Matrix metalloproteinase-12, an indicator potentially contributing to the differential diagnosis and activity assessment of retroperitoneal fibrosis.

Objectives: We aimed to find a diagnostic indicator that contributed to differential diagnosis and activity assessment of retroperitoneal fibrosis (RPF).

Methods: We analysed the expression of MMP-12 in pathological tissues and peripheral blood, and explored their correlations with clinical, laboratory, radical and pathological parameters.

Results: The positive rate of MMP-12 in pathological tissues was significantly higher than that in the healthy controls. It was positively correlated with the positive rates of mTOR, CXCR5, IL-13 in the germinal centres (GCs) and MMP-12, IL-13 in the periphery. The parametric estimate of the area under the ROC curve of the positive rate and its 95% confidence interval were 0.875 and 0.673 ~1.000. The cut-off value and sensitivity and specificity were 16.395%, 0.938 and 0.750. Thickness of RPF mass was more severe in MMP-12 positive group based on this cut-off value. Although the concentration of MMP-12 in peripheral blood did not increase significantly, it was positively correlated with time before treatment and the positive rate of CXCR5 in the GCs.

Conclusions: The positive rate of MMP-12 in the GCs of pathological tissues is a potential marker that contributes to the differential diagnosis of RPF and might be associated with the degree of fibrosis, although MMP-12 in the peripheral blood was not very helpful for disease diagnosis and monitoring of treatment effects. MMP-12 had the potential to become an indicator for the differential diagnosis RPF and monitoring the disease process.