Is there still a role for plasma exchange/PLEX for confirmed or suspected cast nephropathy in multiple myeloma to rapidly reduce light chain burden?

This is a good question that comes up from time to time. The most important thing is time-to-bortezomib, which should be as short as possible.

For light chain only disease, I do not do plasma exchange. My reasons are:

1. It only marginally reduces free light chains (see: Hutchison et al., PMID 17229909)
2. Introduces other complications like blood clots if a new line needs to be inserted
3. I start bortezomib/dex in most and occasionally CyBorD if feeling frisky. As such, important to note that bortezomib is 80% protein bound. This also means that apheresis/bortezomib would need to be timed carefully, and may result in delaying chemotherapy. This is especially important when considering that plasma exchange is most beneficial if doing 3+ sessions.

T...