Urine alpha 1-microglobulin-to-creatinine ratio and beta 2-microglobulin-to-creatinine ratio for detecting CAKUT with kidney dysfunction in children

Application of raman spectroscopy in the non-invasive diagnosis of urological diseases via urine

OBJECTIVES

The objective of this review is to provide a comprehensive overview of the utilization of Raman spectroscopy in urinary system diseases, highlighting its potential in non-invasive diagnostic methodologies for early diagnosis and prognostic assessment of urinary ailments.

METHODS

We searched PubMed, Web of Science, and Google Scholar using 'raman,' 'bladder,' 'kidney,' 'prostate,' 'cancer,' 'infection,' 'stone or urinary calculi,' and 'urine or urinary,' along with 'AND' and 'OR' to refine our search. We excluded irrelevant articles and screened potential ones based on titles and abstracts before assessing the full texts for relevance and quality.

FINDINGS

The findings indicate that RS can furnish data on biomolecules in urine, which is significant for non-invasive diagnostic approaches. It has shown potential within non-invasive diagnostic methodologies and is expected to play a pivotal role in the early diagnosis and prognostic assessment of urinary system diseases, such as malignancies, urinary tract infections, kidney diseases, urolithiasis, and other urinary conditions.

CONCLUSIONS

Raman spectroscopy has demonstrated significant potential in providing precise and rapid diagnostic approaches for clinical use in the context of urinary system diseases. Its ability to analyze biomolecules non-invasively positions it as an increasingly important tool in the early diagnosis and prognostic assessment of these conditions.

School urinary screening program in Japan: history, outcomes, perspectives

In Japan, pediatric urinary screening in schools for asymptomatic hematuria and proteinuria began in 1974 and has been very successful in detecting asymptomatic kidney diseases at an early stage. While the American Academy of Pediatrics recommended discontinuing urinalysis as a public health service in 2007, urinary screening in Japan has proven extremely successful in reducing the incidence of kidney failure with replacement therapy in children and young adults, especially through the early treatment of glomerulonephritis, such as immunoglobulin A nephropathy. Furthermore, the positivity rate on urinary screening in Japan is significantly lower than in the United States where the rate of false positive results is typically very high. Japan's seamless and efficient pediatric urinary screening may be a helpful example for other countries as well. However, the present investigation revealed several, unresolved problems with the system. For example, the methods used varied in terms of their cutoff point, additional examinations, and types of detailed testing. In Japan, various urinary screening methods are being tested to optimize the system for national use. Recently, the authors also recommended a system of detailed examinations, including beta-2 microglobulin testing and ultrasonography, to detect congenital anomalies of the kidney and urinary tract, the most common, underlying disease in kidney failure with replacement therapy, which is often overlooked until the symptoms have become grave. While school urinary screening has been ongoing for about 50 years and should be continued, improvements should also be made to it as needed.

Reference values for urinary protein, albumin, beta 2-microglobulin, and the alpha 1-microglobulin-to-creatinine ratio in Japanese children

BACKGROUND

The importance of the ratio of creatinine to urinary protein, albumin, and low-molecular weight protein as a urinary marker in chronic kidney disease patients is widely recognized. However, no reference values have hitherto been established for these markers in Japanese children. The present study aimed to establish the reference values for these urinary markers in Japanese children.

METHODS

The first morning urine was randomly collected from 1712 pupils aged ≥ 3 to < 18 years during school and kindergarten mass urinary screenings. The upper limit of the reference values was set at the 97.5th percentile of the creatinine ratio per marker.

RESULTS

The urinary protein-to-creatinine ratio (PCR), urinary albumin-to-creatinine ratio (ACR), urinary beta 2-microglobulin-to-creatinine ratio (BMCR), and urinary alpha 1-microglobulin-to-creatinine ratio (AMCR) showed an age-related decrease at the 50th percentile reflecting an age-related increase in urinary creatinine. The appropriate reference value for the PCR and ACR was 0.12 g/gCr and 35 mg/gCr, respectively, in the entire cohort. The appropriate reference value for the BMCR was 0.5 μg /mgCr for age ≥ 3 to < 6 years and 0.35 μg/mgCr for age 6 years or older. The appropriate reference value for the AMCR was 5.0 μg/mgCr for age ≥ 3 to < 6 years and 3.5 μg /mgCr for age 6 years or older.

CONCLUSION

The present study was the first to determine appropriate reference values for the PCR, ACR, BMCR, and AMCR based on an analysis of the first morning urine samples of a large number of children.

Congenital Anomalies of the Kidney and Urinary Tract: A Continuum of Care

Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of kidney failure in children and adolescents. CAKUT describes a wide spectrum of structural disorders with a prenatal origin. The etiology of CAKUT is multifactorial, including environmental, nongenetic, and genetic causes that impact kidney development as well as upper and lower urinary tract development. Adult nephrologists who treat patients with CAKUT may be challenged by the underlying diseases they are not familiar with and the accumulation of chronic kidney disease complications in childhood. This article discusses CAKUT etiology and presentation, the course during childhood and adolescence, as well as adult issues in CAKUT patients including CKD complications, urologic interventions, and genetic counseling. A smooth transition of CAKUT patients from pediatric to adult care can be challenging. Semin Nephrol 43:x-xx © 2023 Elsevier Inc. All rights reserved.

Normal values for pediatric urinary biochemistry in early infancy

BACKGROUND

Urinary levels of N-acetyl-β-D-glucosaminidase (NAG), α1-microglobulin (α1-MG), and β2-microglobulin (β2-MG) are measured as markers of renal tubular damage. We previously determined normal values for these urine biochemical examinations in healthy children over 3 years old. However, the values are not applicable to children younger than 2 years old, and children less than 1 year old, in particular, seem to show very high levels for all these markers. Hence, as normal values for children below 2 years old remain unclear, we determined the normal values for urinary biochemical markers in this age group.

MATERIAL AND METHODS

Fresh urine samples were obtained from 293 healthy children (from newborns to 2-year-old children). All the samples were subjected to normal urinalysis. NAG, α1-MG, β2-MG, and creatinine (Cr) levels in extracted samples were measured immediately in the central laboratory at Kanazawa Medical Center.

RESULTS

The normal values for each biomarker in children below 2 years of age were determined. Additionally, urinary α1-MG levels were observed to decrease most rapidly with age, almost reaching the level at ≥ 3 years by 6 months after birth.

CONCLUSION

Renal tubular function can be evaluated in children < 3 years old using the normal values. Further, the most stable and useful urinary marker from early infancy seems to be urinary α1-MG.

Association of cardio-renal biomarkers and mortality in the U.S.: a prospective cohort study

OBJECTIVE

Diabetes poses a significant threat to human health. There is a lack of large-scale cohort studies to explore the association between mortality risk and indicators beyond blood glucose monitoring in diabetic populations.

METHODS

Multivariable Cox proportional hazards regression models were performed to investigate the association of 13 blood biomarkers with mortality risk in the National Health and Nutrition Examination Survey (NHANES) and biomarker levels were log-transformed and correlated with mortality.

RESULTS

During a median follow-up of 7.42 years, 1783 diabetic patients were enrolled. Compared to traditional risk factors, the addition of hs-cTnT, hs-cTnI, NT-proBNP, creatinine, cystatin C, and β-2 microglobulin biomarkers increased the predictive ability for all-cause mortality by 56.4%, 29.5%, 38.1%, 18.8%, 35.7%, and 41.3%, respectively. However, the inclusion of blood glucose monitoring had no impact on the prediction of all-cause mortality. Compared with the 1st quartiles of creatinine and Cystatin C, the risk of diabetes mortality were higher in the highest quartiles (HR: 5.16, 95% CI: 1.87-14.22; HR: 10.06, 95% CI: 4.20-24.13).

CONCLUSIONS

In the diabetic population, elevated plasma levels of hs-cTnT, hs-cTnI, NT-proBNP, creatinine, cystatin C, and β-2 microglobulin serve as robust and straightforward predictors of long-term mortality compared to blood glucose levels and HbA1c values. Creatinine and cystatin C stand out as more precise markers for predicting diabetes mortality prior to blood glucose monitoring.

CAKUT: A Pediatric and Evolutionary Perspective on the Leading Cause of CKD in Childhood

The global prevalence of chronic kidney disease (CKD) is increasing rapidly, due to increasing environmental stressors through the life cycle. Congenital anomalies of kidney and urinary tract (CAKUT) account for most CKD in children, with a spectrum that can lead to kidney failure from early postnatal to late adult life. A stressed fetal environment can impair nephrogenesis, now recognized as a significant risk factor for the development of adult CKD. Congenital urinary tract obstruction is the leading cause of CKD due to CAKUT and can itself impair nephrogenesis as well as contribute to progressive nephron injury. Early diagnosis by ultrasonography in fetal life by an obstetrician/perinatologist can provide important information for guiding prognosis and future management. This review focuses on the critical role played by the pediatrician in providing timely evaluation and management of the patient from the moment of birth to the transfer to adult care. In addition to genetic factors, vulnerability of the kidney to CKD is a consequence of evolved modulation of nephron number in response to maternal signaling as well as to susceptibility of the nephron to hypoxic and oxidative injury. Future advances in the management of CAKUT will depend on improved biomarkers and imaging techniques.