Paraprotein
Encyclopedia
Plasma cell
Plasma cells, also called plasma B cells, plasmocytes, and effector B cells, are white blood cells which produce large volumes of antibodies. They are transported by the blood plasma and the lymphatic system...
s. Detection of paraproteins in the urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
or blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
is most often associated with benign MGUS
Monoclonal gammopathy of undetermined significance
Monoclonal gammopathy of undetermined significance , formerly benign monoclonal gammopathy, is a condition in which a paraprotein is found in the blood during standard laboratory tests...
(monoclonal gammopathy of undetermined significance), where they remain "silent", and multiple myeloma
Multiple myeloma
Multiple myeloma , also known as plasma cell myeloma or Kahler's disease , is a cancer of plasma cells, a type of white blood cell normally responsible for the production of antibodies...
. An excess in the blood is known as paraproteinemia
Paraproteinemia
Paraproteinemia, or monoclonal gammopathy, is the presence of excessive amounts of a single monoclonal gammaglobulin in the blood...
. Paraproteins form a narrow band, or 'spike' in protein electrophoresis
Protein electrophoresis
Protein electrophoresis is a method for analysing the proteins in a fluid or an extract. The electrophoresis may be performed with a small volume of sample in a number of alternative ways with or without a supporting medium: SDS polyacrylamide gel electrophoresis Protein electrophoresis is a method...
as they are all exactly the same protein.
Monoclonal free light chains in the serum or urine are called Bence Jones protein
Bence Jones protein
A Bence Jones protein is a monoclonal globulin protein found in the blood or urine, with a molecular weight of 22-24 kDa.Finding this protein is often suggestive of multiple myeloma or Waldenstrom's macroglobulinemia....
s.
History
The concept and term were introduced by the BerlinBerlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...
pathologist Dr Kurt Apitz in 1940, at that time the Oberarzt of the pathological institute at the Charité
Charité
The Charité - Universitätsmedizin Berlin is the medical school for both the Humboldt University and the Free University of Berlin. After the merger with their fourth campus in 2003, the Charité is one of the largest university hospitals in Europe....
hospital.
Paraproteins allowed the detailed study of immunoglobulins, which eventually led to the production of monoclonal antibodies
Monoclonal antibodies
Monoclonal antibodies are monospecific antibodies that are the same because they are made by identical immune cells that are all clones of a unique parent cell....
in 1975.
Interpretation upon detection
Blood serumBlood serum
In blood, the serum is the component that is neither a blood cell nor a clotting factor; it is the blood plasma with the fibrinogens removed...
paraprotein levels of more than 30 g/L is diagnostic of multiple myeloma
Multiple myeloma
Multiple myeloma , also known as plasma cell myeloma or Kahler's disease , is a cancer of plasma cells, a type of white blood cell normally responsible for the production of antibodies...
, according to the diagnostic criteria of the International Myeloma Working Group
International Myeloma Working Group
International Myeloma Working GroupThe International Myeloma Working Group was established by the International Myeloma Foundation to provide a forum for researchers to collaborate on cllinical and scientific issues deemed important to the scientific and clinical communities. 134 researchers from...
, which were updated in 2009. Detection of paraprotein in serum of less than 30 g/L is classified as monoclonal gammopathy of undetermined significance
Monoclonal gammopathy of undetermined significance
Monoclonal gammopathy of undetermined significance , formerly benign monoclonal gammopathy, is a condition in which a paraprotein is found in the blood during standard laboratory tests...
in cases where clonal plasma cells constitute less than 10% on bone marrow biopsy and there are no myeloma-related organ or tissue impairment.