The “simple, non-invasive” Congo Red Dot Paper Test detected preeclampsia in 3 minutes, significantly faster than the current gold standard, according to findings recently published in EClinical Medicine.
“[Preeclampsia] has a large spectrum of medical signs and symptoms resulting in a range of clinical phenotypes and outcomes, making a diagnosis on available clinical and laboratory parameters challenging,” Kara Rood, MD, of the department of obstetrics and gynecology, The Ohio State University College of Medicine, and colleagues wrote.
“It is not uncommon when confronted with clinical ambiguity, particularly close to term, for physicians to indicate delivery even in the absence of a true diagnosis,” they added.
Previously published research suggests the current gold standard for preeclampsia, a time-consuming test for hypertension and 300 mg or more of protein in the urine, is error-prone. Liver and chronic kidney diseases also hinder the current test’s effectiveness.
Rood and colleagues conducted a Congo Red Dot Paper test on fresh urine samples from 346 consecutive pregnant women evaluated for preeclampsia at a single medical center. The mean age of patients in the study was 29 years
Researchers found that during the first triage visit, 32% of women received a clinical diagnosis of preeclampsia, and the Congo Red Dye Paper Test was positive in 25% of the cases. Adjudication confirmed preeclampsia in 28% of all cases, and the Congo Red Dye Paper Test outperformed measured serum and urine markers (80.2% sensitivity, 89.2% specificity, 92.1% negative predictive value, 86.7% accuracy). Among women who were discharged without delivering, 38% had at least one additional triage visit and 12 days (interquartile range, 5-34 days) elapsed between the last negative and first positive paper test.
“Our analysis shows that [Congo Red Dye Paper Test] is not only inexpensive, easy to use, highly accepted by the nursing staff, [it also] identifies women with preeclampsia within 3 minutes. ... [A] negative Congo Red Dye Paper Test could improve wait times in obstetrical triage areas, avoid unnecessary admissions and lower the associated health care expenses,” researchers wrote.
“Our findings have potential to improve accurate timing of patients' transfers to higher-acuity hospitals, and more targeted steroids and magnesium sulfate treatment in patients at risk of indicated preterm delivery from preeclampsia,” they added.
Rood explained other ways the Congo Red Dye Paper Test could change clinical findings in an interview with Healio Primary Care Today.
“This test will help rule diagnosis of preeclampsia in or out in women presenting with vague symptoms and/or an unclear diagnosis in timely fashion without the need for invasive blood work. It will also decrease wait times in obstetrical triages and avoid unnecessary antenatal admissions,” she said.
Rood added that the Congo Red Dye Paper Test is now part of a multicenter trial, and an FDA decision on the test should occur within the next 2 years. – by Janel Miller
Reference: Duhig K, et al. F1000Res. 2018;doi:10.12688/f1000research.12249.1
Disclosures: Rood reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.