Lupus-like nephritis with positive anti-neutrophil cytoplasmic antibodies and negative antinuclear antibodies / Nefrite semelhante à lúpica com anticorpos citoplasmáticos antineutrófilos positivos e anticorpos antinucleares negativos

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.

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.

Lupus-like nephritis with positive anti-neutrophil cytoplasmic antibodies and negative antinuclear antibodies.

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.

Cecum perforation associated with a calcium polystyrene sulfonate bezoar - a rare entity / Perfuração do ceco associada a bezoar de poliestirenossulfonato de cálcio - uma entidade rara

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.

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.

Cecum perforation associated with a calcium polystyrene sulfonate bezoar - a rare entity.

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.

Cerebral embolism from Libman-Sacks endocarditis.

Libman-Sacks endocarditis consists of aseptic valvular abnormalities, associated with systemic lupus erythematosus and antiphospholipid syndrome. Embolic ischaemic stroke is a possible clinical presentation. The authors present the case of a woman in her fourth decade who developed central facial palsy after several transient ischaemic attacks with visual loss. Cerebral imaging revealed multiple small ischaemic lesions in the right hemisphere. The transoesophagic echocardiogram showed mitral vegetations and she tested positive for antiphospholipid antibodies. She underwent mitral valve replacement for a mechanical prosthesis due to extensive valvular damage and started anticoagulation. The valve's microbiological exams were negative establishing the diagnosis of libman-sacks endocarditis. Endocarditis should be suspected with sequential cerebral ischaemia in patients of all ages. Valvular surgery is the mainstay of treatment in recurrent embolic events. Association with antiphospholipid antibodies is common yet a poor-known fact. The patient is currently asymptomatic on warfarin and aspirin, with a normal functioning mitral prosthesis.

[Contrast-induced nephropathy]. / Nefropatia de contraste.

Contrast-induced nephropathy (CIN) is an iatrogenic disorder, resulting from procedures requiring the intravascular administration of iodinated contrast media. It has an association with increased morbidity and mortality, increased costs and it remains the third most common cause of hospital-acquired kidney failure. CIN is usually defined as an increase in serum creatinine by either at least 0.5 mg/dl or by 25% from baseline within the first 48 hours after contrast administration, in the absence of other causes of renal function impairment. In its pathogenesis have been implicated 2 main mechanisms: renal vasoconstriction resulting in medullary hypoxia and direct cytotoxic effects of the contrast agents. There are several risk factors for radiocontrast nephrotoxicity but patients with underlying renal insufficiency or diabetic nephropathy with renal insufficiency have the greatest risk. Other classic risk factors include: advanced age, peri-procedural intravascular depletion, congestive heart failure. Finally, toxicity also depends on the volume, type of contrast administered and concomitant use of other nephrotoxic drugs. Since there is no specific treatment for CIN and it is limited to supportive measures, prevention is the best way to deal with this condition. In this setting it is important to use lower doses of a low or iso-osmolal agent and avoid volume depletion. Nowadays it is recommended to do volume expansion prior to and continued for several hours after the procedure. Randomized controlled trials suggest that isotonic intravenous fluids, particularly isotonic bicarbonate, confer better protection. Several pharmacologic approaches have been tested to decrease the risk of CIN in patients with preexisting renal disease, based in the mechanisms by which contrast medium is believed to cause nephrotoxicity. However, with the exception of some antioxidant agents, few of those adjunctive therapies have shown any consistent benefit. N-Acetylcysteine is the most widely studied of all prophylactic strategies and despite conflicting data it is advised to do an elevated dosage orally twice daily, the day before and the day of the procedure, based upon its potential for benefit, low toxicity and cost. This article pretends to review CIN pathogenesis, risk factors, clinical course, treatment and prevention. The authors propose themselves a prevention protocol for risk patients based on the latest clinical evidence.