Portuguese Journal of Nephrology & Hypertension

Renal lithiasis from a nephrologist’s perspective

Man has known urinary lithiasis since antiquity. In Portuguese medicine, this is a pathology seen predominantly from the urology perspective, but renal lithiasis is evaluated and treated preventively by nephrologists worldwide, and its study has contributed significantly to knowledge of how the renal tubule works. Nephrolithiasis is a relatively common disease in the adult population and, in Portugal, is observed in about 7.3% of the population. The main pathophysiological mechanisms of the most frequent types of kidney stones and who and how to conduct the metabolic research are briefly described. Medical treatment is also addressed, keeping in mind that nephrolithiasis is often accompanied by extra-renal manifestations that should be investigated and treated, namely arterial hypertension, obesity, diabetes mellitus and osteo-metabolic disease

Pancreas allocation and diabetic end-stage kidney disease

Transplant options for patients with type 1 diabetes and end-stage kidney disease include deceased donor kidney, live donor kidney, simultaneous pancreas-kidney, pancreas after kidney and islet cell transplantation. Allocation of deceased donor kidneys is prioritized for candidates of multiorgan transplants. Here, outcomes of treatment modalities are reviewed, as well as the ethical implications of multiorgan allocation of kidney-pancreas.

The role of alteplase in preventing relapsing and repeat peritonitis in peritoneal dialysis

Introduction: Peritonitis is a common complication in peritoneal dialysis, playing a weighty role in patient morbidity and a major cause of transfer to hemodialysis Relapsing or repeat episodes are associated with the development of a biofilm-trapping bacteria, and catheter removal is recommended in these cases. Since October of 2013 our peritoneal dialysis unit has developed a protocol that adds a fibrinolytic agent to an intraperitoneal antibiotic, aiming to reduce the number of relapsing/repeat episodes. Objective: To demonstrate the efficacy and safety of associating a fibrinolytic agent to intraperitoneal antibiotics in the prevention of relapsing or repeat peritonitis. Methodology: Observational study comparing the number of relapsing/repeat peritonitis events between two groups during a four-year period: a historic one, treated with intraperitoneal antibiotics only (control group) and one group that received an association of intraperitoneal antibiotics with alteplase (alteplase group). Secondary and fungi peritonitis were excluded from this study. Results: During the study period, a total of 103 peritonitis episodes were registered (control group: 61 episodes; alteplase group: 42 episodes) corresponding to 17 relapsing/repeat events, with statistical significance between groups (control group: 15 episodes (24.6%); alteplase group: 2 episodes (4,7%); p=0.008). There was no difference in demographic characteristics or the presence of exit site infection between the groups. The microorganisms most frequently involved in relapsing/repeat episodes were S.epidermidis and E.coli. Regarding the outcomes of the treatment, no patient in the alteplase group had to undergo catheter removal due to relapsing/repeat episodes of peritonitis. There were no adverse events following alteplase administration. Three deaths due to peritonitis-related sepsis were registered. Conclusion: Although relapsing/repeat peritonitis are still an important cause of catheter removal, this study demonstrates the potential benefit of fibrinolytic association with intraperitoneal antibiotics in preventing these events and potentially reducing modality drop-out.

Nephrocalcinosis in a portuguese pediatric population

Introduction and Aims: Nephrocalcinosis is characterized by the deposition of calcium in the kidney parenchyma and tubules. The renal prognosis depends on the underlying cause, emphasizing the importance of its identification. We aim to review the data of children with nephrocalcinosis concerning etiology, clinical manifestations, growth and renal function at presentation and outcomes. Methods: Retrospective study of the records of children (<18 years) with nephrocalcinosis followed by a pediatric nephrology unit of level III hospital, between 2008-17. Clinical features, etiology, treatment and outcomes were evaluated. Results: We identified 35 cases: 24 isolated (69%) and 11 with nephrolithiasis (31%). The group was mostly constituted of girls (54%). Median age at presentation was 6 years (7 months - 17 years old); 40% of patients were under 2 years of age, 31% between 3 and 9 years and 29% older than 10 years. Mean follow-up was 4 years (1-9). The most common clinical manifestation was failure to thrive in the first year of life (34%) and flank or abdominal pain (20%); in 23% it was an incidental finding. Eleven percent of patients had a systemic syndromic disease. Renal function at diagnosis was normal in all children. The most frequent causes were metabolic abnormalities (23%), hereditary tubulopathies (23%), prematurity (20%) and pharmacologic (14%). Eleven percent were considered idiopathic. In a logistic regression analysis, sex, age of presentation and familiar history of nephrocalcinosis showed no correlation with nephrocalcinosis, nephrocalcinosis and nephrolithiasis or hereditary/metabolic etiologies. Discussion: Despite the small sample, in this study, the hereditary and/or metabolic disorders were the main cause of nephrocalcinosis. Associated symptoms and comorbidities, such as prematurity, growth retardation, intestinal malabsorption, or bone demineralization, should be evaluated for diagnostic purposes. No patient developed chronic kidney disease.

Membranous nephropathy: an update

Great advances have been made in the pathophysiologic and therapeutic areas of membranous nephropathy in the last years. The description of autoantibodies directed against phospholipase A2 receptor in the glomerulus has confirmed the autoimmune nature of the disease and has changed our diagnostic, classification, and treatment strategies. Rituximab has emerged as a great tool in the therapeutic armamentarium of membranous nephropathy, but a one-size-fits-all approach is far from being the rule. Nowadays, an individualized therapeutic scheme based on clinical and serologic data appears to be the most appropriate method to manage patients with membranous nephropathy. We present a review of the most important aspects published in the literature regarding membranous nephropathy, with an emphasis on the most novel topics with the intention of updating clinicians involved in the management of this disease.

Current guidelines in peritoneal dialysis - Part I

A successful peritoneal dialysis program follows evidence-based practice guidelines. In this first article we review the current guidelines on catheter insertion and on prevention of catheter-related infections, both subjects of extreme importance not only to initiate and also to maintain patients on peritoneal dialysis. The treatment of catheter-related infections is not part of the purpose of this article.

Current guidelines in peritoneal dialysis - Part II

A successful peritoneal dialysis program depends on knowledge of the current recommendations and on evidence-based practice guidelines. In this second article, we review the dialysis prescription and the nutritional and cardiovascular management of peritoneal dialysis patients in the light of the existing guidelines advocated by different international societies.

Cerebral vasculitis - a rare presentation of antineutrophil cytoplasmic antibody associated vasculitis relapse

Antineutrophil cytoplasmic antibody (ANCA) associated vasculitis commonly involves kidney, lung, upper respiratory tract, skin, gastrointestinal and occasionally peripheral nervous system. Central nervous system is less commonly affected and is generally part of a multi-organ scenario. We present a case of a 21-year-old female with chronic kidney disease secondary to myeloperoxidase ANCA associated vasculitis, diagnosed at age 19. She then presented with pulmonary-renal syndrome with stage 5 CKD. Three months cyclophosphamide and prednisone were instituted, followed by azathioprine, but she remained dialysis dependent. After 2 years, while on maintenance treatment, she was admitted to the emergency department with tonic-clonic seizures. She had started oral ciprofloxacin 2 days before for acute gastroenteritis. No illicit drugs were noticed. Blood tests showed an increased myoglobin but were otherwise unremarkable. No anomalies were reported on cerebral computed tomography or cerebrospinal fluid analysis. Magnetic resonance imaging showed diffuse cortico-subcortical lesions with T2 and proton density hypersignal suggesting recent ischemia, and segmental irregularities of various cerebral and vertebral arteries, consistent with small and medium size vessel vasculitis. Intravenous methylprednisolone and oral cyclophosphamide were started. Anti-myeloperoxidase ANCA levels were increased (>200 RU/mL), reinforcing our diagnostic hypothesis of central nervous system (CNS) recurrence of ANCA vasculitis. The patient had a favorable clinical course, with no neurological sequelae. Conclusions: This is a case of ANCA associated vasculitis that presented with kidney and lung but no CNS involvement and recurred with primarily cerebral disease. Favorable outcome was seen with standard immunosuppression. Awareness of this rare but severe complication is critical for timely recognition and prompt treatment.

Crescentic IgA nephropathy associated with pleural tuberculosis

Crescentic IgA nephropathy represents an aggressive glomerular injury which can cause renal failure unless diagnosed and treated rapidly. There is currently no consensus on the most effective treatment strategy, although immunosuppressive drugs are usually used. Tuberculosis is rarely associated with glomerulonephritis and raises difficult questions about the safety and usefulness of immunosuppressive agents. We report a rare case of rapidly progressive renal failure associated with pleural tuberculosis in a 68-year-old man. The identification of crescents and fibrinoid necrosis in 12 out of 21 glomeruli and IgA deposits in the renal biopsy suggested the diagnosis of crescentic IgA nephropathy. Corticosteroids in combination with antituberculosis drugs were started with significant improvement in his general condition and cure of his pleural tuberculosis but without recovery of kidney function.

Recurrence of oxalate nephropathy after renal transplantation in a patient with polyarteritis nodosa: a case report

Hyperoxaluria is an important complication of short bowel syndrome (SBS) and a non-negligible cause of chronic kidney disease (CKD). We describe the case of a 56-year-old woman with polyarteritis nodosa (PAN) and SBS who was admitted for acute kidney injury (AKI) 2 months after a successful deceased donor kidney transplantation. The diagnostic investigation was consistent with the diagnosis of oxalate nephropathy (OxN) and a set of lifestyle and therapeutic measures was implemented aiming at the reduction of intestinal oxalates absorption. Despite the short-term benefit of this strategy, a progressive and inexorable deterioration of renal function was observed. In this report, we discuss the limited therapeutic options, the ominous prognosis and the risk of recurrence of this rare entity after renal transplantation. Additionally, we reflect on the value of patient compliance in the successful management of the disease and review potential new strategies that may improve the clinical course of this entity in the future

Endogenous endophthalmitis: a not so rare ophthalmic emergency among hemodialysis patients

Endogenous endophthalmitis is an intraocular infection secondary to the hematogenous spread of microorganisms. It is an ophthalmological emergency associated with serious complications if not promptly diagnosed and treated. Despite the susceptibility of hemodialysis patients to episodes of bacteremia associated with vascular access, it is considered a rare disease. In fact, very few cases are described worldwide. We present 3 cases of endogenous endophthalmitis, secondary to bacteremia associated to vascular access in patients under hemodialysis treatment, aiming to raise awareness of this not so rare metastatic infection, possibly underdiagnosed in this population

Fanconi syndrome after Ifosfamide exposure - case report

Ifosfamide is an antineoplastic drug widely used in the treatment of paediatric malignancies. However, in up to 50% of patients, it is associated with nephrotoxicity ranging from asymptomatic tubulopathy to overt renal failure. A two-year-old Caucasian boy was diagnosed with stage IV Burkitt lymphoma, with hepatic and renal and bone marrow involvement. Baseline evaluation showed GFR of 60 mL/min/1.73 m2. He started chemotherapy with LMB 96 protocol group B with 5 courses of chemotherapy with vincristine, cyclophosphamide, doxorubicin, prednisone, and intrathecal administration of cytarabine and methotrexate. After the first chemo protocol, the patient was in remission and recovered normal renal function, but three months later he relapsed with involvement of the liver and kidneys. The patient initiated a salvage regimen with R-ICE (rituximab - ifosfamide, carboplatin, etoposide) intrathecal methotrexate and cytarabine and allogeneic stem cell transplantation was proposed. After achieving complete remission, he underwent allogeneic stem cell transplantation with busulfan and cyclophosphamide. Graft versus host disease prophylaxis was made with tacrolimus and methotrexate and infection prophylaxis with fluconazole and acyclovir. However, during treatment of the relapse, the patient presented downward crossing of weight and height centiles without recovery after treatment terminus and, following transplantation, consecutive laboratory testing suggested tubulopathy. Upon nephrologist referral, he was diagnosed with Fanconi syndrome and adequate supplementation was initiated with improvement of the patients general condition and slow centile catch up. After literature review, the most probable causing agent was determined to be ifosfamide, as the nephrotoxic effects of the other medications prescribed tend to be reversible after stopping. Nephrotoxicity secondary to chemotherapy is a major cause of morbidity in paediatric cancer survivors. Our case represents a rare situation with unspecific clinical signs. Clinicians must be alert to the necessity of close monitoring to identify renal toxicity, mainly tubular dysfunction, as early as possible and allow adequate supplementation, which is crucial in preventing side effects.

Unmasked by histology

A child with acute kidney injury