Introduction: Venous thromboembolism is the third most frequent acute cardiovascular syndrome after myocardial infarction and stroke, with an important morbimortality and great impact on the health system globally. Although incidence raises with age, this pathology is quite frequent at young age, with ne-phrotic syndrome (NS) as a well known predisposing factor for it. Almost 25% of the patients with NS deve-lop thrombotic events such as deep venous thrombosis, renal veins thrombosis and pulmonary embolism, with an even greater incidence in patient with NS secondary to membranous nephropathy. The ethiopathogenic mechanism behind this correlation is not fully under-stood, however, increased platelet activation, additio-nal erythrocyte aggregation and imbalance between procoagulant and anticoagulant factors seem to deter-mine the excessive thrombotic risk. Current guidelines lack of clear recommendations regarding this category of patients. There is limited data about the type of anti-coagulant, time of administration and use of fibrinoly-tic therapy.

Case presentation: We present the case of a 33 year-old patient, with a history of membranous glomerulo-nephritis (MGn) and secondary SN, on maintenance therapy with prednisone, non-compliant to lifestyle and diet regime, presented to emergency room for pro-gressively worsened right lumbar pain in the last two days. Abdominopelvic ultrasound was suggestive for bilateral renal vein thrombosis with extent to inferior vena cava (IVC). Therefore, contrast thoraco-abdomino-pelvic CT scan is performed which reveals extensi-ve thrombosis of subhepatic VCI to both common iliac veins and renal veins; at the pulmonary level, com-pletely occlusive thrombosis of bilateral inferior lobar arteries was shown. Because of the worsening of the clinico-biological status (oligoanuria) under heparin therapy with therapeutic aPTT, although without hae-modynamic instability, a multidisciplinary team for-med by cardiologist and nephrologist took the decision of systemic thrombolysis with alteplase; the patient did not have absolute or relative contraindications. One-week post-thrombolysis control CT scan revealed re-gression of thrombus from the pulmonary circulation, with stationary aspect in the IVC. Later on, evolution was favourable, the patient being asymptomatic under anticoagulant treatment with low molecular weight he-parin followed by 15 mg rivaroxaban bid for 21 days, then 20 mg od, with a scheduled three month cardio-logy follow-up. Because of the severe proteinuria (29 g/24 hours), it was considered a MGn relapse, which is why transfer to nephrology ward was performed, whe-re treatment with methylprednisolone and cyclopho-sphamide was administered.

Case particularity:

Extensive venous thromboembolism (subhepatic IVC thrombosis, bilateral renal vein thrombosis, bilateral asymptomatic pulmonary embolism) in a young patient with nephrotic syndrome secondary to membranous glomerulonephritis.

Systemic fibrinolytic treatment besides the situation of haemodynamic instability, with a relative success by taking into account the personalized risk-benefit ratio.

Multidisciplinary approach of the pathology with focus on personalization of the therapeutic strategy.