Canagliflozin on top of dual renin-angiotensin system blockade in a woman with partial acquired lipodystrophy, type 2 diabetes and severely proteinuric chronic kidney disease: a case report.

Sodium glucose cotransporter 2 inhibitors have proven strong efficacy in reducing end-stage renal disease in patients with type 2 diabetes. We are presenting here the case of a 40-year-old woman with acquired partial lipodystrophy, type 2 diabetes and essential hypertension complicated by chronic kidney disease and proteinuria in the nephrotic range. She first came to our attention in 2012; estimated glomerular filtration rate (eGFR) was 41.5 ml/min/1.73 m2 and total proteinuria was 375 mg/24h; she was treated with dual renin angiotensin system blocking. Proteinuria significantly increased during the following years, reaching a nephrotic range (>5 g/day). A kidney biopsy revealed a tubule-interstitial involvement compatible with type 2 diabetes. Leptin replacement therapy, started in 2018, improved glycaemic control and lipid profile, also determining a reduction in insulin total daily dose. In 2019, after the publication of the CREDENCE study, canagliflozin was started on top of losartan and ramipril. After an initial, expected eGFR drop, kidney function stabilized, and albuminuria significantly reduced (from 4120 to 984 mg/24h), while serum potassium showed only minimal increase. At last follow-up (2022) total proteinuria was still reducing (510 mg/24h), while kidney function was substantially unchanged (eGFR 40 ml/min/1.73 m2). This case report suggests that, despite not recommended in international guidelines, the use of SGLT2i in combination with dual renin angiotensin system blockade should be considered in specific conditions and under close clinical monitoring.

A Clinical Workflow for Cost-Saving High-Rate Diagnosis of Genetic Kidney Diseases.

SIGNIFICANCE STATEMENT: To optimize the diagnosis of genetic kidney disorders in a cost-effective manner, we developed a workflow based on referral criteria for in-person evaluation at a tertiary center, whole-exome sequencing, reverse phenotyping, and multidisciplinary board analysis. This workflow reached a diagnostic rate of 67%, with 48% confirming and 19% modifying the suspected clinical diagnosis. We obtained a genetic diagnosis in 64% of children and 70% of adults. A modeled cost analysis demonstrated that early genetic testing saves 20% of costs per patient. Real cost analysis on a representative sample of 66 patients demonstrated an actual cost reduction of 41%. This workflow demonstrates feasibility, performance, and economic effect for the diagnosis of genetic kidney diseases in a real-world setting. BACKGROUND: Whole-exome sequencing (WES) increases the diagnostic rate of genetic kidney disorders, but accessibility, interpretation of results, and costs limit use in daily practice. METHODS: Univariable analysis of a historical cohort of 392 patients who underwent WES for kidney diseases showed that resistance to treatments, familial history of kidney disease, extrarenal involvement, congenital abnormalities of the kidney and urinary tract and CKD stage ≥G2, two or more cysts per kidney on ultrasound, persistent hyperechoic kidneys or nephrocalcinosis on ultrasound, and persistent metabolic abnormalities were most predictive for genetic diagnosis. We prospectively applied these criteria to select patients in a network of nephrology centers, followed by centralized genetic diagnosis by WES, reverse phenotyping, and multidisciplinary board discussion. RESULTS: We applied this multistep workflow to 476 patients with eight clinical categories (podocytopathies, collagenopathies, CKD of unknown origin, tubulopathies, ciliopathies, congenital anomalies of the kidney and urinary tract, syndromic CKD, metabolic kidney disorders), obtaining genetic diagnosis for 319 of 476 patients (67.0%) (95% in 21 patients with disease onset during the fetal period or at birth, 64% in 298 pediatric patients, and 70% in 156 adult patients). The suspected clinical diagnosis was confirmed in 48% of the 476 patients and modified in 19%. A modeled cost analysis showed that application of this workflow saved 20% of costs per patient when performed at the beginning of the diagnostic process. Real cost analysis of 66 patients randomly selected from all categories showed actual cost reduction of 41%. CONCLUSIONS: A diagnostic workflow for genetic kidney diseases that includes WES is cost-saving, especially if implemented early, and is feasible in a real-world setting.

Idiopathic Retroperitoneal Fibrosis: What Is the Optimal Clinical Approach for Long-Term Preservation of Renal Function?

BACKGROUND: The aim of this study was to investigate the long-term effects of ureteral stenting and the exact timing of stent removal in favor of surgery in patients with idiopathic retroperitoneal fibrosis (IRF). SUMMARY: Medline research terms of "idiopathic retroperitoneal fibrosis" AND " medical therapy" OR "ureteral stenting" OR "surgical treatment" were done. Systematic reviews and observational and clinical studies were analyzed to obtain indication regarding the objective of the study for a narrative review. Ninety-two papers were analyzed. The treatment of IRF includes the monitoring of retroperitoneal fibrotic process spread and the prevention of abdominal organs entrapment. Treatment of ureteral obstruction includes medical therapy and ureteral stenting (US) or percutaneous nephrostomy (PNS) to overcome the worsening of renal function. Up to now, the timing of US or PNS removal is not yet clear, both for the complexity of evaluating the efficacy of the medical therapy and demonstrating the resolution of obstructive nephropathy. Moreover, it is not yet clear if the long-term ureteral stent placement or PNS is able to maintain an efficient renal function. Ureterolysis with a laparoscopic robot-assisted approach is now considered as an ultimate treatment for ureteral obstruction, limiting the progression of kidney impairment and improving the quality of life of patients, although nephrologists are generally abdicant regarding the potential switch toward the surgical approach. KEY MESSAGES: Prospective studies regarding the long-term effects of US on the renal function impairment in patients with IRF should be structured to obtain adequate information on the exact timing for the surgical approach.

The risks associated with percutaneous native kidney biopsies: a prospective study.

BACKGROUND: The known risks and benefits of native kidney biopsies are mainly based on the findings of retrospective studies. The aim of this multicentre prospective study was to evaluate the safety of percutaneous renal biopsies and quantify biopsy-related complication rates in Italy. METHODS: The study examined the results of native kidney biopsies performed in 54 Italian nephrology centres between 2012 and 2020. The primary outcome was the rate of major complications 1 day after the procedure, or for longer if it was necessary to evaluate the evolution of a complication. Centre and patient risk predictors were analysed using multivariate logistic regression. RESULTS: Analysis of 5304 biopsies of patients with a median age of 53.2 years revealed 400 major complication events in 273 patients (5.1%): the most frequent was a ≥2 g/dL decrease in haemoglobin levels (2.2%), followed by macrohaematuria (1.2%), blood transfusion (1.1%), gross haematoma (0.9%), artero-venous fistula (0.7%), invasive intervention (0.5%), pain (0.5%), symptomatic hypotension (0.3%), a rapid increase in serum creatinine levels (0.1%) and death (0.02%). The risk factors for major complications were higher plasma creatinine levels [odds ratio (OR) 1.12 for each mg/dL increase, 95% confidence interval (95% CI) 1.08-1.17], liver disease (OR 2.27, 95% CI 1.21-4.25) and a higher number of needle passes (OR for each pass 1.22, 95% CI 1.07-1.39), whereas higher proteinuria levels (OR for each g/day increase 0.95, 95% CI 0.92-0.99) were protective. CONCLUSIONS: This is the first multicentre prospective study showing that percutaneous native kidney biopsies are associated with a 5% risk of a major post-biopsy complication. Predictors of increased risk include higher plasma creatinine levels, liver disease and a higher number of needle passes.

The Impact of a Mediterranean-like Diet with Controlled Protein Intake on the Onco-Nephrological Scenario: Time for a New Perspective.

Chronic kidney disease (CKD) represents a frequent comorbidity in cancer patients, especially for patients affected by urological cancers. Unfortunately, impaired kidney function may limit the choice of adequate oncological treatments for their potential nephrotoxicity or due to contraindications in case of a low glomerular filtration rate. For these patients, tailored nephrological and nutritional management is mandatory. The K-DIGO guidelines do not define whether the nutritional management of CKD could be useful also in CKD patients affected by urological cancer. In fact, in clinical practice, oncological patients often receive high-protein diets to avoid malnutrition. In our study, we investigated the nutritional and nephrological impact of a Mediterranean-like diet with a controlled protein intake (MCPD) on a cohort of 82 stage III-IV CKD patients. We compared two cohorts: one of 31 non-oncological CKD patients and the other of 51 oncological patients with CKD. The use of an MCPD had a favorable impact on both the oncological and non-oncological CKD patients with an amelioration in all the investigated parameters and with a better quality of life, with no cases of malnutrition or AKI.

Risk factors for relapse and long-term outcome of idiopathic retroperitoneal fibrosis.

BACKGROUND: Retroperitoneal fibrosis (RF) is a rare disease of unclear etiology characterized by the presence of fibroinflammatory tissue in the retroperitoneal space, which can entrap and obstruct retroperitoneal structures, notably the ureters. The disease responds well to steroid therapy, but tends to recur even after years. The aim of our study was to evaluate the long-term renal outcome of patients affected by idiopathic retroperitoneal fibrosis looking for predictive risk factors for recurrence of the disease and progression to end-stage renal disease. METHODS: Retrospective observational study of patients with idiopathic RF diagnosed from 2004 to 2017 and follow-up of at least 1 year after the end of first course therapy with steroid, with or without tamoxifen (TMX) and with urological procedures when applicable. RESULTS: Forty-three patients were included in the study. The follow-up was 93 ± 52 months. All the patients obtained remission after therapy that was maintained until the last observation in 26 of them. In 17 patients, there was at least one recurrence. Risk factors associated with relapse were identified and resulted in smoking habit, onset with acute kidney injury (AKI), low back pain and antinuclear antibodies (ANA) positivity. Renal function remained fairly stable during the long-term follow-up. The renal end-point (doubling of serum creatinine or ESRD) occurred in 8% of the patients; however, eGFR in patients with relapse was similar to that of non-recurrent at the diagnoses, but it decreased over time more in the relapsing than in non-relapsing patients (p group = 0.20; p time = 0.001; p time × group interactions = 0.04). Based on these 4 predictor conditions, patients were divided into "low risk" (with 0-1 risk factor), and "high risk" (3-4 risk factors). The renal end-point occurred in 40% of high-risk patients, while none of the low-risk patients reached it (p = 0.02). CONCLUSIONS: Smoking habit, AKI at diagnosis, ANA positivity and lumbar pain were associated with relapse of RF after initial remission due to steroid and/or TMX therapy; the combination of these conditions was also predictive of worse renal function outcome. Identification of risk factors for relapse can be useful not only to modulate the choice, the dosage of first-line treatment and the duration of maintenance therapy but also for preventing a progressive loss of kidney function, as well.

Nutritional support in the tertiary care of patients affected by chronic renal insufficiency: report of a step-wise, personalized, pragmatic approach.

BACKGROUND: Dietary treatment is helpful in CKD patients, but nutritional interventions are scarcely implemented. The main concern of the renal diets is its feasibility with regards to daily clinical practice especially in the elderly and co-morbid patients. This study aimed to evaluate the effects of a pragmatic, step-wise, personalized nutritional support in the management of CKD patients on tertiary care. METHODS: This is a case-control study. It included 823 prevalent out-patients affected by CKD stage 3b to 5 not-in-dialysis, followed by tertiary care in nephrology clinics; 305 patients (190 males, aged 70 ± 12 years) received nutritional support (nutritional treatment Group, NTG); 518 patients (281 males, aged 73 ± 13 years) who did not receive any dietary therapy, formed the control group (CG). In the NTG patients the dietary interventions were assigned in order to prevent or correct abnormalities and to maintain a good nutritional status. They included manipulation of sodium, phosphate, energy and protein dietary intakes while paying special attention to each patient's dietary habits. RESULTS: Phosphate and BUN levels were lower in the NTG than in the CG, especially in stage 4 and 5. The prevalence of hyperphosphatemia was lower in the NTG than in CG in stage 5 (13.3 % vs 53.3 %, p < 001, respectively), in stage 4 (4.1 % vs 18.3 % vs, p < 0.001) and stage 3b (2.8 % vs 9.5 % p < 0.05). Serum albumin was higher in NTG than in CG especially in stage 5 . The use of calcium-free intestinal phosphate binders was significantly lower in NTG than in CG (11 % vs 19 % p < 0.01), as well as that of Erythropoiesis stimulating agents (11 % vs 19 %, p < 0.01), and active Vitamin D preparations (13 % vs 21 %, p < 0.01). CONCLUSIONS: This case-control study shows the usefulness of a nutritional support in addition to the pharmacological good practice in CKD patients on tertiary care. Lower phosphate and BUN levels are obtained together with maintenance of serum albumin levels. In addition, a lower need of erythropoiesis stimulating agents, phosphate binders and active Vitamin D preparations was detected in NTG. This study suggests that a nutritional support may be useful in the management of the world-wide growing CKD burden.

[The presence of crystals of sodium polystyrene sulfonate in the colonic wall: innocent bystander or pathogenic factor?]. / La presenza di cristalli di sodio polisterene sulfonato nella parete colica: fattore patogenetico o semplice marker di somministrazione?

Hyperkalemia is a frequent electrolyte disturbance in patients on dialysis or non-dialysis CKD patients, including those using renin-angiotensin system inhibitor drugs. Sodium polystyrene sulfonate (SPS; Kayexalate) is a resin widely used for hyperkalemia treatment. Unfortunately, its use entails some serious unwanted gastrointestinal side effects. We report the case of a 64-year-old male diabetic patient, suffering from ESRD on hemodialysis, who was treated with 30 g of Kayexalate twice a week (long interdialytic interval). This is a quite common case in the clinical practice. The patient experienced an episode of rectal bleeding followed by the diagnosis of non-specific colitis through colonoscopy. Histological examination, showed the presence of crystals of Kayexalate in the colonic mucosa leading to the suspect of iatrogenic intestinal damage caused by Kayexalate administration. Treatment with SPS was stopped. Nevertheless crystals remain evident in the intestinal mucosa in a colonoscopy performed 14 months later due to a new episode of rectal bleeding. Two years after the first episode the patient died because of intestinal infarction. The review of the literature highlights the risk of serious side effects such as necrotizing colitis with perforation both for the drug in sodium phase and in calcium phase. New intestinal potassium-binger agents, apparently without intestinal severe side effects, are under clinical evaluation. This case does not assess if the crystals deposited in the colonic mucosa are inert or have contributed to the final event, but it shows that Kayexalate is a drug with potential harmful effect even when used orally, at very low dosage and without sorbitol. In our opinion, the SPS should be prescribed carefully, especially as chronic administration, and the prescription should be limited to real and pressing requirements.