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.