Membranous nephropathy in a patient with hereditary angioedema: a case report

We present the first reported case of the association of membranous nephropathy and hereditary angioedema in a 43-year-old male Caucasian patient who presented with acute intestinal angioedema, hypertension, acute pancreatitis, renal impairment and generalised body swelling due to severe nephrotic syndrome. We present the challenges involved in the clinical management of the patient.This patient's presentation with severe nephrotic syndrome, renal impairment and hypertension required aggressive treatment of the membranous nephropathy given the high risk for progression to end stage renal failure. The contraindication to angiotensin converting enzyme inhibitors and angiotensin II receptor blockers in this patient, the lack of published evidence on the use of alkylating agents and other immunosuppressive agents in patients with hereditary angioedema and the lack of published data on the management of similar cases presented a clinical challenge in this patient's management.Hereditary C1 esterase inhibitor deficiency (hereditary angioedema; HAE) is a rare (incidence 1 in 10,000 to 1 in 150,000) autosomal dominant inherited disease of the complement system characterised by the absence or dysfunction of the protein C1 esterase inhibitor (C1 INH), which regulates the complement, fibrinolytic, coagulation and kinin cascades [1]. It is the commonest inherited disorder of the complement system which is characteristically associated with non-pruritic angioedema, most commonly affecting the respiratory system, the skin and the gastrointestinal tract [1]. It has been associated with other immunoregulatory disorders (Table 1).The association of HAE with membranous glomerulonephritis has not been reported before, as we far as we know. The management of membranous glomerulonephritis in a patient with HAE would be challenging as angiotensin converting enzyme inhibitors (ACEIs) and angiotensin 2 receptor blockers (ARBs) which effectively reduce proteinuria and slow the progression o