The Role of Immunological Assessment in Patients With Acute Kidney Injury and Possible Myeloma

Acute kidney injury (AKI) in plasma cell multiple myeloma (MM) is a medical emergency requiring a rapid, accurate diagnosis because prompt commencement of therapy and supportive care are essential. Most cases of AKI in MM are caused by cast nephropathy secondary to high levels of nephrotoxic serum free light chains (FLCs). This article reviews the role and relevance of FLC as an immunological biomarker for AKI and MM. We discuss the utility of FLC measurement as a screening tool in the cast nephropathy clinical setting. We present its analytical pitfalls and evolving evidence for the integration of an FLC assay into clinical algorithms.