Today, we discussed the case of an elderly man with remote history of treated TB, who presented with new nephrotic syndrome. We had an interesting discussion on approach to nephrotic syndrome in general, with a specific emphasis on membranous nephropathy.

TOP PEARLS

Like many other etiologies of nephrotic syndrome, membranous nephropathy (MN) can be divided into primary versus secondary MN

Patients with primary MN have a more precipitous onset of symptoms, whereas secondary MN patients have more insidious onset of symptoms.

Membranous Nephropathy (MN)

MN is one of the most common causes of nephrotic syndrome in non-diabetic adults.

MN can be divided into primary (idiopathic) or secondary .

or . Most commonly, MN is primary (75% of cases). There are epitopes that have recently been discovered to be associated with primary GN (Thanks Chi, for sharing these with us): Phospholipase A2 receptor: transmembrane receptor highly expressed in glomerular podocytes and is a major antigen in human idiopathic MN Thrombospondin type-1 domain-containing 7A (THSD7A): another transmembrane protein expressed on podocytes Neutral endopeptidase (NEP): associated with rare antenatal form of MN

Secondary MN can be caused by many causes – drugs (gold, penicillamine, NSAIDs), SLE, malignancy (colon ca), HBV, HCV, thyroiditis, Syphilis, etc.

Clinical manifestations: Most patients with MN (~80%) present with nephrotic syndrome. Remainder are diagnosed with MN after evaluation for asymptomatic proteinuria.

Treatment General therapeutics for nephrotic syndrome: diuresis, angiotensin inhibition, treat hyperlipidemia, supportive care Specific therapies for primary MN: – majority of patients will undergo spontaneous remission with supportive care alone! – For those with progressive disease, can use: cyclophosphamide, cyclosporine, tacrolimus, rituximab, etc (per discussion with Nephrology)



See these prior Moffitt pearls on nephrotic syndrome:

https://ucsfmed.wordpress.com/2016/09/09/moffitt-renal-report-pearls-9916-nephrotic-syndrome-and-albumin/

https://ucsfmed.wordpress.com/2016/08/26/nephrotic-syndrome/

Evernote Link: https://www.evernote.com/shard/s338/sh/5800149a-8002-452f-a62b-3ff318671190/c6b5375956a7f33f9f8ecd2b67455908