title: Serum protein electrophoresis in the evaluation of lytic bone lesions.
abstract: Serum protein electrophoresis (SPEP) is often obtained at the initial evaluation of a radiolucent bone lesion of unknown etiology. The results are considered convincing evidence of the presence or absence of a plasma cell neoplasm. The sensitivity and specificity of the SPEP have not been reported in this clinical scenario. Our purpose is to assess the diagnostic value of the SPEP in the initial work-up of the radiolucent bone lesion. We identified 182 patients undergoing evaluation of a radiolucent bone lesion that included tissue biopsy and an SPEP value. We then calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of SPEP as a diagnostic test for a plasma cell neoplasm in this clinical scenario. Forty-six of 182 (25.3%) patients in our series were diagnosed with a plasma cell neoplasm by histopathologic analysis. The sensitivity of SPEP was 71% and the specificity was 83%. PPV was 47% and NPV was 94%. When analyzing only those presenting with multiple lesions, the percentage of patients diagnosed with multiple myeloma increased to 44.7% (34 of 76 patients). The SPEP, however, did not have a substantially increased diagnostic accuracy with sensitivity of 71%, specificity 79%, PPV 40% and NPV 93%. SPEP lacks sensitivity and positive predictive value to provide a definitive diagnosis of myeloma in radiolucent bone lesions, but has a high negative predictive value which may make it useful in ruling out the disease. We recommend that this test either be performed in conjunction with urine electrophoresis, immunofixation electro-phoresis and free light chain assay, or after biopsy confirming the diagnosis of myeloma.
authors.affiliation: University of Iowa Hospitals & ClinicsDepartment of Orthopaedics & Rehabilitation , 200 Hawkins DriveIowa City , IA 52242.
authors.forename: Lukas M
authors.initials: LM
authors.lastname: Nystrom
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Buckwalter
authors.forename: Sergei
authors.initials: S
authors.lastname: Syrbu
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Miller
mesh_terms: D001797:Blood Protein Electrophoresis; D001859:Bone Neoplasms / Q000097:blood / Q000175:diagnosis*; D006801:Humans; D009101:Multiple Myeloma / Q000097:blood / Q000175:diagnosis*; D010014:Osteolysis / Q000097:blood / Q000175:diagnosis*; D010954:Plasmacytoma / Q000097:blood / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
references.citation: CA Cancer J Clin. 2010 Mar-Apr;60(2):70-98
references.pmid: 20200110
references.citation: Mayo Clin Proc. 2003 Jan;78(1):21-33
references.pmid: 12528874
references.citation: ANZ J Surg. 2006 Aug;76(8):732-5
references.pmid: 16916396
references.citation: Leukemia. 2009 Jan;23(1):3-9
references.pmid: 18971951
references.citation: Orthopedics. 2011 Apr 11;34(4):
references.pmid: 21469628
references.citation: J Urol. 1994 May;151(5):1283-90
references.pmid: 7512659
references.citation: Cancer. 1986 Sep 1;58(5):1088-95
references.pmid: 3015375
references.citation: Can J Urol. 2011 Oct;18(5):5875-83
references.pmid: 22018148
references.citation: Clin Orthop Relat Res. 1982 Jun;(166):96-103
references.pmid: 7083692
references.citation: Clin Chem. 2011 Dec;57(12):1687-92
references.pmid: 21980167
references.citation: J Bone Joint Surg Am. 1993 Sep;75(9):1276-81
references.pmid: 8408149
references.citation: AJR Am J Roentgenol. 2008 May;190(5):1300-6
references.pmid: 18430847
references.citation: Lancet. 2012 Jul 21;380(9838):218
references.pmid: 22817975
references.citation: Clin Orthop Relat Res. 2003 Oct;(415 Suppl):S105-9
references.pmid: 14600599
references.citation: Br J Haematol. 1982 Jul;51(3):361-75
references.pmid: 7104223