Case report of primary membranous nephropathy associated with muscle and peripheral nerve damage

   Primary membranous nephropathy (PMN) typical cause of nephrotic syndrome in adults. The key point in its pathogenesis is the production of IgG4 subclass autoantibodies (IgG4) against podocytic transmembrane phospholipase A2 M-type receptor (anti-PLA2R), followed by the deposition of subepithelial immune complexes (IC) in situ. We present a case of a 37-year-old young man with PMN associated with demyelinating polyneuropathy and idiopathic inflammatory lesions of skeletal muscles demonstrating a possible variant of extrarenal effects of IgG4-anti-PLA2R with an extended analysis of diagnostics and probable mechanisms of imbalance of secreted and intracellular phospholipases.