Serum free light chains: diagnostic and prognostic value in multiple myeloma

Abstract

Background: Measurement of serum free light chains (FLCs) has recently become available for the diagnosis and monitoring of patients with plasma cell dyscrasias. The aim of this study was to investigate the performance of the serum FLC assay as a tumour marker by comparing FLC concentrations with serum protein electrophoresis (PE) results in the diagnosis of multiple myeloma (MM). In addition, we also evaluated the prognostic value of the baseline serum FLC ratio in patients with MM. Methods: We measured FLC concentrations and calculated the kappa/lambda (k/l) FLC ratios for three groups (control, polyclonal gammopathy and MM). Results:The FLC ratio at a cut-off threshold of 2.0 showed higher sensitivity and specificity compared with serum electrophoresis for the diagnosis of MM. We used the median FLC ratio of )57.5 and -0.04 for k and l secretors, respectively, for assessing survival. Survival was 30 months in patients with the k/l ratio of )57.5 and -0.04 compared to 47 months in patients with the ratio -57.5 and )0.04, indicating that more abnormal serum FLC ratios are associated with poorer survival (p-0.011). Conclusions: Despite the limitations of the assay, the results of our study indicate that the FLC assay in combination with serum PE has an increased sensitivity in the diagnosis of MM. Also, baseline measurement of the k/l ratio provides prognostic information in these same patients.

Prognostic Value of Serum Free Light Chains Measurements in Multiple Myeloma Patients

“…The association with these parameters support the prognostic value of sFLC because they are indicative of higher tumour burden, deterioration of renal function and a more aggressive disease. Similar findings have been found previously [12,13]. Furthermore, a positive correlation was confirmed between sFLCR, free kappa and free lambda with plasma cell infiltration in bone marrow, creatinine and B2M (Table 2).…”

“…The results from this study confirmed the prognostic value of sFLCR in a cohort of patients in the southern area of Spain for the first time, with a cut-off sFLCR≥47 predicting a worse outcome. The sFLCR cut-off obtained in this study is higher than reported by Snozek et al (sFLC ratio <0.03 or >32) [11] and by Xu et al (sFLC ratio <0.04 or >25) [14], but it is close to that obtained by Sthaneshwar et al with median sFLC ratios of >57.5 and 0.04 for kappa and lambda secretors MM [13]. …”

“…However, these studies lack consensus with respect to the cut off [11,13,14]. The results from this study confirmed the prognostic value of sFLCR in a cohort of patients in the southern area of Spain for the first time, with a cut-off sFLCR≥47 predicting a worse outcome.…”

The importance of serum immunoglobulin free light chain assessment for predicting outcome in patients with newly diagnosed multiple myeloma in real clinical practice

“…Схожие результаты были получены ранее в исследованиях F. van Rhee и соавт., P. Sthaneshwar и соавт. [20,21].…”

“…Основные исследования по изучению прогнос тической роли СЛЦ при ММ выполнены в Европе и США [15,16,[18][19][20][21][22]. В России прогностическая значимость СЛЦ у пациентов с ММ недостаточно из учена [13,[23][24][25] ввиду малой доступности определе ния данных показателей пациентам с ММ, что явилось основанием для проведения настоящего исследования.…”