Immunoglobulin light chain amyloidosis (AL)

Light chain amyloidosis needs to be considered in the differential diagnosis of patients with nondiabetic nephrotic range proteinuria, unexplained fatigue or heart failure with preserved ejection fraction, a progressive peripheral neuropathy associated with a monoclonal protein, or atypical multiple myeloma. Screening involves serum and urine immunofixation and an immunoglobulin free light chain assay. Most patients can have the diagnosis established via biopsy of the bone marrow and subcutaneous fat. Visceral organ biopsy is rarely needed. The prognosis is determined by the DFLC, the levels of cardiac biomarkers, troponin and BNP. Therapy includes high-dose chemotherapy; and for patients ineligible for high-dose chemotherapy, bortezomib appears to be the single most active agent. Combinations of bortezomib and the inclusion of monoclonal antibodies are the subject of further studies.