[Role of Total Vitamin D, Total Procollagen Type I Amino-Terminal Propeptide and β-CrossLaps in Multiple Myeloma].

Objective: To analyze the significance of total vitamin D (tVD), total procollagen type I amino-terminal propeptide (tPINP) and β-CrossLaps (β-CTx) in the staging and prognosis of patients with multiple myeloma (MM).

Methods: A total of 54 patients with newly diagnosed MM admitted to the Second Affiliated Hospital of Fujian Medical University from 2020 to 2022 were selected as the observation group (MM group), and 50 healthy persons who underwent physical examinations in our hospital were selected as the control group. The expression levels of tVD, tPINP and β-CTx in the two groups were detected by chemiluminescence method. The differences in the expression levels of tVD, tPINP and β-CTx among MM patients at different ISS stages were analyzed. The expression levels of tVD, tPINP and β-CTx in MM patients with different levels of hemoglobin (Hb), serum calcium (Ca), creatinine (Crea), albumin (ALB), β₂-microglobulin (β₂-MG) and lactate dehydrogenase (LDH) were compared. The correlations between the expression levels of tVD, tPINP, β-CTx and the aforementioned clinical parameters were analyzed, respectively. The relationship between the expression levels of tVD, tPINP, β-CTx and the progression-free survival (PFS) of MM patients was analyzed.

Results: The expression level of tVD in the MM group was significantly lower than that in the control group (21.73±14.45 ng/ml vs 30.78±9.94 ng/ml, P =0.022). The expression level of β-CTx in the MM group was significantly higher than that in the control group (1.43±0.99 ng/ml vs 0.53±0.29 ng/ml, P =0.013). The tVD level in MM patients with ISS stage I-II was significantly higher than that of MM patients with ISS stage III (29.50±14.59 ng/ml vs 12.62±7.73 ng/ml, P =0.028), indicating that the higher the ISS stage, the lower the tVD level. The tPINP and β-CTx levels in MM patients with high Ca levels (>2.65 mmol/L) were significantly higher than those in patients with low Ca levels (≤2.65 mmol/L) (P =0.016, P =0.021). The tVD level of MM patients was positively correlated with the ALB level (r =0.570), tPINP was positively correlated with Ca and β₂-MG levels (r =0.791,r =0.673), and β-CTx was positively correlated with tPINP level (r =0.616). The PFS of the low tVD expression group was significantly lower than that of the high tVD expression group (P =0.041).

Conclusion: The expression level of tVD is decreased in MM patients, which can be used as an indicator to evaluate the disease stage and prognosis of the patients. The β-CTx expression level is increased in MM patients. tPINP and β-CTx may be correlated with clinical symptoms such as osteolytic lesions and renal function changes in MM patients.