Scielo RSS <![CDATA[Portuguese Journal of Nephrology & Hypertension]]> vol. 26 num. 4 lang. pt <![CDATA[SciELO Logo]]> <![CDATA[<b>So long, and thanks for all the fish</b>: <b>Farewell from the Editor-in-Chief</b>]]> <![CDATA[<b>How to write and publish a scientific paper</b>]]> <![CDATA[<b>The role of sodium thiosulphate in the treatment of calciphylaxis</b>]]> Calciphylaxis is a rare but important cause of severe morbidity, which predominantly affects patients with advanced chronic kidney disease. It is associated with mortality in excess of 50% at one year, and this has changed little over the last 20 years despite advances in our understanding of its underlying pathophysiology, and evolving treatment strategies. Sodium thiosulphate has played a prominent role in the treatment of calciphylaxis since its first use in 2004, with reports of success both in improving the severe pain associated with the condition and in the healing of calciphylaxis lesions. The literature documenting the use of sodium thiosulphate in the treatment of calciphylaxis is reviewed here, along with a detailed summary of case reports and case series. While there is reason to be optimistic with regard to the efficacy of sodium thiosulphate within a multifaceted and multidisciplinary approach to treatment, there is clearly much yet to be learned <![CDATA[<b>Arteriovenous fistula surveillance</b>: <b>everyone’s responsibility</b>]]> The arteriovenous fistula, as opposed to arteriovenous grafts and central venous dialysis catheters, remains the dialysis access of choice for haemodialysis patients, due to its superior long -term patency, low incidence of stenosis, thrombosis and infection. The basic tenant of vascular access monitoring and surveillance is that stenosis develops over a variable amount of time in a majority of arteriovenous fistula, and if detected and corrected, inadequate dialysis can be prevented, maturation can be facilitated and thrombosis and access loss can be avoided. Large randomised controlled trials are lacking to clearly identify the ideal surveillance strategies and benefits of surveillance, often only supported by observational studies and small single-centre randomised controlled trials. Fistula thrombosis is often used as an endpoint in trials looking at the beneficial effects of surveillance, although this occurs relatively infrequently in native arteriovenous fistula, and therefore other markers are required to define a dysfunctional fistula. Cost-effective ways to improve outcomes in these types of vascular accesses involves formalised training of staff and other healthcare professionals to better identify dysfunctional fistulas by physical examination, with the addition of surveillance studies to support these findings and pre -emptive intervention when stenosis is found. The costs invested in establishing multidisciplinary programmes to facilitate the care of these patients will likely reduce long-term resource utilisation in a growing population of dialysis patients worldwide. In this review, we examine the physiology of a dysfunctional fistula and evaluate available studies in the surveillance of arteriovenous fistulas. In addition, the importance of creating secondary arteriovenous fistula and how healthcare systems need to invest in improving the care of haemodialysis vascular access will be outlined <![CDATA[<b>Results of endovascular procedures performed in dysfunctional arteriovenous accesses for haemodialysis</b>]]> Aim. Percutaneous endovascular procedures have become the standard treatment of arteriovenous fistulae and graft stenosis. This study evaluates the immediate results of angiographic procedures performed by nephrologists in patients with dysfunctional arteriovenous fistulae and arteriovenous graft stenosis. Patients and Methods. A retrospective analysis was performed on patients referred to the three Interventional Nephrology units between April and June, 2010. Clinical data were recorded. Results.A total of 113 procedures were performed: 59 in arteriovenous fistulae and 54 in arteriovenous graft stenosis. The main reasons for referral were increased venous pressure (21%), limb oedema (21%) and decreased intra-access flow (20%). Stenoses were detected in 85% of the procedures, mostly in patients with arteriovenous graft stenosis (56%). The main locations of stenosis were the outflow vein (cephalic/basilic) in arteriovenous fistulae (34%) and venous anastomosis in arteriovenous graft stenosis (48%). Angioplasty was performed in 73% of procedures where stenoses were detected. The immediate success rate was 91% for arteriovenous fistulae and 83% for arteriovenous graft stenosis. Partial success was obtained in 11% of angiographies. The complication rate was 7%. Conclusions.Physical examination findings led, in at least half the cases, to angiography referral and enabled the diagnosis and treatment of stenoses. For this reason, we advocate that this tool should be included in any vascular access monitoring programme. Our results support the safety of these procedures performed by nephrologists and their efficacy in the recovery of dysfunctional arteriovenous fistulae and arteriovenous graft stenosis <![CDATA[<b>C4d detection in renal allograft biopsies</b>: <b>immunohistochemistry vs. immunofluorescence</b>]]> Introduction. Peritubular capillary complement 4d staining is one of the criteria for the diagnosis of antibody-mediated rejection, and research into this is essential to kidney allograft evaluation. The immunofluorescence technique applied to frozen sections is the present gold-standard method for complement 4d staining and is used routinely in our laboratory. The immunohistochemistry technique applied to paraffin-embedded tissue may be used when no frozen tissue is available. Material and Methods.The aim of this study is to evaluate the sensitivity and specificity of immunohistochemistry compared with immunofluorescence. We describe the advantages and disadvantages of the immunohistochemistry vs. the immunofluorescence technique. For this purpose complement 4d staining was performed retrospectively by the two methods in indication biopsies (n=143) and graded using the Banff 07 classification. Results.There was total classification agreement between methods in 87.4% (125/143) of cases. However, immunohistochemistry staining caused more difficulties in interpretation, due to nonspecific staining in tubular cells and surrounding interstitium. All cases negative by immunofluorescence were also negative by immunohistochemistry. The biopsies were classified as positive in 44.7% (64/143) of cases performed byimmunofluorescence vs. 36.4% (52/143) performed by immunohistochemistry. Fewer biopsies were classified as positive diffuse in the immunohistochemistry group (25.1% vs. 31.4%) and more as positive focal (13.2% vs. 11.1%). More cases were classified as negative by immunohistochemistry (63.6% vs. 55.2%). Study by ROC curve showed immunohistochemistry has a specificity of 100% and a sensitivity of 81.2% in relation to immunofluorescence (AUC: 0.906; 95% confidence interval: 0.846-0.949; p=0.0001). Conclusions.The immunohistochemistry method presents an excellent specificity but lower sensitivity to C4d detection in allograft dysfunction. The evaluation is more difficult, requiring a more experienced observer than the immunofluorescence method. Based on these results, we conclude that the immunohistochemistry technique can safely be used when immunofluorescence is not available <![CDATA[<b>Hereditary hypophosphataemic rickets</b>: <b>experience from a paediatric nephrology unit</b>]]> Introduction. Rickets is a paediatric disease which should be suspected in children presenting with failure to thrive, motor developmental delay and orthopaedic abnormalities. Although rare, hereditary hypophosphataemic rickets is the most common form of heritable rickets. Patients and Methods. Retrospective observational study of all children with hypophosphataemic rickets observed at a paediatric nephrology unit of a tertiary paediatric hospital from 1982 to 2012, identified from the unit’s database. Data collected included demographics, risk factors, pre-existing medical conditions, clinical, radiographic and laboratory findings, treatment and morbidity. Results. Eleven children with hypophosphataemic rickets were studied, with a median age at admission of 4.25 years (0.66-10.92). Family history of rickets or orthopaedic abnormalities was found in five children. The first clinical manifestations were delayed/abnormal gait (7/11) and short stature (4/11). Skeletal deformities were present in all children: genus valgum or varum (11/11), thickening of the wrists (7/11), rachitic rosary (4/11), frontal skull bossing (2/11), Harrison’s groove (1/11). Dental abscess was reported in one child and joint pain in six. Laboratory findings included increased alkaline phosphatase (11/11), low serum phosphorus (11/11), normal serum calcium (10/11) and parathyroid hormone values (6/11) and low renal phosphorus reabsorption rate (9/10). None of the children had hypercalciuria. All children were treated with oral phosphorus and calcitriol (8/11 with lack of compliance). Seven children were discharged with a median age of 16.5 years; all had bone deformities, 5/7 had short stature and 1/7 had nephrocalcinosis. Discussion. Hypophosphataemic rickets is a rare disease with significant long-term morbidity. It should be suspected in children presenting with short stature, developmental delay and orthopaedic abnormalities. Increased alkaline phosphatase, low serum phosphorus with normal serum calcium and impaired renal tubular reabsorption of phosphate confirm the diagnosis. Early diagnosis and treatment are essential to minimise morbidity in children <![CDATA[<b>NSAID-related renal tubular dysfunction, an old new conundrum</b>]]> Aim.To report on ten patients who presented withacute kidney injury secondary to nonsteroidal anti-inflammatory drug administration. Renal tubular function test was consistent with acute tubular necrosis; however kidney biopsy in two of them revealed a normal ultrastructural finding, which along with the atypical clinical course refuted the suggested diagnosis. The constellation of features pointed to a clear reversible tubular dysfunction in the absence of tubular necrosis, highlighting a peculiar mechanism that might provoke acute kidney injury, involving the inhibition of the prostaglandin, the integral mediator of the tubular function, in addition to its role in maintaining the perfusion of the glomeruli and supporting the function of the macula densa. Conclusively a potential mechanism, apart from acute tubular necrosis and haemodynamic renal failure, was considered in this cohort of patients to explain nonsteroidal anti-inflammatory drug-related AKI, with an elaborate discussion of the particular findings of renal tubular function test, focusing on the probable physiological aberration that might culminate in nonsteroidal anti-inflammatory drug-related nephropathy. Patients and Methods. Ten patients attended the NMC specialty hospital in Dubai from 2006 through 2011 with acute kidney injury secondary to nonsteroidal anti-inflammatory drug use, which developed within 2-5 days. The main complaints were abdominal pain, nausea and vomiting. Blood pressure was elevated in all of them. Renal tubular function test revealed characteristic findings in all of them. Kidney biopsy was performed in two patients. Results. Investigations revealed prominent renal tubular dysfunction suggestive of acute tubular necrosis, with high sodium fractional excretion of 3-5 %, high uric acid fractional excretion of 12-13 %, urine osmolality to plasma osmolality ratio of 1, urine creatinin to plasma creatinin ratio of 16, and urine specific gravity of 1.010-1.020. However kidney biopsy in two of them showed normal renal tubular architecture, which in combination with the short-term, reversible course of the kidney injury in the rest of the patients coincided with nonstructural acute renal tubular dysfunction. Management was supportive. Most of them improved within 5-7 days and two of them improved within 40-45 days. Conclusion. This report highlights that renal tubular dysfunction might be the consistent primary lesion in some of the cases of nonsteroidal anti-inflammatory drug-related acute kidney injury, notwithstanding that acute tubular necrosis and interstitial involvement were evidently excluded. This might be a new explanation for the mechanism of renal failure in patients with otherwise normal renal function <![CDATA[<b>Bortezomib in the treatment of refractory kidney graft rejection</b>]]> Background. Bortezomib, a 26S proteasome inhibitor, is a novel treatment for refractory acute rejection. The main mechanism proposed for its action is the induction of apoptosis of mature plasma cells leading to an interruption of donor-specific antibody production, but other properties may also be involved. Patients and Methods. Four patients presenting with antibody-mediated rejection were treated with bortezomib as rescue therapy. Renal function, proteinuria and anti-HLA antibodies were monitored for 1-3 years. Results. In three cases, graft function recovery and decreased proteinuria occurred, despite the maintenance of donor-specific antibody levels. However, in one case graft function was lost. Side effects were mostly transient. There were no episodes of opportunistic infection. Conclusion. Bortezomib may be effective in antibodymediated rejection by different mechanisms than simply through reducing donor-specific antibody levels. The timing of its introduction and the length of time that donor-specific antibodies have been present may be determinants of its efficacy <![CDATA[<b>Chronic Q fever in two haemodialysis patients</b>]]> Q fever is a zoonotic disease caused by the highly infectious agent Coxiella burnetii which may manifest as a fairly common acute benign disease, or a much rarer and potentially lethal chronic condition. To our knowledge, chronic Q fever has previously only been described in two dialysis patients. We report a further two cases of haemodialysis patients with chronic Q fever and hypothesise as to its possible underdiagnosis in this population. Both patients had a prosthetic heart valve and although no vegetations were found by transoesophagic echocardiography, they met the Duke criteria for possible infective endocarditis. One patient, diagnosed about 11 months after the initial clinical manifestations, died, while the other, started on doxycycline and chloroquine about 3 months after the initial clinical manifestations, survived. We underline some key points that should lead to suspicion of chronic Q fever, namely the combination of a fluctuant febrile syndrome of unknown origin, anaemia and prior heart valve disease, especially in an immunocompromised patient <![CDATA[<b>“Isolated” granulomatous interstitial nephritis and renal failure</b>: <b>an unusual presentation of sarcoidosis</b>]]> Sarcoidosis is a multisystemic granulomatous disorder of unknown aetiology typically affecting the lungs and lymph nodes. Less frequently, the kidneys may also be affected. Postmortem analysis suggests that 20 percent of patients have histologic changes in the kidney. However, clinical involvement of the kidney is a relatively uncommon condition. Renal failure may occur associated with hypercalcaemia, glomerular disease, or granulomatous interstitial nephritis. Renal failure associated with isolated granulomatous interstitial nephritis is an extremely rare entity, with only 57 cases reported until 1990, and the clinical presentation may be misleading. We report a case of a 52-year-old man complaining of persistence of symptoms of lethargy and anorexia, admitted for hypercalcaemia and progressive renal failure. One year earlier, he presented to his primary care physician with a 3-month history of fatigue, anorexia and weight loss. At that time, laboratory findings showed renal failure with a raised serum creatinine of 2.8 mg/dL, and evidence of mesenteric lymphadenopathy on abdominal CT scan. However, as spontaneous regression of lymphadenopathy occurred, the clinical picture was attributed to a depression syndrome. During hospital stay, patient underwent a renal biopsy which showed a granulomatous interstitial nephritis with Schaumann bodies and led to a diagnosis of sarcoidosis. He was treated with steroids with disappearance of constitutional symptoms and partial recovery of renal function. Renal sarcoidosis should be considered in the differential diagnosis of hypercalcaemia and renal failure. A raised serum angiotensin-converting enzyme may aid in making the diagnosis, but a renal biopsy is essential to confirm the diagnosis. Timely diagnosis is critical to successful therapy, as the condition usually responds to early treatment with corticosteroids