Diagnosing plasma cell dyscrasias

Remember this pearl covered in CUH morning report last week regarding the sensitivity of the work-up for myeloma spectrum disorders:

  1. SPEP alone – sensitivity is 82%
  2. SPEP plus immunofixation– sensitivity is 92%
  3. SPEP plus immunofixation plus either Serum free light chains OR UPEP– sensitivity is 98%

At CUH & Parkland, the new SPEP always reflexes to immunofixation, so really what you should remember to do is send either the serum free light chains or the 24-hour UPEP, keeping in mind that SFLC is much easier logistically to do. If patients are admitted anyway, though, in practice, hematologists will recommend obtaining all 3 SPEP / SFLC / 24-hr UPEP.