Porter, Ivan E.

ABSTRACT Background and hypothesis The MENTOR trial (MEmbranous Nephropathy Trial Of Rituximab) showed that rituximab was noninferior to cyclosporine in inducing complete or partial remission of proteinuria and was superior in maintaining proteinuria remission. However, the cost of rituximab may prohibit first-line use for some patients and health-care payers. Methods A Markov model was used to determine the incremental cost-effectiveness ratio (ICER) of rituximab compared with cyclosporine for the treatment membranous nephropathy from the perspective of a health-care payer with a lifetime time horizon. The model was informed by data from the MENTOR trial where possible; additional parameters including cost and utility inputs were obtained from the literature. Sensitivity analyses were performed to evaluate the impact of reduced-cost biosimilar rituximab. Results Rituximab for the treatment of membranous nephropathy was cost effective (assuming a willingness-to-pay threshold of $50 000 per quality-adjusted life year (QALY) gained; in $US 2021) compared with cyclosporine, with an ICER of $8373/QALY over a lifetime time horizon. The incremental cost of rituximab therapy was $28 007 with an additional 3.34 QALYs compared with cyclosporine. Lower cost of rituximab biosimilars resulted in a more favorable ICER, and in some cases resulted in rituximab being dominant (lower cost and great benefit) compared to cyclosporine. Conclusions Despite the greater cost of rituximab, it may be a cost-effective option for the treatment of membranous nephropathy when compared with cyclosporine. The cost-effectiveness of rituximab is further improved with the use of less expensive biosimilars.

Background: Ambulatory blood pressure monitoring (ABPM) is important for the diagnosis of hypertension (HTN) as well as variants such as nocturnal HTN (NH), masked HTN and a non-dipping pattern. NH and non-dipping, a failure of the normal circadian drop in blood pressure during sleep, have been associated with all-cause mortality and cardiovascular risk. Obstructive sleep apnea is associated with HTN and a growing body of evidence suggests that limb movement disorders of sleep may also influence cardiovascular morbidity. The present study investigates arousals of sleep disorders, limb movement or respiratory, and their relationship to ABPM measurements. Methods: A retrospective review (January 1, 2010 to December 31, 2014) was performed on patients that underwent both ABPM and polysomnography within a six months of each other. Socio-demographic data, results of 24 hour ABPM and polysomnography, concurrent medication use by class, comorbid conditions and laboratory data were recorded. Patients with incomplete polysomnography or ABPM measurements were excluded. Results: 330 individuals met criterion for inclusion; 59% male, 86% white. 211 (64%) were found to have NH, 106 (32%) had uncontrolled HTN and 202 (61%) had a non-dipping pattern. Patients with NH were more likely to have diabetes, hyperlipidemia and chronic kidney disease. Elevated arousal indices were more prevalent in those with NH, uncontrolled HTN and non-dippers. There was an association of NH with the total number of arousals per hour of sleep (p<0.01), whether related to respiratory disturbances or limb movements. Limb movement index (LMI) was related to age (p<0.0001) and was associated with all type arousals (p<0.0001). Conclusions: ABPM revealed a high prevalence of NH, non-dipping, masked and uncontrolled HTN in patients with sleep disorders. Arousals of all types, whether accompanying respiratory or limb movements, were associated with NH and also with LMI.

AbstractBackgroundCalcium oxalate stones are the most common cause of nephrolithiasis in the United States. Smaller studies of <15 patients investigating ezetimibe, a selective cholesterol absorption inhibitor, have suggested increased urine oxalate levels with use of the drug. We attempt to better define this relationship of ezetimibe on urinary oxalate using a larger patient sample analysing multiple urine collections on and off treatment.Materials and MethodsWe retrospectively reviewed all consecutive patients from 01/2018 through 04/2019 evaluated for nephrolithiasis with use of ezetimibe documented in their medical record at Mayo Clinic Florida. Primary outcomes included increase in urinary oxalate with use of ezetimibe and reduction in urinary oxalate with discontinuation of medication.ResultsOf 57 reviewed patients, 30 (53%) met inclusion criteria yielding 117 24‐h urine measurements either on ezetimibe (72 measurements) or off ezetimibe (41 measurements). The mean urinary oxalate level off ezetimibe was 39.86 mg versus 40.45 mg with ezetimibe. After adjusting for age and sex, the estimated difference was 1.239 mg (95% CI, −4.856 to 7.335 mg; p = 0.93). A subset of six patients with urinary oxalate values both on and off ezetimibe showed a difference in 24‐h urinary oxalate levels ranged from −16.40 to 14.95 mg (mean difference = 0.93 mg; median difference = 3.84 mg).ConclusionUse of ezetimibe does not provide clear evidence of a difference in urinary oxalate levels.

Collapsing glomerulopathy (CG) is a rare disease that can be associated with multiple other disorders. It usually leads to poor prognosis with a high percentage of patients progressing to end-stage renal disease. In this article, we illustrate a clinical case of CG associated with systemic lupus erythematosus that had a prompt response to mycophenolate and prednisone. The condition started after sudden cessation of the already established mycophenolate treatment regimen. The patient then presented with acute kidney injury due to kidney biopsy-proven CG. In that circumstance, we hypothesised that mycophenolate may play a role in prevention and development of CG.