New markers in pelvic inflammatory disease

•PID is one of the most common infections in reproductive women.•PTX3, E-cadherin, myeloperoxidase, SDF-1 and MMP-9/MMP-2 ratio may detect PID.•Gas6 in combination with sAxl may elevate the sensitivity of PID detection.•PTX3 and YKL-40 concentrations can predict TOA and clinical course of PID.

Pelvic inflammatory disease (PID) is a common infection in women of reproductive age. However, diagnosis of PID can be difficult due to the wide variation in the symptoms and signs, ranging from subtle or mild symptoms to severe pain in the lower abdomen. Clinical diagnosis alone has only 87% sensitivity and 50% specificity. Therefore, identifying biological factors that are useful for early diagnosis and correlating their expression with the severity of PID could provide significant benefits to women suffering from PID. Pentraxin 3 (PTX3), E-cadherin, myeloperoxidase, stromal cell-derived factor 1 (SDF-1) and the matrix metalloproteinase-9 (MMP-9)/MMP-2 ratio are potential candidates for detecting PID reliably. As PID is often subtle, highly sensitive PID detection methods are needed to promote the prevention of severe sequelae. Growth arrest-specific 6 (Gas6), in combination with its soluble tyrosine kinase receptor, sAxl, could elevate the sensitivity to 92%, which was higher than all other markers tested. Moreover, PTX3, D-dimer and YKL-40 concentrations can predict the clinical course of PID. Although single nucleotide polymorphisms of biomarker genes are not associated with the development of PID, myeloperoxidase SNP − 463 G/A and SDF-1 SNP 801 G/A may affect the aggravated expression of their biomarkers in PID.