Plasmapheresis for Treatment of Light Chain Amyloidosis Related Myopathy

Treatment was discontinued after four consecutive cycles (four weeks of chemotherapy per cycle) due to his neurologic decline despite his post treatment staging showing normalization of light chains and achievement of stringent complete response (sCR) with minimal residual disease (MRD) detectable by flow cytometry on bone marrow aspirate. Previously, plasmapheresis has only shown benefit in systemic amyloidosis with renal complications.4 Current treatments for ALM, including melphalan, daratumumab, and bortezomib-containing regimens, are also used to target the underlying clone but have variable effects in improving ALM. Cauda equina gadolinium enhancement, typically a marker of active demyelinating disease, was unchanged after clinical improvement and remains unexplained.5 These cases highlight a potential role for plasmapheresis in ALM treatment.