[Applied Value of Serum Bone Turnover Markers in Patients with Myeloma Bone Disease].

Objective: To explore the clinical value of serum bone turnover markers including β-CrossLaps (β-CTx), N-MID Osteocalcin (Osteocalcin), and total procollagen type 1 amino-terminal propeptide (TP1NP) in patients with myeloma bone disease (MBD).

Methods: A total of 55 MBD patients(MBD group) and 20 healthy volunteers(control group) were selected, and the serum was collected for detecting β-CTx, Osteocalcin and TP1NP by Roche analyzer of automated electrochemiluminescence. Meanwhile, the imaging techniques such as MRI and CT were used for evaluation of bone destruction and the damage extent in MBD patients.

Results: Measurement data is expressed as median (P25, P75) according to distribution characteristics of data. The detection results showed that concentrations of β-CTx in MBD patients and control group were 0.72(0.48, 1.28) ng/mL and 0.53(0.34, 0.61) ng/mL respectively, the β-CTx concentration in MBD patients was significantly higher than that in control group(P=0.002). The ratio β-CTx to TP1NP (%) in MBD patients and control group was 1.50 (1.05, 3.36) and 1.25 (0.86, 1.35) respectively, the ratio in MBD patients was significantly higher than that in control group (P=0.007). The serum β-CTx concentrations in MBD patients of localized bone destruction type and extensive bone destruction type were 0.41(0.31, 0.66) ng/mL and 1.14(0.72, 1.81) ng/mL respectively, the β-CTx concentration in MBD patients of extensive bone destruction type was significantly higher than that in MBD patients of localized bone destruction type (P＜0.001). The ratio of β-CTx to TP1NP(%) in MBD patients of localized and extensive bone destruction type was 1.30 (0.90, 2.49) and 1.98 (1.18, 3.76) respectively, the ratio in the MBD patients of extensive bone destruction type was significantly higher than that in MBD patients of localized bone destruction type (P=0.019). The serum osteocalcin concentrations in MBD patients of localized and extensive bone destruction type were 14.31 (8.82, 19.39) ng/mL and 21.52 (14.42, 47.76) ng/mL respectively, the osteocalcin concentration in MBD patients of extensive bone destruction type was higher than that in MBD patients of localized bone destruction type (P=0.008). The AUC of β-CTx was 0.88 (95% CI: 0.78-0.98)(P＜0.001), and the cut-off value was 0.69 ng/ml in the diagnosis of extensive bone injury for MBD patients, and the sensitivity and specificity were 80.65% and 83.33% respectively.

Conclusion: The MBD patients show bone resorption hyperthyroidism and high bone turnover. The β-CTx and osteocalcin in serum bone turnover markers can effectively reflect the extent of bone damage in MBD patients, especially the β-CTx is more efficient for the diagnosis of MBD patients of extensive bone destruction type. However, β-CTx, osteocalcin and TP1NP are not relate with the MM disease progression.