Prevention of renal stone disease recurrence. A systematic review of contemporary pharmaceutical options

The rs13347 Polymorphism of the CD44 Gene Is Associated with the Risk of Kidney Stones Disease in the Chinese Han Population of Northeast Sichuan, China

OBJECTIVE

To investigate the association between the rs13347 polymorphism of the CD44 gene and the risk of kidney stone disease (KSD) in the Han population of northeast Sichuan, China, so as to provide a theoretical basis for the treatment of KSD.

METHODS

We used PCR-restriction fragment length polymorphism (RFLP) technique to perform genotyping at rs13347 locus of the CD44 gene in the KSD group and the gontrol group. SNP Hardy-Weinberg equilibrium (HWE) testing was used to confirm the balance of genetic inheritance. Multivariate logistic regression analysis was used for the assessment of rs13347 polymorphism and the risk of developing KSD and to compare the relationship between the polymorphism of rs13347 and clinical characteristics of patients with KSD.

RESULTS

Genotypic results of rs13347 locus of the CD44 gene in the two groups were consistent with the SNP-HWE test, indicating the genetic balance. At the same time, multivariate logistic regression analysis indicated that subjects with CT and TT genotypes at rs13347 in the CD44 gene were more likely to have KSD, and there was a higher prevalence rate in males. Furthermore, carrying allele T at rs13347 was also a risk factor for KSD. In addition, people carrying CT and TT genotypes at rs13347 also have a significantly increased risk of relapsing KSD.

CONCLUSION

The rs13347 polymorphism of the CD44 gene may be associated with the risk of KSD in the Han population of northeast Sichuan in China, and the recurrence rate of KSD in the carriers of CT and TT genotypes is higher.

Three-channel ion chromatograph for improved metabolic evaluation of urolithiasis

Background

Urolithiasis is a multi-etiological disease resulting from a combination of environmental and genetic factors. One of the most challenging aspects of this disease is its high recurrence rate. For most patients, an in-depth metabolic evaluation may reveal the presence of urinary stones. The fact that different urinary stone-related compounds (USRCs) are measured by different methods renders the metabolic evaluation of urolithiasis quite tedious and complex.

Methods

A three-channel ion chromatograph (IC) that automatically measures the concentration of common metabolic indicators of urolithiasis in urine (i.e., oxalate, citrate, uric acid, calcium, and magnesium) was developed to improve the efficiency. To validate its precision and specificity, standard curves were prepared using working solution of these indicators. 100 standard solutions of these indicators were measured with our new IC and three other ICs as the control instruments; analyte concentrations in 100 24-h urine samples from volunteers and 135 calculi patients were also measured.

Results

All analytes had good linear relationships in concentration ranges of 0–10 mg/L. The precision experiments in the standard and urine samples showed that the measurement errors of the newly developed IC were all less than 5%. In urine, the recovery rate ranged from 99.6 to 100.4%, the coefficient of variation ranged from 1.39 to 2.99%, and the results matched between our newly developed IC and the control ICs. The results of the efficiency test showed that we can finish the analysis at the average number of 14 people per day with the new IC. While the average number in the control group is 3.85/day (p = 0.000).

Conclusions

Overall, this multi-channel system significantly improves the efficiency of metabolic evaluation while retaining accuracy and precision.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-021-00914-4.

Polycyclic Aromatic Hydrocarbons and the Risk of Kidney Stones in US Adults: An Exposure-Response Analysis of NHANES 2007-2012

Background

Polycyclic aromatic hydrocarbons (PAHs) exposure may cause various diseases. However, the association between PAHs exposure and kidney stones remains unclear. The purpose of this study was to examine the relationship between PAHs and the risk of kidney stones in the US population.

Methods

The study included a total of 30,442 individuals (≥20 years) from the 2007–2012 National Health and Nutrition Examination Survey (NHANES). Nine urinary PAHs were included in this study. Logistic regression and dose–response curves were used to evaluate the association between PAHs and the risk of kidney stones.

Results

We selected 4385 participants. The dose–response curves showed a significant positive association between total PAHs, 2-hydroxynaphthalene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 9-hydroxyfluorene and the risk of kidney stones after adjusting for confounding factors. Compared with the low group, an increased risk of kidney stones was observed in the high group of total PAHs [OR (95% CI), 1.32 (1.06–1.64), P=0.013], 2-hydroxynaphthalene [OR (95% CI), 1.37 (1.10–1.71), P=0.005], 1-hydroxyphenanthrene [OR (95% CI), 1.24 (1.00–1.54), P=0.046] and 9-hydroxyfluorene [OR (95% CI), 1.36 (1.09–1.70), P=0.007].

Conclusion

High levels of PAHs were positively associated with the risk of kidney stones in the US population.

[Nephrolithiasis: From mechanisms to preventive medical treatment]

Renal lithiasis is a frequent pathology (prevalence ranging from 10 to 12% in France) and a recurrent condition. It is associated with chronic kidney disease and is responsible for 2 to 3% of cases of end-stage renal disease, especially if it is associated with nephrocalcinosis and/or is part of a monogenic disease (1.6% of lithiasis in adults, including 1% of cystinuria). In order to understand the pathophysiology of the nephrolithiasis, the analysis of stones (morphological and by infrared spectrophotometry) as well as a minimal biological evaluation including crystalluria must be carried out. Calcium nephrolithiasis is the most common form (more than 80%). Its preventive medical treatment relies on simple hygienic dietetics: non-alkaline hyperdiuresis greater than 2liters/day, normalization of calcium intakes (1g/day to be distributed over the three meals), restriction of sodium intakes (6g/day) and of protein intakes (0.8-1g/kg of theoretical weight/day), and avoidance of foods rich in oxalate. If there is a hypercalciuria (greater than 0.1mmol/kg of theoretical weight/day with normal calcium intakes), its mechanism should be explored with an oral calcium load test. In the absence of primary hyperparathyroidism, thiazide diuretics can be prescribed, taking care to prevent hypokalemia and iatrogenic hypocitraturia. The treatment of uric acid lithiasis includes alkaline hyperdiuresis (urinary pH 6.2 to 6.8). Allopurinol is only justified if the urinary excretion of uric acid exceeds 4mmol/day. With a well-managed medical treatment, more than 80% of recurrent lithiasis can be stopped, making nephrolithiasis one of the kidney diseases the more accessible to the preventive medical treatment.

Ultrasound guidance can be used safely for renal tract dilatation during percutaneous nephrolithotomy

OBJECTIVES

To compare clinical outcomes in patients who underwent percutaneous nephrolithotomy (PCNL) with renal tract dilatation performed under fluoroscopic guidance vs renal tract dilatation with ultrasound guidance.

PATIENTS AND METHODS

We conducted a prospective observational cohort study, enrolling successive patients undergoing PCNL between July 2015 and March 2018. Included in this retrospective analysis were cases where the renal puncture was successfully obtained with ultrasound guidance. Cases were then grouped according to whether fluoroscopy was used to guide renal tract dilatation or not. All statistical analyses were performed using Stata version 15.1 including univariate (Fisher's exact test, Welch's t-test) and multivariate analyses (binomial logistic regression, ordinal logistic regression, and linear regression).

RESULTS

A total of 176 patients underwent PCNL with successful ultrasonography-guided renal puncture, of whom 38 and 138 underwent renal tract dilatation with fluoroscopic vs ultrasound guidance, respectively. There were no statistically significant differences in patient age, gender, body mass index (BMI), preoperative hydronephrosis, stone burden, procedure laterality, number of dilated tracts, and calyceal puncture location between the two groups. Among ultrasound tract dilatations, a higher proportion of patients were placed in the modified dorsal lithotomy position as opposed to prone, and a significantly shorter operating time was observed. Only modified dorsal lithotomy position remained statistically significant after multivariate regression. There were no statistically significant differences in postoperative stone clearance, complication rate, or intra-operative estimated blood loss. A 5-unit increase in a patient's BMI was associated with 30% greater odds of increasingly severe Clavien-Dindo complications. A 5-mm decrease in the preoperative stone burden was associated with 20% greater odds of stone-free status. No variables predicted estimated blood loss with statistical significance.

CONCLUSIONS

Renal tract dilatation can be safely performed in the absence of fluoroscopic guidance. Compared to using fluoroscopy, the present study demonstrated that ultrasonography-guided dilatations can be safely performed without higher complication or bleeding rates. This can be done using a variety of surgical positions, and future studies centred on improving dilatation techniques could be of impactful clinical value.

Kidney stones and the risk of renal cell carcinoma and upper tract urothelial carcinoma: the Netherlands Cohort Study

Background

We examined the association between kidney stones and renal cell carcinoma (RCC) and upper tract urothelial carcinoma (UTUC) risk in the Netherlands Cohort Study on diet and cancer.

Methods

In total, 120,852 participants aged 55–69 completed a self-administered questionnaire on diet, medical conditions and other risk factors for cancer at baseline (1986). After 20.3 years of cancer follow-up 4352 subcohort members, 544 RCC cases and 140 UTUC cases were eligible for case-cohort analysis. Hazard ratios (HR) and 95% confidence intervals (CIs) were estimated by multivariable-adjusted proportional hazards models.

Results

Kidney stones were associated with an increased RCC risk (HR: 1.39, 95% CI 1.05–1.84), vs. no kidney stones. Kidney stones were associated with an increased risk of papillary RCC (HR: 3.08, 95% CI 1.55–6.11), but not clear-cell RCC (HR: 1.14, 95% CI 0.79–1.65). UTUC risk was increased for participants with kidney stones (HR: 1.66, 95% CI 1.03–2.68). No heterogeneity of associations was found for UTUC in the ureter and renal pelvis. An early kidney stone diagnosis (≤40 years) was associated with an increased RCC and UTUC risk, compared to later diagnosis.

Conclusion

Kidney stones were associated with increased papillary RCC risk, but not clear-cell RCC risk. No heterogeneity was found for UTUC subtypes.

Oxalate-Degrading Enzyme Recombined Lactic Acid Bacteria Strains Reduce Hyperoxaluria

OBJECTIVE

To develop recombinant lactic acid bacteria (LAB) strains that express oxalate-degrading enzymes through biotechnology-based approach for the treatment of hyperoxaluria by oral administration.

MATERIAL AND METHODS

The coding gene of oxalate decarboxylase (ODC) and oxalate oxidase (OxO) was transformed into Lactococcus lactis MG1363. The oxalate degradation ability in vitro was evaluated in media with high concentration of oxalate. Hyperoxaluria rat models through high oxalate diet were given recombinant LAB through oral administration. Twenty-four-hour urinary oxalate was measured, and kidney stone formation was investigated.

RESULTS

LAB recombined with the coding gene of ODC could effectively decrease the amount of oxalate in the media and in the urine of rats. Moreover, the formation of calcium oxalate crystals in kidneys was also inhibited. The acid-induced promoter p170 significantly enhanced the reduction of hyperoxaluria. However, recombinant LAB expressing heterologous OxO showed less efficiency in oxalate degradation even in the presence of p170.

CONCLUSION

LAB expressing ODC is more efficient in degradation of oxalate in vitro and in vivo than that expressing OxO. This present study provided novel recombinant probiotic strains as a potential treatment tool against oxalosis.

[Nephrolithiasis of adult: From mechanisms to preventive medical treatment]

Nephrolithiasis is a very common (prevalence around 10 to 12% in France) and recurrent disorder. Nephrolithiasis is associated to chronic kidney disease and is responsible for 2 to 3% of cases of end-stage renal disease, mainly if it is associated to nephrocalcinosis or to a monogenic disorder (1.6% of nephrolithiasis in adults, among them 1% of cystinuria). To understand the underlying pathophysiological processes, stone analysis (morphology and using infrared spectrophotometry) as well as minimal biological assessment including urine crystal research are required. The calcic nephrolithiasis is the more frequent subtype (>80%). Its medical treatment relies on simple dietary rules: non-alkaline hyperdiuresis>2 liters/day, calcium intake normalization (1 gram per day divided between the three principal meals), normalization of sodium (6 to 7 grams per day) and protein intake (1g/kg of theoretical body weight/day), and eviction of foods rich in oxalate. In case of persistent hypercalciuria (>0.1mmol/kg of theoretical body weight/day on free diet), a thiazide diuretic can be started while being aware to correct iatrogenic decrease in plasma potassium and urine citrate excretion. Measurement of bone mineral density must systematically be performed in patients with high 24 h-urinary calcium excretion. The medical treatment of uric acid nephrolithiasis relies on alkaline hyperdiuresis (goal of urine pH: 6.2 to 6.8). The use of allopurinol is justified only if urine uric acid is over 4mmol/day. Thanks to a well-managed preventive medical treatment, one can expect to stop the activity of nephrolithiasis in more than 80% of cases, making it one of the most accessible renal pathologies to preventive medical treatment.