Simultaneous Evaluation of Serum Immunofixation Electrophoresis and Serum Free Light Chain Measurements Used in the Diagnosis of Monoclonal Gammopathy and Smoldering Multiple Myeloma of Uncertain Significance in the Presence of Risk Factors

INTRODUCTION: This study aimed to investigate the effectiveness of using serum free light chain (sFLC) together with traditional examination methods in diagnosing monoclonal gammopathy of undetermined significance (MGUS) and smoldering multiple myeloma (SMM), especially in patients with MG without hypercalcemia, renal dysfunction, anemia, and bone lesions (CRAB) symptoms, by eliminating the need for bone marrow biopsy (BMb).
METHODS: A total of 160 patients over 50 years of age with an ESR of 50 mm/h and above were included in the study. Serum immunofixation electrophoresis (sIFE) and sFLC levels of these patients were studied simultaneously. Sensitivity and specificity of the sIFE and sFLC for diagnosis of MGUS were estimated by ROC analysis.
RESULTS: MG was detected in 36 (22.5%) patients with sIFE and in 30 (18.7%) patients with sFLC of 160 patients included in the study. There was a total of 44 patients with MG detected by sIFE alone, sFLC alone, and both sIFE and sFLC. Bone marrow biopsy(bmb) was performed on 42 patients with MG who approved the bmb procedure. These patients were diagnosed MGUS, SMM and MM by using test results, bmb results, and clinical and laboratory data. The sensitivity of sIFE in the detection of MG was 82.5% and the specificity was 99.2% (p<0.001). sFLC had a sensitivity of 72.5% and a specificity of 99.2% (p0.001). When siFE and sFLC were performed simultaneously, the sensitivity was 100% and the specificity was 98.3% (p<0.001).
DISCUSSION AND CONCLUSION: Simultaneous monitoring of sIFE and sFLC, which is both non-invasive and with the opportunity to achieve results in less time without BM bx, may be sufficient and reliable in the diagnosis and follow-up of MGUS in the detection of MGs and especially in asymptomatic patients.

Risk Faktörleri Varlýðýnda Önemi Belirsiz Monoklonal Gammopati ve Smoldering Multiple Myeloma Tanýsýnda Kullanýlan Serum Ýmmünfiksasyon Elektroforezi ve Serum Serbest Hafif Zincir Ölçümlerinin Eþ Zamanlý Deðerlendirilmesi

GÝRÝÞ ve AMAÇ: Bu çalýþmada, özellikle hiperkalsemi, böbrek fonksiyon bozukluðu, anemi ve kemik lezyonlarý (CRAB) semptomlarý olmayan monoklonal gamopatili (MG) hastalarda, önemi belirsiz monoklonal gamopati (MGUS) ve smoldering multipl miyelom (SMM) tanýsýnda, serum serbest hafif zincirinin (sFLC) geleneksel tetkik yöntemleri ile birlikte kullanýmýnýn kemik iliði biyopsisi (kib) ihtiyacýný ortadan kaldýrarak etkinliðinin araþtýrýlmasý amaçladýk.
YÖNTEM ve GEREÇLER: Çalýþmaya ESR 50 mm/h ve üzerinde olan, 50 yaþ üstü 160 hasta alýndý. Bu hastalarýn serum immünfiksasyon elektroforezi (sIFE) ve serum hafif serbest zincir (sFLC) düzeyleri eþ zamanlý çalýþýldý. MGUS tanýsý için sIFE ve sFLC'nin duyarlýlýðý ve özgüllüðü ROC analizi ile tahmin edildi.
BULGULAR: Çalýþmaya alýnan160 hastanýn yapýlan sIFE ile 36 (%22,5) hastada ve sFLC ile de 30 (%18,7) hastada monoklonal gammopati (MG) tespit edilmiþtir. Yalnýzca sIFE, yalnýzca sFLC ve hem sIFE hem de sFLC tarafýndan saptanan MG'li toplam 44 hasta vardý. MG tespit edilen ve kemik iliði biyopsi (kib) iþlemine onay veren 42 hastaya kib yapýlmýþtýr. Bu hastalara; test sonuçlarý, kib sonuçlarý, klinik ve laboratuar verileri de kullanýlarak MGUS, SMM ve MM tanýsý konulmuþtur. sÝFE’nin MG tespitinde sensitivitesi %82.5, spesifitesi %99.2 (p<0.001) olarak saptanmýþtýr. sFLC’nin ise sensitivitesi %72.5, spesifitesi %99.2 (p<0.001) olarak saptanmýþtýr. sÝFE ve sFLC eþ zamanlý yapýldýðýnda ise sensitivitesi %100, spesifitesi %98.3 (p<0.001) olarak saptanmýþtýr.
TARTIÞMA ve SONUÇ: MG’lerin tespitinde ve özellikle asemptomatik hastalarda kib yapmadan hem noninvaziv hem de daha kýsa sürede sonuç alma fýrsatý ile sIFE ve sFLC nin eþ zamanlý bakýlmasý MGUS tanýsý koymada ve takip etmede yeterli ve güvenilir olabilir.