Analysis of serum levels of bone turnover biochemical markers in patients with SAPHO syndrome / 中华风湿病学杂志

ABSTRACT

Objective:To evaluate the changes and significance of bone turnover makers in patients with SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome.Methods:Thirty-two patients with SAPHO syndrome who were treated in the department of rheumatology and immunology of Beijing Jishuitan Hospital were collected as the study group, and 28 healthy subjects were taken as the control group. The clinical data and bone turnover markers were compared between the two groups, and the correlation between the bone turnover markers and disease-related indicators were analyzed. Two independent samples were comp-ared by using t test (in line with normal distribution) and rank sum test (not in line with normal distribution). The results of more than two independent samples were compared by one-way analysis of variance, and the correlation between two variables was analyzed by Spearman. Results:Compared with the clinical data of the two groups, hemoglobin (Hb) of the study group [128(122, 140) g/L] was significantly lower than that of the control group [139(125, 154) g/L]( U=306.5, P<0.05), but alkaline phosphatase (ALP) [75.00(66.00, 85.75) mmol/L] was significantly higher than that of the control group [56.00(48.50, 63.25) mmol/L] ( U=153, P<0.01). The comparison of bone turnover markers showed that serum total procollagen type 1 amino-terminal propeptide (tP1NP)[52.51(41.72, 86.11) ng/ml], Beta C-terminal cross-linked telopeptides of type Ⅰ collagen (β-CTX) [0.57(0.39, 0.72) ng/ml] and OC [(20±8) ng/ml] levels in the study group were significantly higher than those in the control group [34.91(28.97, 42.80) ng/ml, 0.34(0.27, 0.49) ng/ml, (15±4) ng/ml] ( U=183, P<0.01; U=223, P<0.01; t=3.180, P<0.01). There was no significant difference in 25-(OH)VD 3 between the two groups [14.73(12.25, 19.23) ng/ml, 16.72(11.74, 20.92) ng/ml] ( P>0.05). The serum biochemical markers of bone turnover were not related to spine, bone and joints involvement. The grouping results of the number of joints involved showed that there were significant differences in serum osteocalcin (OC) levels of patients ( F=3.684, P<0.05), and the more the number of joints involved, the lower the OC value. Correlation analysis showed that serum tP1NP ( r=0.805), β-CTX ( r=0.460) and OC levels were positively correlated with each other(all P<0.01). Levels of tP1NP, β-CTX, OC, and 25-(OH)VD 3 in the study group were not related to age, course of disease, and neutrophil granulocyte (all P>0.05). However, β-CTX was positively correlated with C-reactive protein (CRP) ( r=0.392, P<0.05), and OC was positively correlated with erythrocyte sedimentation rate (ESR) ( r=0.475, P<0.05). Conclusion:The levels of tP1NP, β-CTX and OC in patients with SAPHO syndrome are significantly increased. Levels of β-CTX and OC can reflect the severity of patients' inflammation. The level of OC is related to the number of joint involvement of the patient.