Serum Amyloid A Protein as a Potential Biomarker for Ectopic Pregnancy

Objective: This study compared the concentrations of serum amyloid A (SAA), which is an inflammatory marker, in ectopic and intrauterine pregnancies. Methods: This prospective case-control study was conducted at Tepecik Education and Research Hospital in İzmir, Turkey, between 2015 and 2016. It included 39 patients diagnosed with tubal ectopic pregnancies and 41 patients diagnosed with early intrauterine pregnancies. The SAA, β human chorionic gonadotropin, progesterone and C-reactive protein levels were measured in the serum samples taken from both groups. Data were presented as mean±standard deviation and a p value <0.05 was accepted as statistically significant. The distribution of the variables was measured using the Kolmogorov-Smirnov test, while the independent samples t-test and Mann-Whitney U test were used in the analysis of the quantitative independent data. The impact level and cut-off value were investigated using a receiver operating characteristic curve. Results: SAA levels in the ectopic pregnancy patients (2.4±2.6 µg/mL) was significantly higher than in the intrauterine pregnancies (1.4±1.9 µg/mL) (p=0.008). When using the SAA cut-off value of 0.7 μg/mL for the ectopic pregnancy diagnosis, the sensitivity was 73.2% and the specificity was 63.4%. Conclusion: The inflammation due to tubal tissue damage in an ectopic pregnancy may increase the SAA level in the maternal blood. Even though larger prospective studies are needed, our study suggests that the SAA is an important biomarker for the early diagnosis of an ectopic pregnancy.