Search

Chronic kidney disease (CKD) is characterized by structural changes, such as tubular atrophy, renal fibrosis, and glomerulosclerosis, all of which affect the viscoelastic properties of biological tissues. However, detection of renal viscoelasticity changes because diagnostic markers by in vivo elastography lack histopathological validation through animal models. Therefore, we investigated in vivo multiparametric magnetic resonance imaging (mp‐MRI), including multifrequency magnetic resonance elastography‐based tomoelastography, in the kidneys of 10 rats with adenine‐induced CKD and eight healthy controls. Kidney volume (in mm3), water diffusivity (apparent diffusion coefficient [ADC] in mm2/s), shear wave speed (SWS; in m/s; related to stiffness), and wave penetration rate (PR; in m/s; related to inverse viscosity) were quantified by mp‐MRI and correlated with histopathologically determined renal fibrosis (collagen area fraction [CAF]; in %). Kidney volume (40% ± 29%, p = 0.009), SWS (11% ± 12%, p = 0.016), and PR (20% ± 15%, p = 0.004) were significantly increased in CKD, which was accompanied by ADC (−24% ± 27%, p = 0.02). SWS, PR, and ADC were correlated with CAF with R = 0.63, 0.75, and −0.5 (all p < 0.05), respectively. In the CKD rats, histopathology showed tubule dilation due to adenine crystal deposition. Collectively, our results suggest that collagen accumulation during CKD progression transforms soft‐compliant renal tissue into a more rigid‐solid state with reduced water mobility. We hypothesized that tubule dilation—a specific feature of our model—might lead to higher intraluminal pressure, which could also contribute to elevated renal stiffness. Tomoelastography is a promising tool for noninvasively assessing disease progression, detecting biomechanical properties that are sensitive to different pathologic features of CKD. [ABSTRACT FROM AUTHOR]

Background: Previous experiences with non-medical switching of adalimumab (ADA) in patients with chronic inflammatory rheumatic diseases (CIRD) come mainly from phase III extension of randomised clinical trials and little from routine care. Objectives: To analyse treatment trajectories over 2 years in patients with CIRD conducting a non-medical switch from originator to biosimilar ADA. Design: A retrospective observational cohort study was conducted with data from a third-level rheumatology centre in Germany. CIRD patients on originator ADA who switched to ADA biosimilar from October 2018 onwards were identified and followed until September 2020. Methods: Patients' characteristics were compared between the four a priori defined treatment trajectories 'continued biosimilar ADA therapy', 'back-switch to originator ADA therapy', 'switch to another biological disease-modifying anti-rheumatic drug (bDMARD) therapy' and 'stopped bDMARD therapy/death/drop out'. Factors associated with continuing biosimilar ADA therapy were analysed using Cox proportional hazards regression analyses. Results: A total of 121 CIRD patients were included. Most patients (66.9%) continued therapy with biosimilar ADA over 2 years, with a treatment retention rate of 73.1%. Whereas 21 patients (17.4%) switched back to originator ADA, mainly due to adverse events, and 8 patients (6.6%) switched to a different bDMARD, mainly due to lack of effect. The estimated risk of withdrawal was lower for longer prior duration on originator ADA [hazard ratio (HR): 0.82; 95% CI: 0.69–0.97] and higher for higher C-reactive protein levels at baseline (HR: 1.18; 95% CI: 1.00–1.39). Male patients, older patients and those for whom originator ADA was their first bDMARD tended to have a lower risk of withdrawal. Conclusion: Our results indicated that three of four patients continue biosimilar ADA over 2 years with lower risks of withdrawal for male sex, older age, longer prior duration on originator ADA and originator ADA as first bDMARD. [ABSTRACT FROM AUTHOR]