Unveiling Neglected Concerns: Possible Severe Hepatic Complications after Nephrectomy in Autosomal Dominant Polycystic Kidney Disease - A Case Report.

Introduction: Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic kidney disease and the 4th leading cause of renal replacement therapy in the world. ADPKD is a systemic disorder as cysts may develop in several organs. Liver cysts are the most common extrarenal manifestations and are often incidentally detected. Even though cysts do not influence liver function, they can grow to a very great size and can significantly enlarge liver volume, causing structural distortion of the biliary tree and patient discomfort due to the mass effect. Nephrectomy is frequently considered in preparation for renal transplantation in patients with remarkable kidneys' enlargement. There are currently no globally recognized clinical guidelines for nephrectomy. Although cysts do not normally affect liver function in ADPKD, after nephrectomy cases of liver fibrosis and Budd-Chiari have been reported. These are uncommon disorders due to the obstruction of the blood flow in the hepatic venous causing spleen and liver volume enlargement, portal hypertension, and hepatic cirrhosis. Case Presentation: We present a case of hepatic fibrosis with splenomegaly and severe pancytopenia as a tardive complication after bilateral nephrectomy in 47-year-old ADPKD patient. Conclusion: This finding underscores the critical significance of meticulously examining the anatomical relationship between polycystic kidneys and the liver before performing nephrectomy. Additionally, it highlights the importance of assessing liver involvement and associated complications. By integrating liver assessment into the criteria, we can significantly enhance patient care and improve the overall management of ADPKD before kidney transplantation.

Is denosumab an efficient and safe drug for osteoporosis in dialysis patients? Considerations and state of the art about its use in this setting.

PURPOSE: In patients with chronic kidney disease (CKD), renal osteodystrophy may be associated with a progressive bone mass loss that increases fracture risk. Denosumab, a monoclonal antibody inhibiting osteoclast activity, is an antiresorptive medication used for the treatment osteoporosis. METHODS: Its efficacy and safety were initially established in the FREEDOM study, showing a significant reduction in incident fractures in osteoporotic women treated with denosumab. Subsequent post hoc analyses showed its efficacy in patients stratified by kidney function, but these analyses did not include patients with advanced stages of CKD. The capability of denosumab in improving bone mineral density in uremic patients was evaluated in 12 studies including 461 dialysis patients with low bone mineral density. The improvement of bone mineral density was the final end point in these studies assessed during a follow-up of 6-60 months. Nine of these studies did not have hyperparathyroidism among criteria for patient inclusion and their participants may have low-turnover bone disease. Despite current recommendations, no patients underwent bone biopsy before denosumab therapy. RESULTS: Overall, findings in these studies suggest that denosumab is a viable option for promoting bone mass recovery in patients with advanced stages of CKD having either high or low serum levels of PTH. However, the increase of bone mineral density was lower in patients with low serum markers of bone turnover at baseline. These studies also highlighted the need for calcium and vitamin D supplementation to prevent hypocalcemia that remains a serious concern. CONCLUSIONS: Denosumab emerges as a potentially safe and effective option for enhancing bone health in CKD patients.

[The Educational Aspect in Promoting a Low-Sodium Diet, Physical Activity and Therapy Adherence among Patients with Autosomal Dominant Polycystic Disease: A Literature Review].

Background. Polycystic kidney disease (ADPKD) is the most common monogenic cause of End Stage Renal Disease (ESRD), and, thus, of kidney transplantation and dialysis. Educational interventions aimed to improve adherence to therapy, physical performance, and adequate food intake in patients can slow down disease progression by developing self-care skills, which are useful to promote their autonomy while aligning their life plans and required treatments. The aim of this review is to analyze the adherence of patients with polycystic kidney to pharmacological therapy, low-sodium diet, and physical activity, as evidenced in the clinical literature to guide structured educational interventions. Methods. We conducted a literature review from 01/09/2021 to 30/12/2022 through the combination of free keywords and MeSH terms on the databases: PubMed, CINAHL and Cochrane. Results. Findings in medical literature show that physical activity can improve blood pressure control and a low-sodium diet can slow down the progression towards ESRD. Furthermore, although patients may adhere to the complex drug therapy, unresolved educational demands concern choices and behaviors of daily life that, involving the sphere of feelings and emotions, can evolve into manifestations of anxiety and stress. Conclusion. Among ADPKD patients a personalized educational support, considering disease stage and psychological factors, may enable them to acquire knowledge, skills, and behaviors that can improve clinical outcomes.

Congenital solitary kidney in autosomal dominant polycystic kidney disease: Where do known genes end and the unknown begin?

We present the case of a 41-year-old man patient diagnosed with solitary left kidney with few cysts. He has a family history of unilateral renal agenesis (URA) but no for autosomal dominant polycystic kidney disease (ADPKD). Genetic testing revealed PKD1 gene intron 11 heterozygous nucleotide variant c.2854-23G>T, but no gene mutation implicated in URA. Just eight cases of ADPKD with one kidney have been recorded globally. PC1 and PC2 disruption, causing primary cilia malformation or absence resulting in relevant in the first embryonic development alteration. Cillia's crucial significance in many diseases will require more research.

[Anti-angiogenic drugs and hypertension: from multidisciplinary collaboration to greater care].

Anti-angiogenic drugs are widely used in cancer therapy. Their main targets of action are the vascular endothelial growth factor (VEGF) and its receptors (VEGF-R). Anti-angiogenic drugs are used to reduce the growth of the tumor and its metastases by acting on the phenomenon of tumor neo-angiogenesis. However, they are known for their side effects such as hypertension, acute kidney injury (AKI), and congestive heart failure. Methods: retrospective study conducted on 57 consecutive patients known for ovarian cancer. Patients treated with Bevacizumab, as first-line, relapse, or maintenance treatment (2015-2022). Results: according to FIGO staging, 98.2% (56 out of 57) of the patients in the study had third degree disease (G3). 49% of patients developed hypertension after starting Bevacizumab therapy (82% grade 2 according to CTCAE v.5). 89% of hypertensive patients started treatment and its management was multidisciplinary with nephrological consultation in 68% of cases. Only 3 out of 57 women discontinued treatment due to hypertension, and in only one of them it was not possible to restart it. Conclusions: the evaluation of the patient by a multidisciplinary team (gynecologist and nephrologist) is essential to minimize the morbidity and mortality of patients, and to avoid the interruption of antineoplastic treatment.

New scenarios in secondary hyperparathyroidism: etelcalcetide. Position paper of working group on CKD-MBD of the Italian Society of Nephrology.

Bone mineral abnormalities (defined as Chronic Kidney Disease Mineral Bone Disorder; CKD-MBD) are prevalent and associated with a substantial risk burden and poor prognosis in CKD population. Several lines of evidence support the notion that a large proportion of patients receiving maintenance dialysis experience a suboptimal biochemical control of CKD-MBD. Although no study has ever demonstrated conclusively that CKD-MBD control is associated with improved survival, an expanding therapeutic armamentarium is available to correct bone mineral abnormalities. In this position paper of Lombardy Nephrologists, a summary of the state of art of CKD-MBD as well as a summary of the unmet clinical needs will be provided. Furthermore, this position paper will focus on the potential and drawbacks of a new injectable calcimimetic, etelcalcetide, a drug available in Italy since few months ago.

[New scenarios in secondary hyperparathyroidism: etelcalcetide. Position paper of Nephrologists form Lombardy].

Bone mineral abnormalities (defined as Chronic Kidney Disease Mineral Bone Disorder; CKD-MBD) are prevalent and associated with a substantial risk burden and poor prognosis in CKD population. Several lines of evidence support the notion that a large proportion of patients receiving maintenance dialysis experience a suboptimal biochemical control of CKD-MBD. Although no study has ever demonstrated conclusively that CKD-MBD control is associated with improved survival, an expanding therapeutic armamentarium is available to correct bone mineral abnormalities. In this position paper of Lombardy Nephrologists, a summary of the state of art of CKD-MBD as well as a summary of the unmet clinical needs will be provided. Furthermore, this position paper will focus on the potential and drawbacks of a new injectable calcimimetic, etelcalcetide, a drug available in Italy since few months ago.

Filamin A is reduced and contributes to the CASR sensitivity in human parathyroid tumors.

Parathyroid tumors display reduced sensitivity to extracellular calcium ([Ca2+]o). [Ca2+]o activates calcium-sensing receptor (CASR), which interacts with the scaffold protein filamin A (FLNA). The study aimed to investigate: (1) the FLNA expression in human parathyroid tumors, (2) its effects on the CASR mRNA and protein expression, and (3) on ERK signaling activation, (4) the effect of the carboxy-terminal CASR variants and (5) of the treatment with the CASR agonist R568 on FLNA-mediated ERK phosphorylation in HEK293 cells. Full-length FLNA immunostaining was variably reduced in parathyroid tumors. Immunofluorescence showed that FLNA localized in membrane and cytoplasm and co-localized with CASR in parathyroid adenomas (PAds)-derived cells. Cleaved C-terminus FLNA fragment could also be detected in PAds nuclear protein fractions. In HEK293 cells transfected with 990R-CASR or 990G-CASR variants, silencing of endogenous FLNA reduced CASR mRNA levels and total and membrane-associated CASR proteins. In agreement, FLNA mRNA levels positively correlated with CASR expression in a series of 74 PAds; however, any significant correlation with primary hyperparathyroidism severity could be detected and FLNA transcript levels did not differ between PAds harboring 990R or 990G CASR variants. R568 treatment was efficient in restoring 990R-CASR and 990G-CASR sensitivity to [Ca2+]o in the absence of FLNA. In conclusion, FLNA is downregulated in parathyroid tumors and parallels the CASR expression levels. Loss of FLNA reduces CASR mRNA and protein expression levels and the CASR-induced ERK phosphorylation. FLNA is involved in receptor expression, membrane localization and ERK signaling activation of both 990R and 990G CASR variants.

Glomerular Pathology in Dent Disease and Its Association with Kidney Function.

BACKGROUND AND OBJECTIVES: Dent disease is a rare X-linked disorder characterized by low molecular weight proteinuria and often considered a renal tubular disease. However, glomerulosclerosis was recently reported in several patients. Thus, Dent disease renal histopathologic features were characterized and assessed, and their association with kidney function was assessed. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Clinical renal pathology reports and slides (where available) were collected from 30 boys and men in eight countries who had undergone clinical renal biopsy between 1995 and 2014. RESULTS: Median (25th, 75th percentiles) age at biopsy was 7.5 (5, 19) years with an eGFR of 69 (44, 94) ml/min per 1.73 m2 and a 24-hour urine protein of 2000 (1325, 2936) mg. A repeat biopsy for steroid-resistant proteinuria was performed in 13% (four of 30) of the patients. Prominent histologic findings included focal global glomerulosclerosis in 83% (25 of 30; affecting 16%±19% glomeruli), mild segmental foot process effacement in 57% (13 of 23), focal interstitial fibrosis in 60% (18 of 30), interstitial lymphocytic infiltration in 53% (16 of 30), and tubular damage in 70% (21 of 30). Higher percentages of globally sclerotic glomeruli, foot process effacement, and interstitial inflammation were associated with lower eGFR at biopsy, whereas foot process effacement was associated with steeper annual eGFR decline. CONCLUSIONS: These associations suggest a potential role for glomerular pathology, specifically involving the podocyte, in disease progression, which deserves further study. Furthermore, Dent disease should be suspected in boys and men who have unexplained proteinuria with focal global glomerulosclerosis and segmental foot process effacement on renal biopsy.

Excessive signal transduction of gain-of-function variants of the calcium-sensing receptor (CaSR) are associated with increased ER to cytosol calcium gradient.

In humans, gain-of-function mutations of the calcium-sensing receptor (CASR) gene are the cause of autosomal dominant hypocalcemia or type 5 Bartter syndrome characterized by an abnormality of calcium metabolism with low parathyroid hormone levels and excessive renal calcium excretion. Functional characterization of CaSR activating variants has been so far limited at demonstrating an increased sensitivity to external calcium leading to lower Ca-EC50. Here we combine high resolution fluorescence based techniques and provide evidence that for the efficiency of calcium signaling system, cells expressing gain-of-function variants of CaSR monitor cytosolic and ER calcium levels increasing the expression of the Sarco-Endoplasmic Reticulum Calcium-ATPase (SERCA) and reducing expression of Plasma Membrane Calcium-ATPase (PMCA). Wild-type CaSR (hCaSR-wt) and its gain-of-function (hCaSR-R990G; hCaSR-N124K) variants were transiently transfected in HEK-293 cells. Basal intracellular calcium concentration was significantly lower in cells expressing hCaSR-wt and its gain of function variants compared to mock. In line, FRET studies using the D1ER probe, which detects [Ca2+]ER directly, demonstrated significantly higher calcium accumulation in cells expressing the gain of function CaSR variants compared to hCaSR-wt. Consistently, cells expressing activating CaSR variants showed a significant increase in SERCA activity and expression and a reduced PMCA expression. This combined parallel regulation in protein expression increases the ER to cytosol calcium gradient explaining the higher sensitivity of CaSR gain-of-function variants to external calcium. This control principle provides a general explanation of how cells reliably connect (and exacerbate) receptor inputs to cell function.

The impact of aortic clamping site on glomerular filtration rate after juxtarenal aneurysm repair.

BACKGROUND: Open repair of juxtarenal abdominal aortic aneurysms (JAAAs), which necessitates clamping above one (interrenal clamping, interRC) or both renal arteries (suprarenal clamping, supraRC), is associated with an increased risk of perioperative renal derangements. We reviewed our experience to investigate the impact of aortic clamping site during JAAA repair on peri- and postoperative glomerular filtration rate (GFR). METHODS: Between January 2001 and March 2006, 32 patients (28 male, four female; mean age 70.5+/-5.6 years) were submitted to elective open repair of JAAA. SupraRC was required in 12 patients and performed with cold renal perfusion (CRP) in five cases; interRC was required in 20 and performed with CRP in eight. GFRs were estimated through postoperative day 4 using the Cockcroft-Gault equation and compared to those of concurrent controls undergoing infrarenal AAA repair, matched 1:1 by gender, age, aneurysm size, preoperative GFR, and left renal vein management. GFR values were also evaluated and compared between groups at a mean follow-up of 29.0+/-23.7 months. Renal dysfunction was defined as a decrease of GFR >or=20%. Statistics were determined as appropriate for the variables of interest. RESULTS: No perioperative mortality was recorded and no differences in major complication rates were observed between groups (p=0.16). Operative time was longer in JAAA patients (154+/-47 vs. 132+/-41 min, p=0.019). Mean renal ischemia time was 16.7+/-7.7 min. Postoperatively, GFR values up to day 4 were significantly worse in JAAA patients compared to controls (p=0.0007), with a fourfold risk of renal dysfunction at postoperative day 4 (34% vs. 9%, odds ratio [OR]=4.44, 95% confidence interval [CI] 1.1-18.1; p=0.029). At univariate analysis, supraRC was found to be the only factor associated with perioperative renal dysfunction (OR=11.3, 95% CI 2.0-63.1; p=0.003). At follow-up, two patients with supraRC died and another two required dialysis permanently. When compared to those with interRC or infrarenal clamping, patients with supraRC showed a persistent renal dysfunction at follow-up (p=0.005). CONCLUSION: Elective JAAA repair with renal ischemia time

Vitamin D retains an important role in the pathogenesis and management of secondary hyperparathyroidism in chronic renal failure.

Chronic kidney disease (CKD) causes alterations in mineral metabolism inducing the development of secondary hyperparathyroidism (HPT) and renal osteodystrophy. Recently, it has been suggested that these alterations play an important role in determining extraskeletal calcification and thus cardiovascular morbidity and mortality among CKD patients. An impaired 1 alfa -hydroxylation of 25-hydroxycholecalciferol (25(OH)D3) to 1,25-dihydroxycholecalciferol (1,25(OH)2 D3) with decreased circulating 1,25(OH)2 D3 levels is commonly observed in patients with creatinine clearance below 70 ml/min. The reduction in 1,25(OH)2 D3 production triggers the up-regulation of parathyroid hormone (PTH) synthesis, through a decreased suppression on PTH gene transcription and a decreased intestinal calcium absorption. A reduced expression of vitamin D receptor (VDR) and a less efficient binding of the complex 1,25(OH)2 D3 -VDR to specific DNA segments account for the resistance to 1,25(OH)2 D3 in target cells. Thus, absolute and relative 1,25(OH)2 D3 deficiency is one of the causes of secondary HPT in patients with CKD, together with phosphate retention and skeletal resistance to PTH. Consistently with these pathophysiological mechanisms, the therapeutic use of 1,25(OH)2 D3 still represents a milestone for the treatment of secondary HPT and renal osteodystrophy, even though hypercalcemia and hyperphosphatemia are common adverse events and may increase the risk of cardiovascular calcifications. To reduce the impact of such adverse effects while retaining anti-PTH activity, 1,25(OH)2 D3 analogues with lower calcemic effects have been synthesized and are now available for clinical use.