Comparison of amniotic fluid matrix metalloproteinase-8 and cathelicidin in the diagnosis of intra-amniotic infection.

OBJECTIVE

To evaluate the association of amniotic fluid (AF) matrix metalloproteinase-8 (MMP-8) and cathelicidin concentrations with microbial invasion of the amniotic cavity (MIAC) in pregnancies with preterm prelabor rupture of the membranes or intact membranes.

STUDY

DESIGN

Amniocentesis was performed in 54 singleton pregnancies between 22+0 and 34+2 gestational weeks with suspected intra-amniotic infection. AF-MMP-8 was analysed by immunoassay and AF-cathelicidin by commercial ELISA. Standard biochemical methods, molecular microbiology and culture techniques were used.

RESULTS

MIAC was present in 18 (33%) women. The cutoff value for the diagnosis of MIAC was 41.5 ng ml-1 for AF-MMP-8, and 11.6 ng ml-1 for AF-cathelicidin. With these cutoff values AF-MMP-8 had a sensitivity of 100%, specificity of 69%, positive predictive value of 62% and negative predictive value of 100% for MIAC. The corresponding values for AF-cathelicidin were 89, 81, 70 and 94%.

CONCLUSION

The performance of AF-cathelicidin in the prediction of MIAC is comparable to AF-MMP-8.