24-Hour urine collection for first time pediatric stone formers: Is it worth it?

Pediatric Stone Disease: Current Trends and Future Directions

Pediatric nephrolithiasis is less common in children than in adults but the incidence has been rising rapidly, and it is now a public health and economic burden in the United States. There are challenges unique to children that should be taken into consideration when evaluating and managing pediatric stone disease. In this review, we present the current research on risk factors, emerging new technologies for treatment of stones and recent investigations on prevention of stones in this population.

Pitfalls in the Diagnosis and Management of Hypercortisolism (Cushing Syndrome) in Humans; A Review of the Laboratory Medicine Perspective

Biochemical confirmation of a diagnosis of hypercortisolism (Cushing syndrome) is vital to direct further investigations, especially given the overlap with non-autonomous conditions, such as pseudo-Cushing, and the morbidity associated with missed diagnoses. A limited narrative review was performed focusing on the laboratory perspective of the pitfalls of making a biochemical diagnosis of hypercortisolism in those presenting with presumed Cushing syndrome. Although analytically less specific, immunoassays remain cheap, quick, and reliable in most situations. Understanding cortisol metabolism can help with patient preparation, specimen selection (e.g., consideration of urine or saliva for those with possible elevations of cortisol binding globulin concentration), and method selection (e.g., mass spectrometry if there is a high risk of abnormal metabolites). Although more specific methods may be less sensitive, this can be managed. The reduction in cost and increasing ease of use makes techniques such as urine steroid profiles and salivary cortisone of interest in future pathway development. In conclusion, the limitations of current assays, particularly if well understood, do not impede diagnosis in most cases. However, in complex or borderline cases, there are other techniques to consider to aid in the confirmation of hypercortisolism.

Metabolic evaluation: is there really a future?

PURPOSE OF REVIEW

To confirm the need for a metabolic evaluation in stone formers based on the latest information published in the last 24 months and in the current 2022 American and European urological guidelines.

RECENT FINDINGS

Recent studies suggest that urolithiasis prevalence has been increasing since 1990. Along with it, metabolic abnormalities that contribute to the development of kidney stones are also increasing, such as hyperuricosuria, hyperoxaluria, hypocitraturia, hypomagnesuria, hypocalciuria, hypophosphaturia, and hyperuricemia. Those abnormalities can only be detected through a metabolic evaluation in patients with stone disease.

SUMMARY

It is important for us, urologists, to have in mind the actual stone prevalence worldwide. As part of our initial evaluation of the patient with urolithiasis, we must not forget to perform the basic metabolic analysis and, according to the patient's risk classification, continue with a deep metabolic analysis. This extensive analysis includes blood and urine tests. The urinalysis covers 24-h urinalysis, and it would be accurate to also have an early fresh urine analysis. Moreover, identifying the stone type is intimately correlated with the search for other metabolic parameters.

A comparison of the clinical characteristics of pediatric urolithiasis patients with positive and negative molecular diagnoses

PURPOSE

To compare the clinical characteristics of pediatric urolithiasis patients with positive and negative molecular diagnoses.

METHODS

The clinical characteristics corresponding to pediatric urolithiasis patients that had undergone exome sequencing at our hospital between January 2016 and May 2021 were collected. Genetic analysis results were used to separate patients into positive and negative molecular diagnosis groups. Multivariate logistic regression analyses adjusted for visiting age, sex, ethnicity, province, and body mass index were used to compare differences in medical history, diagnostic imaging findings, and renal function between individuals with and without molecular diagnoses.

RESULTS

In total, 194 patients with pediatric urolithiasis of unknown etiology underwent exome sequencing and were included in the present study, of whom 63 obtained urolithiasis-related molecular diagnoses. Relative to cases without a molecular diagnosis, those with a positive molecular diagnosis were more likely to be associated with a positive family history (OR 2.84, 95% CI 1.29-6.29, p = 0.008), consanguineous parents (OR 24.7, 95% CI 1.34-454, p = 0.002), early onset (OR 1.26, 95% CI 1.09-1.45, p < 0.001), nephrocalcinosis (OR 10.6, 95% CI 3.06-36.6, p < 0.001), cast stone (OR 18.9, 95% CI 4.40-81.1, p < 0.001), multiple stones (OR 13.9, 95% CI 6.39-30.2, p < 0.001), bilateral stones (OR 7.04, 95% CI 3.47-14.2, p < 0.001), a lower estimated glomerular filtration rate (OR 1.17, 95% CI 1.07-1.28, p < 0.001), and chronic kidney disease (OR 26.9, 95% CI 1.42-526, p < 0.001).

CONCLUSION

A positive family history, consanguineous parents, early onset, nephrocalcinosis, severe stone burden, and impaired renal function are signals of concern that are suggestive of inherited urolithiasis.