Low intraindividual variability of activated partial thromboplastin time revealed in a population of 10487 control individuals

摘要

The activated partial thromboplastin time (aPTT) is a routine coagulation test that reflects the activities of multiple coagulation proteins. Given the known genetic elements underlying the different coagulation factor activities, a low intraindividual variability is expected in aPTT values, but has not been demonstrated in a large population. In this regard, we evaluated the intraindividual variability of aPTT by analyzing serial aPTTs from a large population. The study population consisted of control individuals who had three or more consecutive aPTT values at at least 6-month intervals at a single institution. The coefficient of variation of serial aPTT values was determined in each control individual, and the mean value of the coefficient of variations in the control population was calculated. The aPTT values from a total of 10487 individuals [mean age 57 years (range 21-93 years); male-to-female ratio 1:0.9] were included. The mean value of the coefficient of variation of aPTTs in those individuals was 3.75%, which indicates a very low intraindividual variability. This is the first study to demonstrate a low intraindividual variability of aPTT in a large population. The result supports the previous notion that aPTT is a genetically determined parameter and has potential clinical implications.