Significant elevation and correlation of plasma neutrophil gelatinase associated lipocalin and its complex with matrix metalloproteinase-9 in patients with pelvic inflammatory disease

Backgrounds: To detect the expression of plasma neutrophil gelatinase associated lipocalin (NGAL) and its complex with matrix metalloproteinase-9 (MMP-9) in patients with pelvic inflammatory disease (PID). Methods: Enzyme-linked immunosorbent assay was used to measure the levels of plasma NGAL and NGAL/MMP-9 complex. Results: The levels of plasma NGAL or NGAL/MMP-9 complex were increased in patients with PID compared with those in normal controls and decreased significantly after treatment. Pre-treatment plasma level of NGAL was significantly correlated with WBC and neutrophil counts. In patients with PID, plasma level of NGAL/MMP-9 complex was correlated with plasma level of NGAL or MMP-9 significantly. In predicting PID, the sensitivities of NGAL and NGAL/MMP-9 complex were 76.6% and 78.1%; the negative predictive values, 72.7% and 74.5%. Conclusions: Plasma NGAL and NGAL/MMP-9 complex may act as diagnostic adjuvant biomarkers for PID. In patients with PID, about 80% have plasma levels of NGAL or NGAL/MMP-9 complex level > 10.04. ng/ml or 2.33. ng/ml, respectively.