Resumo Os anticorpos anticitoplasma de neutrófilos (ANCAs) estão associados à vasculite de pequenos vasos, no entanto, a sua prevalência não é rara em outras doenças imunológicas. Na nefrite lúpica (LN), o seu papel patológico e relevância clínica têm sido alvo de pontos de vista controversos. Apresentamos um caso de lesão renal aguda e síndrome nefrótica em uma jovem com nefrite proliferativa difusa e membranosa em sua biópsia renal, muito alusivo a NL classe IV + V, com um padrão full house na imunofluorescência, mas sem critérios clínicos e achados laboratoriais para corroborar o diagnóstico de lúpus eritematoso sistêmico (LES). Não obstante, a paciente apresentou títulos elevados de ANCA, que diminuiram progressivamente com a melhoria da função renal e da proteinúria, após tratamento com micofenolato de mofetil (MMF) e esteróide. Os autores acreditam que se trata de um caso de nefrite semelhante à nefrite lúpica, em que os ANCAs são marcadores imunológicos, embora não estejam diretamente envolvidos na patogênese.

Abstract Antineutrophil cytoplasmic antibodies (ANCAs) are associated with small vessel vasculitis but their prevalence is not rare in other immune diseases. In lupus nephritis (LN), their pathological role and clinical relevance have been the target of controversial views. We present a case of acute kidney injury and nephrotic syndrome in a young woman with diffuse global proliferative and membranous nephritis on her kidney biopsy, showing a full-house immunofluorescence pattern, very allusive of class IV + V LN, but lacking associated clinical criteria and laboratory findings to support the diagnosis of systemic lupus erythematosus (SLE). Furthermore, the patient presented with high titers of ANCA, steadily decreasing alongside the renal function and proteinuria improvements, with mycophenolate mofetil (MMF) and steroid treatment. The authors believe this is a case of lupus-like nephritis, in which ANCAs are immunological markers, although they are not directly involved in the pathogenesis.

Introduction: Peritonitis is a common complication in peritoneal dialysis patients and a major cause for dropout. Systematic report and frequent trend analysis are thought to be major drivers for improvement in this area. The authors analysed peritonitis outcomes dating back over 20 years in a peritoneal dialysis unit of a central hospital. Methods: Retrospective study from 1993 to 2018: assessment of demographic, clinical and microbiological profiles of patients with peritonitis. We performed univariate and multivariate analysis (multiple logistic regression) to predict peritonitis risk factors, and survival analysis (Cox proportional hazards model) to determine the impact on outcomes (mortality and technique survival). Results: We included 225 patients, average age of 48.3±14.7 years, average time of follow-up of 38±25 months, with a total of 221 episodes of peritonitis (0.31 peritonitis/patient.year), 76% resulting in cure. Most frequent agents were Staphylococci: Coagulase-Negative (23%) and Staphylococcus aureus (19%, of which 24% were methicillin-resistant). Gram-negative infections led to higher rate of catheter removal, transfer to hemodialysis or death (49% of cases vs. 17% in Gram-positive). Primary end-point was death or transfer to hemodialysis, with a median time of 94 (min 4, max 94) and 66 (min 3, max 105) months, respectively. The occurrence of at least one peritonitis was the major variable that influenced transfer to hemodialysis (OR 3.94 [2.12 - 7.58], p < 0.001*], whereas an event in the first year also negatively affected the time to dialysis technique switch (median time 38.7 [26.2 - 58.4] vs. 67.8 [59.5 - 80.3] months, log-rank = 0.02*), but without impact on mortality. Only the peritoneal dialysis modality (OR: automated peritoneal dialysis vs. continuous ambulatory peritoneal dialysis 0.38 [0.19-0.74]) was predictive of peritonitis in multivariate analysis. Conclusions: In this single-center long-term analysis, where the rate of peritonitis was within recommended values, automated peritoneal dialysis seemed to have a protective impact. The number of peritonitis and peritonitis occurrence during the first year worsened technique survival, emphasizing early peritonitis prevention.

Resumo A hipercalemia é um dos distúrbios eletrolíticos mais comuns, responsável por um grande número de desfechos adversos, incluindo arritmias potencialmente fatais. Quelantes de potássio são amplamente prescritos para o tratamento da hipercalemia, mas infelizmente são muitos os eventos adversos associados ao seu uso, em particular os gastrointestinais. A identificação de pacientes com risco mais elevado para complicações graves associadas aos quelantes de potássio atualmente em uso, como necrose e perfuração do cólon, pode evitar desfechos fatais. O presente artigo descreve o caso de um homem de 56 anos com diabetes secundário e doença renal crônica em tratamento por hipercalemia com poliestirenossulfonato de cálcio (PSC). Posteriormente o paciente apresentou abdômen agudo devido a perfuração do ceco e foi submetido a uma ressecção ileocecal, mas acabou indo a óbito por choque séptico uma semana mais tarde. Durante a cirurgia, uma massa branca sólida foi isolada no lúmen do cólon. A massa foi identificada como um bezoar de PSC, uma massa de fármaco de rara ocorrência formada no trato gastrointestinal que contribuiu para a perfuração. História pregressa de gastrectomia parcial e vagotomia foi identificada como provável fator de risco para o desenvolvimento do bezoar de PSC. Espera-se que os dois novos quelantes de potássio - patiromer e ciclossilicato de zircônio sódico - ajudem a tratar pacientes de alto risco em um futuro próximo.

Abstract Hyperkalemia is one of the most common electrolyte disorders, responsible for a high number of adverse outcomes, including life-threatening arrhythmias. Potassium binders are largely prescribed drugs used for hyperkalemia treatment but unfortunately, there are many adverse events associated with its use, mostly gastrointestinal. Identification of patients at highest risk for the serious complications associated with the current potassium binders, such as colon necrosis and perforation, could prevent fatal outcomes. The authors present a case of a 56-year-old man with secondary diabetes and chronic renal disease that was treated for hyperkalemia with Calcium Polystyrene Sulfonate (CPS). He later presented with acute abdomen due to cecum perforation and underwent ileocecal resection but ultimately died from septic shock a week later. During surgery, a solid white mass was isolated in the lumen of the colon. The mass was identified as a CPS bezoar, a rare drug-mass formed in the gastrointestinal tract that contributed to the perforation. A previous history of partial gastrectomy and vagothomy was identified as a probable risk factor for the CPS bezoar development. Hopefully, the two new potassium binders patiromer and (ZS-9) Sodium Zirconium Cyclosilicate will help treat such high-risk patients, in the near future.

Introdução: Desde que foi identificado, o vírus da hepatite C tem sido implicado na fisiopatologia de diversas doenças linfoproliferativas do tipo B, nomeadamente na criogloblulinemia mista. Caso clínico: Descrevemos o cas crioglobulinemia mista com envolvimento renal, apesar de prévia erradicação do VHC. Discussão: Revemos casos similares descritos na literatura, assim como a fisiopatologia e tratamento desta entidade clínica.

Introduction: Since its identification, hepatitis C virus infection has been implicated in the pathogenesis of several B cell disorders, specifically mixed cryoglobulinemia. Case Report: The authors describe the case of a 41-year-old male, who developed a mixed cryoglobulinemia vasculitis with renal involvement, several years after successful eradication of HCV with interferon therapy. discussion: Similar cases described in the literature are reviewed in this report. Possible explanations for the physiopathology of the disease and its implications in therapy are commented.

O rim é frequentemente atingido por doenças do tecido conjuntivo e pelos seus tratamentos. Apresentamos o caso de uma doente leucodérmica de 45 anos referenciada à consulta de Nefrologia por proteinúria nefrótica (máximo 6200 mg por dia), com história de artrite reumatóide (AR) tratada com anti-malárico, corticoterapia e anti-inflamatórios não esteróides (AINEs). A avaliação clínica permitiu adicionalmente identificar quatro critérios de Lúpus Eritematoso Sistémico (LES). Suspenderam-se os AINEs e após 3 meses sem redução significativa da proteinúria decidiu-se efetuar biópsia renal. O exame histológico revelou nefropatia membranosa estádio 1 (sugestiva de nefrite lúpica classe V). Em menos de seis meses sem AINEs houve uma remissão completa da síndrome nefrótica. Neste artigo discutimos a etiologia da doença glomerular desta doente como efeito adverso do tratamento com AINEs versus doença glomerular associada a AR/LES (Rúpus).

The kidney is often affected by connective tissue diseases and their treatments. We report the case of a 45-year-old Caucasian female who presented to our nephrology department with nephrotic proteinuria (maximum 6200 mg per day) and a history of rheumatoid arthritis (RA) treated with antimalarial, corticotherapy and non-steroidal anti-inflammatory drugs (NSAIDs). Furthermore, on clinical assessment we identified four criteria for systemic lupus erythematosus (SLE). We promptly withdrew the NSAIDs and, after 3 months without significant reduction in proteinuria, we decided to perform a renal biopsy. The histological examination found a stage 1 membranous nephropathy (suggestive of class V lupus nephritis). After less than six months without NSAIDs, there was spontaneous complete clinical remission of the nephrotic syndrome. In this paper we discuss the aetiology of the glomerular disease in this patient as an adverse effect of NSAIDs treatment versus glomerular disease associated to RA/ SLE (Rhupus)