Clinical Significance of Serum Free Light Chain and Its κ/λ Ratio in Patients with Multiple Myeloma / 中国实验血液学杂志

ABSTRACT

OBJECTIVE@#To analyze the clinical significance of serum free light chain (sFLC) and sFLC-κ/λ ratio in patients with newly diagnosed multiple myeloma (MM), so as to provide the theoretical basis for the diagnosis, treatment and prognosis of MM patients.@*METHODS@#A total of 43 patients newly diagnosed as MM in our hospital and 40 cases of other diseases that could cause sFLC increase were selcted. The clinical features of newly diagnosed MM patients were analyzed. On the basis of the type of sFLC, MM patients were divided into sFLC-κ and sFLC-λ group. The correlation of sFLC with clinical index in two groups was analyzed. The difference of sFLC-κ/λ ratio between MM and non-MM patients was analyzed. According to whether the involved/uninvolved sFLC ratio was greater than 100, the MM patients were divided into the low ratio and the high ratio group. The clinical index of these 2 groups were analyzed.@*RESULTS@#Among MM patients, IgG type was the most. In sFLC-κ and -λ groups, the hemoglobin level negatively correlated with sFLC (r=-0.307, r=-0.494, P＜0.05), and the serum β2 microglobulin level positively correlated with sFLC (r=0.453, r=0.689, P＜0.05), and myeloma cells ratio also positively correlated with sFLC (r=0.307, r=0.309, P＜0.05). The concentration of albumin, lactate dehydrogenase and serum calcium did not correlate with sFLC (P＞0.05). The serum creatinine level also did not correlate with sFLC in the sFLC-κ group (P＞0.05), but in the sFLC-λ group they were obviously positive (r=0.697, P＜0.01). The ratio of sFLC-κ/λ ＜0.26 or ＞1.65 in MM patients was higher than that of non-MM patients, and the ratio of involved/uninvolved sFLC≥100 in MM patients was also higher than that of non-MM patients with statistically significant differences (P＜0.01). The levels of serum albumin, creatinine and β2 microglobulin, as well as myeloma cell ratio and ISS international staging of the patients between 2 groups were significantly different (P＜0.05), while the differences in sex, age and levels of hemoglobin, lactate dehydrogenase and blood calcium were not significant between the 2 groups (P＞0.05).@*CONCLUSION@#The light chain type λ in MM patients correlates with renal damage. The abnormalities of sFLC-κ/λ ratio occur mostly in MM patients. The MM patients with involved/uninvolosed sFLC ratio ≥100 show the severe symptoms and poor prognosis.