Urolithiasis Research Articles

Tips for percutaneous nephrolithotomy for transplant kidney stone

IntroductionThe management of urinary tract stones, particularly de novo kidney allograft stones, presents unique challenges for kidney transplant recipients because of their prevalence and specific clinical considerations. Here, we describe a case in which percutaneous nephrolithotomy was successfully used to fragment a large kidney allograft stone ≥20 mm in size.Case presentationA 57‐year‐old woman who underwent ureteroureterostomy post simultaneous pancreas–kidney transplantation presented with gross hematuria after 15 years. Computed tomography revealed a 23‐mm stone in the transplanted kidney. Initial attempts at endoscopic combined intrarenal surgery were changed to percutaneous nephrolithotomy because of poor ureter mobility and tortuosity. Stone fragmentation was achieved using pneumatic and ultrasonic lithotripsy. A second procedure using Swiss LithoClast® Trilogy enabled complete stone clearance and ureteral stent placement.ConclusionBy understanding the peculiarities of the percutaneous approach, we demonstrated the safe and effective use of a pneumatic and ultrasonic lithotripter for kidney allograft stone fragmentation.

Ureteroscopy and lasertripsy for lower pole stones

To investigate the outcomes of ureteroscopy and lasertripsy in lower pole renal stones <2 cm when treated in situ compared to displacement to the upper pole. Using the Medical Literature Analysis and Retrieval System Online (MEDLINE)/PubMed, the Excerpta Medica dataBASE (EMBASE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), the Cochrane Library, and Clinicaltrials.gov we identified adult population, English language, studies published until March 2023 comparing surgical outcomes and stone-free rates (SFRs) in relation to lower pole stones <2 cm managed in situ vs those displaced (International Prospective Register of Systematic Reviews [PROSPERO] identifier: CRD42023432750). Analysis was performed using R with the 'meta' package. Bias analysis was performed using the Cochrane Risk of Bias 2 tool for randomised trials and the Newcastle-Ottawa scale for observational studies. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to ascertain the certainty of evidence. A total of five studies were included, comprising two retrospective cohort studies, three randomised trials, with a total of 408 patients. Meta-analysis demonstrated SFRs are significantly higher in those patients undergoing displacement vs those managed in situ (risk ratio 1.21, 95% confidence interval [CI] 1.10-1.34, P < 0.001). There was no significant difference in complication rates. Operative time was significantly longer in the displacement group (mean difference 5.62 min, 95% CI 0.40-10.83 min; P = 0.03). Overall risk of bias was moderate. Certainty of evidence was moderate for stone-free status, and very low for all other outcomes. This systematic review and meta-analysis demonstrates that for lower pole stones <2 cm displacement strategies have significantly higher SFRs than treatment in situ, with no significant difference in complications. There is significantly increased operative time in the displaced group, but an additional 6 min is unlikely to be clinically significant.

Phytochemical, Nutritional and Medicinal Profile of &lt;i&gt;Cucumis sativus&lt;/i&gt; L. (Cucumber)

Current studies were performed to review the phytochemistry, nutritional benefits, medicinal/therapeutic value, and cosmetic importance of cucumber (Cucumis sativus L.). Cucumber fruits are an important part of the human diet, often used in salads, pickles, and sauces, due to their nutritious qualities and health benefits. They are a good source of vitamins, minerals, soluble carbohydrates, proteins, etc. The leaves, flowers, seeds, fruits, and bark of cucumber are rich in various phytoconstituents, including phenols, glycosides, alkaloids, flavonoids, carotenoids, tannins, steroids, terpenoids, phytosterols, phytoestrogens, saponins, minerals, proteins, carbohydrates, resins, and vitamins. Cucumbers are traditionally used to treat a variety of diseases, including high blood pressure, blood sugar issues, cancer, high cholesterol, kidney stones, constipation, Alzheimer's disease, eczema, hypertension, atherosclerosis, and diabetes-related problems. The therapeutic/pharmaceutical value of cucumbers may be attributed to their laxative, antioxidant, anti-diabetic, analgesic, anti-hepatotoxic, anti-diarrheal, anti-fungal, anti-bacterial, thrombolytic, anti-ulcer, anti-inflammatory, cytotoxic, free radical scavenging, and wound-healing properties. Cucumbers also improve skin quality, promote skin whitening and smoothness, enhance natural beauty, regulate hydration, aid in weight loss, and reduce fat. They are used in cucumber creams, perfumes, face packs, and facials. Cucumber extract is incorporated into several formulations for topical skin treatments. This review article aims to explore the traditional uses, phytochemical contents, nutritional value, cosmetic applications, and pharmacological and therapeutic potential of cucumbers. It will be highly beneficial for a wide range of readers, including the general public, researchers, physicians, farmers, and agricultural stakeholders.

Effect of preoperative Silodosin on facilitating access sheath placement in retrograde intrarenal surgery. A randomized controlled studys

ABSTRACT Introduction to evaluate the effect of preoperative Silodosin on ureteric dilatation to facilitate ureteral access sheath (UAS) placement and reduction of ureteral wall injury in retrograde intrarenal surgery (RIRS). Methods one hundred and twenty patients with renal or ureteric stones were randomly allocated into 2 equal groups. Group A represents patients who received a 7-day preoperative single dose Silodosin before RIRS while Group B represents patients who received a placebo for the same regimen. Our primary outcome was to assess the success rate of (UAS) placement. Our secondary outcomes were to evaluate the perioperative complication rate, stone-free rate, hospital stay, and cost analysis. Results In our study, Silodosin showed a higher success rate for (UAS) insertion compared to placebo with a statistically significant difference (p-value = 0.04). Spontaneous UAS insertion in the Silodosin group was 58.3%, which was increased with active ureteric dilatation to 98.3%. Preoperative Silodosin led to less postoperative pain and analgesics requirements without impacting postoperative hospital stay or stone-free rate. There was less ureteric injury incidence in the Silodosin group compared to placebo with a statistically significant difference (p-value = 0.002). Conclusion Preoperative Silodosin facilitates UAS insertion with a protective role against ureteric injury compared to placebo.

Prevalence, risk factors and effect of curative parathyroidectomy on nephrocalcinosis in Asian-Indian patients with symptomatic primary hyperparathyroidism.

Primary hyperparathyroidism (PHPT) is characterized by inappropriate secretion of parathyroid hormone, causing hypercalcemia and hypercalciuria, leading to renal stone diseases and nephrocalcinosis. The frequency, risk factors, and curative effect on nephrocalcinosis in post-parathyroidectomy have not been identified yet. Therefore, the present study evaluated the clinico-biochemical, radiological parameters and curative effect on nephrocalcinosis. A total of 583 PHPT patients were analysed in four groups viz. Group 1 (PHPT with nephrocalcinosis-98; 16.8%); Group 2 (PHPT with nephrolithiasis-227; 38.9%); Group 3 (PHPT with both nephrolithiasis and nephrocalcinosis-59; 10.1%); and Group 4 (PHPT without renal diseases-199, 34.1%). In the sub-group analysis, younger age(p ≤ 0.05), male gender(p ≤ 0.05), and hematuria(p ≤ 0.005) were significant in Group 1 vs. Group 4. Dysuria and low eGFR were significant in Group 1 vs. Group 2(p ≤ 0.0005; p ≤ 0.05) and Group 1 vs. Group 4(p ≤ 0.0005; p ≤ 0.0005). Polyuria (p ≤ 0.05; p ≤ 0.05, p ≤ 0.005), and gravluria (p ≤ 0.05; p ≤ 0.0005, p ≤ 0.005) were frequent in Group 1 vs. other groups. A significant difference was observed in S.Ca and, 24-hrs U.Ca in Group 1 vs. Group 2 {(12.2 (10.8-13.4) vs. 11.2 (10.7-12.4), p ≤ 0.05; 301 (189.5-465) vs. 180 (92.5-323.1), p ≤ 0.05} and Group 1 vs. Group 4 {(12.2 (10.8-13.4) vs. 11.4 (10.7-12.5), p ≤ 0.05 ; 301 (189.5-465) vs. 213 (110-360), p ≤ 0.0005}. Multivariate logistic regression showed gravluria [aOR = 9.2, p = 0.0001], S.Ca (aOR = 1.30, p = 0.003) and, 24-hrs U.Ca (aOR = 1.02, p = 0.042) to be independent predictors of nephrocalcinosis. Pre and post-operative assessment revealed decreased S. Ca levels [(11.9 ± 1.9) vs. (10.5 ± 1.0) mg/dL; p = 0.04] and complete radiological resolution (10.4%) in PHPT with nephrocalcinosis. Therefore, serum calcium, 24-hrs Urinary calcium, and gravluria were independent predictors of nephrocalcinosis with 10.4% showing complete radiological resolution post-operatively.

Integrated Care in a Large Public System Improves Simple Kidney Stone Management.

In the Los Angeles County Department of Health Services-the second largest public health care system in the United States-clinical integration allows specialists and primary care providers to collaboratively provide specialty care. We used time-driven activity-based costing to compare patient burden and cost of kidney stone diagnosis, workup, and management with and without clinical integration. We interviewed and observed teams of physicians and staff to understand workflow practices and personnel, space, material, and device requirements for stone care in the 2 models. We created process maps that outline the entire arc of care and used time-driven activity-based costing to calculate the all-inclusive costs of kidney stone diagnosis, workup, and scheduling for surgical treatment. The total cost of kidney stone treatment per stone episode in the integrated pathway was $499.04, compared with $699.81 in the traditional, nonintegrated pathway, a difference of 29%. The number of steps needed to arrive at operating room scheduling was 11 with integration and 14 without it. Clinical integration resulted in more efficient and cost-effective care from patient, provider, and health system perspectives. Integrated care may improve access to specialty care and increase the value of care and reduce treatment burden on patients.

The incidence, clinical features and outcome of urinary tract infections in geriatric patients: A prospective longitudinal study

ObjectivesThis study compares the incidence, clinical features, microbial profiles, and outcomes of urinary tract infections (UTIs) in patients aged 65 years and older versus those younger than 65 years. MethodsA longitudinal cohort of 1,123 patients was divided into Group A (≥65 years, n = 560) and Group B (<65 years, n = 563) and followed for 2 years. The study analyzed UTI incidence, clinical features, microbial profiles, and outcomes, including recurrence and antibiotic resistance. ResultsOver 2 years, Group A had a significantly higher UTI incidence (38.0%) compared with Group B (12.8%) (P <0.0001). Complete recovery was less common in Group A (44.6%) than in Group B (70.83%), whereas recurrent UTIs and antibiotic resistance were more frequent in Group A (43.5% vs 22.2%, P <0.0001 and 11.7% vs 2.78%, P = 0.0017, respectively). Escherichia coli was the most prevalent pathogen in both groups, with Klebsiella and Pseudomonas species more common in recurrent UTIs, particularly in older patients. Risk factors for recurrent UTIs included advanced age, female sex, diabetes, immunosuppression, and renal stones. ConclusionsThese findings highlight the need for age-specific UTI prevention and management strategies that account for microbial resistance patterns and higher recurrence rates in older patients, addressing clinical and microbial challenges.

How does percutaneous nephrolithotomy (PCNL) compare with retrograde intrarenal surgery (RIRS) for adults with renal stones?

How does percutaneous nephrolithotomy (PCNL) compare with retrograde intrarenal surgery (RIRS) for adults with renal stones?

Comment on: Low serum testosterone is associated with an increased risk of first-time renal calculi in men without testosterone replacement therapy.

Comment on: Low serum testosterone is associated with an increased risk of first-time renal calculi in men without testosterone replacement therapy.

Hydronephrosis in a Sigmoid Supernumerary Kidney

Supernumerary kidneys are a rare developmental anomaly, often discovered incidentally or during the investigation of complications such as infections or obstructive uropathy. This case report presents a 70-year-old male patient with a sigmoid supernumerary kidney complicated by hydronephrosis and a staghorn calculus. The patient, with a history of poorly controlled hypertension and type 2 diabetes mellitus, was admitted for febrile left lumbar pain and hemodynamic instability. Diagnostic imaging, including renal ultrasound and uro-CT, revealed a major hydronephrosis in the supernumerary kidney caused by an obstructive staghorn calculus, along with signs of advanced local infection and inflammation. This report highlights the critical role of imaging modalities, particularly uro-CT, in diagnosing renal anomalies and planning treatment. We also review the literature on the management of supernumerary kidneys, emphasizing the importance of early detection and appropriate therapeutic intervention to prevent further complications such as renal insufficiency and infection.

Evaluation of Optical Tracking to Distinguish Surgeon Experience During Endoscopic Stone Surgery.

Introduction and Objectives: Optical tracking (OT) has shown potential in assessing surgical skill but has yet to be evaluated for endoscopic urologic surgery. We sought to evaluate the potential for OT to distinguish expert and trainee surgeons during flexible ureteroscopy (fURS) for kidney stone treatment in both simulated and live surgical settings. Methods: We performed OT analysis of six surgeons performing stone localization during fURS in two settings. In the first setting, surgeons were tasked with fiducial localization in three separate kidney phantoms during fURS. In the second setting, surgeons performed stone localization via fURS in five separate patients. Surgeons were categorized as "expert" (n = 3, endourologist, average case volume of >100 fURS per year) or trainee (n = 3, trainee, <100 fURS per year). OT metrics were recorded for both settings using the Microsoft HoloLens 2© as the surgeons viewed the surgical monitor during fURS. Standard OT metrics of experts and trainees were compared, and included: area of eye gaze movement, gaze distance traveled, number of gaze fixation points, percentage of gaze fixation dwell time, and number of saccades. Results: In the simulated setting, the average time for stone localization was greater for trainees compared to experts (318 seconds vs 52 seconds, p < 0.01). Additionally, the mean area of eye gaze movements with area of interest (AOI) was greater for trainees compared to experts (1430 cm2 vs 1060 cm2, p < 0.01). The total gaze distance traveled was also greater for trainees compared to experts (1480 cm vs 730 cm, p < 0.01). In the live surgical setting, average time for stone localization was similar for trainees and experts (74 seconds vs 51 seconds, p = 0.05). The total area of eye gaze movements in AOI was greater for trainees compared to experts (700 cm2 vs 30 cm2, p < 0.01). Additionally, the total gaze distance traveled was greater for trainees compared to experts (14,000 cm vs 680 cm, p < 0.01). This suggests more varied and less point specific concentration on the surgical screen by trainees. There was no difference in percentage of gaze fixation dwell time and number of saccades between experts and trainees in either setting. Conclusions: OT analysis can objectively distinguish surgical experience between experts and trainee surgeons performing fURS in both simulated and live surgical settings. These findings may play a role in future surgical training and skills assessment.

Association between cardiometabolic index and kidney stone from NHANES: a population-based study.

The Cardiometabolic Index (CMI) is a novel marker of visceral obesity and dyslipidemia. Our study aimed to explore the association between CMI and kidney stones among US adults. This cross-sectional study was conducted among adults with complete records of CMI and kidney stones information from the 2011 to 2018 National Health and Nutrition Examination Survey (NHANES). Inverse probability treatment weighting (IPTW) was used to balance the baseline characteristics of the study population. The independent relationship between CMI and kidney stones was evaluated using IPTW-adjusted multivariate logistic regression, restricted cubic splines (RCS), and subgroup analysis. A total of 9,177 participants, with an average CMI of 0.72 (0.99), were included in this study. The IPTW-adjusted logistic regression revealed that CMI was an independent risk factor for kidney stones. The adjusted odds ratio (OR) for kidney stones were 1.39 (95% CI: 1.24 - 1.56, P < 0.001) for the second CMI tertile and 1.31 (95% CI: 1.17 - 1.47, P < 0.001) for the third CMI tertile, compared with the first CMI tertile. A linear relationship between CMI levels and kidney stone risk was observed in the RCS analysis. Subgroup analysis showed that the association between CMI levels and kidney stone risk remained stable across groups. A positive association between CMI level and the risk of kidney stones was observed among US adults in our study. Further large-scale prospective studies are needed to validate our findings.

The association between novel negative pressure ureteroscopic lithotripsy combined with flexible ureteroscopy versus percutaneous nephrolithotomy on stone-free rates: implications for clinical practice and policy

The correlation between novel negative pressure ureteroscopic lithotripsy (NP-URL) combined with flexible ureteroscopy (FU) and percutaneous nephrolithotomy (PCNL) on stone-free rates (SFR) remains unclear. There is a lack of evidence from Chinese populations regarding the relationship between SFR and NP-URL combined with FU (NP-URL-FU) versus PCNL. We aimed to assess the association between NP-URL-FU and PCNL on SFR. We conducted a cohort study involving 166 participants with 2–4 cm kidney stones. Data on SFR (7 days and 2 months) were collected from all participants. Logistic regression analysis was used to substantiate the research objectives. NP-URL-FU versus PCNL showed an 86% decrease in the 7-day SFR (OR = 0.14, 95% CI 0.07–0.29). The results remained stable even after adjusting for potential confounders. However, no statistically significant association was found between the surgical method and the 2-month SFR. Further exploratory subgroup analyses showed no significant interactions, with all P values > 0.05. Among patients with 2–4 cm kidney stones, NP-URL-FU was associated with a lower risk of incident 7-day SFR than PCNL. However, no statistically significant difference was found in the long-term stone removal rate. Therefore, NP-URL-FU may be a viable alternative surgical option for patients seeking minimally invasive procedures.

SGLT2 Inhibitors and Their Effect on Urolithiasis: Current Evidence and Future Directions.

Urolithiasis (UL) is increasingly prevalent due to rising cardiorenometabolic diseases, posing significant management challenges despite advances in urological techniques. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, primarily used for type 2 diabetes mellitus, chronic kidney disease, and heart failure, have emerged as a potential novel approach for UL treatment. These inhibitors may help reduce the risk of urolithiasis, particularly in patients with diabetes, by improving glycemic control and altering urinary chemistry, which are crucial factors in stone formation. However, the changes in urinary composition induced by SGLT2 inhibitors might also increase the risk of uric acid stone formation. This review evaluates the potential of SGLT2 inhibitors in managing UL, highlighting both the benefits and the risks. While these inhibitors show promise in reducing new and recurrent urinary stones in patients with diabetes, data on their effects in patients without diabetes who form stones are limited. Current human evidence largely comes from post hoc analyses of randomized controlled trials (RCTs) and large-scale database studies, with only one study providing detailed stone composition data. Experimental studies in animal models and cell lines have focused on calcium oxalate (CaOx) stones, showing that SGLT2 inhibitors specifically target CaOx stone formation and related renal inflammation. Although primarily studied for CaOx stones, their potential impact on other calcium-containing stones, such as calcium phosphate, remains promising. Further research is needed to explore their therapeutic potential and optimize treatment strategies.

Optimizing antigen preparation for oxalyl-CoA decarboxylase enzyme diagnostic kit and ELISA system cutoff determination.

The prevalence of kidney stone disease is increasing globally, with calcium oxalate stones being the most common type. Oxalyl-CoA decarboxylase (OXC), an enzyme produced by the gut bacterium Oxalobacter formigenes, plays a crucial role in oxalate metabolism. Deficiencies in OXC activity can lead to the accumulation of oxalate, contributing to kidney stone formation. This study aimed to develop a reliable diagnostic assay for OXC by optimizing antigen production and establishing a cutoff value for an enzyme-linked immunosorbent assay (ELISA). We cloned, expressed, and purified recombinant OXC protein in Escherichia coli BL21(DE3), and generated specific polyclonal antibodies in rabbits. The ELISA system was optimized and validated using serum samples from 40 healthy individuals and 6 patients with oxalate-related disorders. The cutoff value was determined using the formula (M + 2SD), where (M) is the mean and (SD) is the standard deviation of the healthy sample results. The calculated cutoff value of 0.656750 effectively distinguished between healthy and affected individuals, with a sensitivity of 97.5% and a specificity of 83.3%. These findings provide a valuable tool for the early detection and management of oxalate-related disorders, with significant implications for clinical practice.

Evaluating the role of urine chemistry in shock wave lithotripsy outcomes.

Extracorporeal Shock Wave Lithotripsy (ESWL) is a commonly used method for the noninvasive treatment of kidney stones. However, achieving optimal treatment outcomes and minimizing potential damage to the kidney necessitates careful consideration for the total amount of energy utilized. This study aims to investigate whether urine pH and urine specific gravity have an impact on the total amount of energy applied during SWL. Between January 2023 and December 2023, 129 patients with renal stones underwent SWL in our department using the Storz Medical Modulith Inline lithotripter. Stone-free rates, complications, and the impact of patient, urine, and stone characteristics on energy use were analyzed. Urine samples were analyzed for pH and specific gravity. Stone characteristics, including size, HU, and skin-to-stone distance, were recorded. The obtained data were evaluated regarding the possible relationship between the total energy amount (determined as a risk factor) and the age, BMI, urine pH, urine specific gravity, stone size, HU, and skin-to-stone distance by using the Pearson correlation coefficient. p-value of < 0.05 was considered statistically significant. Evaluation of our findings revealed a negative linear relationship between total amount of energy used and the urine pH, indicating a decrease in the total energy amount as urine pH shifts towards alkaline values (p = 0.038; p < 0.05). However, no statistically significant relationship was observed between age, BMI, urine specific gravity, stone size, HU, and skin-to-stone distance and the total energy amount. Our findings demonstrated a significant relationship between urine pH and the total amount of energy applied during SWL sessions, suggesting the need for further prospective research to better understand the possible association between these two parameters. Such investigations could contribute to the development of more reasonable and effective strategies for kidney stone treatment in an attempt to minimize the potential kidney damage.

Comparative analysis of retro vs. transperitoneal laparoscopic pyelolithotomy for large renal stones.

The objective of this study is to compare the outcomes and complications of retroperitoneal and transperitoneal laparoscopic pyelolithotomy (RLP and TLP, respectively) in the treatment of large kidney stones. In this retrospective cohort effort, data of all patients who underwent laparoscopic pyelolithotomy for renal pelvic stone (N = 273) in three referral urology hospitals were retrieved. Operation duration, length of hospital stay, postoperative stone-free rate, hemoglobin (Hb) and creatinine (Cr) changes and complications were compared between the two groups before and after propensity score matching. A total of 199 TLP and 74 RLP cases were examined. Stone size was significantly higher in the TLP vs. RLP group (29.8 ± 10.9 vs. 26.5 ± 8.8mm; P = .022). Length of operation and hospital stay were comparable (P = .672 and P = .396, respectively). Rate of conversion to open surgery, postoperative blood transfusion rate, postoperative urinary leakage, postoperative stone-free rate, Hb drop and Cr change were similar between the two groups (P = .348, 0.190, 0.828, 0.411, 0.780 and 0.134, respectively). Postoperative fever was significantly more prevalent in TLP compared to RLP (21.6% vs. 0.0%, respectively; P < .001). Propensity score matched analyses showed similar results in all aspects; particularly demonstrating higher postoperative fever in TLP compared to RLP (18.9% vs. 0.0%, respectively; P < .001). RLP can be considered as an alternative to TLP; especially owing to a lower chance of postoperative fever.

Intelligent control of pressure based on ureteral access sheaths: renal pelvic pressure during flexible ureteroscope perfusion at different sites.

This study aimed to evaluate the accuracy and effectiveness of renal pelvic pressure (RPP) control during flexible ureteroscopic perfusion at various sites. Flexible ureteroscopy for the intelligent control of RPP was based on a ureteral access sheath (UAS) that integrated pressure measurement and suction functions (with automatic adjustment). Eleven consecutive patients with indurating nephrostomy tubes were enrolled. The nephrostomy tube was connected to a disposable invasive blood pressure sensor. The RPP was zeroed after the pressure stabilized. The flow rate and control value were set at 100ml/min and - 5 mmHg, respectively. An 8.5 Fr flexible ureteroscope was irrigated at the renal pelvis, as well as the upper, middle, and lower calyces of the kidney for 1min. All 11 patients with upper urinary tract calculi underwent successful UAS placement. Pressures measured by the sheath and fistula during perfusion were - 5.07 ± 1.41 and - 4.89 ± 1.07 mmHg at the renal pelvis, -5.16 ± 1.36 and - 5.12 ± 1.32 mmHg at the upper calyces, -4.98 ± 0.87 and - 5.39 ± 1.01 mmHg at the middle calyces, as well as -4.95 ± 1.56 and - 5.64 ± 1.24 mmHg at the lower calyces, respectively. There were no significant differences in pressure between the sheath and fistula groups or in sheath and fistula pressures among parts. The RPP fluctuated; however, all values were within the safe limit of 20 mmHg. The UAS-based pressure monitoring technology can accurately and reliably monitor and control RPP within a set range.

Deconvolution of Human Urine across the Transcriptome and Metabolome.

Early detection of the cell type changes underlying several genitourinary tract diseases largely remains an unmet clinical need, where existing assays, if available, lack the cellular resolution afforded by an invasive biopsy. While messenger RNA in urine could reflect the dynamic signal that facilitates early detection, current measurements primarily detect single genes and thus do not reflect the entire transcriptome and the underlying contributions of cell type-specific RNA. We isolated and sequenced the cell-free RNA (cfRNA) and sediment RNA from human urine samples (n = 6 healthy controls and n = 12 kidney stone patients) and measured the urine metabolome. We analyzed the resulting urine transcriptomes by deconvolving the noninvasively measurable cell type contributions and comparing to plasma cfRNA and the measured urine metabolome. Urine transcriptome cell type deconvolution primarily yielded relative fractional contributions from genitourinary tract cell types in addition to cell types from high-turnover solid tissues beyond the genitourinary tract. Comparison to plasma cfRNA yielded enrichment of metabolic pathways and a distinct cell type spectrum. Integration of urine transcriptomic and metabolomic measurements yielded enrichment for metabolic pathways involved in amino acid metabolism and overlapped with metabolic subsystems associated with proximal tubule function. Noninvasive whole transcriptome measurements of human urine cfRNA and sediment RNA reflects signal from hard-to-biopsy tissues exhibiting low representation in blood plasma cfRNA liquid biopsy at cell type resolution and are enriched in signal from metabolic pathways measurable in the urine metabolome.

Identifying effects of volatile organic compounds exposure on kidney stone prevalence in U.S. adults: a cross-sectional analysis of NHANES 2007-2020.

Our aim was to comprehensively investigate the relationship between blood volatile organic compounds (VOCs) and kidney stone prevalence for U.S. adults. In this cross-sectional study, 10,052 participants from the 2007-2020 National Health and Nutrition Examination Survey (NHANES) were included. Multivariate logistic regression model was employed to investigate the association between 9 blood VOCs and kidney stones. We explored the dose-response relationship between blood VOCs and kidney stones using restricted cubic spline (RCS) analysis. Additionally, weighted quantile sum (WQS) regression model was performed to assess the overall association of 9 blood VOCs with kidney stones. Finally, subgroup analyses were conducted to identify the findings in different populations at high prevalence. Logistic regression analysis and dose-response risk curves revealed that blood benzene (aOR = 1.308, 95% CI: 1.118-1.530, P = 0.001), blood ethylbenzene (aOR = 1.280, 95% CI: 1.054-1.554, P = 0.013), blood m-/p-xylene (aOR = 1.187, 95% CI: 1.008-1.398, P = 0.040), blood 2,5-dimethylfuran (aOR = 1.319, 95% CI: 1.135-1.533, P < 0.001) and blood furan (aOR = 1.698, 95% CI: 1.305-2.209, P < 0.001) were positively associated with the prevalence of kidney stones. WQS regression analysis revealed that exposure to mixed blood VOCs was positively correlated with kidney stone prevalence (OR = 1.34, 95% CI: 1.14-1.57), with furans carrying the greatest weight. Subgroup analyses suggested that kidney stones were more susceptible to the effects of blood VOCs in young and middle-aged, female, overweight and obese, non-hypertensive, and non-diabetic populations. In this study, the results indicated that high VOC exposure was positively and independently associated with kidney stones in U.S. adults. This finding highlighted the need for public health strategies to reduce VOC exposure and its role in kidney stone prevention and treatment.