Light chain multiple myeloma: an evaluation of its biochemical investigations

ABSTRACT

Multiple myeloma is a type of plasma cell dyscrasia, characterised by presence of paraprotein ormonoclonal (M)-protein in serum or urine. The M-protein may consist of an intact immunoglobulin,the heavy chain only or the light chain only. The latter, designated as light chain multiplemyeloma (LCMM) makes up almost 20% of myelomas. Clinical manifestation is often heraldedby hypercalcaemia, renal impairment, normocytic normochromic anaemia and bone lesions,reflecting end-organ damage, collectively known as the acronym CRAB. In particular, free lightchain nephrotoxicity accounts for the high prevalence of renal impairment seen in LCMM. Thiscase illustrates a typical presentation of LCMM with focal discussion on its initial and diagnostic,as well as prognostic biochemical investigations.