Causes and Prevention of Thromboembolic Disease in Nephrotic Syndrome

Inclusion Criteria: Nephrotic patients - no intervention * Age 18-79 years * Estimated Glomerular Filtration Rate (eGFR) \> 49 mL/min/1.73 m2 * P-albumin \< 30 g/L * U-Albumin excretion \> 2.2 g/day * Known glomerular disease including membranous nephropathy, which may cause nephrotic syndrome or diagnostically unresolved nephrotic syndrome with a planed kidney biopsy. Inclusion Criteria: Nephrotic patients treated with Dalteparin * Age 18-79 years * eGFR \> 49 mL/min/1.73 m2 * P-albumin \< 25 g/L * U-Albumin excretion \> 2.2 g/day * Known glomerular disease including membranous nephropathy, which may cause nephrotic syndrome or diagnostically unresolved nephrotic syndrome with a planed kidney biopsy. Inclusion Criteria: Nephrotic patients treated with Apixaban * Age 18-79 years * eGFR \> 49 mL/min/1.73 m2 * P-albumin \< 25 g/L * U-Albumin excretion \> 2.2 g/day * Membranous Nephropathy Inclusion Criteria: Patients with atrial fibrillation treated with Apixaban * Age 18-79 years * eGFR \> 49 mL/min/1.73 m2 * P-albumin \> 36 g/L * U-Albumin excretion \< 300 mg/day * Atrial Fibrillation Exclusion Criteria: * Contraindication to Apixaban * Contraindication to Dalteparin * Known allergy or intolerance to Apixaban * Known allergy or intolerance to Dalteparin * Treatment with anticoagulation for other reasons. * Treatment with cyclooxygenase-1-inhibitors or Adenosine Diphosphate (ADP) receptor inhibitors. * Known acquired or congenital coagulation defect non related to nephrotic syndrome or thromboembolic disease within 3 months. * Known diabetes mellitus. * Lack of compliance, comorbidity or other conditions that, in the patients unfit to participate in the trial. * Pregnancy