Serum amyloid A as a diagnostic marker for histologic chorioamnionitis in preterm premature rupture of membranes: A diagnostic accuracy study

Background: Chorioamnionitis is an acute inflammation of the fetal membrane in mothers with preterm premature rupture of the membrane (PPROM). The diagnosis of chorioamnionitis is based on clinical findings; however, laboratory tests may help diagnose the disease. Objective: It aimed to evaluate the accuracy of maternal serum-amyloid A (SAA) protein levels in diagnosing histopathologic chorioamnionitis following PPROM mothers; secondarily, it assessed their accuracy for diagnosing clinical chorioamnionitis. Materials and Methods: In this diagnostic accuracy study, ۹۴ PPROM pregnancies, referred to Namazi, Hafez, and Zeinabiyeh hospitals, Shiraz, Iran, from March ۲۰۲۲ to March ۲۰۲۳ were followed. All placentas were examined for histopathological evidence of chorioamnionitis, and participants were classified into ۲ pathologic chorioamnionitis and normal placenta groups. Results: From the ۹۴ participants, ۵۰ (۴۳.۲۰%) were pathologically diagnosed with chorioamnionitis as pathologic chorioamnionitis group, and the remaining ۴۴ (۴۶.۸۰%) belonged to control “normal placenta group”. In addition, ۵۰% (۲۵/۵۰) of women with pathological chorioamnionitis were clinically diagnosed with chorioamnionitis as clinic chorioamnionitis group, and the remaining ۵۰% (۲۵/۵۰) with no clinical signs of chorioamnionitis belonged to their control. Pathologic at-delivery SAA were more in the pathologic chorioamnionitis group compared with normal placenta group; adjusted odds ratio (۹۵% confidence interval); ۱۵.۲۰ (۲.۶۲-۸۸.۲۰); the area under curve values (cutoff point, sensitivity, specificity, negative predictive value, positive predictive value, and accuracy) were ۰.۸۳ (> ۰.۵۴ mg/dl, ۹۵%, ۷۰%, ۸۶%, ۸۸%, and ۸۴%) for pathologic at-delivery SAA. However, clinic at-delivery SAA did not significantly change between clinic chorioamnionitis group and not having clinic chorioamnionitis. A no-clinic chorioamnionitis PPROM mother could be chorioamnionitis one by a ۵۰% chance, even with no clinical sign. Conclusion: Pathologic at-delivery SAA level could be a supplementary test in PPROM mothers. At-delivery SAA serial measurements and long-term evaluation of infants born to these mothers are recommended.

کلیدواژه ها:

Serum amyloid A protein ، Chorioamnionitis ، Fetal membranes ، Premature rupture. ، پروتئین آمیلوئید A سرم ، کوریوآمنیونیت ، غشای جنین- پارگی زودرس.