Portuguese Journal of Nephrology & Hypertension

Are cranberry capsules effective and safe in preventing urinary tract infections in kidney transplantation? A randomized pilot clinical trial

Introduction: Kidney transplant (KT) recipients are highly susceptible to urinary tract infections (UTIs). Few data are available regarding the effects of cranberry products in KT recipients. Subjects and methods: This was a randomized double-blind study comparing daily treatment with a cranberry capsule versus a placebo capsule for 6 months. The study protocol was conducted in accordance with the Helsinki Declaration and was approved by the local ethics committee. The study group comprised women undergoing KT for over 1 year, and the exclusion criteria included simultaneous antibiotic UTI prophylaxis. The primary endpoint was UTI occurrence, and the secondary endpoints were the time to first UTI, hospitalization, antibiotic resistance, graft function, immunosuppressive dose changes, and side effects. Results: 55 KT women at a single centre were included as follows: 25 were randomized to the cranberry group, and 30 were assigned to the placebo group. During the study period, 16.4% of the participants presented with a UTI. A diagnosis of UTI within the previous year and KT duration, but not cranberry use (p=0.95) were independent predictors of UTI. Discussion: Cranberry capsules appear to be safe in KT women; however, no clinical efficacy of UTI prophylaxis was demonstrated in this well-designed but underpowered study. Further multicentric and longer trial should be performed to determine cranberry clinical efficacy

Renal involvement in rheumatoid arthritis: analysis of 53 renal biopsies

Background: Rheumatoid arthritis (RA) is a systemic inflammatory disorder characterized by joint inflammation, associated with autoantibody production. Renal involvement arises as a complication of treatment or can be related to the disease itself. Methods: 53 biopsies from patients with RA from 1989 to 2015 were reviewed. Histologic diagnosis, age, gender, duration of RA, drug therapy, renal function, proteinuria and haematuria were analyzed. Results: Amyloidosis was the most common renal histologic pattern (21 patients). Membranous Nephropathy (MN) was found in 12 patients, followed by Mesangial Proliferative Glomerulonephritis (n=4) and Focal and Segmental Glomerulosclerosis (n=4), IgA Nephropathy (n=3), Necrotizing Glomerulonephritis (n=3), Chronic Interstitial Nephritis (n=3), Endocapillary Proliferative Glomerulonephritis (n=2) and Minimal Change Disease (n=1). Amyloidosis correlated with long duration RA (14.9±6.66 years vs 8.84±6.37 years; p<0.001), presenting with nephrotic proteinuria in the majority of the cases (5.11±2.94 g/24h vs 3.52±2.71 g/24h p=0.03), which correlates with dominant glomerular amyloid deposition (7.0±2.28 g/24h vs 3.04±2.08 g/24h; p<0.001). In patients with MN, renal function was preserved (serum creatinine 0.83±0.21mg/dl vs 2.03±0.21mg/dl; p<0.001) and one third of the cases presented with haematoproteinuria. Disease modifying antirheumatic drugs (DMARDs) could be related with MN in six cases. Patients with Necrotizing Glomerulonephritis had a severe renal involvement, as did patients with Chronic Interstitial Nephritis. Conclusion: We found a wide spectrum of histological lesions that cannot be predicted with only clinical and laboratory findings. Thus, renal biopsy is essential to ensure correct diagnosis in RA patients who present with urinary abnormalities or deteriorated renal function

24-hour ambulatory blood pressure monitoring in chronic kidney disease and its influence on treatment

Introduction: Chronic kidney disease (CKD) is strongly associated with hypertension (HTN) and each can cause or aggravate the other. Misclassification of BP control is an important problem in hypertensive patients with CKD, making ambulatory blood pressure monitoring (ABPM) an important tool. The aim of our study was to review the influence of ABPM results in antihypertensive treatment and BP control in hypertensive CKD patients. Methods: Retrospective observational study; inclusion of hypertensive CKD patients stages 1 to 5 not on dialysis who performed ABPM in our department; data collected from clinical records and ABPM reports. Results: A total of 54 hypertensive CKD patients were reviewed. Reasons appointed for requesting ABPM included suspicion of resistant hypertension (40.7%), uncontrolled hypertension (29.6%), white coat hypertension (16.7%), hypotension (9.2%) and masked hypertension (3.8%). Interestingly, pre-ABPM clinical interpretation of BP control was found inadequate in 55.6% of patients. Conclusion: Misclassification of BP was a significant problem. As a result of these findings our department incorporated ABPM more routinely as recommended best practice

Survival of hemodialysis patients: A new reality?

Introduction: Survival rates of haemodialysis patients have increased worldwide over the last decade. The purposes of this study were to analyze the 10-year survival rate and to identify mortality risk factors in a Portuguese cohort. Subjects and Methods: Data was collected from 273 incident patients on facility haemodialysis treatments between 2005 and 2015. Sociodemographic data, medical history, clinical and analytic parameters were collected. A statistical analysis using Kaplan-Meier survival analysis and Cox regression were performed. Results: Median age was 71 ± 15.5 [22; 91] years, 56.8% were male. Fistula was the first access in 68.5%. Median survival rate was 89 ± 8.8 months. There were 93 deaths (34%). Of the 23 deaths occurring in the first year, 65% (n=15) were during the first 90 days. Mortality risk factors were residence in a nursing home (OR 2.8; p<0.05), coronary heart disease (OR 2.3; p<0.05), central venous catheter use (OR 2.1; p<0.05), history of hospitalizations in year prior to dialysis admission (OR 1.9; p<0.05) and advanced age (OR 1.5; p<0.05). Conclusions: Patients starting haemodialysis in the last decade are mainly elderly and have a prolonged lifespan, reflecting good levels of care. Functional status and dependence, extremes of age, central venous catheter use and high cardiovascular burden are related with greater mortality and should prompt consideration for a more conservative approach

Membranous nephropathy: A diagnostic and therapeutic challenge?

Membranous nephropathy (MN) is the most common cause of nephrotic syndrome in Caucasian adults aged over 60 years old. Approximately two thirds of cases of membranous nephropathy (MN) in adults are primary (idiopathic), and the remaining are secondary forms which have been attributed to a variety of agents or conditions. Recent advances in pathophysiology and the availability of new laboratory diagnostic methods reinforce the importance of differentiating idiopathic from secondary MN, given the repercussions on therapy. We present the case of a 71-year-old Caucasian male referred to Nephrology due to nephrotic syndrome. He had a history of gastric adenocarcinoma and of parathyroid cancer, but was considered cured. Investigation excluded immunologic disease, dysproteinaemia, chronic infection and active malignancy. Kidney biopsy was performed and confirmed MN. Histological characterization of IgG subtypes was not available, nor was biopsy study for the reactivity for PLA2 receptor. The patient was started on conservative treatment, but, after a one-year follow-up, presented persistent nephrotic proteinuria (5g/day) and renal function decline (serum creatinine of 1.6mg/dL). Serological determination of phospholipase A2 receptor antibody was positive, but with borderline titer. Considering his history of malignancy as well as kidney function deterioration, Rituximab was prescribed. At one year of follow-up the patient has proteinuria of 500 mg/day, stable renal function (serum creatinine of 1.2 mg/dL) and negative serum anti-PLA2 receptor antibody. Despite the recent availability of serological determination of phospholipase A2 receptor antibody and histological characterization of IgG subtypes, in this case they did not allow us to safely distinguish between idiopathic and secondary MN. Therefore the past medical history played a significant part in the therapeutic option. Recent studies suggest that Rituximab has similar results to non-specific immunosuppression, promoting remission in patients with severe and persistent MN, with less adverse effects, and thus can be considered as first-line therapy

Rare aetiology of obstructive kidney injury: Bilateral ureteral endometriosis

Endometriosis is highly prevalent in women at the reproductive age, ranging from 6-10%, though ureteral involvement is rare, only seen in 0.1% of the cases, but may lead to urinary tract obstruction with potential renal function loss. As endometriosis has a non-specific symptomology, diagnosis may be elusive, though it must be considered in order to prevent irreversible kidney injury and resultant morbidity. Here we present a 29-year-old Caucasian female with a past medical history of infertility and dysmenorrhoea who presented with a stage II acute kidney injury. On initial diagnostic approach, moderate bilateral ureterohydronephrosis was detected by ultrasound, assuming extrinsic compression, but no specific cause was recognizable. In order to diagnose the obstructions aetiology, Magnetic Resonance Imaging was used. This did not reveal an objective cause. Given the circumstances, workup ended in an explorative laparotomy, revealing a frozen pelvis due to endometriosis, confirmed histologically. Due to difficult ressecability, a conservative approach was taken through hormonal treatment and bilateral ureteral pigtail placement, given the necessity to salvage renal function and decrease disease burden.

Kidney transplantation in patients with preformed and exclusively anti-HLA-Cw donor specific antibody

We report a patient who had received a first kidney transplant and had preformed DSA anti-HLA-Cw, developing AMR C4d+ soon after transplant. Classically anti-HLA-Cw are considered less immunogenic and are not considered in many organ allocation systems or immunologic risk stratification algorithms, including in Portugal. However, data from literature confirms that their presence is as deleterious as DSA anti-HLA A/B/DR/DQ. Thus we should take HLA-C typing and respective antibody identification into account in sensitized patients, in order to access risk stratification and establish the need for correct induction or desensitization therapies

A challenging case of metastatic pulmonary calcification in a predialysis patient

A 45-year old white female with personal history of psychiatric disorder, severe hypokalaemia, medullary sponge kidney and chronic kidney disease, not on dialysis, was admitted to the Emergency Department after syncope. She was hypotensive and dehydrated. Arterial blood revealed metabolic alkalosis and no hypoxaemia. Laboratory tests revealed altered renal function, hypokalaemia, hyperparathyroidism, normal calcaemia and slightly elevated phosphorus. Exuberant alterations on chest radiography led to performing a chest computed tomography, which was suggestive of pulmonary metastatic calcification. She also had signs of calcification of the kidney. The main diagnoses were chronic kidney disease, medullary sponge kidney, hypokalaemia, dehydration, hypotension and pulmonary metastatic calcification. Tissue calcification can be metastatic or dystrophic. Pulmonary metastatic calcification is most commonly due to chronic kidney disease. Risk factors for tissue calcification in this patient were chronic kidney disease, hyperparathyroidism and elevated phospho-calcium product. The hyperparathyroidism was most probably secondary. Treatment aimed at correcting the water and electrolyte disturbances and admission to the psychiatric ward, with improvement of renal function, normalization of blood pressure and correction of the hypokalemia. To treat hyperparathyroidism, she was referred for parathyroidectomy

Lupus nephritis in a patient without evidence of systemic lupus erythematosus

Lupus nephritis is a common complication of systemic lupus erythematosus (SLE), usually developing early in the course of the disease. Almost all patients with lupus nephritis present with positive ANA and anti-dsDNA, Hypocomplementaemia and renal manifestations (haematuria, proteinuria and/or renal failure). However, in a small number of patients, the initial presentation is lupus nephritis with absent serology or clinical features of systemic lupus erythematosus