Portuguese Journal of Nephrology & Hypertension

A new millennium for women and kidney disease

Fighting glomerular hegemony: giving the renal tubule the credits it deserves

Hemodialysis arteriovenous fistula outcomes in elderly patients: a single-centre cohort

The cohort of older age pre-dialysis patients is growing steadily. However, Fistula First may not always be the best strategy due to poorer arteriovenous fistula outcomes in this population. This retrospective cohort study included data from 157 predialysis patients who underwent fistula placement in our centre. Their mean age was 68.1±12.4 years. 64.3% were male and 53.5% were diabetic. The median nephrology follow-up was 3.04 years (IQR: 0.95-5.17). Two groups were created based on patients age at fistula placement: <75 years (n=102) and ≥75 years (n=55). Further analysis is shown, for the younger group vs. the elderly group, respectively. The groups differed only in smoking history (29.4% versus 12.7%, p=0.019) and in hypertensive (3.9% versus 23.6%, p<0.001) and autosomal dominant polycystic kidney disease aetiologies (13.7% versus 0%, p=0.004). Mean estimated glomerular filtration rate at referral for fistula placement was 16.1±4.3 vs. 14.5±4.0ml/min/1.73m2 (p=0.026). Primary fistula failure occurred in 17.6% vs. 32.7%, p=0.032 (RR 1.85 [1.05-3.26]): in 4.9% vs. 5.5% due to thrombosis (p=0.881), in 12.7% vs. 25.5% due to maturation failure (p=0.044; RR 2.0 [1.01-3,94]) and in 2.0% vs. 1.8% due to complications which lead to surgical closure (p=1). During the follow-up period, 52.0% vs. 43.6% patients started hemodialysis (p=0.32). Of these patients, 79.2% vs. 50.0% started hemodialysis with a functioning fistula, p=0.009 (RR 0.63 [0.41-0.96]) while the remaining needed a central venous catheter (RR 2.41 [1.24-4.67]). In multivariate analysis, age ≥75 years and the number of previous fistulawere predictors of failure: OR 3.70 (CI: 1.37-9.98) and 11.65 (CI: 5.04-26.93), respectively. In conclusion, elderly patients had more primary fistula failure. The need of central venous catheter due to non-functioning fistula at time of dialysis initiation was higher in the elderly. Older age (≥ 75 years) and the number of previously placed fistulas seem to predict fistula failure

Tell me your weight before kidney transplant and I’ll tell you your risks

Introduction and aims: Overweight is highly prevalent in kidney transplant candidates and it has been associated with multiple post-transplant complications. In this study, we evaluated the occurrence of complications in the first year after kidney transplantation according to the pre-transplant Body Mass Index of the recipients. Material and methods: Retrospective analysis of patients with age >18 years who underwent first kidney transplantation, between 1st January 2012 and 31st December 2015 in our Center. We analyzed 144 patients, with Body Mass Index: <25 kg/m2 in 48 patients (group 1), 25-30 Kg/m2 in 41 patients (group 2) and ≥30 kg/m2 in 55 patients (group 3), maximum of 38.3 Kg/m2. Complications in the first year after the transplant (infection, delayed graft function, surgical/urological complications, cardiovascular disease, hematologic disorders, diabetes, acute rejection, neoplasm, glomerular filtration rate and mortality). were compared between the groups. Statistical analysis was conducted using R Statistical Software version 3.2.5. Results: We found differences between the groups in recipient age and pre-transplant diabetes mellitus and in donor gender. The total number of post-transplant complications was higher in the first 3 months, and >50% occurred in group 3. Infections, mostly urinary, were the main complications during the whole study period, particularly in group 3 (p<0.05). Surgical/urological complications (p<0.01) were also significantly higher in this group during the first 3 months. There was a negative correlation between Body Mass Index and Glomerular Filtration Rate at the time of discharge (regression estimate -0.83 adjusted for age, p=0.018), but not at 1 year post-transplant (regression estimate 0.02, p=0.960). This study highlights the importance of controlling weight before kidney transplantation as obesity is a risk factor for early posttransplant complications, particularly urinary infections and surgical/urological complications

Color doppler ultrasound assessment of juxta-anastomotic stenosis in radiocephalic arteriovenous fistulas: endovascular or surgical approach

Background: Juxta-anastomotic stenosis (JAS) is a common complication of radiocephalic arteriovenous fistulas. There is diverging data as to the best therapeutic approach being angioplasty or surgery. Pre-operative color Doppler ultrasound (CDU) is accurately used for initial assessment of the vascular access and follow-up monitoring. The aim of this study was to evaluate immediate and long-term results of endovascular versus open surgical intervention of juxta-anastomotic venous stenosis of forearm radiocephalic fistulas and to test if CDU assessment can be used to ameliorate preoperative strategy and long-term outcomes. Methods: This retrospective cohort study included 63 patients with JAS radiocephalic fistulas referred to vascular access consultation. CDU was used to assess preoperative morphological, functional and hemodynamic stenosis characteristics and according to specific criteria, allocate patients to endovascular or surgical treatment. Results: Surgical revision was proposed in 68.2% of patients (N=43), namely the creation of a new proximal fistula (N=41), while angiographic evaluation was proposed in 31.7% of the cases (N=20). Mean follow-up time was 720±524 days with a maximum follow-up of 4.6 years. In the surgical group, primary patency was 92% and 84% at 6 and 12 months respectively, while in the endovascular group, it was 76% and 47% (p=0.013). There was no significant difference in the assisted primary patency between the interventional groups at 12 months: 94% in the endovascular vs. 93% in the surgical group (p=0.542). Conclusion: Pre-operative CDU assessment of JAS and specific allocation criteria with an access-centered approach choosing the best option in each fistula allowed the correct diagnosis of the lesion, improved the global results of the treatment and optimized the financial resources by reserving PTA for selected cases where surgery could be more difficult with higher risk of access loss

Urine volume and residual renal function decline among patients on peritoneal dialysis - searching for associations

Introduction: Preservation of urine volume and residual renal function in patients on peritoneal dialysis (PD) is a major concern. Some factors have been associated with better prognosis, such as the use of biocompatible solutions, furosemide, or renin-angiotensin-aldosterone system blockers. However, results from previous studies have not been consistent. We thus aimed to study the relation between baseline characteristics of incident patients on PD, treatment characteristics, glomerular filtration rate (GFR) and urine volume (UV) variation. Subjects and methods: We retrospectively analyzed incident patients on PD (first option) in our unit in terms of variation of UV and GFR after 24 months of follow-up. We studied the association between GFR and UV decline and baseline characteristics (age, gender, diabetes mellitus or hypertension diagnoses, body mass index, CKD etiology, and use of beta-blockers, diuretics, renin-angiotensin-aldosterone system blockers) as well as PD treatment characteristics (PD modality, use of icodextrin, dialysis days per week, presence of peritonitis, membrane characteristics such as Ca125 peritoneal level and dialysate-to-plasma creatinine), dwell hours per day and glucose load) using Spearman correlation for numerical variables and differences of means for binomial variables. Results: We analyzed 25 patients. Urine volume decreased on average 0.59 mL after 24 months and glomerular filtration rate declined from 7.9 to 7.03 mL/min/1.73m2. All patients used biocompatible solutions. We did not find any association between glucose-exposure, use of diuretics or renin-angiotensin-aldosterone system blockers and urine volume or glomerular filtration rate decline. There was a significant relation between diuresis and GFR changes. Discussion: Our patients present a slower decline of residual renal function than that described in the literature. Strategies to preserve diuresis, including the use of biocompatible solutions, may explain these results.

Clinical implications of anti-HLA antibodies testing in kidney transplantation

Alloantibodies against donor human leukocyte antigens (HLA), termed as donor-specific antibodies (DSA), are one of the most important factors for both early and late kidney allograft dysfunction. In the past, these antibodies were mainly detected through cell-based crossmatch tests. Recently, new techniques such as solid phase immunoassays (SPI) have revealed these antibodies in patient sera with a high degree of detail, previously unimaginable. They have allowed us to accurately determine recipients allosensitization status, improve pre-transplant risk assessment with a potential donor and post-transplant alloimmune monitoring. However, the high sensitivity of these new assays has also created areas of uncertainty about their clinical impact. In the pre-transplant setting, the presence of preformed DSA has been associated with an increased risk of antibody-mediated rejection (AMR) and subsequent allograft loss. Nevertheless, several studies have shown that not all DSA are deleterious. Hence, understanding the clinical correlations of DSA characteristics, namely strength, HLA class, complement-fixing ability or IgG subclasses, is paramount for an adequate stratification of the immunological risk at transplant. Furthermore, given that the number of allosensitized patients on waiting lists is increasing, the added information from these new SPI is essential to improve their chance of being transplanted with an admissible immunological risk. After transplantation, the appearance of de novo DSA (dnDSA) has also been associated with a deleterious effect on kidney allograft survival. Moreover, it has been acknowledged that a majority of late allograft failures are caused by alloantibody-driven injury. The current challenges, in this setting, are determining cost-effective DSA screening protocols and understanding which patients could benefit from specific interventions. Furthermore, although therapeutic strategies to control antibody-induced damage remain limited, the longitudinal surveillance of dnDSA emergence and the clinical correlations of their characteristics will play a crucial role in the improvement of late kidney allograft survival.

Diagnosis of monoclonal gammopathy of renal significance

Monoclonal gammopathies are a heterogeneous group of disorders characterized by clonal proliferation of immunoglobulin produced by B-lymphocytes or plasma cell clone. The term monoclonal gammopathy of renal significance (MGRS) was introduced to distinguish monoclonal gammopathies that result in the development of kidney disease from those that are benign. Screening for monoclonal immunoglobulin and an appropriate hematologic workup are fundamental and sometimes a difficult challenge, with therapeutic and prognostic implications. Kidney biopsy is essential to determine the exact nature of the lesion and to evaluate the severity of renal disease. In this review we discuss the clinical and pathologic features of MGRS, highlighting the most diagnostic difficulties and current therapeutic options

Off-target effects and adverse outcomes of fibroblast growth factor 23 in chronic kidney disease

Chronic kidney disease (CKD) patients have a high risk of death, especially cardiovascular death. High fibroblast growth factor 23 (FGF23) levels are independently associated with higher risk of death and cardiovascular events in these patients, as well as with a greater risk of severe inflammation. Chronic inflammation contributes to the progression of renal disease, the pathogenesis of cardiovascular disease, and mortality. Moreover, clinically, the CKD-associated defect in the immune system also has a relevant impact on morbidity and mortality. Recent findings showing that excess FGF23 may affect non-traditional, off-target organs independently of αKlotho give support to the potential clinical relevance of the adverse effects of FGF23 in CKD, and even in non-CKD patients. In this review, we provide an update on FGF23 and briefly discuss its future in clinical practice

C3 glomerulonephritis disguised as Postinfectious GN

It is not uncommon for atypical cases of postinfectious glomerulonephritis (PIGN) to be confused with C3 glomerulonephritis (C3GN) due to considerable overlap of their clinical and histopathological features. We present a case of a 42-year-old man who was hospitalized with hematuria and worsening renal function after an episode of pharyngitis. Following a complete negative serological examination, the indolent clinical course associated with the findings of diffuse proliferative and exudative glomerulonephritis with dominant C3 staining and subendothelial and mesangial electron-dense deposits on the kidney biopsy were fundamental for the final diagnosis. The genetic test identified two mutations involved in the alternative complement pathway. Steroids and mycophenolate mofetil were initiated with improved renal function. This case alerts us that the presence of atypical clinical or histological features of apparent PIGN should raise suspicion of C3 glomerulopathy (C3G) because only a correct diagnosis will allow adequate treatment and a better long-term prognosis

C3 glomerulopathy: a rare kidney histological presentation of multiple myeloma

C3 Glomerulopathy is a rare disease caused by abnormal control of the alternative complement pathway, resulting in a predominant glomerular C3 deposition. Its association with multiple myeloma has been reported in recent literature. We present a case of a 66-year-old women, referred for a nephrology consultation with a stage 4 chronic kidney disease, microhematuria, leukocyturia, sub-nephrotic range proteinuria (1.3 g/24hours), albumin 3.7 g/dl and dyslipidemia. She had been previously studied in a Hematology consultation for a normocytic anemia and an IgG Kappa monoclonal gammopathy, with 16% of plasma cells in bone marrow aspiration, but no hypercalcemia or lytic bone lesions. Autoimmune tests (ANCA, ANA, Anti-dsDNA antibody), C3 and C4 were negative. Eight months later, the patient complained of hypertension and edema, and presented a mild decrease in serum C3 (0.86 g/L [0.90-1.80]) and progressive nephrotic proteinuria (from 4.5 to 6.1 g/24h), with hypoalbuminemia. A kidney biopsy was performed, and we found mild chronic non-specific glomerular and tubule-interstitial findings, on light microscopy, and mesangial C3 deposits (+++), without immunoglobulin deposits, on immunofluorescence. Immunofluorescence with protease-digested paraffin sections was also negative. Genetic study found no complement gene mutation. She was treated with prednisone 1mg/Kg/day, with a favorable clinical and laboratorial response, but whether this treatment is enough it is still being pondered between nephrologists and hematologists

Prostate involvement in granulomatosis with polyangiitis: response to rituximab treatment

Granulomatosis with polyangiitis is an autoimmune vasculitic condition strongly associated with anti-neutrophil cytoplasm antibodies. It classically affects the respiratory tract and the kidney, but it can manifest in a multitude of other organs. Urological involvement is uncommon and can be difficult to diagnose. We present two cases of GPA with prostatic involvement, with distinct clinical manifestations. Both cases responded well to treatment with rituximab

Coexistence of pheochromocytoma and renal artery stenosis in a pediatric patient with hypertension

Pheochromocytoma and renal artery stenosis are surgically treatable causes of hypertension. Although rare, the coexistence of pheochromocytoma and renal artery stenosis has been described in case reports. Common pathophysiological mechanisms other than extrinsic compression may be involved in this association, such as catecholamine-induced vasospasm. The early recognition of the association of pheochromocytoma with renal artery stenosis is essential for appropriate treatment planning. We present the case of a previously healthy tenyear-old boy who presented with hypertensive encephalopathy, tachycardia and diaphoresis. Hypertension was found to be secondary to a catecholamine-producing tumor associated with coexisting renal artery stenosis. Hypertension resolved a few months after successful pheochromocytoma excision, without renal artery revascularization