Primary AL Amyloidosis: An Experience with a Patient Accompanied by Immunoglobulin M Monoclonal Gammopathy

Amyloid light chain amyloidosis (AL amyloidosis) is a systemic disease induced by tissue deposition of amyloid fibrils originated from monoclonal immunoglobulin (Ig) light chains. Various types of paraproteins can lead to amyloid deposits, with the free lambda light chain IgG and IgA being the most common components, while the disease associated with IgM paraproteinemia is an extremely uncommon variant. We herein report such a case in a 66-year-old male patient presenting with nephrotic syndrome. The management concerns of IgM-related AL amyloidosis are also discussed. We believe that an awareness of the link between AL amyloidosis and IgM paraproteinemia remains a challenge for physicians because of its rarity; we therefore strongly recommend the accumulation of more cases similar to our own, allowing us to clarify the nature of the disease more precisely.

Keywords: AL amyloidosis, IgM, monoclonal gammopathy, nephrotic syndrome, abdominal fat biopsy.