[Clinical significance of the ratio of serum beta-CTX/PINP in multiple myeloma bone diseases and bone metastases].

To explore the clinical significance of serum bone metabolites β C-termianl telopeptide of type Ⅰ collagen(β-CTX), Procollagen type Ⅰ N-terminal peptide(PINP) concentration and ratio of beta -CTX/PINP in multiple myeloma bone disease (MMBD) and bone metastases. A total of 31 cases of MM, 46 cases of bone metastases and 12 healthy controls were enrolled in the department of hematology, oncology and physical examination center of Henan Provincial People's Hospital respectively from October 2016 to October 2017. According to the imaging findings, MMBD was divided into 0-4 grades, group A included the patitents with grade 0-2 of osteopathy (=8), and group B included the grade 3-4 (=23). After two courses of chemotherapy, the curative effect was evaluated. MM group were divided into effective group (above partial remission , =22) and uneffective group (unreached partial remission, =9). ELISA method was used to detect the concentration of serum beta -CTX and PINP, and the ratio of beta -CTX/PINP was calculated. The serum beta -CTX concentration in newly diagnosed MM, bone metastases and healthy control were (3 563 ± 544)ng/L, (6 690±343)ng/L, (2 726±1 026)ng/L (χ=22.207, <0.001), PINP concentration were (72 ± 14) ng/L, (112 ± 62) ng/L, (171 ± 62) ng/L (χ=7.418, =0.024) , and beta -CTX/PINP ratio were 93±19, 141±21, 17±8 (χ=20.192, <0.001), the differences were statistically significant. The ratio of initial MM beta -CTX/PINP was higher than that of healthy control (=0.001). The concentration of beta -CTX (=0.003) and the ratio of beta -CTX/PINP(<0.001) in bone metastases were higher than those in healthy controls. The serum concentration of beta-CTX in newly diagnosed MM was lower than that in bone metastases (<0.001). Before chemotherapy, the serum levels of beta -CTX and PINP in A and B groups were not statistically significant, but the ratio of serum beta -CTX/PINP in A group was lower than that in group B, and the difference was statistically significant. After two courses chemotherapy, the concentration of serum beta -CTX (=0.023) and the ratio of beta -CTX/PINP (<0.001) were decreased in MM group. There were no significant difference of serum beta -CTX, PINP concentration, and beta-CTX/PINP ratio before and after treatment in Group A. Patients in the group B, there was no significant difference in the changes of serum PINP concentration, but both serum beta -CTX concentration and beta-CTX/PINP ratio decreased after two courses[(4 027 ± 648)ng/L vs (2 370± 460) ng/L, =0.043; 111± 23 vs 30± 6, =0.002]. The ratio of serum beta-CTX/PINP decreased in the effective group, and the difference was statistically significant. There was no significant difference in serum beta-CTX, PINP concentration and beta-CTX/PINP ratio before and after treatment in the uneffective group. There is a difference between newly diagnosed MMBD and bone metastases in serum beta-CTX, which might be helpful for differential diagnosis, and the ratio of beta-CTX/PINP is positively correlated with the severity of MMBD, which might be used to evaluate the severity of bone disease and have a certain monitoring significance for the treatment of MM.