Volume Balance in Chronic Kidney Disease: Evaluation Methodologies and Innovation Opportunities.

BACKGROUND: Patients affected by chronic kidney disease are at a risk of cardiovascular morbidity and mortality. Body fluids unbalance is one of the main characteristics of this condition, as fluid overload is highly prevalent in patients affected by the cardiorenal syndrome. SUMMARY: We describe the state of the art and new insights into body volume evaluation. The mechanisms behind fluid balance are often complex, mainly because of the interplay of multiple regulatory systems. Consequently, its management may be challenging in clinical practice and even more so out-of-hospital. Availability of novel technologies offer new opportunities to improve the quality of care and patients' outcome. Development and validation of new technologies could provide new tools to reduce costs for the healthcare system, promote personalized medicine, and boost home care. Due to the current COVID-19 pandemic, a proper monitoring of chronic patients suffering from fluid unbalances is extremely relevant. Key Message: We discuss the main mechanisms responsible for fluid overload in different clinical contexts, including hemodialysis, peritoneal dialysis, and heart failure, emphasizing the potential impact provided by the implementation of the new technologies.

Significance of serum Myostatin in hemodialysis patients.

BACKGROUND: Malnutrition and muscle wasting are common in haemodialysis (HD) patients. Their pathogenesis is complex and involves many molecules including Myostatin (Mstn), which acts as a negative regulator of skeletal muscle. The characterisation of Mstn as a biomarker of malnutrition could be useful in the prevention and management of this condition. Previous studies have reported no conclusive results on the actual relationship between serum Mstn and wasting and malnutrition. So, in this study, we evaluated Mstn profile in a cohort of regular HD patients. METHODS: We performed a cross-sectional study, enrolling 37 patients undergoing bicarbonate-HD (BHD) or haemodiafiltration (HDF) at least for six months. 20 sex-matched healthy subjects comprised the control group. Mstn serum levels were evaluated by ELISA before and after HD. We collected clinical and biochemical data, evaluated insulin resistance, body composition, malnutrition [by Malnutrition Inflammation Score (MIS)] and tested muscle function (by hand-grip strength, six-minute walking test and a questionnaire on fatigue). RESULTS: Mstn levels were not significantly different between HD patients and controls (4.7 ± 2.8 vs 4.5 ± 1.3 ng/ml). In addition, while a decrease in Mstn was observed after HD treatment, there were no differences between BHD and HDF. In whole group of HD patients Mstn was positively correlated with muscle mass (r = 0.82, p < 0.001) and inversely correlated with age (r = - 0.63, p < 0.01) and MIS (r = - 0.39, p = 0.01). No correlations were found between Mstn and insulin resistance, such as between Mstn levels and parameters of muscle strength and fatigue. In multivariate analysis, Mstn resulted inversely correlated with fat body content (ß = - 1.055, p = 0.002). CONCLUSIONS: Circulating Mstn is related to muscle mass and nutritional status in HD patients, suggesting that it may have a role in the regulation of skeletal muscle and metabolic processes. However, also considering the lack of difference of serum Mstn between healthy controls and HD patients and the absence of correlations with muscle function tests, our findings do not support the use of circulating Mstn as a biomarker of muscle wasting and malnutrition in HD.

[Superior Cava Vein stenosis in a hemodialysis patient with long-term central venous catheter and vascular graft: a case report].

Recently, the use of central venous catheters (CVC) as a vascular access in patients undergoing hemodialysis is significantly increased, mainly because of the aging of this population and the presence of several comorbidities. However, the implantation and the long stay of CVC are associated with many complications. Among them, central venous stenosis represents one of the most common problems that, if not properly diagnosed, could lead to vascular thrombosis and consequent vascular access malfunction. Here, we report a case of a 38-year-old patient, who underwent hemodialysis firstly by a CVC long-term into right jugular vein and then by a prosthetic fistula in the ipsilateral limb. The patient presented many episodes of vascular access thrombosis that required endovascular interventions. The ultrasound screening and CT-angiography revealed an asymptomatic stenosis of the superior cava vein, which treatment with the implantation of vascular stent resulted in an initial improvement of vascular access performance. However, in the following months, a restenosis was observed that required new interventions to reestablish a satisfactory vascular access function. This case highlights that patients on hemodialysis should undergo proper clinical and instrumental follow-up in order to prevent or early recognize vascular access complications.

[Report for the World Kidney Days in Italy 2015-2016].

World Kidney Day (WKD) is a global campaign, promoted by International Federation of Kidney Foundations (IFKF) and International Society of Nephrology (ISN) aimed at raising awareness among people on importance of our kidneys. This campaign includes many events across the globe. The main purpose of WKD is to create and spread awareness about preventive behaviours and risk factors for renal diseases. In Italy WKD is organized by the Italian Kidney Foundation (FIR) in collaboration with Italian Society of Nephrology (SIN) and the Red Cross of Italy. It takes place in hospitals, public spaces and in schools, where each participant is provided with informative material together with blood pressure and urine dipstick testing. Here, we present the data collected during the 2015 and 2016 WKD campaigns.

Severe cyclophosphamide-related hyponatremia in a patient with acute glomerulonephritis.

Cyclophosphamide is frequently used to treat cancer, autoimmune and renal diseases, such as rapidly progressive glomerulonephritis. Its side effects are well-known, including bone marrow depression, infections, alopecia, sterility, bladder malignancy and hemorrhagic cystitis. Moreover, in some cases cyclophosphamide use has been related to the onset of hyponatremia, by development of a syndrome of inappropriate antidiuresis. Indeed, severe hyponatremia has been previously reported in patients treated with high-dose or moderate-dose of intravenous cyclophosphamide, while only few cases have been reported in patients treated with low dose. Here, we discuss a case of a syndrome of inappropriate antidiuresis followed to a single low-dose of intravenous cyclophosphamide in a patient with a histological diagnosis of acute glomerulonephritis, presenting as acute kidney injury. After cyclophosphamide administration (500 mg IV), while renal function gradually improved, the patient developed confusion and headache. Laboratory examinations showed serum sodium concentration dropped to 122 mmol per liter associated with an elevated urinary osmolality of 199 mOsm/kg, while common causes of acute hyponatremia were excluded. He was successfully treated with water restriction and hypertonic saline solution infusion with the resolution of the electrolyte disorder. This case, together with the previous ones already reported, highlights that electrolyte profile should be strictly monitored in patients undergoing cyclophosphamide therapy in order to early recognize the potentially life-threatening complications of acute water retention.

[Spontaneous rupture of a simple renal cyst: clinical management]. / Rottura spontanea di cisti renale semplice: gestione clinica.

Spontaneous renal bleeding mainly occurs in patients with polycystic kidney diseases or cancer. Indeed, despite the high prevalence of simple cysts, their spontaneous atraumatic rupture is a rare event. Underlying mechanisms may involve the increase of intracystic pressure and/or the development of a haemorrhage into the cyst. Management of this condition includes surgery, interventional radiology or conservative strategies. Here, we report a case of spontaneous rupture of a simple renal cyst, successfully managed with conservative treatment.

["Deep" purple urine bag syndrome: physiopathology and clinical implications]. / La Sindrome delle urine viola: patogenesi e significato clinico.

Urinalysis is a key part of the clinical evaluation of patients with kidney disease. It can provide several useful information for the diagnosis and management of diseases of kidneys and urinary tract. In particular, urine color can be affected by the presence of blood, infection and endogenous metabolites, such as bilirubin, or exogenous, for instance those derived from drugs. Therefore, the analysis of urine color may be helpful in identifying different clinical conditions. Here we report a case of a patient who presented purple-colored urine, the so-called " Purple urine bag syndrome", discussing the predisposing factors and the pathogenesis of this condition. We believe that this information can be useful to clinicians who might face this particular situation.