Dr JULIEN NITHIANANDAN1, Dr CHAU WANG NG1,2
1Department of Renal Medicine, Bendigo Health, , Australia, 2School of Rural Health, Monash University, , Australia
Biography:
Julien is a nephrology advanced trainee who has worked in Victoria and the Northern Territory. His interests include chronic disease management, lupus nephritis, and the health of Aboriginal and Torres Strait Islander peoples.
Background:
Systemic lupus erythematosus (SLE) is a multisystem, autoimmune disease with many clinical manifestations including lupus nephritis. Patients with membranous lupus nephritis can present with nephrotic syndrome associated with a hypercoagulable state. Most cases of pulmonary embolism (PE) in SLE occur in patients with established disease or antiphospholipid syndrome (APLS). We present a case of saddle PE as a rare initial presentation of membranous lupus nephritis.
Case Report:
A female in her 40s from the Philippines presented with recurrent syncope, without chest pain or dyspnoea. Her only medical history was adenomyosis managed with oral contraceptive pill and Implanon. Initial haemodynamics were stable without hypoxia. She had bilateral lower limb pitting oedema. Wells’ PE score was zero. PERC score was one. ECG showed sinus rhythm. Urine dipstick revealed 3+ protein. eGFR >90mL/min/1.73m2, creatinine 70umol/L, troponin 1200ng/L. She then became hypoxic. CTPA showed massive saddle PE with right heart strain. She was thrombolysed with alteplase.
Nephrotic syndrome was confirmed, with urinary albumin-creatinine ratio 382mg/mmol, urinary protein-creatinine ratio 1090mg/mmol, serum albumin 13g/L, and total cholesterol 9.7mmol/L. She had microscopic haematuria (28×106/L erythrocytes), positive ANA 1:160 (speckled), elevated dsDNA 306IU/mL, positive SSA/Ro, but normal complement levels and negative APLS antibodies.
Despite thrombolysis and therapeutic anticoagulation, she had recurrent chest pain with large clot burden, and associated subsegmental pulmonary infarction. She was transferred to a quaternary centre. An IVC filter was inserted to facilitate kidney biopsy. It showed membranous lupus nephritis, without crescents, interstitial fibrosis or tubular atrophy. She was subsequently treated with hydroxychloroquine, mycophenolate, tacrolimus, prednisolone and apixaban.
Conclusion:
Clinicians should consider nephrotic syndrome-induced hypercoagulability as a cause for PE. Urine dipstick is a quick and easy screening test for nephrotic syndrome.