Non-light-chain immunoglobulin amyloidosis: time to expand or refine the spectrum to include light+heavy chain amyloidosis?

Among the various systemic amyloidoses, deposits derived from the immunoglobulin light chain (AL) account for 85% of cases. In this issue, Nasr et al. report 16 cases of renal heavy and light+heavy chain amyloidosis and compare them with renal light chain amyloidosis. While additional studies are needed to shed light on the heavy and light+heavy chain amyloidoses, several observations by the authors suggest important practical implications, including differences in clinical picture, prognosis and pathologic diagnosis.