Abstract
Fibrin degradation product (FDP) and D-dimer are useful fibrinolytic markers for diagnosis and therapeutic assessment in patients with disseminated intravascular coagulation (DIC) and deep vein thrombosis (DVT). We describe a case report in which dithiothreitol (DTT) was useful for detecting a non-specific reaction caused by IgM in a patient with marked inversion values of D-dimer and FDP. A seven-month-old female infant was referred to our hospital for evaluation of dilated cardiomyopathy. Her test results showed FDP of 3 μg/ml and D-dimer of 92.8 μg/ml. When the samples were diluted 10 to 100 times, the value of D-dimer fluctuated with the increase in the dilution ratio. Next, the value of D-dimer was 81.6 μg/ml after absorption of the sample with anti-Fbg antibody, compared with 67.2 μg/ml of the control. These suggest a false positive due to a non-specific reaction. Next, the sample was treated with DTT, and the value was 1.2 μg/ml compared with 73.6 μg/ml of the control. These findings suggest a non-specific reaction due to IgM. DTT is a cheap and easily available product that may be useful in the analysis of the non-specific IgM reaction to measure D-dimer.
