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The activated partial thromboplastin time-clot waveform analysis in hemophilia: Does it help in differentiation?
Khalid Abdul Mannan1, Narender Kumar1, Jasmina Ahluwalia1
1Department of Hematology, Postgraduate Institute of Medical Education and Research, Sector 12, Chandigarh, India.
Introduction:
The clot waveform analysis (CWA) provide valuable information beyond clotting time. The present study was planned to assess whether the activated partial thromboplastin time (aPTT)-CWA can differentiate between hemophilia A (HA), hemophilia B (HB), or hemophilia A with inhibitors (HAWI).
Methods:
The aPTT-CWA was generated by an optical detection system (ACL-TOP™ 500 coagulation analyzer) and the other tests were performed as per instructions from the manufacturer in the kit.
Results:
A total of 75 samples (47-HA, 16-HAWI, and 12-HB) with prolonged aPTT were recruited. On analyzing the quantitative aPTT-CWA data of HA (non-inhibitors) and HB samples, the width of acceleration 1 [+] peak was the differentiating finding. Among the significant parameters, the second derivative [+] peak was lower in both mild and moderate HA, equating to HB. The time for the height of 1/2 fibrin formation and width of velocity was significantly higher in mild, moderate and severe HA. The study did not show any significant differentiating finding while comparing HAWI and hemophilia A non-inhibitors (HANI). In the subgroups of HAWI and HANI with aPTT <70 s and 70-100 s, the second derivative [+] peak (2A) was higher and the time for the height of 1/2 fibrin formation (1C) was lesser in HAWI.
Conclusion:
The aPTT-CWA parameters may be supportive for the differentiation of hemophilia including its severity and the existence of inhibitors.
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