Evaluation of the effectiveness of modified CRD tests in the diagnosis of preeclampsia

Abstract

BACKGROUND: Preeclampsia is a multisystem complication of pregnancy associated with an increased risk of maternal / perinatal morbidity and mortality. In this regard, the development and following improvement of low-cost and convenient methods for diagnosis of preeclampsia is essential for accurate prediction, quick confirmation of the diagnosis and convenient monitoring of the pathology.
 AIM: The aim of this study was to optimize a preeclampsia diagnosis test system based on the binding of proteins to the Congo red dye (CRD test).
 MATERIALS AND METHODS: The study used 70 urine samples obtained from patients diagnosed with preeclampsia (n = 25) and from non-preeclampsia pregnant women (n = 45). The samples were stained with Congo red and the dye retention in the sample on the membrane after washing was calculated. Before staining, protein concentrations in the urine samples were equalized using centrifugal concentrators or the samples were used with the original protein concentrations. To wash the samples from the unbound dye, either methanol or ethanol was used. To compare the effectiveness of four CRD test variants differing in sample preparation, staining, and washing, ROC analysis was performed (IBM SPSS Statistics 20 software).
 RESULTS: The express CRD test was designed as an optimization of the conventional CRD test. The effectiveness of the express test (the area under the ROC curve being 0.9) was higher than that of the other three test options (the area under the ROC curve ranges from 0.67 to 0.82). The developed express CRD test can provide 95% specificity and 73% sensitivity, which indicates the promise of using this method in clinical diagnostics for the specific detection of preeclampsia patients.
 CONCLUSIONS: Optimization of the CRD test has provided more effective protocols for diagnosis of preeclampsia from urine samples using Congo red (express CRD test) and has simplified the routine application of this test in clinical practice.