Short-Term Changes in Urinary Relative Supersaturation Predict Recurrence of Kidney Stones: A Tool to Guide Preventive Measures in Urolithiasis.

PURPOSE: Kidney stone disease is characterized by a relatively high rate of recurrence. In our study we analyzed the association between relative supersaturation and the risk of stone recurrence. Additionally, we examined the association between the risk of recurrence and changes in relative supersaturation and urinary composition after 1 week of medical treatment. MATERIALS AND METHODS: We performed a post hoc analysis of data from a previously published randomized controlled trial comparing the effect of 2 diets in 120 men with recurrent calcium oxalate stones and hypercalciuria. Baseline and followup 24-hour urine parameters were used to calculate the relative supersaturation of calcium oxalate, calcium phosphate and uric acid using the EQUIL2, JESS and LithoRisk computer programs. Cox models were used to calculate the estimated association between each baseline relative supersaturation, and 1-week changes and the risk of recurrence during followup. RESULTS: During a 5-year followup 35 patients (34%) experienced recurrence. A reduction in calcium oxalate relative supersaturation at 1 week was significantly associated with a lower risk of recurrence using the EQUIL2 calculation (for every 10% reduction from baseline HR 0.92, 95% CI 0.86-1.00, p = 0.044). However, there was no association for relative supersaturation calculated by other methods or for the relative supersaturation of other salts. Changes in the 24-hour urine excretion of citrate, potassium and magnesium were significantly associated with a risk of recurrence. CONCLUSIONS: In recurrent stone formers with hypercalciuria baseline values and changes in the relative supersaturation of calcium oxalate may be associated with the risk of recurrence. Changes in urinary citrate, potassium and magnesium following dietary intervention may also be predictive.

Fragility Fractures in End-Stage Chronic Kidney Disease (CKD) Population: Patient-Related and CKD-Related Factor Analysis-A Single-Center Experience.

Background: Chronic kidney disease (CKD) stands as a prevalent global health concern, and mineral and bone disease are among the most impactful consequences. A severe complication arising from mineral and bone disease is the occurrence of fragility fractures, which disproportionately affect individuals with CKD compared to the general population. The prevalence of these fractures impacts both survival rates and quality of life. The aims of this study are analyzing and identifying (i) patient-related risk factors and (ii) CKD-related risk factors to contribute to the development of preventive measures for fragility fractures for this population. Methods: A retrospective, single-center observational study was conducted, encompassing patient data from the years 2021 to 2023. Registry data were recorded, including patient-related and CKD-related data. Patients were interviewed about traumatological history, and their answers were recorded. Logistic regression analysis was employed to investigate the association between independent variables and dependent variables. Results: Eighty-four patients, with a mean age of 64.3 ± 15.2 years and a male percentage of 58.3%, were included in this study. Among them, 19.5% exhibited smoking habits. The mean Charlson Comorbidity Index was 3.06 ± 1.21. All patients were diagnosed with end-stage chronic kidney disease, with mean durations of 208 months from the diagnosis and 84.5 months from the beginning of dialysis. The logistic regression analysis, adjusted for age, sex, and CCI, revealed that smoking habits play a significant role as a risk factor for fragility fractures in lower limbs (p: 0.011 *). The incidence of fragility fractures increases directly proportionally to the time since diagnosis (p-value: 0.021 *) and the beginning of dialysis treatment (p-value: 0.001 *). Conclusions: Among patient-related factors, smoking habits seem to significantly affect lower-limb fracture rates (p < 0.05), whereas among CKD-related factors, time since CKD diagnosis and time since the beginning of dialysis treatment are directly related to higher risks of fragility fractures. No relevant correlations emerged in the studied treatments, except for a reduction in proximal femur fracture occurrence when patients underwent a combined treatment of a calcimimetic and a vitamin D analog.

Potential Add-On Benefits of Dietary Intervention in the Treatment of Autosomal Dominant Polycystic Kidney Disease.

Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited cause of renal failure. The pathogenesis of the disease encompasses several pathways and metabolic alterations, including the hyperactivation of mTOR and suppression of AMPK signaling pathways, as well as mitochondrial dysfunction. This metabolic reprogramming makes epithelial cyst-lining cells highly dependent on glucose for energy and unable to oxidize fatty acids. Evidence suggests that high-carbohydrate diets may worsen the progression of ADPKD, providing the rationale for treating ADPKD patients with calorie restriction and, in particular, with ketogenic dietary interventions, already used for other purposes such as in overweight/obese patients or in the treatment of refractory epilepsy in children. Preclinical studies have demonstrated that calorie restriction may prevent and/or slow disease progression by inducing ketosis, particularly through increased beta-hydroxybutyrate (BHB) levels, which may modulate the metabolic signaling pathways altered in ADKPK. In these patients, although limited, ketogenic intervention studies have shown promising beneficial effects. However, larger and longer randomized controlled trials are needed to confirm their tolerability and safety in long-term maintenance and their additive role in the therapy of polycystic kidney disease.

Percutaneous renal sympathetic nerve ablation for loin pain haematuria syndrome.

Loin pain haematuria syndrome (LPHS) is a severe renal pain condition of uncertain origin and often resistant to treatment. Nephrectomy and renal autotrasplantation have occasionally been performed in very severe cases. Its pathogenesis is controversial. A 40-year-old hypertensive lady was diagnosed with LPHS after repeated diagnostic imaging procedures had ruled out any renal, abdominal or spinal conditions to justify pain. Notwithstanding treatment with three drugs, she had frequent hypertensive crises during which the loin pain was dramatically exacerbated. Vascular causes of the pain and hypertension were investigated and excluded. Her renal function was normal. The patient was referred to a multidisciplinary pain clinic, but had no significant improvement in her pain symptoms despite the use of non-steroidal anti-inflammatory drugs, adjuvant antidepressants and opioid-like agents. The pain and the discomfort were so severe that her quality of life was very poor, and her social and professional activities were compromised. Nephrectomy and renal autotransplantation have occasionally been performed in these cases. Since visceral pain signals flow through afferent sympathetic fibres, we felt that percutaneous catheter-based radiofrequency ablation of the renal sympathetic nerve fibres (recently introduced for the treatment of drug-resistant hypertension) could be valuable for pain relief. We treated the patient with radiofrequency ablation (Medtronic Symplicity Catheter) applied only to the right renal artery. After a 6-month follow-up, the patient is pain free and normotensive with all drugs withdrawn. She has experienced no hypertensive crises in the meantime. This observation suggests that percutaneous sympathetic denervation could prove to be an effective mini-invasive strategy for the treatment of chronic renal pain, and LPHS in particular.

Combined treatment with renin-angiotensin system blockers and polyunsaturated fatty acids in proteinuric IgA nephropathy: a randomized controlled trial.

BACKGROUND: Currently, several therapeutic protocols exist for IgA nephropathy (IgAN); results in slowing the progression to end-stage renal disease (ESRD) are variable, but approximately 30-40% of patients require replacement therapy (dialysis or renal transplantation) by 20 years from the onset. The adverse effects brought by the chronic assumption of drugs can be a potential limit. Actually, the most used therapies for IgAN are renin-angiotensin system blockers (RASB), glucocorticoids and immunosuppressive agents. Trials with polyunsaturated fatty acids (PUFA) in IgAN have been done since the first successful attempt by Hamazaki in 1984, resulting in alternate answers, but no trials have ever been done testing the efficacy of combined therapy with RASB and PUFA. METHODS: We tested the effect of a 6-month course of PUFA (3 grams/day) in a group of 30 patients with biopsy-proven IgAN and proteinuria already treated with RASB randomized to receive PUFA supplementation or to continue their standard therapy. The primary end-point was the percent reduction of proteinuria from the baseline. Secondary end-points were modifications in glomerular filtration rate (GFR), blood pressure, serum triglycerides and erythrocyturia. RESULTS: At the end of the 6-month trial, the percent reduction of proteinuria was 72.9% in the PUFA group and 11.3% in the RASB group (P < 0.001). A reduction of >or=50% of baseline proteinuria was achieved in 80.0% of PUFA patients and 20.0% of RASB patients (P = 0.002). Erythrocyturia was significantly lower in the PUFA group (P = 0.031). No significant changes in renal function, blood pressure and triglycerides were observed. CONCLUSIONS: PUFA associated with RASB reduced proteinuria in patients with IgAN more than RASB alone.

[Recurrent Kidney Stones in a patient with Malabsorption Syndrome].

Enteric hyperoxaluria is one of the most frequent complications of bariatric surgery. In this setting the prevalence of kidney stones is increased. Currently the treatment of enteric hyperoxaluria is based not only on the reduction of urinary oxalate but even controlling other lithogenic risk factors, like urinary volume and urinary citrate levels. This case report suggests a possible benefit using magnesium citrate in addition to calcium supplementation, in the treatment of hyperoxaluria caused by enteric malabsorption.

[A young girl with recurrent calculosis and hypercalcemia].

Mutations of the CYP24A1 gene are associated with alterations in the activity of the enzyme 25-OH-D-24-hydroxylase, resulting in dysfunction of the metabolism of vitamin D. This enzymatic deficiency may cause hypercalcemia, low parathyroid hormone levels, hypercalciuria, nephrolithiasis and nephrocalcinosis. The clinical case of a young woman with recurrent renal lithiasis, hypercalcemia and hypercalciuria is described. These features are linked to deficiency of the enzyme 25-OH-D-24-hydroxylase, therefore to a biallelic mutation of the CYP24A1 gene.

[The pathway of vasopressin as a pharmacological target in nephrology: a narrative review].

ADH is a hormone secreted by neurohypophysis that plays different roles based on the target organ. At the renal level, this peptide is capable of causing electrolyte-free water absorption, thus playing a key role in the hydro-electrolytic balance. There are pathologies and disorders that jeopardize this balance and, in this field, ADH receptor inhibitors such as Vaptans could play a key role. By inhibiting the activation pathway of vasopressin, they are potentially useful in euvolemic and hypervolemic hypotonic hyponatremia. However, clinical trials in heart failure have not given favourable results on clinical outcomes. Even in SIADH, despite their wide use, there is no agreement by experts on their use. Since vaptans inhibit the cAMP pathway in tubular cells, their use has been proposed to inhibit cystogenesis. A clinical trial has shown favourable effects on ADPKD progression. Because vaptans have been shown to be effective in models of renal cysts disorders other than ADPKD, their use has been proposed in diseases such as nephronophthisis and recessive autosomal polycystic disease. Other possible uses of vaptans could be in kidney transplantation and cardiorenal syndrome. Due to the activity of ADH in coagulation and haemostasis, ADH's activation pathway by Desmopressin Acetate could be a useful strategy to reduce the risk of bleeding in biopsies in patients with haemorrhagic risk.