Introduction Patients with sickle cell disease (SCD) are at risk of chronic kidney disease (CKD) and acute kidney injury (AKI). The risk of AKI associated with contrast media (CM) exposures in this population is uncertain. The objective was to investigate this temporal association in a multicentric case series. Methods We performed a retrospective self-controlled case series (SCCS) in adults followed-up in SCD centers of the Greater Paris University Hospitals who experienced AKI while hospitalized between 2013 and 2022. SCCS estimates the relative incidence (RI) of events during exposure periods (around CM exposure) compared to control periods within the same individual. Analyses were restricted to hospitalizations periods and accounted for time-varying confounders such as age, presence of albuminuria, reduced estimated glomerular filtration rate, and stay in a medical ward or intensive care unit. Results In the main analysis, that included 529 patients and 755 cases of AKI, AKI incidence increased significantly during the 7-day pre-exposure period (RI 2.53, 95% CI: 2.02–3.16), the 0–3 days post-exposure (RI 2.52, 95% CI: 1.99–3.19) and the 4–7 days post-exposure (RI 1.57, 95% CI: 1.20–2.06). Similar patterns were observed for stage 2 or 3 AKI, with higher RI. Conclusion In this cohort of hospitalized adults with SCD, mainly young patients with preserved kidney function and few comorbidities, the RI of AKI was twice as high both before and after CM exposure, suggesting the role of underlying clinical conditions and related medical interventions rather than a causal effect of CM.

Abstract Introduction Tenofovir‑based preexposure prophylaxis (PrEP) is widely used and proved its efficacy for HIV prevention, and kidney function monitoring relies primarily on serum creatinine-based estimation of the glomerular filtration rate (eGFR). Oral creatine supplementation can increase serum creatinine without reflecting a true reduction in glomerular filtration rate (GFR). As is not widely known it can potentially lead to inappropriate PrEP discontinuation. Case description We report three clinical cases of healthy men who have sex with men (MSM) receiving tenofovir‑based PrEP who referred to a nephrologist for declining serum creatinine‑based eGFR while taking oral creatine supplements for muscle development associated with sport. Serum creatinine compared to cystatin C-based eGFR was performed and measured GFR (DTPA‑Tc99) when available to assess kidney function. In the first case, a 45‑year‑old man taking daily PrEP and oral creatine presented with elevated serum creatinine (1.39 mg/dl) and reduced creatinine‑based eGFR (61 ml/min/1.73 m2). Cystatin C-based eGFR indicated a preserved kidney function (83 ml/min/1.73 m2). After discontinuing creatine, serum creatinine decreased to 1.17 mg/dl and creatinine‑based eGFR improved to 75 ml/min/1.73 m2, aligning with cystatin C estimates. In the second case, a 38‑year‑old man using on‑demand PrEP and taking oral creatine referred to the nephrologist with a decline in creatinine‑based eGFR from 112 to 78 ml/min/1.73 m2 over four years. Despite this apparent decline, measured GFR was in range (113 ml/min/1.73 m2) aligned with cystatin C-based eGFR (107 ml/min/1.73 m2). In the third case, a reduced creatinine-based eGFR was observed in a 41‑year‑old man who was taking daily PrEP with the supplement. Moreover, a one‑day interruption of creatine prevented this artifact, with both serum creatinine and cystatin C returning to normal ranges. A last serum creatinine measurement performed four days after creatine was reintroduced reduced the eGFR by 20 ml/min/1.73 m2. Discussion Oral creatine supplementation, frequently used by tenofovir-based PrEP users, can artifactually elevate serum creatinine and lead to underestimation of kidney function. Cystatin C-based eGFR is not affected by creatine and so its use can be an easy tool for PrEP prescribers for an accurate assessment of kidney function. Its use may prevent risky and unjustified PrEP interruptions and reduce nephrological referral. Creatine metabolism permits a withdrawal one day before the PrEP follow-up lab tests.

OBJECTIVES:To develop and validate explainable machine learning (ML) models predicting urinary stone composition from routinely available clinical variables and standardised morphological features, and to quantify the incremental value of morphology. PATIENTS AND METHODS:This retrospective cohort study included consecutive patients undergoing endourological treatment or spontaneous stone expulsion, with laboratory analysis showing a major component exceeding 50% of stone composition, between 2019 and 2024. The outcome was dominant stone composition, classified into five categories: calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD), calcium phosphate, uric acid, and cystine. Predictors included demographics, comorbidities, stone metrics, procedural details, and Daudon-based morphological descriptors. Data were split into stratified training and validation cohorts (80% and 20%, respectively). Predictor stability was assessed using repeated-resampling multiclass Least Absolute Shrinkage and Selection Operator (LASSO). Multiple supervised classifiers (logistic regression, support vector machine, random forest, ExtraTrees, Adaptive Boosting [AdaBoost] variants, Extreme Gradient Boosting [XGBoost], Categorical Boosting [CatBoost]) were fine-tuned using GridSearch. Discrimination was assessed using macro-averaged one-vs-rest area under the curve (AUC) and accuracy. Explainability relied on SHapley Additive exPlanations (SHAP). RESULTS:Among 442 patients (median age 51 years; 67% male), stone composition was COM in 41.0% (n = 181), COD in 24.9% (n = 110), calcium phosphate in 19.7% (n = 87), uric acid in 10.9% (n = 49), and cystine in 3.6% (n = 16). LASSO stability highlighted reproducible predictors, including age, hereditary disease type, stone density, maximal diameter, and location. Clinical-only models achieved good discrimination (macro-AUC up to 0.809). Adding morphological features markedly improved performance, with ensemble models achieving excellent discrimination in validation (macro-AUC up to 0.983 with CatBoost). Morphological variables ranked among the strongest contributors on SHAP. CONCLUSIONS:A clinical-only model can predict the major stone component and may support preoperative decision-making. Performance further improved when morpho-constitutional features were added, confirming Daudon's classification as the ground truth; however, this combined model relies on intra- and postoperative descriptors and is best regarded as an intra- or postoperative decision-support tool rather than a preoperative one. External prospective validation is needed before clinical implementation.

Introduction: Patients with sickle cell disease (SCD) are at risk of chronic kidney disease (CKD) and acute kidney injury (AKI). The risk of AKI associated with contrast media (CM) exposures in this population is uncertain. The objective of this study was to investigate this temporal association in a multicentric case series. Methods: We performed a retrospective self-controlled case series (SCCS) in adults followed-up in SCD centers of the Greater Paris University Hospitals who experienced AKI during hospitalization between 2013 and 2022. SCCS estimates the relative incidence (RI) of events during exposure periods (around CM exposure) compared with control periods within the same individual. Analyses were restricted to hospitalizations periods and accounted for time-varying confounders such as age, presence of albuminuria, reduced estimated glomerular filtration rate, and stay in a medical ward or intensive care unit (ICU). Results: In the main analysis, that included 529 patients and 755 cases of AKI, AKI incidence increased significantly during the 7-day pre-exposure period (RI: 2.53, 95% confidence interval [CI]: 2.02-3.16), the 0 to 3 days postexposure (RI: 2.52, 95% CI: 1.99-3.19) and the 4 to 7 days postexposure (RI: 1.57, 95% CI: 1.20-2.06). Similar patterns were observed for stage 2 or 3 AKI, with higher RI. Conclusion: In this cohort of hospitalized adults with SCD, mainly young patients with preserved kidney function and few comorbidities, the RI of AKI was twice as high both before and after CM exposure, suggesting the role of underlying clinical conditions and related medical interventions rather than a causal effect of CM.

Context:Hypercalcemic (HPHPT) and normocalcemic primary hyperparathyroidism (NHPT) are distinct conditions with different biological and histological characteristics. Understanding their histological patterns could improve disease characterization. Objective:This study aimed to compare the histological features of NHPT and HPHPT parathyroid glands, but also rims of normal tissue, focusing on the expression of calcium-sensing receptor (CaSR), 1-α hydroxylase (CYP27B1), and vitamin D receptor (VDR). Methods:A retrospective observational study was conducted on histological and immunohistochemical data from parathyroid gland samples. The study included 50 hypercalciuric renal stone patients, of whom 18 had NHPT and 32 had HPHPT. Histological and immunohistochemical analyses were performed to evaluate cell distribution and marker expression. Parathyroid gland weight, cell distribution, and CaSR, CYP27B1, and VDR expression were analyzed and compared between NHPT, HPHPT, and rim biopsies. Results:Parathyroid gland weight and cell distribution were similar in both groups. A rim of normal tissue was more frequent in HPHPT (69% vs 37%; P = .02). In HPHPT, CaSR expression was decreased, while CYP27B1 and VDR expressions were increased in chief cells compared to rim tissue (P = .005, .004, and <.001, respectively). NHPT showed no CaSR or CYP27B1 alterations but a decreased VDR expression in oxyphil cells compared to HPHPT (P = .02). Conclusion:The NHPT hallmark phenotype is normal CaSR, CYP27B1/VDR expression in chief cells, with decreased VDR expression in oxyphil cells. HPHPT chief cell patterns show a marked CaSR decreased expression along with an increased CYP27B1/VDR expression, suggesting an appropriate autocrine/paracrine counterregulation to hypercalcemia/high PTH.

In 3.4% of Randall's plaques, monosodium urate can be detected. The formation mechanism of these Randall's plaques is unrevealed and the clinical and biochemical characteristics of affected patients are unknown. In this single centre study, we retrospectively analysed the clinical and biochemical characteristics of patients with kidney stone formation related to monosodium urate-containing Randall's plaques (NaUr pos RP) and those with stone formation related to "classical" Randall's plaques (NaUr neg RP). There was a significantly higher urinary calcium and magnesium excretion in the NaUr neg RP group (6.09 vs. 4.61 mmol/24 h, p = 0.03 and 4.78 vs. 3.55 mmol/24 h, p = 0.02). There was no significant difference in urinary uric acid excretion or urinary pH between both groups. The NaUr pos RP group tended to have more frequent hyperuricemia (71.4 vs. 44.8%, p = 0.08) and to be more frequently male (92.9 vs. 70.1%, p = 0.10) and had higher median age (53.5 vs. 27.5, p < 0.001) and serum creatinine (96.4 vs. 77.0 µmol/L, p < 0.001). Additionally, there was a signal of higher prevalences of hypertension, dyslipidemia, cardiovascular disease and gout in the NaUr pos RP group. Different formation mechanisms seem implicated in the formation of NaUr pos RP and NaUr neg RP - associated kidney stones. We hypothesize a mechanism of interstitial monosodium urate precipitation at the renal papilla driven by high systemic uric acid serum concentration to be involved in NaUr pos RP formation. Treatment with xanthine oxidase inhibitors may reduce the risk of recurrent stone formation on this specific Randall's plaque.

Purpose:Most kidney stones are made of calcium oxalate. Many kidney stone formers stop drinking tea, resulting in reduced diuresis. The oxalate in tea diffuses rapidly during infusion. We hypothesized that pre-infusion of tea could significantly reduce its oxalate content. Methods:Tea bags were infused for 0.5, 1, 2 or 3 minutes, with or without a pre-infusion of 10, 30 or 60 seconds (16 conditions, n=4/condition). Oxalate concentration was measured and a blind organoleptic analysis was carried out by 4 operators. Results:A 10 seconds pre-infusion reduced the oxalate concentration of tea by 10 to 33% (p<0.05). A 30 seconds pre-infusion reduced it by 38 to 51% (p<0.05) and a 1 minute pre-infusion by 59 to 65% (p<0.05). Pre-infusion had no significant impact on satisfaction scores for taste, smell or visual appearance. Conclusion:Pre-infusion of tea significantly reduces oxalate intake (by up to 2/3 depending on conditions).

Background/Objectives: Monitoring of 24 h urine analysis is currently used to assess diet-related stone risk factors due in most cases to low hydration and high osmole intake accounting for urine supersaturation. The aim of our study is to test whether urine conductivity could be a relevant surrogate marker of urine osmolality and a useful tool for monitoring salt and protein diets in primary care centers. Methods: 113 patients with kidney stone history referred for a routine evaluation of fasting and 24 h urine samples were included. Biochemical analysis of urine was performed, including measured osmolality (mUosm) and conductivity. Results: Among our population, 45% of patients have a low diuresis (high-risk group of stone recurrence) below the target of 2 L/day, with lower daily mUOsm and conductivity outflow compared to the low-risk patient group > 2 L/day (718 versus 852 mosm/Day, p < 0.0001, and 13,730 versus 17,890 mS/cm/day, p < 0.0001, respectively). Conversely to urine sodium and urea concentration, daily sodium and protein intake estimated by natriuresis and urea excretion are significantly lower in the high-risk group (p = 0.01 and <0.0001, respectively). In 24 h urine samples, osmolality and conductivity were strongly associated with diuresis. Moreover, a strong association between urinary osmolality and urine conductivity enables an estimated osmolality (eUosm) according to the following equation: eUosm = −41.656 + 0.057 × conductivity (r2 = 0.93; p < 0.001) with a 95% limit of agreement (LoA) ranging from −7.2% to +7.3%. An eUosm threshold value < 900 mOsm/day is independently associated with sodium and protein intake targets (odd ratio: 19.2 and 6.4-fold, respectively, p < 0.0001 and 0.01). Conclusions: 24 h urine measured conductivity appears to be a reliable, easy-to-use tool for the screening and monitoring of diet-related stone patients in primary care centers.

BACKGROUND:A non-invasive location of the abnormal parathyroid glands (PT) is recommended, by pairing ultrasonography (US) with a functional imaging modality, the most accurate being 18F-fluorocholine (FCH) PET/CT. Limited evidence is available about optimization of presurgical imaging in renal hyperparathyroidism (rHPT). We performed a head-to-head comparison of the detection of abnormal parathyroid glands pairing those two imaging modalities in this context. We also investigated whether awareness of the results of the examination carried out first improved the sensitivity of the interpretation of the second examination, aiming to determine the most effective sequence for performing those paired examinations (PEs). METHODS:FCH PET/CT has been performed as part of presurgical work-up for rHPT in one single PET center, paired with ultrasonography (US) (PE: paired examinations), without predefined sequence order, in a real-world context. Were selected from our database 159 PEs performed between September 2012 and September 2022. PET/CT was acquired 20-30 min after FCH injection of 3 MBg/kg body mass; US was performed from the angle of the mandible to the mediastinum with a high-frequency linear probe and a microconvex probe for deep structures. The interpretation reports have been carried out-on site after each examination, aware of the elements of the patient's file, including the result of the 1st PE for interpreting the 2nd PE. Each abnormal focus or image was rated as positive or equivocal for an abnormal parathyroid gland (PT), or of another origin. The positivity rate was determined for each imaging modality. We were aware of PT (re)operation after 98 PEs; 227 abnormal PTs were resected, histology being the standard-of-truth to determine the gland-based sensitivity. The Fisher's Test was used to compare the gland-based sensitivity of each imaging modality, according to being performed first or second. RESULTS:The patient-based positivity rate of FCH PET/CT was greater than that of US (P<0.0001), equivocal foci or images being considered either as negative (91% vs. 64% respectively) or as positive (92% vs. 69%). Accordingly, the gland-based sensitivity of FCH PET/CT was also greater than that of US (P<0.0001), equivocal foci or images being considered either as negative (85% vs. 58%, respectively) or as positive (89% vs. 62%, respectively). Interestingly, the diagnostic performance of US was significantly greater if practiced and interpreted aware of FCH PET/CT results (gland-based sensitivity, equivocal images considered as negative: 50% US 1st vs. 74% US 2nd after FCH PET/CT, P<0.0006). For FCH PET/CT, the difference was not significant. CONCLUSIONS:This is currently the largest of published series about preoperative imaging with FCH PET/CT in rHPT. Our results confirmed superior gland-based sensitivity of FCH PET/CT and also substantiated performing US after FCH PET/CT, whose results can guide US practice and interpretation, both PEs contributing for an optimal surgical protocol. We conclude that optimal imaging sequence in rHPT is FCH PET/CT performed first and not just part of the first line imaging examinations.

To evaluate long-term surgical and functional outcomes of cystinuric patients exclusively treated with Ureteroscopy (URS). Data from patients treated for cystine stones at a single academic center were retrospectively analyzed. The management protocol consisted of (i) treating symptomatic or > 7 mm stones, (ii) multi-staged URS for voluminous stones, (iii) referring patients to a dedicated nephrological clinic. The eGFR was calculated according to the MDRD formula. CKD category was assessed according to the NKF classification. Relevant CKD was defined as CKD category ≥ 3a. Descriptive statistics were used to analyze the cohort data. Data from 46 cystinuric patients treated with 332 URS were available. Median age at diagnosis and at first URS in our center were 18 and 32 years, respectively. Median follow-up was 101 months. Median number of URS and recurrences per patient were 6 and 2, respectively. The median interval between the first and the last available creatinine level was 64 months. Median first and last eGFR were 72 and 74 mL/min, respectively. Overall, 83

One of the hallmarks of chronic kidney disease (CKD) is the development of vascular calcification. Inorganic pyrophosphate is a potent inhibitor of calcification, and previous studies have reported low plasma pyrophosphate levels in hemodialysis patients. A long-term mouse model of CKD-accelerated vascular calcification was developed to study pyrophosphate metabolism and to test whether oral pyrophosphate supplementation attenuates the propensity for arterial calcification. CKD was induced by repeated injections of aristolochic acid in wild-type and Abcc6-/- mice, which tend to develop vascular calcifications. CKD accelerated the development of vascular calcifications in Abcc6-/- mice, in the aorta and small renal arteries, and decreased circulating pyrophosphate levels. Oral pyrophosphate supplementation for 6 months attenuated CKD-induced vascular calcification in this model. These results show that oral pyrophosphate may be of interest in preventing vascular calcification in patients with CKD.

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.

L’hyperparathyroïdie primaire (HPT1) est classiquement caractérisée par une PTHémie élevée du fait d’une ou plusieurs glandes parathyroïdes hyperfonctionnelles (PT) entrainant une hypercalcémie. Cependant, dans certains cas d’HPT démontrée par une épreuve de surcharge et/ou Ca ionisée anormale, PTHémie et/ou calcémie « totale » peuvent être dans les limites de la normale. Nous avons évalué les performances de la TEP/TDM FCH pour détecter les PT anormales selon que PTHémie et calcémie étaient ou pas dans l’intervalle normal. Parmi 1003 TEP/TDM FCH chez 971 patients atteints de HPT1, excluant HPT secondaire, en particulier IRC de grade >3 ou hémodialyse ou greffe rénale, et aussi HPT familiale génétiquement prouvée, 4 groupes ont été constitués : G0 (n=474) hypercalcémie avec PTHémie élevée, groupe de référence ; G1 (n=327) PTHémie élevée mais normocalcémie (<=2,6mmol/L) ; G2 (n=109) hypercalcémie (>2,6mmol/L) avec PTHémie inappropriée mais dans les limites de la normale ; G3 (n=93) calcémie et PTHémie normales. Nous avons déterminé dans chaque groupe le taux de positivité de la TEP FCH puis, chez les patients opérés (PTX), la sensibilité (Se) au niveau patient, la détection d’HPT multiglandulaire (MG), la Se et la spécificité (Sp) au niveau de la glande, avec l’histologie des PT reséquées pour étalon de vérité. Les foyers FCH douteux ont été considérés comme négatifs. Les résultats du groupe G0 ont été comparés à ceux des autres groupes par le test du chi-2, * note une différence significative p<0,05 si le test global 4x2 est significatif.

CONTEXT:Primary hyperparathyroidism (PHPT) is commonly diagnosed in the setting of hypercalcemia, whereas normocalcemic primary hyperparathyroidism (NHPT) may be misdiagnosed. OBJECTIVE:Our objective was to compare patients with hypercalcemic hyperparathyroidism (HPHPT) vs patients with NHPT hypercalciuric renal stones. METHODS:We took advantage of a routine calcium load test performed in patients with hypercalciuric renal stones to assess retrospectively among patients with PHPT the prevalence and characteristics of NHPT and HPHPT under a calcium-restricted diet. RESULTS:Among 1671 patients with hypercalciuria, 91 patients had a final diagnosis of PHPT (postload ionized calcium [iCa] > 1.31 mmol/L and parathyroid hormone [PTH] > 30 pg/mL). Prevalence of NHPT is 40% of all PHPT; however, according to total serum calcium, 4/35 NHPT and 7/56 HPHPT cases would have been misclassified in the other group. Eighteen of 35 NHPT and 40/56 HPHPT cases underwent parathyroidectomy. No significant characteristics relating to parathyroid weight, stone composition, or bone remodeling biomarkers were detected between groups. Although iCa is higher in HPHPT in the fasting state and after calcium load, we found no difference for calcium diet, 24-hour calciuria, or calcitriol. Renal calcium excretion postload increased by 303% in NHPT but only 176% in HPHPT (P = .01) likely explained by a lesser PTH decrease (P = .02). However, a strong negative association (P < .0001) detected between pooled preload and postload iCa and PTH only in the NHPT group suggests a persistent efficient PTH-CaSR control within the parathyroid glands in this group. CONCLUSION:Our data show the relevance of dynamic tests to unmask NHPT in patients with hypercalciuric renal stones.

The urine concentration impairment in sickle cell anemia is an osmotic diuresis related to an impaired renal medullary gradient leading to an ADH plateau effect. The fasting plasma ADH was high in the context of a basic state of close-to-maximal urine concentration probably driven by short nephrons maintaining a cortex-outer medullary gradient (about 400 milliosmoles). The patients had a low daily osmoles intake without evidence of thirst dysregulation so no one experienced polyuria.

Introduction Les recommandations du comité Lithiase de l’Association Française d’Urologie (CLAFU) ont été émises en 2022 sous format internet et édité au format papier en 2023. L’objectif de cette étude était d’évaluer l’impact et la diffusion de ces recommandations du CLAFU auprès des urologues membres de l’AFU. Méthodes Une enquête nationale au moyen d’un questionnaire en ligne anonyme était réalisée entre avril et mai 2024. Le questionnaire, développé par des membres du CLAFU, était constitué de 18 questions abordant les caractéristiques démographiques, le mode d’activité et sa part représentée par la prise en charge des calculs urinaires, la connaissance des nouvelles recommandations, leur mode de diffusion ainsi que leur impact potentiel sur la pratique des urologues. Après relecture par un panel (endourologues expert et internes d’urologie), le questionnaire était partagé via les réseaux sociaux et l’AFU. L’analyse statistique comprenait une description générale et une analyse en sous-groupes (activité libérale/hospitalière, urologues certifiés/en formation). Résultats Au total, 228 urologues ont participé à l’enquête dont 86 % avaient connaissance des recommandations 2022 du CLAFU (Figure 1). Les participants étaient pour 83 % des urologues expérimentés (MCU-PH, PH, PHU, PU-PH ou urologue libéral), avec des proportions similaires entre urologues libéraux et hospitaliers(54 vs 46 %, respectivement). Pour 55 %, la prise en charge des calculs représentait 11 à 30 % de leur activité et pour 25 % 31 à 50 %. Au total, 74 % utilisaient les recommandations du CLAFU et 19 % celle de l’EAU et du CLAFU dans leur pratique. La version synthétique des recommandations était préférée à la version complète (51 %vs 31 %). L’impact médian des recommandations sur les pratiques était de 6/10 (4 ; 8). Parmi les participants, 53 % souhaitaient un autre mode de diffusion plus interactif type podcasts (55 %) et/ou vidéos éducatives (53 %). L’analyse en sous-groupes ne retrouvait pas de différence entre les urologues libéraux et public sur le besoin d’autres modes de diffusion ou l’impact des recommandations sur leur pratique, alors que la version complète était préférée par les hospitaliers (35 % vs 26 %), à l’inverse de la synthèse(42 % vs 59 %)(p=0,04). Des résultats similaires étaient rapportés entre urologues en formation et certifiés pour la lecture complète (44 % vs 28 %) ou synthèse (33 % vs 54 %), p=0,02 (Figure 2). Conclusion Cette enquête montre une bonne diffusion des recommandations CLAFU aussi bien auprès des urologues certifiés qu’en formation, hospitaliers que libéraux. Des modes de diffusions plus interactifs sont cependant demandés, type audio ou vidéo.

[This corrects the article DOI: 10.1016/j.ekir.2021.11.035.].

INTRODUCTION: The prevalence of uric acid (UA) stones increases regularly due to its high correlation with obesity, hypertension, metabolic syndrome, type 2 diabetes, and aging. Uric acid stone formation is mainly due to an acidic urinary pH secondary to an impaired urinary ammonium availability responsible for UA ratherthan soluble urate excretion. Alkalization of urine is therefore advocated to prevent UA crystallization and considered effective therapy. METHODS: We report a large series of 120 patients with UA lithiasis who were successfully treated with potassium (K)-citrate for stone dissolution (n=75) and/or stone recurrence prevention (n=45) without any urologic intervention, with a median 3.14 years followup. The K-citrate was diluted in 1.5 L of water, avoiding gastrointestinal disorders. RESULTS: Among 75 patients having stones in their kidney at initiation of therapy, a complete chemolysis was obtained in 88% of cases. Stone risk factors decreased under treatment, mainly due to increased diuresis, urinary pH, and citrate excretion. Treatment was stopped in only 2% of patients due to side effects, with no hyperkalemia onset despite a median urinary potassium increase of 44 mmol/day. CONCLUSIONS: Contrary to other reports, our data show that medical treatment of UA kidney stones is well-tolerated and efficient if regular monitoring of urinary pH is performed.