Evaluation of an automated latex D-dimer immunoassay in the clinical assessment of suspected venous thromboembolism.

Because the reliability of clinical signs in venous thromboembolism (VTE) is poor, a highly sensitive, non-invasive test may improve the selection of patients requiring further investigation. We assessed the sensitivity and negative predictive value of an automated D-dimer latex immunoassay (IL-Test ) in 68 patients presenting with suspected VTE. The plasma D-dimer concentration was estimated and an appropriate diagnostic radiological investigation performed. Control values were obtained from healthy young and elderly volunteers. Using a cut-off value of 330 ng/ml, the assay had a sensitivity of 100% and negative predictive value of 100% for VTE. We conclude that the IL-Test. automated D-dimer assay has a suitably high sensitivity and adequate negative predictive value to be included in a pre-test clinical probability protocol for the evaluation of patients with suspected VTE.