Bence-Jones Proteins

Alternative name: BJP/urine electrophoresis/urinary light chains/myeloma studies
Description: Bence Jones proteins are monoclonal immunoglobulin light chains found in urine (and plasma) of some patients with myeloma or other lymphoid malignancies. Because of their relatively small size, light chains are readily excreted into the urine. The presence of significant amounts of Bence Jones proteins in urine is indicative of malignant B cell proliferation. Small amounts (< 0.05g/L) may occur with benign B cell proliferation but these levels are not usually detected by standard electrophoretic techniques. Recently deveoped techniques allow the detection of free light chains in serum samples (see free light chains)
Indication: It is important to look at both blood and urine in the investigation of myeloma. Many myelomas secrete free light chains as well as intact immunoglobulin. Some secrete only light chain which could be missed on serum electrophoresis. All patients with these suspected lymphoid malignancy should be investigated for Bence Jones proteins.
Interpretation: The presence of significant amounts of Bence Jones Proteinuria are indicative of malignant B cell proliferation. The marked variability in the excretion of BJP makes this test unreliable for monitoring myeloma.
Sample: Plain urine in universal
Assay details: Gel Electrophoresis: Immunofixation of monoclonal proteins.
Restrictions: For urine electrophoresis please send a 30mL screwtop (white cap universal) . If there is any delay in transport keep at +4 degrees (fridge). If not already done, please also send an SST for serum protein electrophoresis.
Reference range: Qualitative report: negative/positive: 24 hour Bence jones protein excretion can be monitored(see specific sheet).
Assay Range Notes: Nature of Bence Jones protein is defined as lambda, kappa together with whole IgG, IgA or IgM if present.
Turnaround time: 5 – 7 days
Analysing laboratory: Immunology The James Cook University Hospital