Portuguese Journal of Nephrology & Hypertension

Infective endocarditis in renal transplant recipients: one center’s experience

Background: Infective endocarditis (IE) is rarely described among renal transplant recipients. Methods: We conducted a retrospective study to identify all cases of IE in our renal transplant unit between 1992 and 2012 to elucidate IEs clinical features and outcomes. Modified Duke criteria were applied to confirm diagnosis and patient evolution was evaluated. Results: Between 1992 and 2012, our renal transplant unit performed 1065 renal transplants. Seven episodes of IE were identified in six patients. Median age at presentation was 59 years and most cases occurred in males (71.4%). Blood cultures were negative in 42.9% of patients. Gram positive coccus were the most frequent etiologic agents. There were no fungal endocarditis. Aortic valve was involved in all patients. Three patients underwent cardiac surgery. Mortality at 30 days and 2 years were 16.7%. Conclusion: Infective endocarditis in renal transplant patients remains a rare disease. The diagnosis is challenging considering nonspecific presentation and the high proportion of negative blood cultures.

Management of end-stage vascular access failure patients: a retrospective analysis

Vascular access (VA) dysfunction is an important cause of morbidity and mortality in the hemodialysis (HD) population. Regardless of the increasing prevalence of HD patients with complex VA, the definitions of VA failure (VAF) or end-stage VA failure (ES-VAF) are still being discussed and there is no current guideline that provides recommendation for solving the problem of complicated vascular access. The aim of this study was to review the management approach for resuming the continuity of RRT in patients with problematic vascular accesses, based on our center experience. In a retrospective analysis of 30 patients with VAF or ES-VAF over an 11-year period, twenty patients were transferred to peritoneal dialysis (PD), seven patients remained in HD after the placement of a non-standard site VA and three patients had a renal transplant (RT). In half of these patients, the initial therapeutic option eventually failed, leading to multiple reinterventions and RRT changes. Mean survival was 47 ± 32.7 months. Ten patients died, the majority within the first year of VAF diagnosis. The management of end-stage renal disease patients includes vessel preservation, the combination of RRTs to extend life expectancy and VA care to maintain long-term function. Our approach stratifies patients according to exhausted VA sites in order to plan for RT, transition to PD or alternative VA site management. This allows for better management of the VAF patient and highlights the need to individualize patient care.

Are peritoneal protein losses related to peritonitis risk in patients on peritoneal dialysis?

Background: Peritoneal protein losses (PPL) are an inevitable process in peritoneal dialysis (PD). Few studies have supported a positive correlation between PPL and infections or general morbidity and mortality. The aim of this study was to investigate whether PPL was a risk factor of peritonitis. Methods: We retrospectively studied all incident PD patients in a PD single unit during the previous 10 years. We recorded baseline PPL (bPPL) and relevant analytic and clinical data. Patients were distributed into one of 2 bPPL groups (group 1: ≤5.89g/day and group 2: >5.89g/day) to compare their peritonitis risk. Results: 104 Patients were included, with a median follow-up of 29 months. Higher bPPL patients were more likely to have peritonitis (group 1: 43%, group 2: 72%, p<0.01). After adjustment for covariates, bPPL remained an independent predictor of peritonitis (p=0.01). The time to first peritonitis was shorter in the group with higher bPPL (p=0.01) although after adjustment for other covariates no significant associations were found. In the Poisson regression, more elevated bPPL were associated with higher peritonitis rates after adjustment for other independent variables (p=0.02). Conclusion: In this retrospective study, higher bPPL were able to independently predict risk of peritonitis, reflecting its impact on the morbidity of PD patients. Patients with higher bPPL levels presented shorter peritonitis-free time to first peritonitis episode and higher probability of more peritonitis episodes over time.

Renal denervation for resistant hypertension: a glimpse of hope on the horizon?

Renal denervation by a minimally-invasive catheter-based procedure has been extensively studied over the last decade as a powerful tool for treating resistant hypertension, a high-risk condition the clinical management of which remains a major challenge. Initial promising results from uncontrolled pilot studies set the stage for a plethora of larger randomized, sham-controlled trials which, however, had unexpectedly negative findings. Despite this transient setback, positive although weak results from the latest Symplicity Spyral studies and a series of new procedural approaches beyond radiofrequency have rekindled enthusiasm for this procedure. New studies are warranted to fully elucidate, once and for all, the limits and potential of and indications for renal denervation in the treatment of resistant hypertension

Heart failure in chronic kidney disease patients: a summary of non-traditional risk factors

Introduction: Patients with chronic kidney disease are at higher risk of heart failure than the general population. Such increased risk is multifactorial, being partly due to a higher prevalence of traditional cardiovascular risk factors in this population and to the existence of non-traditional/chronic kidney disease-specific risk factors. Non-traditional risk factors should prompt special considerations in diagnosis and management of heart failure in these patients. Material and methods: We searched PubMed and Medline during 2017 and 2018, for the terms Chronic kidney disease and Heart failure. Other search terms were included according to the content found. We mainly focused on publications concerning chronic kidney disease-specific risk factors for heart failure and its pathophysiology. Further publications regarding management of heart failure in chronic kidney disease patients were sought. Results and discussion: Heart failure is an important cardiovascular complication in chronic kidney disease. Specific risk factors for heart failure, which are not often found in the general population, include, among others, mineral bone disease, uremic toxins, neuro-hormonal activation, inflammation, oxidative stress, anemia, malnutrition, albuminuria and hyperhomocysteinemia. Management of heart failure in this group of patients is challenging and patients are often undertreated. Conclusion: Research into non-traditional risk factors for heart failure in chronic kidney disease patients is lacking and its pathophysiology is not properly understood. Such understanding is vital to provide proper care, as in the general population. We also question whether some of these specific risk factors could also play a role in heart failure among the general population.

Congenital kidney and urinary tract anomalies: a review for nephrologists

Kidney and urinary tract development disorder are two of the most prevalent congenital malformations and the main cause of chronic kidney disease in pediatric age patients. As such, it is very important that the nephrologist understands these pathologies to improve transition and ensure a good continuity between pediatric and adult nephrological care. The purpose of this article is to present a brief review of congenital anomalies of the kidney and urinary tract (CAKUT). Kidney malformations are classified according to macroscopic and microscopic anatomic features, and are the result of the following abnormal renal developmental processes: malformations of the renal parenchyma, abnormalities of the embryonic migration of the kidneys and abnormalities of the developing urinary collecting system.

Urinary schistosomiasis: a forgotten and challenging Diagnosis

Urinary schistosomiasis is a parasitic disease with a high global burden, especially in poor communities. Although rare in industrialized countries, schistosomiasis is expected to be seen with increasing frequency and poses a diagnostic challenge. We describe three cases of children presenting with gross hematuria caused by Schistosoma haematobium with the purpose of bringing awareness to this uncommon and treatable cause of hematuria in developed countries. All three patients were African male adolescents and presented with terminal hematuria. The long incubation period (as long as 2 years in one of our patients), the differential diagnosis with urinary tract infection prompting prescription of inadequate broad-spectrum antibiotics and the low sensitivity of urine standard examination for the presence of infecting schistosomes were the main challenges in these three patients. To increase the detection rate, urine samples can be taken after a mid-day session of physical exercise and a cystoscopy with tissue biopsies may be required if there are solid masses in the bladder wall on ultrasound. The presented cases aim to show the importance of interdisciplinary collaboration between clinical, surgical specialties and pathologists.

Persistent knee pain in a patient with systemic lupus erythematosus

The evaluation of chronic kidney disease-mineral and bone disorder (CKD-MBD) is based on clinical, laboratory, radiology and histological data. However, these data may not always be entirely concordant, leading to significant doubt over therapeutic options. We present a challenging CKD-MBD case report. A 26-year-old female patient presented a past medical history of systemic erythematosus lupus and end-stage renal disease. She had been on hemodialysis and transited to peritoneal dialysis due to multiple vascular access failure. Medication included calcium carbonate, cholecalciferol, calcitriol, and cinacalcet but adherence to medication was low, leading to PTH values often higher than 1000 pg/mL. She presented right knee pain for two months. Radiology exams revealed iliac, femoral and tibial osteolytic lesions. A bone biopsy was performed, detecting disperse multinucleated giant cells compatible with brown tumors. However, poor therapeutic adherence did not allow persistent control of hyperparathyroidism, with PTH levels often >1000 pg/mL, and parathyroidectomy was considered. A tetracycline-labeled bone biopsy showed high turnover bone disease in the past, evolving to low-bone turnover/adynamic bone disease. This led to the decision of optimizing medical treatment and avoiding parathyroidectomy. Significant clinical improvement was observed with knee pain resolution and transient reduction of PTH to stage 5 chronic kidney disease reference levels. Four years later an imagiological re-evaluation was performed, revealing bilateral tibial, femoral and iliac enlarged bone lesions, and bone scintigraphy confirmed hypermetabolic lesions. She was then submitted to subtotal parathyroidectomy and subsequently to deceased-donor renal transplantation. This case report shows the importance of closely following CKD-MBD patients, even in asymptomatic patients. Treatment decision should not solely include bone histology criteria. Repeated evaluations at different time points of clinical, laboratory, and radiology data might be particularly useful

Membranous nephropathy successfully treated with a Ponticelli regimen in a patient with HIV: do not assume that a well-known secondary cause is the real cause!

Idiopathic membranous nephropathy with high-risk criteria for renal disease progression is considered an indication for immunosuppressive treatment. HIV infection has been associated with membranous nephropathy in a minority of patients. A 44-year-old female diagnosed with HIV infection 11 years ago was referred for a nephrology consultation due to nephrotic syndrome. She presented with peripheral edema for 2 months and normal blood pressure. Serum creatinine was 0.74 mg/dL, total cholesterol 490 mg/dL, albumin 2.0 g/dL; urinary examination revealed leukoerythrocyturia and 24h proteinuria was 4.5g. Renal ultrasound showed normal-sized kidneys with preserved corticomedullary differentiation. Kidney biopsy showed thickening of the glomerular basal membrane and staining with Masson trichrome showed sub-epithelial humps. Immunofluorescence was negative except for IgA (+), C3c (+) and IgG (+). A diagnosis of membranous nephropathy was made. Secondary causes, such as neoplasic, infectious and autoimmune, were ruled out. Despite 6 months of conservative measures, proteinuria increased to 11 g/day. Since HIV viral load had been undetectable for several years, along with a CD4+ T cell count persistently above 400/mm3, a modified Ponticelli regimen was started: 3 pulses of methylprednisolone (1g/day), followed by 60 mg of prednisolone/day at months 1, 3 and 5, and cyclophosphamide 200mg/day at months 2, 4 and 6. At the end of the treatment, there was a partial response with proteinuria 3.94 g/day, albumin 3.2 g/dL, and creatinine 0.8 mg/dL. At 48 months of follow-up, the patient is asymptomatic, with creatinine 0.84 mg/dL and proteinuria 0.97 g/day. Conclusion: Membranous nephropathy should be considered in the differential diagnosis in patients with HIV infection complicated by nephrotic syndrome even in the absence of other coinfections and comorbidities typically associated with membranous nephropathy. In patients with sustained negative viral loads and at high risk of progression to end-stage renal disease, in whom secondary causes have been excluded, immunosuppressive therapy might be considered.

Therapeutic plasma exchange in the treatment of severe hypertriglyceridemia: a case report

Severe hypertriglyceridemia is defined as a serum triglyceride level >885mg/dl. It is an uncommon condition associated with serious complications, mainly acute pancreatitis. Treatment includes lifestyle changes, medical therapy and, more recently, extracorporeal apheresis techniques. Herein, we report a case of severe hypertriglyceridemia managed with therapeutic plasma exchange. Our patient presented with severe upper abdominal pain. Bloodwork showed extremely severe hypertriglyceridemia (14871mg/dl) and hypercholesterolemia (1536mg/dl) with only slight elevation of amylase and lipase and no echographic signs of acute pancreatitis. Two sessions of therapeutic plasma exchange were performed, with a mean 3L of plasma treated per session. The triglyceride levels dropped to 2325mg/dl after the first session and to 1207mg/dl after the second. Medical therapy was started, and the patient was discharged a week later. After 36 months of follow-up she remains stable, with triglyceride levels 427mg/dl. In this case therapeutic plasma exchange was an effective and well tolerated treatment for severe hypertriglyceridemia

Streamlining diagnosis with urinary sediment microscopy: a case of deteriorating renal function in a kidney transplant patient

Hyperkalemia: this time, not the usual suspect