Screening panels for detection of monoclonal gammopathies.
BACKGROUND
The repertoire of serologic tests for identifying a monoclonal gammopathy includes serum and urine protein electrophoresis (PEL), serum and urine immunofixation electrophoresis (IFE), and quantitative serum free light chain (FLC). Although there are several reports on the relative diagnostic contribution of these assays, none has looked at the tests singly and in combination for the various plasma cell proliferative disorders (PCPDs).


METHODS
Patients with a PCPD and all 5 assays performed within 30 days of diagnosis were included (n = 1877). The diagnoses were multiple myeloma (MM) (n = 467), smoldering multiple myeloma (SMM) (n = 191), monoclonal gammopathy of undetermined significance (MGUS) (n = 524), plasmacytoma (n = 29), extramedullary plasmacytoma (n = 10), Waldenström macroglobulinemia (WM) (n = 26), primary amyloidosis (AL) (n = 581), light chain deposition disease (LCDD) (n = 18), and POEMS syndrome (n = 31).


RESULTS
Of the 1877 patients, 26 were negative in all assays. Omitting urine from the panel lost an additional 23 patients (15 MGUS, 6 AL, 1 plasmacytoma, 1 LCDD), whereas the omission of FLC lost 30 patients (6 MM, 23 AL, and 1 LCDD). The omission of serum IFE as well as urine lost an additional 58 patients (44 MGUS, 7 POEMS, 5 AL, 1 SMM, and 1 plasmacytoma).


CONCLUSIONS
The major impact of using a simplified screening panel of serum PEL plus FLC rather than PEL, IFE, and FLC is an 8% reduction in sensitivity for MGUS, 23% for POEMS (7 patients), 4% for plasmacytoma (1 patient), 1% for AL, and 0.5% for SMM. There is no diminution in sensitivity for detecting MM, macroglobulinemia, and LCDD.
Katzmann
Jerry A
JA
Division of Clinical Biochemistry & Immunology, Department of Laboratory Medicine & Pathology, Mayo Clinic, Rochester, MN, 55905, USA. katzmann.jerry@mayo.edu
Kyle
Robert A
RA
Benson
Joanne
J
Larson
Dirk R
DR
Snyder
Melissa R
MR
Lust
John A
JA
Rajkumar
S Vincent
SV
Dispenzieri
Angela
A
D001798:Blood Proteins / Q000032:analysis; D015331:Cohort Studies; D004586:Electrophoresis / Q000379:methods; D005260:Female; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000097:blood; D007160:Immunoproliferative Disorders / Q000175:diagnosis*; D008297:Male; D008499:Medical Records; D010265:Paraproteinemias / Q000175:diagnosis*; D011507:Proteinuria / Q000652:urine*; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*
D001798:Blood Proteins; D007147:Immunoglobulin Light Chains