Bence-Jones protein

Last edited 09/2022

Bence Jones protein (BJP) is the name given to monoclonal light chains which are filtered by the kidney. There presence in the urine indicates a paraproteinaemia, often multiple myeloma.

Classically BJP is detected by heating urine to 45-55 deg.C. whereupon the protein coagulates. The precipitant redissolves on boiling.

BJP is most accurately detected by urine protein electrophoresis. Immunofixation allows the monoclonal nature of the constituent light chains to be confirmed.

Note that NICE guidance now recommends the use of serum free light chains (SFLC) rather than urinary Bence Jones protein (BJP) in the assessment of possible multiple myeloma, and studies have validated this:

SFLC replaces BJP in these guidelines (1)

  • although it is noted that BJP may still be required for some clinical trials

Urine albumin:creatinine ratio along with troponin and Nterminal pro-B-type natriuretic peptide (NT-proBNP) can be a useful screening tool for detecting amyloid.


  • Sive, J., Cuthill, K., Hunter, H., Kazmi, M., Pratt, G., Smith, D. and (2021), Guidelines on the diagnosis, investigation and initial treatment of myeloma: a British Society for Haematology/UK Myeloma Forum Guideline. Br. J. Haematol., 193: 245-268.