Surgical Aortic Valve Replacement and Renal Dysfunction: From Acute Kidney Injury to Chronic Disease

Background: Surgical aortic valve replacement (SAVR) is often complicated by acute kidney injury (AKI). Identifying patients at risk of AKI is important to start nephroprotective strategies or renal replacement therapy (RRT). This study investigated the incidence and risk factors of post-operative AKI in SAVR patients. Chronic kidney disease (CKD) developed in the post-cardiac-surgery follow-up period was also assessed. Methods: A total of 462 SAVR patients were retrospectively enrolled. The primary endpoint was the occurrence rate of AKI after surgery. Kidney recovery, during two planned outpatient clinic nephrological visits within 12 months after the surgery, was assessed. Results: A total of 76 patients experienced an AKI event. A Kaplan-Meier analysis revealed that subjects with CKD stage IV had a time to progression of 2.7 days, compared to patients with stages I-II, who were characterized by the slowest progression time, >11.2 days. A Cox regression indicated that CKD stages predicted a higher risk of AKI independently of other variables. During their ICU stay, 23 patients died, representing 5% of the population, most of them requiring RRT during their ICU stay. A severe CKD before the surgery was closely related to perioperative mortality. During the follow-up period, 21 patients with AKI worsened their CKD stage. Conclusions: AKI represents a common complication for SAVR patients in the early post-operative period, prolonging their ICU stay, with negative effects on survival, especially if RRT was required. Pre-operative CKD >3 stage is an independent risk factor for AKI in patients undergoing SAVR.

Left Ventricular Mass Index Predicts Renal Function Decline in Patients with Chronic Kidney Disease

Background and Objectives: Several studies revealed a relation between abnormal cardiac remodeling and glomerular filtration rate (GFR) decline, but there are limited data regarding echocardiographic changes in chronic kidney disease (CKD). This study evaluated the abnormal cardiac structures characterizing patients with CKD, assessing the independent association between echocardiographic parameters and the risk of decline in renal function. Materials and Methods: In total, 160 patients with CKD were studied. All patients underwent an echocardiographic exam and 99mTc-DTPA renal scintigraphy to measure the GFR. After the baseline assessments, patients were followed prospectively for 12 months, or until the endpoint achievement, defined as a worsening in renal function (doubling of baseline serum creatinine, GFR decline ≥25%, the start of dialysis). Results: Patients with GFR values of 34.8 ± 15 mL/min, identifying stages III-IV of CKD, were associated with high levels of left ventricular mass index (LVMi) (101.9 ± 12.2 g/m2), which was related to proteinuria, systolic blood pressure, and pulmonary artery systolic pressure in a multiple regression model. During the observational period, 26% of patients reached the endpoint. Regression analysis revealed LVMi as a predictor of change in renal function after adjusting for kidney and cardiac risk factors. Multiple Cox regression indicated that an increase in LVMi was associated with a 12% increased risk of kidney disease progression (HR: 1.12; 95% CI: 1.04-1.16; p = 0.001). Conclusions: In patients with CKD, high LVMi represents an independent predictor of the progressive decline of the renal function, until the start of renal replacement therapy. Echocardiography can help identify patients at high risk for renal disease worsening in patients with CKD independently of clinical cardiac involvement.

Therapeutic Management of Children with Vesicoureteral Reflux

Contrasting data refer to therapies for vesicoureteral reflux (VUR), such as surgical treatments and continuous antibiotic prophylaxis (CAP). This study evaluated the effectiveness of these approaches in children with VUR, analyzing the recurrence of febrile urinary tract infections (UTIs) and the resolution of VUR after the treatment. A total of 350 pediatric patients underwent contrast-enhanced voiding urosonography (ceVUS) to diagnose a VUR, whereas renal scintigraphy evaluated potential scars. After 12 months from the treatment, the VUR, the relapse of febrile UTIs, and reflux-related nephropathy were analyzed. Twenty-seven children had recurrent febrile UTIs after surgical therapy, with a greater rate of relapses observed in III and V VUR grades. Thirteen patients who underwent surgery had scars, independently of VUR grades and gender, with evidence of chronic renal failure at the end of the follow-up period. A total of 140 subjects were treated with CAP, and 30% of them continued to suffer from febrile UTIs. Ninety-five patients with VUR underwent ceVUS after 12 months, with persistent reflux in fifty-two patients. All of them had severe VUR, correlating with the age at diagnosis and gender. CAP therapy prevented scarring better than surgery, especially in children with III and V grades of VUR. A late onset of VUR or VUR involving neonatal patients is rarely a reversible process. This study identified predictors of success or failure of surgical or CAP therapies, evaluating the relapse of UTIs or persistent reflux after the treatment and giving prognostic information in children with VUR.

Acute Kidney Injury and Sepsis after Cardiac Surgery: The Roles of Tissue Inhibitor Metalloproteinase-2, Insulin-like Growth Factor Binding Protein-7, and Mid-Regional Pro-Adrenomedullin

BACKGROUND

Identifying a panel of markers detecting kidney injury before the glomerular filtration rate reduction is a challenge to improving the diagnosis and management of acute kidney injury (AKI) in septic patients. This study evaluated the roles of tissue inhibitor metal proteinase-2, insulin growth factor binding protein-7 (TIMP2*IGFBP7), and mid-regional pro-adrenomedullin (MR-proADM) in patients with AKI.

PATIENTS AND METHODS

This study was prospectively conducted in an intensive care unit (ICU) enrolling 230 patients who underwent cardiac surgery. Biomarkers were evaluated before and after 4 h of the cardiac surgery.

RESULTS

Whereas urine and creatinine alterations appeared at 23.2 (12.7-36.5) hours after cardiac surgery, urinary TIMP2*IGBP7 levels were higher at 4 h in AKI patients (1.1 ± 0.4 mg/L vs. 0.08 ± 0.02 mg/L; p < 0.001). Its concentration > 2 mg/L increases AKI risk within the following 24 h, clearly identifying the population at high risk of renal replacement therapy (RRT). In patients with sepsis, MR-proADM levels were 2.3 nmol/L (0.7-7.8 nmol/L), with the highest values observed in septic shock patients (5.6 nmol/L (3.2-18 nmol/L)) and a better diagnostic profile than procalcitonin and C-reactive protein to identify septic patients. MR-proADM values > 5.1 nmol/L and urine TIMP2*IGBP7 levels > 2 mg/L showed a significantly faster progression to RRT, with a mean follow-up time of 1.1 days.

CONCLUSIONS

TIMP2*IGBP7 and MR-proADM precociously diagnose AKI in septic patients after cardiac surgery, giving prognostic information for RRT requirement.

The Switch from Ferric Gluconate to Ferric Carboxymaltose in Hemodialysis Patients Acts on Iron Metabolism, Erythropoietin, and Costs: A Retrospective Analysis

Background and Objectives: Iron deficiency and anemia characterize patients on chronic hemodialysis (HD). Available intravenous iron agents, such as ferric gluconate (FG) and ferric carboxymaltose (FCM), vary in dosing regimens and safety profiles. The aim of the present study was to analyze the modification of the iron status, the correction of anemia, and the economic implications after the shift from FG to FCM therapy in chronic HD patients. We evaluated, during the study, the variations in iron metabolism, assessing ferritin and transferrin saturation, erythropoietin-stimulating agent (ESA) doses and the number of administrations, the effects on anemic status, and consequent costs. Materials and Methods: A retrospective study was performed with a follow-up period of 24 months, enrolling forty-two HD patients. The enrolment phase started in January 2015, when patients were treated with iv FG, and continued until December 2015, when FG was discontinued, and, after a wash-out period, the same patients were treated with FCM. Results: The iron switch reduced the administered dose of ESA by 1610.500 UI (31% of reduction; p < 0.001) during the entire study period and reduced the erythropoietin resistance index (ERI) (10.1 ± 0.4 vs. 14.8 ± 0.5; p < 0.0001). The FCM group had the highest percentage of patients who did not require ESA treatment during the study period. The FCM patients were characterized by higher levels of iron (p = 0.04), ferritin (p < 0.001), and TSAT levels (p < 0.001) compared to the FG patients. The annual cost during FG infusion was estimated at EUR 105,390.2, while one year of treatment with FCM had a total cost of EUR 84,180.7 (a difference of EUR 21,209.51 (20%), saving EUR 42.1 per patient/month (p < 0.0001). Conclusions: FCM was a more effective treatment option than FG, reducing ESA dose requirements, increasing Hb levels, and improving iron status. The reduced ESA doses and the decreased number of patients needing ESA were the main factors for reducing overall costs.

Tolvaptan resistance is related with a short-term poor prognosis in patients with lung cancer and syndrome of inappropriate anti-diuresis

Purpose: Tolvaptan (TVP), a vasopressin receptor antagonist, represents a therapeutic option in the syndrome of inappropriate anti-diuresis (SIAD). The aim of this study was to evaluate the effect of TVP to treat and solve hyponatremia in oncologic patients. Methods: 15 oncologic patients who developed SIAD have been enrolled. Patients receiving TVP belonged to group A, whereas group B was characterized by hyponatremic patients treated with hypertonic saline solutions and fluid restriction. Results: In group A, the correction of serum sodium was achieved after 3.7±2.8 days. In group B, the target levels were obtained more slowly, after 5.2±3.1 days (p: 0.01) than in group A. The hospital stay and incidence of re-hospitalization were higher in group B than in group A. In this latter, 37% of patients had hyponatremic relapses, notwithstanding the progressive increase of doses from 7.5 to 60 mg per day of TVP, revealing a complete lack of response to TVP. In these patients, a growth of tumor mass or new metastatic lesions has been revealed. Conclusion: TVP improved hyponatremia more efficiently and stably than hypertonic solutions and fluid restrictions. Positive consequences have been obtained about the rate of chemotherapeutical cycles concluded, hospital stay, rate of relapse of hyponatremia, and re-hospitalization. Our study also suggested potential prognostic information that could be deduced from TVP patients, in whom sudden and progressive hyponatremia occurred, despite TVP dosage increase. A re-staging of these patients to rule out tumor mass growth or new metastatic lesions is suggested.

Acute Kidney Injury: Advances in Clinical Management

Acute kidney injury (AKI), closely related to increased mortality, involved 15-20% of hospitalized patients with higher incidence, with about 50% in the intensive care unit (ICU) [...].

Free Light Chains, High Mobility Group Box 1, and Mortality in Hemodialysis Patients

Background: Uremic toxins are associated with immune dysfunction and inflammation. The inadequate removal by hemodialysis (HD) of serum free light chains (FLCs) determines their accumulation. This study evaluated FLCs in HD patients, analyzing their relations with other biomarkers, such as serum high mobility group box 1 (HMGB1). Methods: FLC and HMGB1 were evaluated in a cohort of 119 HD patients. κFLC and λFLC were summated to give a combined (c) FLC concentration. Patients were followed prospectively until the end of the observation period of four years, or until the endpoint: the patient’s death. Results: cFLC values in HD patients were 244.4 (197.9−273.5) mg/L. We detected a significant reduction in CD8+ cells and a decreased CD4+/CD8+ ratio. HMGB1 levels were 94.5 (55−302) pg/mL. After multivariate analysis, cFLCs correlated with β2-microglobulin and the CD4+/CD8+ ratio. Subjects with cFLC values above 263 mg/L and with sHMGB1 values < 80 pg/mL experienced a significantly faster evolution to the endpoint (mean follow-up time to progression of 27.5 and 28.5 months, respectively; p < 0.001). After an adjusted multivariate Cox analysis, cFLCs were associated with 11% increased risk of death, whereas low sHMGB1 increased this risk by 5%. Conclusions: cFLCs and HMGB1 reflect the inflammation and immune dysfunction in HD patients representing two strong and independent risk markers of mortality.

The Next Evolution of HemoDialysis eXpanded: From a Delphi Questionnaire-Based Approach to the Real Life of Italian Dialysis Units

INTRODUCTION

Impact assessment of new technologies in chronic hemodialysis (HD) is challenging due to HD patient frailty, the complexity of HD clinical trials and practice variability among countries. Among the most recent HD innovations, medium cut-off (MCO) dialyzers present an optimized membrane geometry that provides enhanced clearances for middle and large molecular weight uremic toxins (UT). These toxins are poorly cleared by available HD techniques and largely contribute to patient morbidity and mortality. The aim of this paper is to assess the available clinical evidence about MCO membranes and to identify the next steps needed to generate conclusive data on their use in HD.

METHODS

With this purpose, we first reviewed and compared the current HD technologies aimed to improve the clearance of middle and large UT; subsequently, we used a Delphi questionnaire to identify and discuss the consensus about MCO efficacy within a large sample of the Italian Nephrology community.

RESULTS AND CONCLUSIONS

Our investigation gathered a significant degree of consensus on the beneficial role of MCO membrane and expanded HD. Finally, we used our results to propose future trial designs and clinical investigations aimed to improve evidence quality about the use of these membranes in the present clinical scenario of dialysis units.

Fabry disease and kidney involvement: starting from childhood to understand the future

The accumulation of globotriaosylceramide (Gb-3) in multiple organs, such as the heart, kidney, and nervous system, due to mutations in the galactosidase alpha (GLA) gene, represents the key point of Fabry disease (FD). The common symptoms appear in childhood or adolescence, including neuropathic pain, angiokeratoma, acroparesthesia, and corneal opacities. A multi-organ involvement induces a significant deterioration in the quality of life with high mortality in adulthood. The accumulation of Gb-3 involves all types of kidney cells beginning at fetal development, many years before clinical manifestations. A decline in the glomerular filtration rate is rare in children, but it can occur during adolescence. Pediatric patients rarely undergo kidney biopsy that could assess the efficacy of enzyme replacement therapy (ERT) behind its diagnostic role. To date, diagnosis is achieved by detecting reduced α-Gal-A activity in leukocytes and plasma, allowing for the early start of ERT. This review focuses on pediatric kidney involvement in FD, analyzing in depth its diagnostic processes and treatment options.

MO902SERUM FREE LIGHT CHAINS IN HEMODIALYSIS PATIENTS: A BRIDGE BETWEEN INFLAMMATION, IMMUNE SYSTEM DYSFUNCTION AND MORTALITY RISK

Background and Aims

Uremic toxins, poor removed by conventional hemodialysis (HD), represent independent risk factors for mortality in end-stage renal disease (ESRD).

Middle uremic toxin molecules were associated to pathological features of uremia, such as immune dysfunction and inflammation. These two entities are not mutually exclusive, but they could represent two sides of the same coin. ESRD-associated inflammation is closely related to the activation of innate immune system. Free light chain (FLC) may be a specific assessment of inflammation, representing a direct function of adaptive immunity through B-cell lineage production rather than a general marker of inflammation.

While several studies have assessed the relation between FLCs and mortality risk in chronic kidney disease (CKD), FLCs, as uremic toxins in non-multiple myeloma dialyzed patients, were marginally analyzed.

The aim of this prospective study was to evaluate the clinical impact of FLCs levels in HD patients, during a 2-years follow-up analysing the relations with biomarkers of inflammation, such as C-reactive protein (CRP) and procalcitonin (PCT), main lymphocytes subsets, such as CD4+ and CD8+ T cell count and high mobility group box (HMGB) -1 levels, as expression of the innate immune system. The potential link between FLCs levels and mortality risk was assessed.

Method

190 patients on chronic hemodialysis at the Nephrology and Dialysis Unit of Papardo Hospital in Messina, Italy, were enrolled and followed for 2 years. Inclusion criteria were: age &gt;18 years, absence or &lt;200 ml/die residual diuresis, κ/λ ratio within the renal reference range (0.37–3.1).

Receiver operating characteristics (ROC) analysis was performed to estimate the cut-off points of HMGB-1 and cFLC. Kaplan-Meier survival analysis and Cox proportional multivariate hazards model were used for clinical outcome.

Results

HD patients were characterized by high FLC levels. κFLC values were 182.3 (IQR: 140.2 – 216.1) mg/L, whereas λFLC levels were 108.2 (IQR: 72.7 – 143.2) mg/L. The median combined (c) FLC concentration was 182.9 mg/L (IQR = 207.8 – 330.2), which was extremely greater than the median reported in the general population (normal range = 9.3 – 43.3 mg/L) and in CKD patients [68.9 mg/L (IQR = 49.4 – 100.9)].

No differences in cFLC levels were revealed according to dialysis techniques.

HD patients showed significant reduction of CD4+ and CD4+/CD8+ ratio. High HMGB1 levels were detected in HD patients (161.3 ± 39.7 ng/ml) and positively related to PCT and cFLC (r = - 0.38; p &lt; 0.001), with an inverse relation to CD4+/CD8+ ratio.

cFLC positively correlated with β2 microglobulin, hemoglobin, and HMGB1. Conversely, an inverse correlation was revealed with surrogate markers of inflammation, such as CRP, procalcitonin, neutrophil counts.

There were 49 deaths during the follow-up. The majority (23/49) of deaths were attributed to cardiovascular disease, the remainder to infection and malignancy.

cFLCs and sHMGB-1 levels in this group were significantly elevated. By ROC analysis, HMGB-1 levels &gt; 100.9 ng/mL and cFLC &gt; 223.4 mg/l were associated with a significantly lower survival rate (p &lt; 0.02 by log-rank test) than for patients with lower levels when using Kaplan-Meier analysis. After adjusting for confounding factors, by Cox proportional hazards method, the difference remained statistically significant (p = 0.02)

Conclusion

Our study demonstrated an independent relation between high cFLC levels and mortality in HD patients. cFLCs represent a potential biomarker of “inflammunity”, a physiopathological process playing a pivotal role in ESRD, based on a vicious circle between inflammation and immune dysfunction.

Further in-depth examinations should be verify our findings, determining whether therapeutic measures targeting cFLC balance, such as hemodiafiltration and expanded dialysis, would be helpful to reduce the “inflammunity” process, characterizing dialyzed patients.

HMGB-1 and TGFβ-1 highlight immuno-inflammatory and fibrotic processes before proteinuria onset in pediatric patients with Alport syndrome

INTRODUCTION

Alport syndrome (ALP) is a rare genetic condition characterized by progressive involvement of the basal membranes and renal dysfunction. The purpose of the study was to evaluate urinary (u) and serum (s) levels of tumor growth factor (TGF)-beta(β) and high mobility group box (HMGB)-1 in ALP patients with normal renal function, albuminuria and proteinuria.

METHODS

A prospective, single-center study was performed with a follow-up period of 12 months, enrolling 11 pediatric ALP patients and 10 healthy subjects (HS). Normal values of serum creatinine, albuminuria and proteinuria, as well as unaltered estimated glomerular filtration rate (eGFR) were required at enrollment.

RESULTS

ALP patients had significantly higher levels of serum and urinary HMGB1 compared to HS. The same trend was observed for TGF-β1, with higher values in ALP patients than in HS. HMGB1 and TGF-β1 correlated with each other and with markers of renal function and damage. Urinary biomarkers did not correlate with eGFR, whereas sHMGB1 and sTGF-β1 were negatively related to filtration rate (r: - 0.66; p = 0.02, r: - 0.96; p < 0.0001, respectively). Using proteinuria as a dependent variable in a multiple regression model, only the association with sTGF-β1 (β = 0.91, p < 0.0001) remained significant.

CONCLUSIONS

High levels of HMGB1 and TGF-β1 characterized ALP patients with normal renal function, highlighting the subclinical pro-fibrotic and inflammatory mechanisms triggered before the onset of proteinuria. Further studies are needed to evaluate the role of HMGB1 and TGFβ-1 in ALP patients.

Updates on hemodialysis techniques with a common denominator: The personalization of the dialytic therapy

Hemodialysis (HD) is a life-saving therapy for patients with end-stage renal disease. In dialyzed patients, the prevalence of multi-morbidity is rising driven by various factors, such as the population aging, the incomplete correction of uremia, and the side effects of the dialysis therapy itself. Each dialyzed patient has their own specific clinical and biochemical problems. It is therefore unthinkable that the same dialysis procedure can be able to meet the needs of every patient on chronic dialysis. We have very sophisticated dialysis machines and different dialysis techniques and procedures beyond conventional HD, such as hemodiafiltration (HDF) with pre- and post-dilution, acetate-free biofiltration (AFB), hemofiltration (HF), and expanded HD. Each of these techniques has its own specific characteristics. To solve some intradialytic clinical issues, such as arterial hypotension and arrhythmias, we have biofeedback systems with automatic regulation of the blood volume, body temperature, arterial pressure, as well as potassium profiling techniques in the dialysis bath. New technical innovations, such as citrate-containing dialysate or heparin-coated membranes, could reduce the risk of bleeding. To better address to patient needs, the strengths and weaknesses of each of these systems must be well-known, in order to have a personalized dialysis prescription for each patient.

Ferric carboxymaltose versus ferric gluconate in hemodialysis patients: Reduction of erythropoietin dose in 4 years of follow-up

Background

Ferric carboxymaltose (FCM) is a parenteral, dextran-free iron formulation designed to overcome the limitations of existing iron preparations. The main aim of this study was to retrospectively examine results obtained from a long period of FCM therapy in hemodialysis patients who have been previously treated with ferric gluconate (FX). Markers of iron metabolism, erythropoietin (EPO) doses, and effects on anemic status have been analysed.

Methods

The study was performed with a follow up period of 4 years, when patients were treated before with FX and then switched to FCM. A total of 25 patients were included in the study.

Results

FCM increased transferrin saturation (TSAT) levels by 11.9% (P < 0.001) with respect to FX. Events of TSAT less than 20% were reduced during FCM. The monthly dose of EPO was reduced in the FCM period (-6,404.1 international unit [IU]; 95% confidence interval, -10,643.5 IU; -2,164.6 IU; P = 0.003), as well as the erythropoietin resistance index (P = 0.004). During the period with FCM, ferritin levels were higher than during FX (P < 0.001), while transferrin was reduced (P = 0.001).

Conclusion

During FCM treatment, minor doses of EPO were administered if compared to those delivered during FX therapy. Stable and on target levels of hemoglobin were maintained with better control of anemia through high levels of ferritin and TSAT.

Acute and chronic kidney disease after pediatric liver transplantation: An underestimated problem

Acute and chronic kidney injuries represent critical issues after liver transplantation (LTx), but whereas renal dysfunction in adult transplant patients is well documented, little is known about its prevalence in childhood. It is a challenge to accurately evaluate renal function in patients with liver disease, due to several confounding factors. Creatinine-based equations estimating glomerular filtration rate, validated in nephropathic patients without hepatic issues, are frequently inaccurate in end-stage liver disease, underestimating the real impact of renal disease. Moreover, whereas renal issues observed within 1 year from LTx were often related to acute injuries, kidney damage observed after 5-7 years from LTx, is due to chronic, irreversible mechanisms. Most immunosuppression protocols are based on calcineurin inhibitors (CNIs) and corticosteroids, but mycophenolate mofetil or sirolimus could play significant roles, also in children. Early diagnosis and personalized treatment represent the bases of kidney disease management, in order to minimize its close relation with increased mortality. This review analyzed acute and chronic kidney damage after pediatric LTx, also discussing the impact of pre-existent renal disease. The main immunosuppressant strategies have been reviewed, highlighting their impact on kidney function. Different methods assessing renal function were reported, with the potential application of new renal biomarkers.

Non-Invasive Imaging for Evaluating Cardiovascular Involvement in Patients with Primary and Lupus Nephritis

Background:

Evidence suggests that proteinuric diseases, such as primary or secondary glomerulonephritis, increase cardiovascular risk, but few studies confirmed this association.

Methods:

This is a cross-sectional, observational study on 32 patients, 17 with Primary Glomerulonephritis (PG) and 15 with Lupus Glomerulonephritis (LG). The control group consisted of 32 healthy individuals. Intima-media thickness (IMT) of the left common carotid artery, carotid bifurcation and internal carotid artery was measured by ultrasound. Left ventricular myocardial deformation was assessed by the use of the Global Circumferential Strain (GCS) and the Global Longitudinal Strain (GLS) following 2-Dimensional (2D) echocardiography in all participants.

Results:

Patients with glomerulonephritis in both groups showed significantly lower GLS compared with controls (p=0.0005). There was also a significant difference in common carotid IMT values between the LG and GP group (0.45±0.09 vs. 0.58±0.17 mm, respectively; p=0.01), but there was no difference with the control group. In patient group (n=32), a significantly positive correlation was observed between C-reactive protein and proteinuria (r=0.98; p<0.0001), whereas negative correlations were found between common carotid IMT and creatinine clearance (r=-0.97; p<0.0001) and between carotid bifurcation IMT and phosphate levels (r=-0.97; p<0.0001)

Conclusion:

Subclinical systolic myocardial dysfunction is present early in the course of glomerular disease. The use of 2D GLS revealed that LG and PG patients with no cardiovascular symptoms or history and a preserved left ventricle ejection fraction on conventional echocardiography had subclinical reduction in LV global longitudinal systolic function compared with controls.

Erythropoiesis and chronic kidney disease-related anemia: From physiology to new therapeutic advancements

Erythropoiesis is triggered by hypoxia and is strictly regulated by hormones, growth factors, cytokines, and vitamins to ensure an adequate oxygen delivery to all body cells. Abnormalities in one or more of these factors may induce different kinds of anemia requiring different treatments. A key player in red blood cell production is erythropoietin. It is a glycoprotein hormone, mainly produced by the kidneys, that promotes erythroid progenitor cell survival and differentiation in the bone marrow and regulates iron metabolism. A deficit in erythropoietin synthesis is the main cause of the normochromic normocytic anemia frequently observed in patients with progressive chronic kidney disease. The present review summarizes the most recent findings about each step of the erythropoietic process, going from the renal oxygen sensing system to the cascade of events induced by erythropoietin through its own receptor in the bone marrow. The paper also describes the new class of drugs designed to stabilize the hypoxia-inducible factor by inhibiting prolyl hydroxylase, with a discussion about their metabolism, disposition, efficacy, and safety. According to many trials, these drugs seem able to simulate tissue hypoxia and then stimulate erythropoiesis in patients affected by renal impairment. In conclusion, the in-depth investigation of all events involved in erythropoiesis is crucial to understand anemia pathophysiology and to identify new therapeutic strategies, in an attempt to overcome the potential side effects of the commonly used erythropoiesis-stimulating agents.

The Myth of Water and Salt: From Aquaretics to Tenapanor

The impact of water intake has been studied in several renal diseases. For example, increasing water intake is useful to prevent primary and secondary nephrolithiasis. In autosomal dominant polycystic kidney disease, arginine vasopressin (AVP) is involved in the progression of the disease, and water intake could play a therapeutic role by inhibiting the synthesis of AVP, but its efficacy is still controversial. Conversely, the use of aquaretics, which are antagonists of AVP V2 receptors, results in the reduction of the increase rate of total kidney volume with a slower decline of glomerular filtration rate. In chronic kidney disease, AVP contributes to glomerular hyperfiltration, arterial hypertension, and synthesis of renin, resulting in renal sclerosis. Increased water intake could reduce AVP activation determining a potential protective effect on the kidney, but its efficacy has not yet been clearly demonstrated. On the other side, sodium and potassium play an important role in the control of arterial blood pressure and are involved in the development and progression of chronic kidney disease. Reduction of sodium intake and increase of potassium intake determine a decrease of arterial blood pressure with a beneficial effect on the kidney; however, adherence to sodium restriction is very poor. Regarding this, sodium-hydrogen exchanger isoform 3 inhibitors may reduce sodium absorption in the gut. The most recent sodium-hydrogen exchanger isoform 3 inhibitor, known as tenapanor, reduces extracellular fluid volume, left ventricular hypertrophy, albuminuria, and blood pressure in experimental studies and increases fecal loss of sodium in humans.

Role of Vitamin D in Vascular Complications and Vascular Access Outcome in Patients with Chronic Kidney Disease

Vitamin D has been known for a long time as a major factor involved in the calcium- phosphate balance and homeostasis, along with parathyroid hormone (PTH). While vitamin D effects on calcium and phosphate are fully known, recent studies attempted to link vitamin D status and cardiovascular diseases. The involvement of vitamin D on vascular remodeling is mediated by several mechanisms such as activation of renin-angiotensin-aldosterone system (RAAS), cell proliferation and anti-apoptotic cell pathways. This correlation is highlighted by the fact that the activated form of vitamin D (1,25 (OH)2 D3) can be synthesized by the same endothelial cells, due to the constitutive presence of endothelial 1α-hydroxylase. Vitamin D reduces the expression of angiotensin 2 receptor (AT2R) on the endothelial cell surface (AT2R), leading to a cascade of events that result in the synthesis of vasodilators, such as nitric oxide. The activation of vitamin D receptors (VDRs) on endothelial cells induces changes in the metabolic activity of the endothelium and is responsible for cell survival, proliferation and neoangiogenesis. Moreover, altered signaling of VDR due to gene polymorphisms has been demonstrated in patients with cardiac disorders and chronic kidney disease (CKD). Recently, vascular access outcome has been associated with vitamin D status. Future studies will help to better define the need of vitamin D supplementation for a better cardiovascular as well as vascular access outcome in patients with CKD.

Higher serum sclerostin levels and insufficiency of vitamin D are strongly associated with vertebral fractures in hemodialysis patients: a case control study

In hemodialysis patients, vertebral fractures were associated with elevated sclerostin levels, suggesting that sclerostin could reflect bone fragility in these patients.

INTRODUCTION

Fragility fractures are common in hemodialysis patients. The aims of our study were to determine the prevalence of vertebral fracture and analyze associations between sclerostin serum levels and vertebral fractures in hemodialysis patients.

METHODS

Ninety-two hemodialysis patients and 100 controls matched for age and sex were studied. Bone mineral density was measured by ultrasonography at non-dominant heel. The markers of bone turnover included serum osteocalcin, C-terminal telopeptide, and sclerostin. All participants underwent radiography of the thoracic and lumbar spine to ascertain the presence of vertebral fractures.

RESULTS

Bone ultrasound parameters at calcaneus were significantly lower in hemodialysis patients compared with controls; bone turnover markers and parathyroid hormone level were significantly higher, while serum of 25-OH-D3 was significantly lower in hemodialysis group. One or more moderate or severe vertebral fractures were found in 38 hemodialysis patients, whereas in control group, 10 patients had a vertebral fracture. In hemodialysis group, the comparison between patients with and without vertebral fractures showed that the patients with vertebral fractures had the serum sclerostin levels statistically higher than patients without vertebral, while serum levels of 25-OH-D3 was significantly lower in patients with vertebral fractures compared to the patients without vertebral fractures. Multivariate analysis disclosed that sclerostin levels were associated with an increased risk of vertebral fractures in hemodialysis patients after adjusting for multiple variables.

CONCLUSIONS

Our data shows high prevalence of vertebral fractures in hemodialysis patients and that it is associated with elevated sclerostin levels, reflecting bone fragility in these patients.

Renoprotective effect of erythropoietin in zebrafish after administration of gentamicin: an immunohistochemical study for β-catenin and c-kit expression

BACKGROUND

Gentamicin is an aminoglycoside antibiotic widely used in the treatment of infections caused by Gram-negative bacteria. The main limitation to its therapeutic effectiveness is the potential nephrotoxicity. Erythropoietin has a tissue protective effect widely demonstrated in the kidney. The aim of the present study was to evaluate the renoprotective effects of erythropoietin in a model of zebrafish (Danio rerio) after administration of gentamicin.

METHODS

Sixty adult zebrafish were subdivided into three groups: group A was treated with gentamicin; group B received gentamicin and, 24 h later, epoetin alpha; group C received drug diluent only. In order to analyze the renoprotective activity of erythropoietin, the expression of c-kit and β-catenin was evaluated by immunohistochemistry.

RESULTS

Generally, the zebrafish renal tubule regenerates 15 days after an injury. Conversely, 7 days after gentamicin administration, animals treated with erythropoietin (group B) showed a better renal injury repair as documented by: increased expression of β-catenin, less degenerated tubules, greater number of centers of regeneration, positivity for c-kit only in immature-looking tubules and lymphohematopoietic cells.

CONCLUSION

The expression of c-kit and β-catenin suggests that erythropoietin may exert a role in regeneration reducing the extent of tubular damage from the outset after gentamicin administration.

Lipid disorders in patients with renal failure: Role in cardiovascular events and progression of chronic kidney disease

The spectrum of lipid disorders in chronic kidney disease (CKD) is usually characterized by high triglycerides and reduced high dense lipoprotein (HDL), associated with normal or slightly reduced low dense lipoprotein (LDL)-cholesterol. This dyslipidemia is associated with an increased risk for atherosclerotic cardiovascular disease. Keys for the cardiovascular risk reduction in these patients are lowering the number and modifying the composition of the cholesterol-carrying atherogenic lipoprotein particles. Statins have an important role in primary prevention of cardiovascular events and mortality in non-hemodialyzed CKD patients. The benefits in terms of progression of renal failure are contradictory. Patient education regarding dietary regimen should be part of the CKD clinical management.

3 Tesla-Diffusion Tensor Imaging in Autosomal Dominant Polycystic Kidney Disease: The Nephrologist's Point of View

BACKGROUND/AIMS

CT, MRI and ultrasound are currently used for screening and follow-up of individuals affected by autosomal dominant polycystic kidney disease (ADPKD). Dynamic contrast-enhanced MRI studies renal perfusion after gadolinium administration, with possible side effects, such as nephrogenic systemic fibrosis. The aim of our study was to evaluate the clinical application of 3 Tesla (3T)-diffusion tensor image (DTI) in ADPKD patients, correlating its parameters, such as fractional anisotropy (FA), and apparent diffusion coefficient (ADC) with kidney function tests.

METHODS

Eight ADPKD patients and 6 healthy volunteers (HS) were enrolled. FA and ADC mean values were calculated. And correlations between DTI-parameters, creatinine and estimated glomerular filtration rate (eGFR) were evaluated.

RESULTS

Parenchymal FA was significantly lower in ADPKD than HS (FA: 0.17 ± 0.03 vs. 0.22 ± 0.01; p = 0.02), whereas parenchymal ADC was higher in patients than controls (2.48 (×10-3) ± 0.16 vs. 2.28 (×10-3) ± 0.09), but a statistically significant difference was not achieved (p = 0.27). Direct correlations were revealed between eGFR and FA (r = 0.82; p = 0.0003), whereas an inverse correlation was found with creatinine (r = -0.77; p = 0.001). Similarly, ADC closely correlated with creatinine (r = 0.79; p = 0.0006) and eGFR (r = -0.620; p = 0.01).

CONCLUSION

3T-DTI is a promising radiological tool that could be used by nephrologists to evaluate ADPKD patients, highlighting early micro-structure alterations, without side effects and contrast agent administration.

Renal biopsy: Still a landmark for the nephrologist

Renal biopsy was performed for the first time more than one century ago, but its clinical use was routinely introduced in the 1950s. It is still an essential tool for diagnosis and choice of treatment of several primary or secondary kidney diseases. Moreover, it may help to know the expected time of end stage renal disease. The indications are represented by nephritic and/or nephrotic syndrome and rapidly progressive acute renal failure of unknown origin. Nowadays, it is performed mainly by nephrologists and radiologists using a 14-18 gauges needle with automated spring-loaded biopsy device, under real-time ultrasound guidance. Bleeding is the major primary complication that in rare cases may lead to retroperitoneal haemorrhage and need for surgical intervention and/or death. For this reason, careful evaluation of risks and benefits must be taken into account, and all procedures to minimize the risk of complications must be observed. After biopsy, an observation time of 12-24 h is necessary, whilst a prolonged observation may be needed rarely. In some cases it could be safer to use different techniques to reduce the risk of complications, such as laparoscopic or transjugular renal biopsy in patients with coagulopathy or alternative approaches in obese patients. Despite progress in medicine over the years with the introduction of more advanced molecular biology techniques, renal biopsy is still an irreplaceable tool for nephrologists.

Sclerostin levels in uremic patients: a link between bone and vascular disease

Sclerostin is a marker of low-turnover bone disease in end stage renal disease patients. The aim of this study was to evaluate serum sclerostin in uremic patients, analyzing its behavior during a single hemodialysis session. Twenty-one adult patients on intermittent hemodialysis treatment were enrolled. Acetate Free Bio-filtration (AFB) was the technique employed. Uremic patients were characterized by higher levels of serum sclerostin when compared with values observed in healthy subjects. Sclerostin assessed in pre-dialysis samples was 1.4 ± 1.02 ng/mL, whereas, in post dialysis samples, a reduction of sclerostin values was observed (0.8 ± 0.6 ng/mL; p: 0.008). Sclerostin correlated with parameters of dialysis adequacy, such as creatinine levels and Kt/V values, and it was significantly associated with atherosclerotic disease. Receiver operating characteristics analysis revealed a good diagnostic profile in identifying atherosclerotic disease. Sclerostin, a full dialyzable substance during AFB dialysis, is closely associated with atherosclerotic disease. Its reduction obtained through AFB could represent a defensive mechanism, improving vascular disease and renal osteodystrophy.

Kidney-lung connections in acute and chronic diseases: current perspectives

Lung and kidney functions are intimately related in both health and disease. The regulation of acid-base equilibrium, modification of partial pressure of carbon dioxide and bicarbonate concentration, and the control of blood pressure and fluid homeostasis all closely depend on renal and pulmonary activities. These interactions begin in fetal age and are often responsible for the genesis and progression of diseases. In gestational age, urine is a fundamental component of the amniotic fluid, acting on pulmonary maturation and growth. Moreover, in the first trimester of pregnancy, kidney is the main source of proline, contributing to collagen synthesis and lung parenchyma maturation. Pathologically speaking, the kidneys could become damaged by mediators of inflammation or immuno-mediated factors related to a primary lung pathology or, on the contrary, it could be the renal disease that determines a consecutive pulmonary damage. Furthermore, non immunological mechanisms are frequently involved in renal and pulmonary diseases, as observed in chronic pathologies such as sleep apnea syndrome, pulmonary hypertension, progressive renal disease and hemodialysis. Kidney damage has also been related to mechanical ventilation. The aim of this review is to describe pulmonary-renal interactions and their related pathologies, underscoring the need for a close collaboration between intensivists, pneumologists and nephrologists.

Delayed graft function and chronic allograft nephropathy: diagnostic and prognostic role of neutrophil gelatinase-associated lipocalin

CONTEXT

Available markers are not reliable parameters to early detect kidney injury in transplanted patients.

OBJECTIVE

Examine neutrophil gelatinase associated lipocalin (NGAL) in early detection of delayed graft function (DGF) and as a long-term predictor of graft outcome.

PATIENTS AND METHODS

NGAL was evaluated in 124 transplanted patients.

RESULTS

Urinary NGAL levels were associated to a 10% (HR: 1.10; 95% CI: 1.04-1.25; p < 0.001) and 15% (HR: 1.15; 95% CI: 1.09-1.26; p < 0.001) increased risk of DGF and allograft nephropathy progression, respectively.

CONCLUSION

NGAL reflects the entity of renal impairment in transplanted patients, representing a biomarker and an independent risk factor for DGF and chronic allograft nephropathy progression.

Phosphate binders for the treatment of chronic kidney disease: role of iron oxyhydroxide

Chronic kidney disease-mineral bone disorder is frequent in patients with renal failure. It is characterized by abnormalities in mineral and bone metabolism with resulting hyperphosphatemia, low serum vitamin D, secondary hyperparathyroidism, altered bone morphology and strength, higher risk of bone fractures, and development of vascular or other soft tissue calcifications. Besides the recommendation to reduce phosphorus dietary intake, many drugs are currently available for the treatment of calcium/phosphate imbalance. Among them, phosphate binders represent a milestone. Calcium-based binders (calcium carbonate, calcium acetate) are effective in lowering serum phosphate, but their use has been associated with an increased risk of hypercalcemia and calcifications. Calcium-free binders (sevelamer hydrochloride, sevelamer carbonate, and lanthanum carbonate) are equally or slightly less effective than calcium-containing compounds. They would not induce an increase in calcium levels but may have relevant side effects, including gastrointestinal symptoms for sevelamer and risk of tissue accumulation for lanthanum. Accordingly, new phosphate binders are under investigation and some of them have already been approved. A promising option is sucroferric oxyhydroxide (Velphoro(®), PA21), an iron-based phosphate binder consisting of a mixture of polynuclear iron(III)-oxyhydroxide, sucrose, and starches. The present review is focused on pharmacology, mode of action, and pharmacokinetics of sucroferric oxyhydroxide, with a discussion on comparative efficacy, safety, and tolerability studies of this drug in chronic kidney disease and patient perspectives such as quality of life, satisfaction, and acceptability. Sucroferric oxyhydroxide has proven to be as effective as sevelamer in reducing phosphatemia with a similar safety profile and lower pill burden. Experimental and clinical studies have documented a minimal percentage of iron absorption without inducing toxicity. In conclusion, the overall benefit-risk balance of sucroferric oxyhydroxide is deemed to be positive, and this new drug may therefore represent a good alternative to traditional phosphate binders for the treatment of hyperphosphatemia in dialysis patients.

The concept of the urine test and specific reaction of the urine in various diseases according to Enrico Cauchi - member of the medical council of Malta (1933)

The Study of urine from the outset has always aroused the interest of scientists and physicians all over the world, from ancient Greeks and Romans to Hindus , Hulcos in Mexico, Australian native etc. The urine in such case was considered not only as a waste product but also as a therapeutic product. In the late XIX century scientific knowledge had already identified the function of substances that favor the increase of urinary output, and physicians over the centuries have always tried to analyze urine in various ways. In Cauchis work in 1933 all chemistry and pathophysiological knowledge of the time was condensed. Cauchi signed the preface as Member of the medical council of Malta. He was a medical doctor of the early20thcentury, He wrote about the physiopathology of urine ranging from chemical and physical behavior, to the analysis of sediments and the special reactions of the urine in various pathologies. In particular Cauchi emphasizes the main diseases of the time combines the behavior of the reaction of urine as a diagnostic and prognostic instrument, stressing the importance of the urine test and describing the method used for analysis at the time. The analyses of the text in the issue seems to belong to archaic medicine, and it is difficult to think today, that what was presented as very up-to-date- science at that time, took place only 80 years ago. Reading the full original text with today experience we are led to consider the increasing importance that scientific community gave in the past, and still gives to urine test.

Thalassaemia major and infectious risk: High Mobility Group Box-1 represents a novel diagnostic and prognostic biomarker

High mobility group box -1 (HMGB1) represents a common causal agent for various types of diseases, including infective pathologies. This study aimed to investigate the role of HMGB1 in β-thalassemia major (TM) by evaluating its diagnostic and prognostic role. Fifty-one TM patients and 30 healthy subjects (HS) were enrolled. Receiver operating characteristics (ROC) analysis was employed to calculate the area under the curve (AUC) for HMGB1 to determine the best cut-off values capable of identifying infectious episodes. Adjusted risk estimates for infective events were calculated using univariate followed by multivariate Cox proportional hazard regression analysis. Serum HMGB1 levels were higher in TM patients than in HS (14·6 ± 8·7 vs. 2·08 ± 0·9 ng/ml, P < 0·0001). Patients who underwent splenectomy were characterized by lower levels of HMGB1, when compared with patients with an intact spleen (10·2 ± 8 vs. 19·1 ± 7 ng/ml, P = 0·004). ROC analyses revealed an AUC for serum HMGB1 of 0·801, with a sensitivity and specificity of 92·3% and 68·2% to detect an infectious episode. Low HMGB1 levels predicted high risk of infective events (HR: 0·81; P = 0·006). HMGB1 represents a prognostic marker for TM patients and a predictive factor for infectious events.

Sevalamer Hydrochloride, Sevelamer Carbonate and Lanthanum Carbonate: In Vitro and In Vivo Effects on Gastric Environment

Hyperphosphatemia is common in patients with chronic renal failure. Phosphate binders are associated with gastric intolerance, representing the main reason of drug discontinuation. The aim of this study was to compare the effects in vitro and in vivo of sevelamer hydrochloride (SH), sevelamer carbonate (SC) and lanthanum carbonate (LC) on gastric microenvironment. We have also evaluated the efficacy and tolerability of these drugs in hemodialysis (HD) patients. In vitro analysis: Dissolution time, ability to uptake phosphorus, changes in pH starting from gastric milieu and the amount of carbon dioxide (CO(2)) produced were the variables analyzed. In vivo analysis: 24-h esophago-gastric pH measurement was evaluated in 24 HD patients treated with phosphate binders and proton pump inhibitor (PPI). In vitro: LC dissolved over a longer time compared with SC (58 ± 2.4 vs. 12 ± 0.6 min; P < 0.001) and SH (58 ± 2.4 vs. 10.3 ± 0.8 min; P < 0.001), determining the most alkaline pH. SC had the highest chelation power, binding 4.00 × 10(-9)  mol/L of phosphoric acid. CO2 volume released was increased in LC solution (53.2 ± 7.8) compared to SC (33.9 ± 6.2; P < 0.001) and SH (2.3 ± 1.8; P < 0.001). In vivo: gastric pH increased after administration of phosphate binder. The most alkaline pH was recorded in patients treated with SC. The alkalinization of the gastric environment was not prevented by PPI therapy. 424 episodes of esophageal reflux were registered, 74% of them were alkaline. The LC group was characterized by the highest number of episodes. Sevelamer carbonate had a greater capacity and rapidity to chelate phosphorus, with a mild tolerability, due to its low CO(2) production. Sevelamer HCl was the most tolerated chelator because it did not produce CO(2), while lanthanum carbonate was the least soluble.

HIGH-MOBILITY GROUP BOX 1 IN ALLERGIC AND NON ALLERGIC UPPER AIRWAY INFLAMMATION

High mobility group box 1, an evolutionary ancient protein conserved in the eukaryotic kingdom, exerts intra- and extra- cellular functions, orchestrating a homeostatic defensive response in challenged tissues. Its action associated with various inflammatory cells is essential for the occurrence, progression, and persistence of asthma, rhinitis, and nasal polyposis. The recent discovery of High mobility group box 1, as a critical mediator of inflammation, stimulated an increasing interest in the field of inflammation research, suggesting new therapies for atopic and non-atopic inflammatory processes.

Semaphorin 3A serum levels are influenced by haemodialysis: what clinical significance?

AIM

Semaphorin 3A urinary levels represent an early, predictive biomarker of acute kidney injury and positively correlate with albumin-to-creatinine ratio and serum creatinine in hypertensive patients with chronic kidney disease. Our purpose has been to evaluate semaphorin 3A serum levels in a cohort of haemodialysis (HD) patients, the influence of a single HD session on its concentrations, and the potential correlation with clinical and biochemical parameters.

METHODS

We enrolled 18 patients receiving HD with Acetate-Free Biofiltration technique and 16 healthy subjects as controls. Peripheral venous blood samples were obtained from patients at different intervals: start of dialysis (pre-HD), middle, and end of the treatment (post-HD). We also collected dialysate samples by the Quantiscan monitoring system (Hospal, Bologna, Italy).

RESULTS

Semaphorin 3A was significantly lower in HD patients at baseline compared to controls (median 19.50 (interquartile range 1.00-65.00) versus 97.50 (23.50-161.00) ng/mL, P = 0.0237). A statistically significant reduction was seen during a single HD session (from 19.50 (1.00-65.00) to 0.86 (0.82-4.21) ng/mL, P < 0.0001), with a reduction ratio of 65.92 ± 33.51%. The median concentration in dialysate was 54.00 (15.00-102.00) ng/mL. Pre-HD values were directly related to serum vitamin D (r = 0.872; P = 0.001) and inversely correlated with calcium levels (r = -0.426; P = 0.012) and calcium × phosphate product (r = -0.422; P = 0.0252).

CONCLUSION

Semaphorin 3A removal during HD may be clinically relevant due to its involvement in different aspects of cell physiology and in bone remodelling. Semaphorin 3A both inhibits osteoclastic bone reabsorption and increases osteoblastic new bone formation, thus playing a dual osteoprotective role.

Emerging markers of cachexia predict survival in cancer patients

BACKGROUND

Cachexia may occur in 40% of cancer patients, representing the major cause of death in more than 20% of them. The aim of this study was to investigate the role of leptin, ghrelin and obestatin as diagnostic and predictive markers of cachexia in oncologic patients. Their impact on patient survival was also evaluated.

METHODS

140 adults with different cancer diagnoses were recruited. Thirty healthy volunteers served as control. Serum ghrelin, obestatin and leptin were tested at baseline and after a follow-up period of 18 months.

RESULTS

Ghrelin levels were significantly higher in cancer patients than in healthy subjects (573.31 ± 130 vs 320.20 ± 66.48 ng/ml, p < 0.0001), while obestatin (17.42 ± 7.12 vs 24.89 ± 5.54 ng/ml, p < 0.0001) and leptin (38.4 ± 21.2 vs 76.28 ± 17.48 ng/ml, p < 0.0001) values were lower. At ROC analyses the diagnostic profile of ghrelin (AUC 0.962; sensitivity 83%; specificity 98%), obestatin (AUC 0.798; sensitivity 74.5%; specificity 81.5%) and leptin (AUC 0.828; sensitivity 79%; specificity 73%) was superior to that of albumin (AUC 0.547; sensitivity 63%, specificity 69.4%) for detecting cachexia among cancer patients. On Cox multivariate analyses ghrelin (HR 1.02; 95% CI 1.01 - 1.03; p < 0.0001) and leptin (HR 0.94; 95% CI 0.92 - 0.96; p < 0.0001) were significant predictors of death even after correction for other known risk factors such as presence of metastasis and chronic kidney disease.

CONCLUSION

Ghrelin and leptin are promising biomarkers to diagnose cachexia and to predict survival in cancer patients.

Acute pulmonary exacerbation and lung function decline in patients with cystic fibrosis: high-mobility group box 1 (HMGB1) between inflammation and infection

Airway inflammation plays a central role in cystic fibrosis (CF) lung disease, and biomarkers of inflammation, such as high-mobility group box 1 (HMGB1) could be used to monitor disease activity. The main aim of this study was to confirm the role of HMGB1 in CF patients, correlating its serum and sputum levels with pulmonary function and inflammation. Serum and sputum HMGB1 were evaluated in a cohort of 31 CF patients and 30 non-smoking healthy subjects (HS group). Acute pulmonary exacerbation events and lung function decline have been also evaluated during a 3-year follow-up period. Serum HMGB1 levels were significantly higher than those measured in HS, such as sputum HMGB1. Kaplan-Meier survival curves revealed that patients with high HMGB1 values experienced a significantly faster evolution to decline of lung function. A multiple Cox regression analysis assessed that an increase of serum HMGB1 was associated with 5% increased risk of pulmonary disease progression, whereas elevated sputum HMGB1 was related to a 10% increased risk of lung function decline. In CF patients, HMGB1 closely reflects the entity of pulmonary impairment and represents a strong and independent risk marker for progression of lung function decline.

Endocrinopathies, metabolic disorders, and iron overload in major and intermedia thalassemia: serum ferritin as diagnostic and predictive marker associated with liver and cardiac T2* MRI assessment

INTRODUCTION

Endocrinopathies and metabolic disorders-characterized β thalassemic (βT) patients and the prevention and treatment of these comorbidities are important targets to be achieved. The aim of the study was to analyze the diagnostic and prognostic role of ferritin for endocrinopathies and metabolic disorders in βT patients. The ability of iron chelators to treat iron overload and to prevent or reverse metabolic disorders and endocrinopathies was also evaluated.

PATIENTS AND METHODS

Seventy-two βT patients were treated with different chelation strategies during the study. Receiver operating characteristics analysis was employed to calculate the area under the curve for serum ferritin to find the best cutoff values capable of identifying endocrine dysfunction in thalassemic patients. Kaplan-Meier curves were generated to assess the incidence of endocrinopathy. Adjusted risk estimates for endocrinopathy were calculated using univariate followed by multivariate Cox proportional hazard regression analysis.

RESULTS

High ferritin levels were observed in patients with hypothyroidism [1500 (872.5-2336.5) μg/L], hypogonadism [878 (334-2010) μg/L], and in patients with hypoparathyroidism or osteoporosis [834 (367-1857) μg/L]. A strict correlation between ferritin and T2* magnetic resonance imaging of heart (r = -0.64; P:0.0006) and liver (r = -0.40; P:0.03) values was observed. Patients with ferritin values above 1800 μg/L experienced a significantly faster evolution to hypothyroidism [log-rank (χ(2) ):7.7; P = 0.005], hypogonadism [log-rank (χ(2) ):10.7; P = 0.001], and multiple endocrinopathies [log-rank (χ(2) ):5.72; P = 0.02]. Ferritin predicted high risk of endocrine dysfunction independently of confounding factors (HR:1.23; P < 0.0001). The intensification of chelation therapy led to an amelioration of hypothyroidism.

CONCLUSIONS

Ferritin represents a prognostic marker for βT patients and a predictive factor for progression to endocrine dysfunctions. Intensive chelation therapy allows the reversibility of hypothyroidism.

Does erythropoietin always win?

The synthesis of recombinant human erythropoietin has marked a turning point in the treatment of anaemia secondary to chronic kidney disease. However, the potentially fatal cardio- and cerebrovascular complications of the intake of high-doses of ESAs (erythropoiesis-stimulating agents), such as those observed in athletes who resort to doping, reason out the ever-prevalent debate concerning the balance between the risks and benefits of ESA administration for therapeutic purposes. Hence, there is still a discussion as to what values haemoglobin should ideally be maintained at. Additional concerns arise in cancer patients due to the ability of erythropoietin to act as an angiogenic and, in general, as a cell growth factor, because this might favour the progression of neoplastic disease. We summarized the prominent points of the latest guidelines on the management of anaemia in nephropathic patients, also identifying the possible risks that may result from the tendency to aim at too low haemoglobin levels.