Histologic characterization and risk factors for persistent albuminuria in adolescents in a region of highly prevalent end-stage renal failure of unknown origin

Pediatric kidney dimensions and risk of persistent albuminuria in Mexican adolescents

In Mexico, chronic kidney disease of unknown origin is highly prevalent. Screening studies in adolescents have shown persistent microalbuminuria (pACR), adaptive podocytopathy and decreased kidney volume (KV). Here, we sought to develop normality tables of kidney dimensions by ultrasound in the Mexican state of Aguascalientes pediatric population (0 to 18y) and evaluate the relationship between the KV and pACR among the region's adolescents in a cross-sectional study. Kidney length (KL) and KV were determined by ultrasound. Our findings were compared with those in international literature of different populations where tables and graphs of normal kidney dimensions by ultrasound were reported. We compared organ dimensions in individuals above the age of 11 without albuminuria with those in patients with pACR recruited through screening studies in adolescents in Aguascalientes. This included 1068 individuals to construct percentile tables and graphs of the KL. Kidney dimensions were significantly lower when compared with all international comparisons. From a total 14,805 screen individuals, we compared 218 adolescents with pACR and 377 individuals without significant albuminuria. The Total KV adjusted to body surface (TKVBS) was significantly associated with pACR (odds ratio 1.03, 95% confidence interval 1.02-1.03). The upper quartile of TKVBS was highly associated with pACR (7.57, 4.13-13.87), hypertension (2.53, 1.66-3.86), and hyperfiltration (26 vs 11.5%). Thus, TKVBS is directly associated with pACR while greater KV, arterial hypertension, and hyperfiltration in patients with pACR suggest that the increase in volume is secondary to kidney hypertrophy. Additionally, the adaptative podocytopathy with low fibrosis seen on kidney biopsy which was performed in a subset of patients, and the smaller kidney dimensions in our population point to prenatal oligonephronia as the primary cause of the detected kidney disease.

Oligonephronia: another piece in the CKDu jigsaw?

Rates of chronic kidney disease of unknown etiology are high in Aguascalientes, Mexico. Kidneys of adolescents are small by ultrasonography, compatible with oligonephronia, whereas proteinuria and higher estimated glomerular filtration rates and blood pressures among those with relatively higher kidney volumes probably flag relatively greater degrees of compensatory hypertrophy. Glomerulomegaly and podocytopathy, and later segmental glomerulosclerosis in biopsies, suggest a cascade driven by nephron deficiency. Better measures of glomerular number and volume should improve understanding, facilitate risk assessment, and guide interventions.

Novel Approaches in Chronic Renal Failure without Renal Replacement Therapy: A Review

Chronic kidney disease (CKD) is characterized by renal parenchymal damage leading to a reduction in the glomerular filtration rate. The inflammatory response plays a pivotal role in the tissue damage contributing to renal failure. Current therapeutic options encompass dietary control, mineral salt regulation, and management of blood pressure, blood glucose, and fatty acid levels. However, they do not effectively halt the progression of renal damage. This review critically examines novel therapeutic avenues aimed at ameliorating inflammation, mitigating extracellular matrix accumulation, and fostering renal tissue regeneration in the context of CKD. Understanding the mechanisms sustaining a proinflammatory and profibrotic state may offer the potential for targeted pharmacological interventions. This, in turn, could pave the way for combination therapies capable of reversing renal damage in CKD. The non-replacement phase of CKD currently faces a dearth of efficacious therapeutic options. Future directions encompass exploring vaptans as diuretics to inhibit water absorption, investigating antifibrotic agents, antioxidants, and exploring regenerative treatment modalities, such as stem cell therapy and novel probiotics. Moreover, this review identifies pharmaceutical agents capable of mitigating renal parenchymal damage attributed to CKD, targeting molecular-level signaling pathways (TGF-β, Smad, and Nrf2) that predominate in the inflammatory processes of renal fibrogenic cells.

Treatment of asymptomatic bacteriuria in the first 2 months after kidney transplant: A controlled clinical trial

BACKGROUND

The incidence of urinary tract infections (UTIs) in the first 2 months postrenal transplantation (pRT) is very high. We evaluate the efficacy of asymptomatic bacteriuria (AB) screening and treatment on the incidence of UTI in the first 2 months pRT METHODS: We conducted a randomized controlled clinical trial. A urine culture was obtained in all patients on the day of the bladder catheter removal, on week three, and before removal of the ureteral catheter. The intervention group received treatment for AB. The control group did not receive treatment. The primary outcomes were the cumulative incidence of UTI and/or graft pyelonephritis and the time to the first episode of UTI and/or graft pyelonephritis RESULTS: Eighty patients were randomized, 40 in each group, and the median follow-up was 63 days (IQR 54-70). The average age was 29.8 years and 33.7% (n = 27) were women. The incidences of UTI (n = 10, 25 % vs. n = 4, 10%, p = .07) and pyelonephritis (n = 6, 15% vs. n = 1, 2.5%, p = .04) were greater in the intervention group, as also shown in the survival analysis: UTI (HR2.8, 95% CI 0.8-9.1, p = .07) and pyelonephritis (HR 6.5, 95% CI 0.8-54.7, p = .08), respectively. The most commonly isolated bacterium was Escherichia coli (n = 28, 59.5%), and over half were E. coli with extended-spectrum beta-lactamases (n = 15). A major limitation was not obtaining the calculated sample size due to a delay in patient recruitment resulting from the COVID-19 pandemic CONCLUSION: Treatment of AB in the first 2 months pRT does not decrease the incidence of UTI or graft pyelonephritis and may actually increase their frequency. Routine treatment of AB during the first months after renal transplantation should not be a standard procedure.

Low birth weight, nephron number and chronic kidney disease

Chronic kidney diseases have a significant impact on morbidity and mortality worldwide. Low birth weight, fetal growth restriction and prematurity are indicators of fetal growth and development disorders associated with a congenital reduction in nephron number, which predisposes to an increased risk for chronic kidney disease. On an individual basis, a small nephron number at birth is not always enough to determine the onset of chronic kidney disease, but it decreases the ability of the kidneys to resist any insults to renal tissue that may occur later in life, such as exposure to nephrotoxic drugs or episodes of acute kidney injury. The high incidence of low birth weight and preterm birth globally suggests that, at the population level, the impact of alterations in fetal development on the subsequent onset of chronic kidney disease could be significant. The implementation of strategies aimed at reducing the incidence of prematurity, fetal growth restriction, as well as other conditions that lead to low birth weight and a reduced nephron number at birth, provides an opportunity to prevent the development of chronic kidney disease in adulthood. For these purposes the coordinated intervention of several specialists, including obstetricians, gynecologists, neonatologists, nephrologists, and family doctors, is necessary. Such strategies can be particularly useful in resource-poor countries, which are simultaneously burdened by maternal, fetal and child malnutrition; poor health; epidemics caused by communicable diseases; and little access to screening and primary care.

Solving the riddle of Aguascalientes nephropathy: nephron number, environmental toxins and family clustering

Aguascalientes, Mexico, has a high incidence and prevalence of advanced chronic kidney disease (CKD). CKD is especially frequent in young people ages 20-40 years in whom the cause of CKD was unknown, although kidney biopsies frequently showed focal segmental glomerulosclerosis (FSGS) and glomerulomegaly. Macias-Diaz et al. have now pursued this lead by screening teenagers in Calvillo, one of the hardest hit municipalities. They uncovered clinical, laboratory, kidney biopsy and exposure findings that define a new entity, Aguascalientes nephropathy, and are consistent with familial exposure to common environmental toxins, potentially consisting of pesticides. They hypothesize that prenatal exposure to these toxins may decrease nephron number. The young age of persons with FSGS would be consistent with a novel environmental toxin introduced more than 50 years ago but not present in the environment before. Key takeaways from this research are the need to screen teenagers for albuminuria, to provide kidney-protective strategies to patients identified as having CKD and for the research community to support Aguascalientes nephrologists and health authorities to unravel the cause and potential solutions for this CKD hotspot. In this regard, the screening approach and the cohort generated by Macias-Diaz et al. represent a giant step forward. The next steps should be to screen younger children for albuminuria and kidney size and to identify the putative toxins.