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Poor vitamin D status is common in patients with impaired renal function and represents one main component of the complex scenario of chronic kidney disease–mineral and bone disorder (CKD–MBD). Therapeutic and dietary efforts to limit the consequences of uremia-associated vitamin D deficiency are a current hot topic for researchers and clinicians in the nephrology area. Evidence indicates that the low levels of vitamin D in patients with CKD stage above 4 (GFR < 15 mL/min) have a multifactorial origin, mainly related to uremic malnutrition, namely impaired gastrointestinal absorption, dietary restrictions (low-protein and low-phosphate diets), and proteinuria. This condition is further worsened by the compromised response of CKD patients to high-dose cholecalciferol supplementation due to the defective activation of renal hydroxylation of vitamin D. Currently, the literature lacks large and interventional studies on the so-called non-calcemic activities of vitamin D and, above all, the modulation of renal and cardiovascular functions and immune response. Here, we review the current state of the art of the benefits of supplementation with native vitamin D in various clinical settings of nephrological interest: CKD, dialysis, and renal transplant, with a special focus on the effects on bone homeostasis and cardiovascular outcomes.

The sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a relatively new class of antidiabetic drugs that, in addition to emerging as an effective hypoglycemic treatment, have been shown to improve, in several trials, both renal and cardiovascular outcomes. In consideration of the renal site of action and the associated osmotic diuresis, a negative sodium balance has been postulated during SGLT2i administration. Although it is presumable that sodium and water depletion may contribute to some positive actions of SGLT2i, evidence is far from being conclusive and the real physiologic effects of SGLT2i on sodium remain largely unknown. Indeed, no study has yet investigated how SGLT2i change sodium balance in the long term and especially the pathways through which the natriuretic effect is expressed. Furthermore, recently, several experimental studies have identified different pathways, not directly linked to tubular sodium handling, which could contribute to the renal and cardiovascular benefits associated with SGLT2i. These compounds may also modulate urinary chloride, potassium, magnesium, phosphate, and calcium excretion. Some changes in electrolyte homeostasis are transient, whereas others may persist, suggesting that the administration of SGLT2i may affect mineral and electrolyte balances in exposed subjects. This paper will review the evidence of SGLT2i action on sodium transporters, their off-target effects and their potential role on kidney protection as well as their influence on electrolytes and mineral homeostasis.

Chronic kidney disease (CKD) exacerbating vascular disease poses a major challenge to nephrology. Surgically placed vascular fistulas, as an aid to hemodialysis prior to kidney transplant, have extended many lives, while post-surgical restenosis closure of the fistula by smooth muscle cells affects many lives. When post-surgical restenosis is developed, palliative measures are almost always surgical: there are no effective drug treatments. In this study, we offer a testable hypothesis that effects of CKD on widely distributed vascular diseases and the phenomenon of fistula restenosis are both driven by the pathologic creation of non-dividing smooth muscle cells via asymmetric division of exponentially increasing metakaryotic stem cells. In slow growing atherosclerotic plaques, the Benditts demonstrated clonality of smooth muscle cells that we posit originate in a single mutated metakaryotic stem cell of fetal/juvenile vasculogenesis. In the fast process of fistula restenosis, we posit quiescent metakaryotic stem cells "on call" for wound healing among which are rare stem cells that have lost the ability to cease division. These hypotheses and suggestions for specific research paths toward development of effective drug therapies are built on (a) our shared discoveries of the role of metakaryotic stem cells in organogenesis, carcinogenesis, and atherosclerotic plaque formation and (b) the recent finding that metakaryotic cancer stem cells are constitutively resistant to radio- and chemotherapies yet sensitive to killing by a wide range of existing drugs. We propose to test these hypotheses in discarded fistulas and stem cells derived therefrom, and, if supported, to test drug-eluting devices to block fistula restenosis.

Background/Aims: Vitamin D deficiency is associated with endothelial dysfunction in uremic patients, possibly by the impairment in the number and function of endothelial progenitor cells (EPCs). In 89 hemodialysis patients, we investigated the factors associated with the number of circulating EPCs (CD34+/CD133+/KDR+ and CD34+/CD133–/KDR+ cells), the presence of VDR and the determinants of VDR expression on EPCs, in particular in calcitriol therapy. Methods: EPC counts, percentages of VDR-positive EPCs and VDR expression were assessed by flow cytometry. Cells isolated from a subgroup of patients were cultured to analyze colony-forming units, specific markers expression and a capillary-like structure formation. Results/Conclusions: Our study demonstrates the presence of VDR on EPCs. In our dialysis patients, the parameters studied on both CD34+/CD133+/KDR+ and CD34+/CD133–/KDR+ cells, in particular VDR expression, seem to be influenced by uremia-related factors, including anemia, inflammation, diabetes, 25(OH)D serum levels and calcitriol therapy.

BACKGROUND.: Cardiovascular disease (CVD) represents the main cause of morbidity and mortality after renal transplantation. In view of the modern paradigm of atherosclerosis as an inflammatory disease, this study investigated the impact of inflammatory cytokine polymorphisms on posttransplant CVD. METHODS.: The association between cytokine polymorphisms and CVD was assessed in a case-control study to identify the differences in genotype distributions between kidney allografts with or without posttransplant CVD. To validate our results in two independent groups, we divided a cohort of 798 renal transplant recipients according to geographic area: an evaluation cohort of 478 patients from Emilia-Romagna and a validation cohort of 320 patients from the rest of Italy. Tumor necrosis factor (TNF)-alpha, transforming growth factor-beta1, interleukin (IL)-10, IL-6, interferon-gamma, and IL-8 polymorphisms were analyzed, and thereafter, the cytokine production genotype was assigned. RESULTS.: In the evaluation cohort, the patients in the CVD and no-CVD groups differed significantly in TNF-alpha and IL-10 genotype frequencies. Using multivariate analyses to test the association with CVD, the TNF-alpha high-producer genotype was associated with a significantly increased cardiovascular risk (odds ratio [OR]=4.41, 95% confidence interval (CI)=2.53-7.67). Conversely, the IL-10 high-producer genotype resulted protective against CVD (OR=0.07, 95% CI=0.02-0.29). These findings were confirmed in the validation cohort where the carriers of the TNF-alpha high-producer genotype proved to be at 2.45-fold increased cardiovascular risk (OR=2.45, 95% CI=1.29-4.63), whereas the IL-10 high-producer genotype was associated with a 0.08-fold reduced risk (OR=0.08, 95% CI=0.02-0.36). CONCLUSIONS.: This work suggests a prognostic value of TNF-alpha and IL-10 genotypes, which might represent cardiovascular risk markers in renal transplant.

Background: Hemodialysis (HD) patients have a greatly increased risk of cardiovascular morbidity and mortality. For this reason, attempts are often made to normalize hyperhomocysteinemia. This randomized prospective study sought to determine which risk factors are predictors of mortality and whether high doses of folates or 5-methyltetrahydrofolate (5-MTHF) could improve hyperhomocysteinemia and survival in HD patients. Methods: 341 patients were divided into two groups: group A was treated with 50 mg i.v. 5-MTHF, and group B was treated with 5 mg/day oral folic acid. Both groups received i.v. vitamin B(6) and B(12). By dividing patients into C-reactive protein (CRP) quartiles, group A had the highest survival for CRP

Chronic kidney disease-mineral and bone disorder (CKD-MBD) is common in kidney transplant recipients (KTRs), where secondary hyperparathyroidism (HPTH) and post-transplantation bone disease (PTBD) are potential effectors of both graft and vascular aging. Reduced 25(OH)D levels are highly prevalent in KTRs. Experimental and clinical evidence support the direct involvement of deranged vitamin D metabolism in CKD-MBD among KTRs. This review analyzes the pathophysiology of vitamin D derangement in KTRs and its fall out on patient and graft outcome, highlighting the roles of both nutritional and active vitamin D compounds to treat PTBD, cardiovascular disease (CVD) and graft dysfunction. Fibroblast growth factor-23-parathyroid hormone (PTH)-vitamin D axis, immunosuppressive therapy and previous bone status have been associated with PTBD. Although several studies reported reduced PTH levels in KTRs receiving nutritional vitamin D, its effects on bone mineral density (BMD) remain controversial. Active vitamin D reduced PTH levels and increased BMD after transplantation, but paricalcitol treatment was not accompanied by benefits on osteopenia. Vitamin D is considered protective against CVD due to the widespread pleiotropic effects, but data among KTRs remain scanty. Although vitamin deficiency is associated with lower glomerular filtration rate (GFR) and faster estimated GFR decline and data on the anti-proteinuric effects of vitamin D receptor activation (VDRA) in KTRs sound encouraging, reports on related improvement on graft survival are still lacking. Clinical data support the efficacy of VDRA against HPTH and show promising evidence of VDRA's effect in counteracting post-transplant proteinuria. New insights are mandatory to establish if the improvement of surrogate outcomes will translate into better patient and graft outcome.

The oto-renal axis describes the relationship between hearing loss and chronic nephropathy. Several clinical studies have investigated the incidence of hypoacusia in patients affected by chronic renal failure, but the etiopathogenic mechanism is not fully understood. In this context, there is a general agreement that hypoacusia is usually neurosensorial and the cochlea is the main site of lesion. Inner ear and kidney present an interesting similarity in terms of structure and function. In particular, the presence of pericytes and podocytes in inner ear and in glomeruli, respectively, evidence common characteristics of microcirculation. Defects in microcirculation in the inner ear mainly cause an electrolytic imbalance with the consequent impairment of endocochlear potential and sensorial transduction. In kidney, microvessels and podocytes contribute to glomerular stability and function. Microcirculation dysfunction often occurs during the inflammatory status, frequently reported both in chronic nephropathy and in cardiovascular disease. Clinical studies aimed to describe the hypoacusia in nephropathy patients are summarized. Then, in order to speculate the etiopathogenic mechanism of hearing loss in chronic nephropathy, we report the similarities between pericytes and podocytes in inner ear and glomeruli microcirculation in terms of structure and function. Finally, we propose a model in which inflammation plays an important role in oto-renal dysfunction. Our model proposes the inflammation, as an etiopathogenic mechanism of hypoacusia in chronic nephropathy and the defective cross-talk between pericytes/podocytes and vascular endothelium, as the initial event of the degenerative process.

Background: The effects of vitamin D receptor (VDR) and osteocalcin (OC) expression as well as VDR agonist (VDRA) therapy on circulating endothelial progenitor cells (EPCs) has not been elucidated yet. Methods: We therefore analyzed EPCs in 30 healthy controls and 82 patients undergoing dialysis (no VDRA therapy: 28; oral calcitriol: 30, and intravenous paricalcitol, PCTA: 24). The percentage of EPCs (CD34+/CD133-/KDR+/CD45-) expressing VDR or OC, and VDR and OC expression defined by mean fluorescence intensity (MFI) were analyzed using flow cytometry. The in vitro effect of VDRAs was evaluated in EPCs isolated from each patient group. Results: The percentage of VDR+ EPCs correlated positively with VDRA therapy and 25(OH)D, and negatively with diabetes, C-reactive protein, hemoglobin and osteopontin. VDR-MFI correlated positively with VDRA therapy, parathyroid hormone (PTH) and 25(OH)D, and negatively with diabetes and osteopontin. The percentage of OC+ EPCs correlated positively with the calcium score, PTH and phosphate, and negatively with 25(OH)D. OC-MFI correlated positively with calcium score, PTH, phosphate and hemoglobin, and negatively with albumin, 25(OH)D and osteopontin. Cell cultures from patients without VDRA therapy had the highest levels of calcium deposition and OC expression, which both significantly decreased following in vitro VDRA administration: in particular extracellular calcium deposition was only reduced by adding PCTA. Conclusions: Our data suggest that 25(OH)D serum levels and VDRA therapy influence VDR and OC expression on circulating EPCs. Since OC expression may contribute to vascular calcification, we hypothesize a putative protective role of VDRA therapy.

Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides are characterized by blood vessel inflammation resulting in organ dysfunction or in the patient’s death. The peak of incidence was observed in patients over 75 years of age. We describe an unusual ANCA vasculitis presentation in a 90-year old patient admitted to the emergency room for severe dyspnea, oliguria and a recent onset cutaneous purple rush. Plain chest radiography disclosed pulmonary edema and diffuse bilateral reticulonodular infiltrates. Creatinine was 7.3 mg/dl, azotemia 202 mg/dl, hemoglobin 6.8 g/dl. CPAP (continuous positive airway pressure), furosemide 20 ml/h, nitroglycerin 8γ/kg/min, blood transfusions and i.v. methylprednisolone 60 mg/day were administered. On day 1 a femoral venous catheter was placed and hemodialysis (HD) treatment started for acute renal failure. The patient underwent 13 HD sessions without heparin (EVAL dialyzer). On day 7 renal function had still not recovered and a new plain chest radiogram was unchanged. Proteinase 3(PR3) ANCA were 81 IU/ml (ELISA), C-reactive protein (CRP) was 18 mg/dl, C3 42 mg/dl, C4 5 mg/dl. A high resolution computed tomography considering that the 53% of cases were managed with glucocorticoids alone. Nonetheless, Walsh et al’s metanalysis showed that patients who received a course of glucocorticoid therapy for more than 12 months suffered fewer relapses of ANCA vasculitis. In patients older than 80 years any immunosuppressive therapy is associated with a significantly lower risk of ESRD and death, but the rate of infections is higher than in younger patients. In our patient the CY dose related to the body surface area was reduced to 200 mg in view of age, risk of infection and renal failure, but glucocorticoid therapy was maintained. During the 2 year follow-up no infections were reported, the Birmingham vasculitis score was lower than 10 and reached the 50% reduction of the initial disease activity score recommended. A good outcome was obtained and it seems to be related both to CY and to the long-term maintenance therapy with glucocorticoids.

Thrombosis-related malfunction of tunneled-cuffed central venous catheters (TCC) for hemodialysis (HD) currently leads to a high rate of untimely catheter removal. Urokinase (UK) therapy is used for TCC thrombosis/malfunction, but no consensus exists on the adequate dose to obtain thrombolysis. We selected 72 HD patients with TCC and a mean age and HD vintage of 74 years (range 65-87) and 36 months (range 12-61), respectively. All patients received warfarin therapy with a target international normalized ratio (INR) of 1.8-2.5. Coagulative assessment of the patients was obtained by checking the INR, activated partial thromboplastin time, fibrinogen, hemoglobin, and platelets. Sixty-five thrombotic events were recorded during a 3-year follow-up (median 0.3 events/patient/year). The patients selected were randomized into two groups according to a different thrombolytic therapy. Group A comprised 29 thrombotic events in 32 patients who received UK 25,000 IU in both arterial and venous lines of the TCC for each event. UK restored an adequate blood flow rate (BFR) for HD (≥ 250 mL/min) in 4/29 events (13.7%), whereas addition of 50,000 IU to both arterial and venous lines was required in 25/29 events (86.3%). For the same 25 events in the second HD session, a further 75,000 IU of UK was needed for each TCC lumen. Group B comprised 36 thrombotic events in 40 patients who received 100 000 IU of UK in the arterial and venous lumen of the TCC for each event. An adequate BFR was recovered in all events. In 12/36 events (33.3%), 100,000 IU UK for both lumens were needed in the second HD. In conclusion, group B patients obtained (i) a significantly better TCC patency than group A patients; (ii) a low UK administration in the following HD sessions; and (iii) no bleeding complications.

Purpose The aim of this study was to ascertain the role of different vascular access types in inflammatory status, monocyte activation, and senescence in hemodialysis patients. Methods We recruited 126 hemodialysis patients, including 51 with arterovenous fistula (AVF), 32 with arterovenous graft (AVG), and 43 with tunneled cuffed catheters (TCC). In dialysis patients enrolled in the study and in a control group of 40 healthy subjects, we measured the serum levels of albumin, CRP, IL-6, and TNF-α, the expression of CD14, CD44, and CD32 on monocyte surface, and the percentage of monocytes exhibiting a senescent phenotype (CD14+CD32+). Results The patients with AVG compared to those with AVF had: a) higher levels of CRP and TNF-α; b) increased expression of CD14 and CD32 on monocyte surface, with no difference in CD44 expression; c) no difference in the percentage of CD14+CD32+ monocytes. In the comparison of TCC vs. AVF group, we observed significantly higher values of: a) circulating inflammatory markers (CRP, IL-6, TNF-α); b) monocyte surface expression of cellular activation markers (CD14, CD44 and CD32); c) relative count of CD14+CD32+ monocytes. When comparing TCC vs. AVG group, we found: a) no difference in serum levels of CRP, IL-6, and TNF-α; b) no difference in the expression of CD14, CD44, and CD32 on monocyte surface; c) no difference in the percentage of CD14+CD32+ monocytes. Conclusions These results suggest that the use of AVG and TCC for dialysis vascular access is associated with serological and cellular indexes of inflammatory reaction, also resulting in a higher degree of monocyte activation and senescence.

BACKGROUND: This randomized crossover study investigated the effects of unfractioned heparin (UFH) and low-molecular-weight heparin (LMWH) on intra- and post-dialytic blood levels of osteoprotegerin (OPG), receptor activator of nuclear factor kappa B ligand (RANKL) and inflammatory cytokines. METHODS: Forty patients on haemodialysis for at least 12 months were selected. UFH or LMWH was randomly assigned and maintained for 1 month, and then, in the following month, each patient was switched to the other form of heparin. In the mid-week session, we determined the changes in anti-Xa activity, OPG, RANKL, IL-1β, IL-6 and TNF-α values before heparin administration and after 15 min, 4, 8 and 24 h (T0, T1, T2, T3 and T4 respectively). Since these parameters at the various experimental times showed a non-normal distribution, log transformation was applied in order to run parametric ANOVA, with Bonferroni correction for multiple comparisons. RESULTS: The changes in anti-Xa activity over time were similar but not the same for the UFH and LMWH. A highly significant (P < 0.001) increase in anti-Xa activity was detected at T1, regardless of the type of heparin, as confirmed in the comparison of T0 vs T1 using one-way ANOVA. Moreover, with both heparins, significant differences were found in the comparisons of anti-Xa activity at T1 vs T2 (both P < 0.001) and at T2 vs T3 (P = 0.0003 with UFH; P < 0.001 with LMWH). Conversely, the difference in anti-Xa activity at T3 vs T4 was still significant with UFH (P = 0.0186) but not significant with LMWH (P = 0.728). When comparing anti-Xa activity at T4 vs T0, no significant differences were found either with UFH (P = 0.1996) or with LMWH (P = 0.7470), thus indicating that 24 h after heparin infusion, anti-Xa activity returned back to the pre-infusion values. When we analysed the changes in OPG levels over time, we found that the administration of heparin, regardless of the type, determined an increase in circulating OPG with a zenith at 15 min (T1), with a return back to the baseline levels within the 24th hour post-infusion. One-way ANOVA revealed significant differences in OPG blood levels at T0 vs T1 with both UFH (P = 0.0112) and LMWH (P = 0.0288), whereas no significant difference was observed in the comparisons of OPG levels at T1 vs T2, T2 vs T3, T3 vs T4 and T4 vs T0, either with UFH or with LMWH. The circulating levels of RANKL, IL-1β, IL-6 and TNF-α at the different intra- and post-dialytic times did not show significant variations following heparin administration, either with UFH or with LMWH. One-way ANOVA performed on the log-transformed values of RANKL, IL-1β, IL-6 and TNF-α at the various experimental times (T0 vs T1, T1 vs T2, T2 vs T2, T3 vs T4 and T4 vs T0) revealed no significant intra- and post-dialytic changes in their blood levels, thus confirming that heparin infusion did not affect their blood levels. CONCLUSIONS: These results suggest that heparin-regulated cyclic increases of OPG might play a role in the vascular pathology of haemodialysis patients.

Hemodiafiltration (HDF) is a dialysis technique characterized by the combination of diffusive and convective depuration. This allows the removal of both low and medium-high molecular weight toxins, keeping the intradialytic hemodynamic status of the patient more stable. Technical innovations in HDF technology aim to enhance the depurative efficacy of the treatment and reduce intradialytic hypotensive events and intolerance. Among these techniques, mixed HDF, middilution HDF and HFR Aequilibrium have particular innovative significance. Mixed HDF and mid-dilution HDF are clinically indicated to enhance the depurative efficacy of HDF and HFR Aequilibrium may serve to widen the depurative range in patients suffering from the malnutrition-inflammation complex syndrome and intradialytic hypotension or intolerance. Mixed HDF and mid-dilution HDF allow to improve the infusion volumes thanks to the intradialytic modulation of the pre/post-infusion ratio (mixed HDF) or the high-volume intradialyzer pre/postinfusion (mid-dilution HDF). HFR Aequilibrium is based on a) separation between convection (first chamber) and diffusion with body weight decrease (second chamber); b) infusion of endogenous ultrafiltrate purified by resin adsorption; c) use of dialysate sodium and ultrafiltration profiles automatically elaborated by a mathematical model incorporated in the software of the dialysis machine.

The aim of the study was to assess the factors potentially involved in coronary artery calcifications (CAC) in end-stage renal disease patients. 253 hemodialysis (HD) patients (92 females, 161 males), aged 62.5 ± 13.5, who had been on HD treatment for at least 6 months, were enrolled in a cross-sectional study. Calcium-phosphate product (Ca × P), body mass index (BMI), fetuin-A, osteoprotegerin (OPG), osteopontin, transforming growth factor-β1 (TGF-β1), fibroblast growth factor-23 (FGF-23) and matrix Gla protein (MGP) were considered. CAC was assessed using multislice spiral computed tomography and calcium score was quantified by means of the Agatston score. The median calcium score was 364 Agatston (range 0–7,336). CAC was detected in 228/253 patients (90.1%). Multivariate regression analysis, adjusted for age and for dialysis vintage, showed that TGF-β1, OPG and days with Ca × P >55 mg/dl are independent predictors of CAC, while MGP was shown to be a protective factor. Surprisingly, results showed that BMI was a protective factor too: the interpolation with cubic spline function revealed a significant reduction in calcium score in patients with a high BMI (>28). However, when diabetes was considered in the regression analysis, only OPG emerged as a predictor of a high CAC score. The interpolation with spline function continued to show a significant reduction in CAC score in nondiabetic and in diabetic patients with the highest BMI quartile. The protective effect of a high BMI on CAC might represent another example of inverse biology in dialysis patients but it needs to be further addressed in larger longitudinal studies.

The effect of high-flux hemodialysis membranes on patient survival has not been unequivocally determined. In this prospective, randomized clinical trial, we enrolled 738 incident hemodialysis patients, stratified them by serum albumin < or = 4 and >4 g/dl, and assigned them to either low-flux or high-flux membranes. We followed patients for 3 to 7.5 yr. Kaplan-Meier survival analysis showed no significant difference between high-flux and low-flux membranes, and a Cox proportional hazards model concurred. Patients with serum albumin < or = 4 g/dl had significantly higher survival rates in the high-flux group compared with the low-flux group (P = 0.032). In addition, a secondary analysis revealed that high-flux membranes may significantly improve survival of patients with diabetes. Among those with serum albumin < or = 4 g/dl, slightly different effects among patients with and without diabetes suggested a potential interaction between diabetes status and low serum albumin in the reduction of risk conferred by high-flux membranes. In summary, we did not detect a significant survival benefit with either high-flux or low-flux membranes in the population overall, but the use of high-flux membranes conferred a significant survival benefit among patients with serum albumin < or = 4 g/dl. The apparent survival benefit among patients who have diabetes and are treated with high-flux membranes requires confirmation given the post hoc nature of our analysis.

Cardiovascular disease is the leading cause of mortality and morbidity in renal transplant recipients as well as the leading cause of death with a functioning graft. The high cardiovascular risk is attributable to the prolonged exposure to multiple traditional and nontraditional risk factors in the pretransplant and posttransplant period. Particular attention must be paid to cardiovascular screening of candidates for kidney transplantation. After a transplant, treatment and prevention strategies should be focused on the modifiable risk factors including smoking, dietary habits, physical activity, weight control, hypertension, and dyslipidemia. Further studies on these factors are needed to better define the pharmacological approaches (hypotensive or hypolipemic drugs) and therapeutic targets. In view of the role of immunosuppressive therapy in the onset or worsening of several risk factors, it is important to tailor the treatment approach and dosage to the cardiovascular risk profile of the individual patient.

Kidney transplant patients show a significantly elevated incidence of gastrointestinal disorders. Protonic pump inhibitors (PPI) are considered to be the correct therapy in the treatment of peptic ulcers, as they have proven to be safe and efficient. The metabolization of the PPIs mainly occurs on a hepatic level; therefore, there is no need to change the therapy accordingly, as there is with the inhibitors of the histamine receptors (anti-H2). The PPIs currently available are omeprazole, pantoprazole, lansoprazole, esomeprazole, rabeprazole which present different pharmacokinetic characteristics and different metabolic routes which are responsible both for differences in terms of efficacy between the different molecules, and for the possible side-effects they may have. All the PPIs, apart from rabeprazole, are metabolized through an oxidization and sulphurization processes which involves the enzymatic system of the P450 cytochrome. The rabeprazole metabolism is different from the other molecules of the same category in that it only moderately involves the CYP450 (CYP3A4 and CYP2C19) from the moment its metabolization begins through nonenzymatic routes and 80% is involved in a thioether non enzymatic reduction mechanism. Consequently, rabeprazole represents: a) a potentially low pharmacological interaction with immunosuppressive drugs; b) a pharmacokinetic aspect much less subject to interindividual differences between one patient and another, due to genetically determined polymorphisms of the CYP2C19 and of the CYP3A4. Moreover, rabeprazole may be administered safely in standard doses with no need to change the dosage of the other pharmaceutical drugs taken simultaneously in nephropathic patients, patients undergoing dialysis and transplanted patients.

Background Chronic oral anticoagulation is currently used to avoid thrombosis and the malfunction of tunneled cuffed catheters (TCCs) for hemodialysis (HD). The aim of the study was to assess the efficacy of early warfarin administration, after TCC placement, in comparison to its administration after the first thrombosis or malfunction event of the TCC. Patients and methods One hundred and forty-four chronic dialysis patients, who underwent TCC placement between June 2001 and June 2005, were randomized into two groups: 81 patients, group A, started oral anticoagulation 12 hr after the TCC placement (target international normalized ratio (INR) 1.8–2.5), in association with ticlopidine 250 mg/die; 63 patients, group B, started warfarin after the first thrombosis/malfunction episode (target INR 1.8–2.5) in association with ticlopidine 250 mg/die. The efficacy of oral anticoagulation therapy in preventing TCC thrombotic complications was evaluated in a 12-month follow-up period, after TCC placement, in terms of: a) the number of patients with thrombotic-malfunction events; b) the number of thrombotic-malfunction events with urokinase infusion (events/patient/year); c) intradialytic blood flow rate (BFR, ml/min); d) negative blood pressure (BP) from the arterial line of the TCC (AP, mmHg); e) positive BP, in the extracorporeal circuit from the venous line (VP, mmHg); and f) bleeding complications. Results Ten patients (12%) in group A showed TCC thrombosis/malfunction vs. 33 patients (52%) in group B (pConclusions Early warfarin therapy allows a significant reduction in TCC thrombotic complications and an improvement in both arterial and venous fluxes in comparison with the same therapy administered after the first TCC thrombotic/malfunction event. This therapy did not induce any bleeding complications in the patients included in the study.

Paget's disease is the second most common bone disease after osteoporosis and causes an excessive bone turnover. Moreover, chronic kidney failure causes an impairment of bone mineral metabolism and electrolytes and PTH homeostasis. As far as we know, this is the first reported case of Paget's disease in a hemodialysis patient: the patient was also affected by secondary hyperparathyroidism and was successfully treated with clodronate, cinacalcet and paracalcitol. The safety and efficacy of this combined therapy was periodically revised in a 12-month follow-up considering the common markers of bone turnover as well as the dosage of OPG, RANKL, IL-6 and MCSF, involved in the pathophysiology of Paget's disease.

The demographic characteristics of hemodialysis (HD) patients increase the need for the tunneled cuffed permanent catheter (TCC) as a definitive vascular access (VA) for HD. The internal jugular vein is increasingly being used as a route for TCC or temporary catheter placement and can be associated with serious complications. Among them other authors have described arteriovenous fistula (AVF) creation between the common carotid artery and the right jugular vein. We describe a case of an AVF between the right internal jugular vein and the right internal mammary artery. The fistula was detected during the TCC placement in a patient who underwent several jugular and subclavian catheterisms for HD in her clinical history.

Purposeβ2-microglobulin amyloidosis (Aβ2M) is one of the main long-term complications of dialysis treatment. The incidence and the onset of Aβ2M has been related to membrane composition and/or dialysis technique, with non-homogeneous results. This study was carried out to detect: i) the incidence of bone cysts and CTS from Aβ2M; ii) the difference in Aβ2M onset between cellulosic and synthetic membranes; iii) other risk factors besides the membrane.Methods480 HD patients were selected between 1986 to 2005 and grouped according to the 4 types of membranes used (cellulose, synthetically modified cellulose, synthetic low-flux, synthetic high-flux). The patients were analyzed before and after 1995, when the reverse osmosis treatment for dialysis water was started at our center, and the incidence of Aβ2M was compared between the two periods. Routine plain radiography, computer tomography (CT) and nuclear magnetic resonance imaging (MRI) as well as electromyography were used to investigate the clinical symptoms.ResultsBone cysts occurred in 29.2% of patients before 1995 vs. 12.2% after 1995 (p2M.ConclusionsThe findings that the inflammatory status as well as low albumin and the residual GFR of the uremic patient are predictive of Aβ2M lesions suggests that Aβ2M has a multifactorial origin rather than being solely a membrane- or technique-related side effect.