[A systemic disease mimicking a rheumatoid arthritis]. / Une maladie systémique mimant une polyarthrite rhumatoïde.

INTRODUCTION: Rare systemic diseases such as amyloidosis can mimic inflammatory rheumatic diseases. Because of their poor prognosis, physicians should rule them out at the onset of inflammatory rheumatism. We report a case of AL amyloidosis misdiagnosed as rheumatoid arthritis. CASE REPORT: A 71-year-old woman was referred for seronegative rheumatoid arthritis, resistant to three biologic therapies. She had an IgA lambda monoclonal gammopathy of undetermined significance (MGUS). The patient subsequently developed glomerular proteinuria. Abdominal fat and accessory salivary glands biopsies revealed amyloid light-chain (AL) amyloidosis. Treatment with bortezomib-cyclophosphamide-dexamethasone, led to complete hematologic, renal and rheumatologic remission. Ten months after treatment interruption, the patient had an articular and hematologic relapse. CONCLUSION: Amyloid light-chain amyloidosis arthropathy is probably underdiagnosed. A review of amyloid arthropathy associated with multiple myeloma found that 33% of patients had been misdiagnosed with rheumatoid arthritis.

[Pulmonary embolism as a presentation of nephrotic syndrome]. / Embolie pulmonaire révélant un syndrome néphrotique.

BACKGROUND: Nephrotic syndrome (NS) in adults is defined by proteinuria>3g/24h or 50mg/kg/d, hypoproteinemia<60g/24h and hypoalbuminemia<30g/L. The final diagnosis is guided by the histopathology evidence when a renal biopsy is possible. The consequences of NS are multiple: high blood pressure, undernutrition, infections and a hypercoagulable state. OBSERVATION: We report the case of a patient presenting with thromboembolic disease, occurring in the absence of other thromboembolic risk factors, which revealed NS with spontaneously favorable evolution. CONCLUSION: Thromboembolic disease in NS is frequent but underestimated and may remain underdiagnosed. Thorough investigation - including serum protein levels and testing for proteinuria - are essential in thromboembolism, as is excluding cancer or another cause. The treatment of thromboembolic disease in NS is based on anticoagulation for as long as the NS persists. There is no consensus about primary prophylaxis but an albumin level below 20g/L should be considered as a risk factor of thrombosis and prophylactic anticoagulation should be started.