduced FA, AD and RK and increased ODI in the WM of non-NPSLE patients (P < 0.05, family-wise error corrected), and ODI showed the best discriminative ability. Atlas-based ROI analysis found increased ODI values in anterior thalamic radiation (ATR), inferior frontal-occipital fasciculus (IFOF), forceps major (F_major), forceps minor (F_minor) and uncinate fasciculus (UF) in non-NPSLE patients, and the right ATR showed the best discriminative ability. ODI in the F_major was positively correlated to C3.
Conclusion: This study suggested that DKI and NODDI metrics can complementarily detect WM abnormalities in non-NPSLE patients and revealed ODI as a more sensitive and specific biomarker than DKI, guiding further understanding of the pathophysiological mechanism of normal-appearing WM injury in SLE.
Background: Previously, fragments from Sirtuin 1 (SIRT1) were identified in preclinical and clinical samples to display an increase in serum levels for N-terminal (NT) SIRT1 vs. C-terminal (CT) SIRT1, indicative of early signs of OA. Here we tested NT/CT SIRT1 levels as well as a novel formulated sandwich assay to simultaneously detect both domains of SIRT1 in a manner that may inform us about the levels of full-length SIRT1 in the circulation (flSIRT1) of clinical cohorts undergoing knee joint distraction (KJD).
Methods: We employed an indirect ELISA assay to test NT- and CT-SIRT1 levels and calculated their ratio. Further, to test flSIRT1 we utilized novel antibodies (Ab), which were validated for site specificity and used in a sandwich ELISA method, wherein the CT-reactive served as capture Ab, and its NT-reactive served as primary detection Ab. This method was employed in human serum samples derived from a two-year longitudinal study of KJD patients. Two-year clinical and structural outcomes were correlated with serum levels of flSIRT1 compared to baseline.
Results: Assessing the cohort, exhibited a significant increase of NT/CT SIRT1 serum levels with increased osteophytes and PIIANP/CTX-II at baseline, while a contradictory increase in NT/CT SIRT1 was associated with less denuded bone, post-KJD. On the other hand, flSIRT1 exhibited an upward trend in serum level, accompanied by reduced denuded bone for 2-year adjusted values. Moreover, 2 year-adjusted flSIRT1 levels displayed a steeper linear regression for cartilage and bone-related structural improvement than those observed for NT/CT SIRT1.
Conclusions: Our data support that increased flSIRT1 serum levels are a potential molecular endotype for cartilage-related structural improvement post-KJD, while NT/CT SIRT1 appears to correlate with osteophyte and PIIANP/CTX-II reduction at baseline, to potentially indicate baseline OA severity.
Background: Tofacitinib is an oral Janus kinase inhibitor for treatment of ankylosing spondylitis (AS). Time to improvement in core domains of AS was estimated in tofacitinib-treated patients with AS.
Methods: This post hoc analysis used phase 3 trial data from patients with AS receiving tofacitinib 5 mg twice daily or placebo to week (W)16; all patients received open-label tofacitinib W16-48.
Outcomes: nocturnal pain; total back pain; fatigue, spinal pain, peripheral joint pain/swelling, enthesitis, and morning stiffness (Bath AS Disease Activity Index [BASDAI] questions 1-6); BASDAI total score; AS Disease Activity Score (ASDAS). Median time to improvement events was estimated using non-parametric Kaplan-Meier models. Improvement events were defined as initial (first post-baseline observation) and continued (sustained for 2 consecutive visits) ≥ 30% and ≥ 50% improvement in back/nocturnal pain or BASDAI questions/total scores, or ASDAS improvement ≥ 1.1 and ≥ 2.0 points.
Results: 269 patients (tofacitinib: n = 133; placebo-to-tofacitinib: n = 136) were assessed. Median time to improvement was shorter, and more patients experienced improvements with tofacitinib vs. placebo-to-tofacitinib; differences observed from W2 (first post-baseline assessment). Median time to initial (continued) ≥ 30% pain improvement was 4 (4-8) weeks for tofacitinib vs. 24 (24) weeks for placebo-to-tofacitinib (8 [8] weeks post-switch). Median time to initial (continued) ≥ 50% improvement of pain, peripheral joint pain/swelling and enthesitis, morning stiffness, BASDAI total score, and fatigue was 8-24 (12-40) weeks with tofacitinib vs. 24-32 weeks (32 weeks-not estimable [NE]) with placebo-to-tofacitinib. Median time to initial (continued) ASDAS improvement ≥ 1.1 points was 4 (8) weeks for tofacitinib vs. 24 (24) weeks for placebo-to-tofacitinib, and NE for improvement ≥ 2.0 points with either treatment.
Conclusions: Improvements in AS core domains occurred more rapidly with tofacitinib vs. placebo-to-tofacitinib. Half of tofacitinib-treated patients with AS will likely experience improvements ≥ 30% in pain and ≥ 1.1 points in ASDAS during month (M)1, ≥ 50% improvement in nocturnal pain and enthesitis by M2, and in morning stiffness by M3. Results show that initiating tofacitinib as soon as possible is associated with quicker improvements in AS core domains vs. delaying treatment.
Trial registration: ClinicalTrials.gov, NCT03502616, 11 April 2018.