The long pentraxin PTX3: a novel serum marker to improve the prediction of osteoporosis and osteoarthritis bone-related phenotypes.

Background: The long pentraxin PTX3 is generating great interest given the recent discovery of its involvement in bone metabolism. This study investigates the role of circulating PTX3 as a marker of bone-related phenotypes in patients with osteoporosis (OP) and osteoarthritis (OA).
Methods: Serum PTX3 levels were determined using an enzyme-linked immunosorbent assay (ELISA) in a total of OP (n=32), OA (n=19) patients and healthy controls (CTR; n=25). ROC curve analysis was carried out to evaluate the potential of PTX3 for the diagnosis of bone-related phenotypes. In addition, the association between PTX3 serum levels and biochemical markers was estimated by Spearman correlation analysis.
Results: Serum analysis reveals a statistically significant increase of PTX3 levels in OP and OA patients, compared to CTR subjects (**** p < 0.0001, **** p < 0.0001). ROC curve of PTX3 levels exhibits an excellent sensitivity and specificity for OP and OA diseases (**** p < 0.0001 and **** p < 0.0001, respectively). Moreover, serum PTX3 levels are positively associated with ALP (r = - 0.5257, p = 0.0083) and PTH levels (r = 0.4704, p = 0.0203) in OP patients.
Conclusions: These results confirm the pivotal role of PTX3 in bone metabolism and suggest its potential use as a predictor of OP and OA bone-related phenotypes.