Analysis of APTT Mixing Test Results in Factor Ⅷ Inhibitor-Positive Hemophilia Patients / 中国实验血液学杂志

OBJECTIVE@#To analyze the results of activated partial thromboplastin time (APTT) mixing test in coagulation factor Ⅷ inhibitor-positive hemophilia patients, so as to increase the value of APTT mixing test in the screen of factor Ⅷ inhibitor.@*METHODS@#Eighty plasmas samples with different titers of coagulation factor Ⅷ inhibitors had been collected and diluted for routine immediate APTT mixing test and at 37 ℃ 2 hours incubation APTT mixing test. Fifteen samples were selected for immediate and normal temperature incubation for 15 min, 30min, 1 hour, 2 hours and 37 ℃ for 30 min, 1 hour, 2 hours APTT mixing test.@*RESULTS@#The results of APTT mixing test were significantly correlated with the titers of coagulation factor Ⅷ inhibitors. The ROC curve result showed that the best diagnostic cut-off value for 2 hours incubation APTT mixing test at 37 ℃ to determine the presence or absence of coagulation factor Ⅷ inhibitors was 43.8 s (sensitivity and specificity was 85.90% and 100%, respectively), while the best diagnostic cut-off value for distinguishing high-titer and low-titer Ⅷ inhibitors was 52.4 s (sensitivity and specificity was 98.18% and 95.65%, respectively). The critical coagulation factor Ⅷ inhibitor titer that could not be corrected by immediate APTT was 5.14 BU/ml, while that could not be corrected by 37 ℃ 2 hours incubation APTT was 1.31 BU/ml. Paired samples t -test was performed on the APTT mixing test results at different times and temperatures, and the differences were statistically significant (P < 0.05).@*CONCLUSIONS@#The APTT mixing test can be used as a screening index for coagulation factor Ⅷ inhibitors. APTT mixing test result shows a significant time-temperature dependence with lower titers of coagulation factor Ⅷ inhibitor. Patients with hemophilia who cannot be corrected by immediate APTT mixing test should be alert to the possibility of high titer of coagulation factor Ⅷ.

Acquired Hemophilia in a Patient Presenting with Swollen Left Limb / 가정의학회지

Acquired hemophilia is a rare, potentially life-threatening disease that usually remains under-recognized especially in a primary setting; thus, diagnosing this disease is very challenging. Given its prevalence in elderly patients, awareness and diagnosis of this condition in the aging population (particularly those with unexplained bleeding or prolonged activated partial thromboplastin time) should be improved and better managed by the clinicians. Early diagnosis and prompt treatment are usually effective in preventing the adverse outcomes of this disease. In this report, we discuss a case of an elderly patient with acquired hemophilia who initially presented with swelling of his lower left limb. The diagnosis of acquired hemophilia was made a month after the appearance of symptoms. Early diagnosis with proper treatment could have been provided to this patient, if the initial assessment had been thoroughly conducted.