Rationale & Objective Anorexia nervosa is often intractable and induces various physical disorders, including kidney disease and mineral disorders, occasionally progressing to kidney failure. No consensus-based clinical practice guidelines have been established for patients with anorexia nervosa referred to a nephrologist. Study Design Patients with anorexia nervosa–associated kidney disease diagnosed were analyzed retrospectively. Kidney outcomes were defined as doubling of serum creatinine level and/or progression to end-stage kidney disease. Setting & Participants Patients with a history of anorexia nervosa with kidney disease, including electrolyte abnormalities, who were referred to our hospital between 1992 and 2017 were included. Results 14 female patients were included. The time from anorexia nervosa onset to the initial visit with a nephrologist was 17.8 years. At the first visit, median body mass index was 13.4 kg/m 2 , median serum creatinine level was 1.9 mg/dL, and median serum potassium level was 2.7 mmol/L. All patients showed hypokalemia and addictive vomiting or diuretic/laxative abuse. During the median observation period of 3.1 years, kidney outcomes occurred in 9 patients, and 2 died due to their anorexia nervosa. 4 patients underwent kidney biopsy. The kidney biopsy findings of these patients included hypertrophy of the juxtaglomerular apparatus, advanced glomerular collapse, and interstitial fibrosis, consistent with ischemic kidney injury and hypokalemic nephropathy. Limitations The sample size was small, and kidney function was assessed based on serum creatinine levels in patients with anorexia nervosa with low muscle mass. Conclusions Most patients with anorexia nervosa referred to nephrologists had kidney disease at the time of the first visit. Improving kidney outcomes of patients with anorexia nervosa may require earlier collaboration between psychiatrists and nephrologists.

Rationale & Objective The response to corticosteroid therapy may differ among patients with minimal change disease (MCD). Previous studies have suggested that glomerular hypertrophy or low areal glomerular density in biopsy specimens, which may be related to fewer nephrons, is associated with such a difference. We examined the associations between nephron number and the therapeutic response to corticosteroids in patients with MCD. Study Design Retrospective cohort study. Setting & Participants 75 adult patients with a histologic diagnosis of MCD. Exposure Nephron number per kidney estimated based on the combination of unenhanced computed tomography and nonsclerotic volumetric glomerular density in kidney biopsy specimens. Outcomes Complete remission and relapse following corticosteroid therapy. Analytical Approach Multivariable Cox proportional hazard analyses of associations between factors, including nephron number, and outcomes. Results Mean age of patients was 45.9 years and 60.0% were men. Patients had an estimated glomerular filtration rate of 64.6 mL/min/1.73 m 2 and proteinuria of 8.7 g/d. The estimated total number of nonsclerotic glomeruli ranged from 1.07 to 18.77 ×10 5 per kidney among all patients. There were no significant differences in total amounts or selectivity of urinary protein excretion at biopsy among the tertile groups categorized by nephron number. All patients responded to corticosteroid therapy, but those with fewer nephrons had a delayed achievement of complete remission. Multivariable Cox proportional hazard analyses identified nephron number as a significant independent explanatory variable for the achievement of complete remission, with a hazard ratio of 1.10 (95% CI, 1.02-1.19)/100,000 nephrons per kidney. Nephron number in these patients was not associated with achievement of partial remission or relapse following complete remission. Limitation Retrospective design and sampling bias of needle biopsy. Conclusions A small nephron number in patients with MCD is associated with longer time to complete remission.

Background: Single nephron dynamics in progressive IgA nephropathy (IgAN) have not been studied. We applied novel methodology to explore single nephron parameters in IgAN. Methods: Non-globally sclerotic glomeruli (NSG) and globally sclerotic glomeruli (GSG) per kidney were estimated using cortical volume assessment via unenhanced computed tomography and biopsy-based stereology. Estimated single-nephron GFR (eSNGFR) and urine protein excretion (SNUPE) were calculated by dividing eGFR and UPE by the number of NSG. Associations with CKD stage and clinicopathologic findings were cross-sectionally investigated. Results: This study included 245 IgAN patients (mean age 43 y, 62% male, 45% on renin-angiotensin aldosterone system [RAAS] inhibitors pre-biopsy) evaluated at kidney biopsy. CKD stages were 10% CKD1, 43% CKD2, 19% CKD3a, 14% CKD3b and 14% CKD4-5. With advancing CKD stage, NSG decreased from mean 992,000 to 300,000 per kidney whereas GSG increased from median 64,000 to 202,000 per kidney. In multivariable models, advancing CKD stage associated with lower numbers of NSG, higher numbers of GSG, and lower numbers of GSG+NSG, indicating potential resorption of sclerosed glomeruli. In contrast to the higher mean glomerular volume and markedly elevated SNUPE in advanced CKD, the eSNGFR was largely unaffected by CKD stage. Lower SNGFR associated with Oxford scores for endocapillary hypercellularity and crescents whereas higher SNUPE associated with segmental glomerulosclerosis and tubulointerstitial scarring. Conclusions: SNUPE emerged as a sensitive biomarker of advancing IgAN. The failure of eSNGFR to increase in response to reduced number of functioning nephrons suggests limited capacity for compensatory hyperfiltration by diseased glomeruli with intrinsic lesions.

Patients with atypical hemolytic uremic syndrome (aHUS) associated with a C3 p.Ile1157Thr mutation show a relatively high renal survival and low mortality rates, but renal histopathological findings after recurrence have been rarely reported. A 30-year-old man with a C3 p.Ile1157Thr mutation experienced a third recurrence of thrombotic microangiopathies with neurological and gastrointestinal disorders. A renal biopsy performed during the recovery phase of acute kidney injury revealed collapsed glomeruli and arteriolar vacuolization. Approximately 10% of glomeruli were globally sclerotic, despite the absence of arterio-/arteriolosclerosis. These findings suggest substantial progression of irreversible injuries in multiple organs, including kidneys, which occurs in aHUS patients with repeated thrombotic microangiopathies.

Urinary tract infections (UTIs) are a common and expensive condition that impacts women and society. The aim of this analysis was to determine cost savings for water intake in preventing UTIs in premenopausal women. Methods: In a prospective, randomized trial we compared water intake to standard care for premenopausal women who are low drinkers with recurrent UTIs. 140 healthy premenopausal women were randomly assigned to drink additional 1.5 liters of water or to maintain their usual fluid intake. A health care cost questionnaire related to the UTI event was completed at the end of every symptomatic event confirmed by positive urine culture. Data on cost of UTI were obtained from the literature for 9 countries. Differences of cost between the two treatment groups were used to extrapolate potential cost difference by implementing increased fluid intake for prevention of UTIs. Results: In the randomized trial, the estimated mean annual number of cystitis episodes was 1.7 in Water Group (WG) compared with 3.2 in Control Group (CG) (p<0.001). Overall, there were 327 cystitis episodes, 111 in WG and 216 in CG over 12-month study period. The estimated mean annual number of antimicrobial regimens used to treat cystitis episodes was 1.9 (95% CI, 1.7-2.2) in WG compared with 3.6 (95% CI, 3.3-4.0) in CG (p<0.001). Loss of work was 69 days and 139 days in the water group and control group, respectively for an average of 0.63 days per UTI. On an individual basis there was a significant cost savings per patient ranging from 126 BGN in Bulgaria to $540 in US. Annual cost savings in different countries were significant with over $100 million in US and tens of millions of Euros in countries such as France and Italy. Conclusions: Increased water intake reduced risk of recurrent UTIs in premenopausal, low drinking women. This results in a direct reduction in rate of antibiotic use and loss of work. This has significant implications on reducing costs for women and society by using a simple and inexpensive prevention.