Blood Clots, General Medicine, UCSD / 19.05.2014
Pulmonary Embolism: Urine Fibrinopeptide B As Screening Tool
MedicalResearch.com Interview with
Timothy Fernandes, M.D., M.P.H.
University of California, San Diego
La Jolla, CA
MedicalResearch: What are the main findings of this study?
Dr. Fernandes: The fibrinopeptides are cleaved off of fibrinogen by thrombin during the generation of a new clot. These small molecules are excreted into the urine and we have developed a urine assay to measure the level of FPB. We examined the performance of urine FPB as a screening test for acute pulmonary embolism, blood clots that travel to the lungs.
The study group consisted of 344 patients: 61 (18%) with pulmonary embolism and 283 (83%) without. At a threshold of 2.5 ng/ml, urine FPB demonstrated sensitivity of 75.4% (95% CI: 62.4-85.2%), specificity of 28.9% (95% CI: 23.8-34.7%), and negative likelihood ratio of 0.18 (0.11-0.29), weighted by prevalence in the sample population. However, the thresholds of 5 ng/ml and 7.5 ng/ml had sensitivities of only 55.7% (95% CI: 42.5-68.2%), and 42.6% (30.3-55.9%), respectively.
The urine fibrinopeptide B assay at a cut-off of 2.5 ng/ml had a sensitivity of 75.4% for detecting pulmonary embolism. For diagnosis of PE, this sensitivity is comparable to previously published values for the first generation plasma latex and whole blood D-dimer assays (not as well and the D dimer ELISA assay).
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