Clinical application of a new latex photometric immunoassay reagent, LPIA-GENESIS D-dimer, and its performance in patient-derived plasma samples

Clinical application of a new latex photometric immunoassay reagent, LPIA-GENESIS D-dimer, and its performance in patient-derived plasma samples

Introduction

We previously reported an antibody MIF‐220 that recognizes a specific structure induced on the surface of thrombin‐activated E‐domain of one fibrin molecule bound with the D‐domains of other fibrinogen/fibrin molecules. Utilizing MIF‐220, we produced a test kit for cross‐linked fibrin degradation products (XDP), LPIA‐GENESIS D‐dimer (LG‐DD), and evaluated basic performance characteristics for clinical application. We then attempted to apply LG‐DD to see its eligibility in clinical plasma samples.

Method

The characteristic performances requested for clinical use were studied including limit of quantitation, within‐run imprecision, day‐to‐day imprecision, antigen excess, interference study, and method comparison with LPIAACE‐Ddimer (ACE‐DD) available on the market.

Results

The performance characteristics were all satisfactory. Extraordinarily high concentrations of XDP are occasionally obtained by ACE‐DD in samples with collection problems, but not by LG‐DD, indicating that a certain XDP species present in the former was not measured by LG‐DD. Structural studies suggested that the “B‐b” set of polymerization sites must be involved as well in the maintenance of cross‐linked fibrin in vivo.

Conclusion

LG‐DD was able to measure a wide range of XDP, that is, 0.20‐35.0 μg FEU/mL that covers the levels of XDP in most of the clinical samples. LG‐DD was found to almost avoid false‐positive results noticed in samples as mentioned above, and this feature seems to be preferable to established kits for the measurement of XDP.