Activated partial thromboplastin time (APTT) test is a blood test to measure time taken by the blood to clot after administration of blood thinning agents. It is used to investigate bleeding disorders and monitor patient’s response to anti-clotting drugs such as heparin therapy. This test unlike partial thromboplastin time (PTT) uses activator to speed up the clotting time and consequently results into narrowing of reference range. The reference range for APTT is 30 seconds to 40 seconds. APTT signifies spontaneous bleeding if found to be more than 70 seconds. APTT is found to be abnormally elevated in cases of hemophilia and also by intravenous heparin therapy. The test requires few milliliters of blood. The APTT is generally checked approximately six hours post initiation of treatment, with intravenous heparin, by the time the effect of heparin has achieved. This determines the dose adjustments for the heparin infusion therapy, based on the APTT result. The APTT does not measure the effect of treatment with low-molecular weight heparin injections. APTT testing also helps in screening of specific coagulation factor deficiencies, and detection of coagulation inhibitors such as certain factor inhibitors, lupus anticoagulant, and nonspecific inhibitors.
The global APTT testing market is segmented based on testing location and geography. The various testing locations include emergency rooms, physician offices, cancer clinics, ICUs/CCUs, ambulatory care centers, surgery centers, nursing homes and birth centers. Geographically, the market has been segmented into four major regions namely, North America, Europe, Asia-Pacific and Rest of the World. Coagulation testing comprising laboratory as well as point of care (POC) testing is expected to continue accounting for the major share in in the global in vitro diagnostics market in the near future. Moreover, many of the new models of laboratory testing including prothrombin time (PT) and activated partial thromboplastin time (APTT), is expected to witness greater automation and the integration of more esoteric coagulation tests and assays.
Activated partial thromboplastin time (APTT) testing is used as a diagnostic tool for monitoring other than heparin therapeutic monitoring, wherein the specimens should be devoid of any residual heparin to avoid false results. APTT testing does not detect all lupus anticoagulants or coagulation inhibitors. The APTT represents the time for clot formation after adding activators such as calcium, phospholipids, and kaolin to a sample of citrated blood. APTT is found to be prolonged due to heparin in blood, direct thrombin inhibitors, a deficiency of or inhibitor of factors in the intrinsic and common pathways. Such factors include factors II, V, VIII, IX, X, XI, and XII. Vitamin K deficiency, lupus anticoagulant, or severe liver disease may also lead to prolongation of APTT. However, prolongation of APTT may not occur on the slightest deficiencies of coagulation factors.
Use of automated methods is required by most laboratories in cases where clot formation is deemed to have occurred when the optical density of the mixture has exceeded a certain threshold. Micronized silica and ellagic acid are the commonly used activators for automated analyzers. A phospholipids substitute called Cephalin replaces platelet phospholipids in the test. Since this test uses plasma that is poor in platelet content, it requires a source of phospholipids such Cephalin for coagulation to occur.
The key players contributing to the global APTT testing market include Abbott, Accumetrics, American Labor Alere, BioCytex, Behnk Elektronik, Beckman Coulter, Bio/Data, Cepheid, Chrono-Log, CoaguSense, Diagnostica Stago, Helena, Haemonetics, HYPEN, Instrumentation Laboratory, ITC, Medtronic, LABiTec, Pentapharm, Sekisui, Roche, Siemens, Sienco, Spartan, Sysmex, Tcoag, Technoclone, TECO, and Universal.