A decrease or increase of the M-spike that is greater than 0.5 g/dL is considered a significant change. However, if the monoclonal protein falls within the beta region (most commonly an IgA or an IgM) quantitative immunoglobulin levels may be a more useful tool to follow the monoclonal protein level than SPE. The initial identification of an IgM, IgA, or IgG M-spike greater than 4 g/dL, greater than 5 g/dL, and greater than 6 g/dL, respectively, a SVISC / Viscosity, Serum should be tested to rule out hyperviscosity syndrome.Īfter the initial identification of a monoclonal band, quantitation of the M-spike o n follow-up SPE can be used to monitor the monoclonal gammopathy. The initial identification of a serum M-spike greater than 1.5 g/dL on SPE should be followed by MPU / Monoclonal Protein Studies, 24 Hour, Urine.
#No monoclonal protein detected free#
An abnormal serum free light chain (FLC) kappa/lambda (K/L) ratio in the presence of a normal MALDI-TOF MS suggests a monoclonal light chain process and should be followed by MPU / Monoclonal Protein Studies, 24 Hour, Urine. A monoclonal IgM of greater than 3 g/dL is consistent with macroglobulinemia. A monoclonal IgG or IgA of less than 3 g/dL may be consistent with monoclonal gammopathy of undetermined significance (MGUS), primary systemic amyloidosis, early or treated myeloma, as well as a number of other monoclonal gammopathies. A monoclonal IgG or IgA of greater than 3 g/dL is consistent with multiple myeloma (MM). Matrix-assisted laser desorption/ionization-time of flight mass spectrometry ( MALDI-TOF MS ) is performed to identify any immunoglobulin heavy and light chains present. The finding of an M-spike, restricted migration, or hypogammaglobulinemic SPE pattern is suggestive of a possible monoclonal protein. A characteristic monoclonal band (M-spike) is often found on serum protein electrophoresis (SPE) in the gamma globulin region and, more rarely, in the beta or alpha-2 regions. In addition, if the patient is asymptomatic and has a diagnosis of MGUS, the monoclonal gammopathy screen provides the information (size of M-spike, monoclonal protein isotype, FLC kappa/lambda ratio) needed for a MGUS progression risk assessment (see Interpretation). Once a monoclonal gammopathy has been diagnosed, the size of the clonal abnormality can be monitored by SPE or FLC and, in some instances, by quantitative immunoglobulins. If a monoclonal protein pattern is detected by MALDI-TOF MS, immunofixation electrophoresis, or FLC, a diagnosis of a monoclonal gammopathy is established.
While the identification of the monoclonal gammopathy is a laboratory diagnosis, the specific clinical diagnosis is dependent on a number of other laboratory and clinical assessments. Monoclonal gammopathies may be present in a wide spectrum of diseases that include malignancies of plasma cells or B lymphocytes (multiple myeloma, macroglobulinemia, plasmacytoma, B-cell lymphoma), disorders of monoclonal protein structure (primary amyloid, light chain deposition disease, cryoglobulinemia), and apparently benign, premalignant conditions (monoclonal gammopathy of undetermined significance, smoldering MM).
#No monoclonal protein detected for free#
The FLC assay is specific for free kappa and lambda light chains and does not recognize light chains bound to intact immunoglobulin. This expanded monoclonal protein testing panel provides the highest diagnostic sensitivity for the monoclonal light chain diseases such as primary amyloidosis and light chain deposition disease disorders that often do not have serum monoclonal proteins in high enough concentration to be detected and quantitated by SPE. In addition, the MALDI-TOF method can detect glycosylated light chains that have been demonstrated to be a risk factor for amyloidosis. The detection of M-proteins by matrix-assisted laser desorption/ionization-time of flight mass spectrometry ( MALDI-TOF MS) has shown to be more analytically and clinically sensitive than immunofixation. If amyloidosis is suspected, a 24-hour monoclonal protein studies should be performed. The International Myeloma Working Group guidelines state that to adequately screen for a monoclonal protein, serum protein electrophoresis (SPE), immunofixation electrophoresis, and a serum free light chain (FLC) analysis should all be used. Monoclonal proteins are markers of plasma cell proliferative disorders.
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