Diagnosing a Challenging Case of Primary Amyloidosis using Capillary Electrophoresis

Abstract

Amyloid Light chain (AL) amyloidosis is characterised by deposition of intact free light chains or their fragments in extracellular space. Here, authors describe the journey of a diagnostically challenging patient who presented with features of nephrotic syndrome and was finally diagnosed with AL amyloidosis. A 45-year-old female presented to the Outpatient Department (OPD) with gradually progressive generalised body swelling. On examination, hepatomegaly, cardiomegaly and macroglossia were observed. Renal biopsy, capillary serum protein electrophoresis, immunotyping and serum free light chain assay were performed along with routine blood and urine investigations to detect the presence of monoclonal protein. Bone marrow biopsy was conducted for confirmation of diagnosis. Proteinuria with hypoalbuminaemia 1.8 g/dL was detected during routine investigations. Renal biopsy showed presence of amyloid deposits in glomerular mesangium and walls of medium sized blood vessels which tested positive for Immunoglobulin (Ig) G, IgA, kappa and lambda chains on immune florescence. Serum protein capillary electrophoresis findings demonstrated increase in beta 2 fraction and distortion in gamma region. Immuno typing showed presence of monoclonal IgA heavy chains and lambda light chains. Bone marrow biopsy confirmed presence of plasma cell dyscrasia. Based on these findings authors concluded that capillary gel electrophoresis is more sensitive method than agarose gel electrophoresis in detecting beta migrating monoclonal proteins.