Correlation Between Serum Procalcitonin and Disease Activity Score in Patients with Ankylosing Spondylitis That Have Hip Involvement.

BACKGROUND

To study the correlation analysis between serum procalcitonin (PCT) and Ankylosing Spondylitis Disease Activity Score (ASDAS) in ankylosing spondylitis (AS) patients with hip involvement.

METHODS

This prospective study collected 100 r-axSpA patients and 52 healthy controls. The BASRI-hip score was used to categorize r-axSpA patients into groups with no hip involvement (BASRI-hip=0, 1), mild involvement (BASRI-hip=2), and moderate-to-severe involvement (BASRI-hip=3, 4). Clinical characteristics of the groups were compared. The correlation between PCT, ASDAS, and BASRI-hip was assessed using the Spearman correlation analysis. ROC (Receiver Operating Characteristic) curves were produced to determine the area under the curve (AUC) of PCT and ASDAS in predicting the occurrence of hip involvement and the degree of hip involvement. Factors influencing hip involvement in r-axSpA were analyzed by multifactorial logistic regression.

RESULTS

PCT levels were higher in r-axSpA patients than in healthy controls (p < 0.001). PCT and ASDAS were higher in the group with moderate-to-severe r-axSpA hip involvement than in the group without involvement and the group with mild involvement, while mild involvement was higher than that in the group without involvement (p < 0.05). Spearman correlation showed a positive correlation between PCT, ASDAS, and the degree of hip involvement. The area under the ROC curve (AUC) of PCT, ASDAS were 0.723 and 0.754 in predicting hip involvement, respectively; and the AUC of the severity of hip involvement were 0.733 and 0.718, respectively. PCT (OR = 1.11, 95% CI 1.04-1.18, p < 0.01) and ASDAS (OR = 6.19, 95% CI 1.52-235.12, p = 0.011) were the risk factors for hip involvement.

CONCLUSION

PCT and ASDAS show positive correlation with hip involvement in r-axSpA, and have a certain predictive value to react to hip involvement in r-axSpA.