Urine and serum L-type fatty acid-binding protein levels in preeclampsia: A prospective cohort study

Abstract Background We aimed to examine the relationship of maternal urine and serum L-type fatty acid-binding protein (L-FABP) levels with the severity of preeclampsia (PE) and the effectiveness of these biomarkers as predictors of maternal and fetal deterioration in PE. Methods This study included women with singleton pregnancies. Urine and blood samples were collected at the diagnosis of PE. The cases were classified as 1) PE cases that worsened and required delivery within 1 week from sample collection (PE-delivery group) and 2) PE cases that did not result in delivery within 1 week from sample collection (PE-control group). We analyzed the relationship between L-FABP levels and the severity of PE and compared the data between the two groups. Results In total, 53 singleton pregnancies were analyzed and classified into the PE-delivery (32 pregnancies) and PE-control groups (21 pregnancies). No significant differences were observed in urine (median 12.3 µg/gCr vs. 27.4, p = 0.449) and serum L-FABP levels (median 2.73 ng/mL vs. 1.67, p = 0.279) between severe [43 (71.7%)] cases and non-severe [17 (28.3%)] PE cases. Urine (median 79.7 µg/gCr, p = 0.044) and serum L-FABP levels (median 9.52 ng/mL, p < 0.001) were significantly higher in cases of severe PE due to maternal factors than in the non-severe PE cases. In the PE-delivery group, 26 (70.3%) pregnancies had maternal indications and 11 (29.7%) had fetal indications. Urine and serum L-FABP levels were significantly higher in cases with delivery owing to maternal indications in the PE-delivery group than in the PE-control group (median 57.4 vs. 2.83 µg/gCr; p < 0.001; median 3.47 vs. 1.18 ng/mL; p < 0.001, respectively); no significant difference was found in cases with delivery owing to fetal indications in the PE-delivery group compared to such cases in the PE-control group (median 1.93 µg/gCr; p = 0.555; median 1.18 ng/mL; p = 0.68, respectively). The areas under the concentration-time curve and optimal cutoff values for urine and serum L-FABP levels for delivery within 1 week owing to maternal indications were 0.901 (12.3 µg/gCr) and 0.819 (1.64 ng/mL), respectively. Conclusions Urine and serum L-FABP levels were significantly higher in cases of PE, reflecting maternal conditions, and were highly accurate predictive factors of maternal deterioration in PE.