- Bence Jones protein
A Bence Jones protein is a monoclonal
globulin proteinfound in the bloodor urine. Finding this protein in the context of end-organ manifestations such as malignant bone marrow cancer, renal failure, lytic bone disease, or anemia, or large numbers of plasma cellsin the bone marrowof patients can be diagnostic of multiple myeloma, in which it is present in 2/3 of cases.cite book |author=Hoffbrand V, Moss P, Pettit J |title=Essential Haematology (Essential) |edition=5th edition |publisher=Blackwell Publishing Professional |location= |year=2006 |pages=218 |isbn=1405136499 |oclc= |doi=]
The proteins are
antibody immunoglobulinfree light chains ( paraproteins) and are produced by neoplastic plasma cells. They can be kappa (most of the time) or lambda. The light chains can be immunoglobulin fragments or single homogenous immunoglobulins. They are found in urine as they are small and hence easily cleared by the kidneys. The light chains can be detected by heating or electrophoresisof concentrated urine. Light chains precipitate when heated to 50 - 60 degrees C and redisolve at 90 -100 degrees C. These tests are essential in patients suspected of having Bence Jones proteins in their urine as these proteins don't react with the reagents normally utilized in urinalysisdipsticks. This leads to false negative results in people with Bence Jones proteins in their urine undergoing standard urinalysis. There are various rarer conditions which can produce Bence Jones proteins, such as Waldenström's macroglobulinemiaand other malignanices.
The Bence Jones protein was described by the English physician
Henry Bence Jonesin 1847 and published in 1848. [cite journal |author=Jones HB |title=On a new substance occurring in the urine of a patient with mollities ossium |journal=Phil Trans R Soc Lond |year=1848 |volume=138 |pages=55–62 |doi=10.1098/rstl.1848.0003] The protein was later sequenced by Frank Putnam at the laboratory of Fred Sangerin Cambridge, who was the first to report the entire sequence.
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