Meta-analysis guided development of a standard artificial urine

In this study, we present the first meta-analysis of human urine reported in the literature, drawing data from a total of 35 articles with a combined participant count of 14,021. Through this analysis, we have developed an artificial urine (AU) composition that can be adjusted within typical physiological parameters for in vitro applications. Our findings demonstrate the utility of this AU in determining the solubility of nitrofurantoin, particularly in the context of crystalluria. Notably, we observe that in saline, nitrofurantoin solubility, within the framework of its urinary pharmacokinetics, suggests a risk of crystalluria. However, in AU, this risk is mitigated due to complexation with urea. More broadly, we anticipate that our developed formulation will serve as a foundation for translational studies across biomedical and pharmaceutical sciences.

Sulfamethoxazole-induced crystal nephropathy: characterization and prognosis in a case series

Cotrimoxazole (Trimethoprim/Sulfamethoxazole-SMX) is frequently used in critically ill and immunocompromised patients. SMX is converted to N-acetyl-sulfamethoxazole (NASM) and excreted by the kidneys. NASM may form crystals in urine, especially in acid urine, that may induce a crystalline nephropathy. However, the imputability of crystals in acute kidney injury (AKI) has not been proven. We aimed to assess whether NASM crystals may promote AKI and to investigate risk factors associated with NASM crystalline nephropathy. Patients from Ile-de-France, France who developed AKI under SMX treatment introduced during hospitalization and had a crystalluria positive for NASM crystals were selected. Patients with excessive preanalytical delay for crystalluria or missing data regarding SMX treatment were excluded. We used the Naranjo score to assess the causal relationship between SMX and the development of AKI in patients with positive NASM crystalluria. Fourteen patients were included. SMX was the probable cause of AKI for 11 patients and a possible cause for 3 patients according to Naranjo score. Patients were exposed to high doses of SMX (but within recommended ranges), and most of them had a preexisting chronic kidney disease and were hypoalbuminemic. Urine pH was mildly acid (median 5.9). AKI occured more rapidly than expected after introduction of SMX (median 4 days) and recovered rapidly after drug discontinuation in most, but not all, cases. SMX is a probable cause of crystalline nephropathy. Monitoring of crystalluria in patients exposed to SMX may be of interest to prevent the development of crystalline nephropathy. Approval number of the study: BPD-2018-DIAG-008.

Crystalluria in adolescent and adult patients with congenital heart disease

INTRODUCTION

Crystalluria is a frequent finding in normal individuals and in patients suffering from urolithiasis. As nephrolithiasis has been associated with cardiovascular risk factors and most congenital heart disease (CHD) patients reach adulthood, the objective of this study is to determine the presence of crystalluria and if it influences their cardiovascular outcome.

METHODS

Case-control and observational prospective study design of patients with CHD older than 14 years with a stable CHD verified with imaging tests and a control population.

RESULTS

214 patients with CHD [median age 21 (17-35) years and 41 (19%) males] and 345 controls were studied and followed up. None of them had symptoms of renal calculi. Nine (4%) patients with CHD and 24 (7%) patients in the control group showed crystalluria (p = 0.180), all of them composed of calcium oxalate. No significant differences were seen in age, sex, body mass index, CHD complexity, cardiovascular risk factors, NYHA functional class, cyanosis, and medical treatment between CHD patients with and without crystalluria. In relation to survival, 18 patients with CHD had a major acute cardiovascular event (MACE) (3 strokes, 2 myocardial infarction, 9 cardiovascular death and 4 non cardiovascular mortality) during the follow up time [7.3 (4.4-8.5) years] without significant differences in the Kaplan-Meier analysis (p = 0.358) between patients with and without crystalluria.

CONCLUSION

No significant differences were found between CHD and control patients in relation to crystalluria and it had no impact on the occurrence of cardiovascular events in the medium term follow up of patients with CHD.