TY - JOUR
T1 - Elimination of the need for urine studies in the screening algorithm for monoclonal gammopathies by using serum immunofixation and free light chain assays
AU - Katzmann, Jerry A.
AU - Dispenzieri, Angela
AU - Kyle, Robert A.
AU - Snyder, Melissa R.
AU - Plevak, Matthew F.
AU - Larson, Dirk R.
AU - Abraham, Roshini S.
AU - Lust, John A.
AU - Melton, L. Joseph
AU - Rajkumar, S. Vincent
N1 - Funding Information:
This work was supported in part by research grants CA107476 and CA62242 from the National Cancer Institute.
PY - 2006/12
Y1 - 2006/12
N2 - OBJECTIVE: To determine the relative diagnostic contribution of urine assays as part of the screening algorithm for monoclonal gammopathies. PATIENTS AND METHODS: We identified 428 patients with a monoclonal gammopathy and monoclonal urinary protein at initial diagnosis of plasma cell dyscrasia who had also undergone serum immunofixation and serum free light chain quantitation within 30 days of diagnosis. The laboratory results for serum protein electrophoresis, serum immunofixation, serum free light chain, urine protein electrophoresis, and urine immunofixation were reviewed. RESULTS: The patients had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. All 428 had a monoclonal urine protein, 85.7% had an abnormal serum free light chain κ/λ ratio, 80.8% had an abnormal serum protein electrophoresis, and 93.5% had an abnormal serum immunofixation result. All 3 serum assays were normal in only 2 patients, 1 of whom had monoclonal gammopathy of undetermined significance (idiopathic Bence Jones proteinuria) and 1 whose urine sample contained an intact monoclonal immunoglobulin but whose serum and subsequent urine samples showed no evidence of a monoclonal gammopathy. CONCLUSION: Discontinuation of urine studies and reliance on a diagnostic algorithm using only serum studies (protein electrophoresis, immunofixation, and free light chain quantitation) missed 2 (0.5%) of the 428 monoclonal gammopathies with urinary monoclonal proteins, and these 2 cases required no medical intervention.
AB - OBJECTIVE: To determine the relative diagnostic contribution of urine assays as part of the screening algorithm for monoclonal gammopathies. PATIENTS AND METHODS: We identified 428 patients with a monoclonal gammopathy and monoclonal urinary protein at initial diagnosis of plasma cell dyscrasia who had also undergone serum immunofixation and serum free light chain quantitation within 30 days of diagnosis. The laboratory results for serum protein electrophoresis, serum immunofixation, serum free light chain, urine protein electrophoresis, and urine immunofixation were reviewed. RESULTS: The patients had diagnoses of multiple myeloma, primary amyloid, monoclonal gammopathy of undetermined significance, smoldering multiple myeloma, solitary plasmacytomas, and other less frequently detected monoclonal gammopathies. All 428 had a monoclonal urine protein, 85.7% had an abnormal serum free light chain κ/λ ratio, 80.8% had an abnormal serum protein electrophoresis, and 93.5% had an abnormal serum immunofixation result. All 3 serum assays were normal in only 2 patients, 1 of whom had monoclonal gammopathy of undetermined significance (idiopathic Bence Jones proteinuria) and 1 whose urine sample contained an intact monoclonal immunoglobulin but whose serum and subsequent urine samples showed no evidence of a monoclonal gammopathy. CONCLUSION: Discontinuation of urine studies and reliance on a diagnostic algorithm using only serum studies (protein electrophoresis, immunofixation, and free light chain quantitation) missed 2 (0.5%) of the 428 monoclonal gammopathies with urinary monoclonal proteins, and these 2 cases required no medical intervention.
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U2 - 10.4065/81.12.1575
DO - 10.4065/81.12.1575
M3 - Article
C2 - 17165636
AN - SCOPUS:33845334882
VL - 81
SP - 1575
EP - 1578
JO - Mayo Clinic Proceedings
JF - Mayo Clinic Proceedings
SN - 0025-6196
IS - 12
ER -