Fibrin Degradation Products (FDP and D-dimer (DD))

FDP (Fibrin Degradation Products), or Fibrin (Pro) Degradation Products, is a general term for a variety of degradation products of fibrin/fibrinogen produced by the action of fibrinolytic enzymes.FDPs include the products of fibrinogen (Fg) and fibrin monomers (FM) (FgDPs), and the degradation products of cross-linked fibrin ( FbDPs), where FbDPs include D-dimers and other fragments.FDP primarily reflects the solubilizing function of fibrin (pro). FDP levels are markedly elevated when primary hyperfibrinolysis occurs, which is triggered by the breakdown of large amounts of fibrinogen. FDP is also elevated in secondary hyperfibrinolysis caused by hypercoagulability, pulmonary embolism, malignant tumors, venous thrombosis, and thrombolytic therapy. It can be seen that FDP is a sensitive indicator of hyperfibrinolysis, and its level can be increased in the occurrence of primary hyperfibrinolysis.

DD (D-Dimer), that is, D-dimer, refers to the specific degradation product fragments produced by the hydrolysis of fibrinolytic enzymes after the formation of stable cross-linked fibrin by cross-linking of fibrin monomers by XIIIa, Ca2+, including YY/DXD fragments, YD/DY fragments, DD/E fragments, DD fragments, etc. D-Dimer is a specific product of the degradation of fibrin, and the determination of D-dimer can determine whether fibrin has been formed or not. can determine whether fibrin has formed. High values can be demonstrated in the occurrence of secondary hyperfibrinolysis, such as in DIC, thrombophilia, infectious, and malignant tumors. Therefore D-dimer is an important indicator of deep vein thrombosis (DVT), pulmonary embolism (PTE), and diffuse intravascular coagulation (DIC).

KMD Bioscience, as a supplier of raw materials for in vitro diagnostics, has been committed to the rapid development and large-scale production of proteins and antibodies for in vitro diagnostics. KMD Bioscience successfully develops many recombinant proteins, antibodies, antibody drug target proteins, industrial enzymes, diagnostic raw materials and other related reagents for scientific research and new drug discovery. KMD Bioscience adheres to independent innovation and breakthroughs in key technologies, and has obtained the national patent pilot unit and laboratory ISO9001:2015 quality management system certification and adhere to the continuous optimization, effectively guaranteeing the quality and stability of products in the production process and final delivery. All antibodies supplied by KMD Bioscience are rigorously tested to ensure their purity and sensitivity for use in a variety of different diagnostic platforms, such as LFIA, ELISA, CLIA, POCT, and so on.

The inventory of reagents associated with Fibrin Degradation Product (FDP) and D-Dimer (DD) that KMD Bioscience can offer:

Difference between FDP and DD:

One of the biggest differences between FDP and D-dimer is that FDP can use fibrinogen as a substrate, whereas D-dimer uses fibrin as a substrate for its action. Therefore, D-dimer levels are not increased in primary fibrinolysis, whereas FDP Therefore, D-dimer levels are not increased in primary fibrinolysis, while FDP levels are increased. In other pathologies, such as DIC, the two changes are essentially parallel. The main difference between primary and secondary fibrinolysis is the presence or absence of coagulation at the time of fibrinolysis.D-dimer, as one of the molecular markers of hypercoagulability and secondary hyperfibrinolysis in vivo, is direct evidence that the thrombus has been lysed.FDP is a sensitive indicator of hyperfibrinolysis, and it is intentionally elevated in the presence of both primary and secondary fibrinolysis. Therefore, the detection of D-dimer and FDP is important for the early diagnosis, therapeutic observation and prognosis of hypercoagulable states and thrombotic diseases, and the combination of D-dimer and FDP can significantly improve the positive detection rate and negative exclusion rate of hypercoagulable states and thrombotic diseases; and it has high specificity and sensitivity.

Figure 1 Schematic diagram of FDP molecular structure

Biological functions of FDP and DD

Under physiological conditions, coagulation and anticoagulation in the inner wall of blood vessels of normal people maintain a dynamic balance to maintain a normal flow state within the blood. Once the coagulation is too strong, thrombus will be formed within the organism, and fibrin is the main component in the formation of thrombus. Fibrinolytic system, i.e., fibrinolytic system, the body through the production of activated enzymes (fibrinolytic enzymes) can be degraded components of the thrombus (fibrin), the formation of a variety of degradation products, including D-dimer and FDP, D-dimer is the complete degradation of fibrin to form dimeric fragments, and the FDP includes a series of degradation of fibrinogen and fibrin together a series of fragments of the mixture. The various types of small fragments formed will be discharged from the body with the blood flow, through the detection of these two indicators, you can determine the risk of thrombosis, and the effect of thrombolytic therapy. FDP mainly reflects the function of fibrinolysis, when the plasma FDP is abnormally elevated often indicates that the state of thrombosis. In addition, FDP inhibits fibrin formation, has antithrombin effects, and inhibits platelet adhesion, aggregation, and release.Elevated levels of D-dimer indicate the presence of hypercoagulability and secondary hyperfibrinolysis in the body. Therefore, D-dimer is one of the specific targets for thrombotic diseases and is of great significance.

KMD Bioscience offers high quality antibody materials of multiple product lines for test kit development. Antibodies are tested on multiple platforms (time-resolved immunoassay, fluorescence chromatography, colloidal gold, chemiluminescence, latex turbidimetric, enzyme-linked immunoassay, etc.) and correlation validated to enable the development of diagnostic kits for different platforms. In addition, by analyzing the performance indicators (specificity, activity, stability, etc.) of antibodies/antigens and comparing them with the reagents of international manufacturers, we ensure that the IVD raw materials are characterized by small batch-to-batch/intra-batch variations, wide linear ranges, good stability, high sensitivity, and so on.