Chokri Ben Lamine: Causes and Diagnostic Approach to PTT Prolongation
Chokri Ben Lamine, Adult Hematology and Stem Cell Transplantation Assistant Consultant at Oncology Center of Excellence at King Faisal Specialist Hospital and Research Center, shared a post on, recently shared on X:
“PTT Prolongation — Causes and Approach for Hema Fellows
Causes
- Factor deficiencies: VIII, IX, XI, XII
- Combined defects: Hemophilia A/B, vWD (type 2N), combined factor deficiencies
- Anticoagulants: UFH, argatroban, dabigatran
- Inhibitors: Lupus anticoagulant, acquired FVIII inhibitor
- Consumptive: DIC, massive transfusion
- Contact pathway defects: prekallikrein, HMW kininogen deficiency (no bleeding)
- Liver disease: decreased synthesis of multiple factors
Approach
- Check clinical context — bleeding vs thrombosis
- Repeat PTT — exclude lab error
- Mixing study:
- Corrects → factor deficiency → assay factors VIII, IX, XI, XII
- No correction → inhibitor → lupus anticoagulant or factor inhibitor workup
- If on anticoagulant — check drug level / anti-Xa / TT
- If prolonged with normal PT — think intrinsic pathway
- If prolonged PT and PTT — consider liver disease, DIC, multiple deficiencies
Written Exam Pearl
Isolated prolonged PTT + no bleeding → think lupus anticoagulant or contact factor deficiency.
OSCE Practical Tip
•Scenario: Post-op patient with thrombosis, PTT 65s, normal PT
Don’t rush to transfuse FFP — think lupus anticoagulant → do mixing study + DRVVT.
•Always ask about heparin flushes from lines before labs.
References:
1.Kitchens CS et al. Consultative Hemostasis and Thrombosis, 5th ed, 2023.
2.ISTH Guidelines 2024 — Lupus Anticoagulant Testing.
3.ASH Education Program 2022 — Approach to Abnormal Coagulation Tests.”
Stay updated on the latest with Hemostasis Today.
-
Aug 13, 2025, 06:44Chokri Ben Lamine: Causes and Diagnostic Approach to PTT Prolongation
-
Aug 13, 2025, 05:41ISTH 2025 Recorded Sessions Now Available on ISTH Academy
-
Aug 13, 2025, 01:39Radoslaw Kaczmarek: Challenges Limiting Gene Therapy Use in Hemophilia
-
Aug 12, 2025, 20:03David McIntosh Urges WHO, the European Blood Alliance, the International Plasma and Fractionation Association to Stop Opposition to VRCD
-
Aug 12, 2025, 18:44Maxime Dely: Does Whole Blood Deserve a Greater Role in Modern Transfusion Medicine?
-
Aug 13, 2025, 06:13Pip Nicolson: Understanding VITT From COVID-19 Vaccines
-
Aug 13, 2025, 05:23Baseline Hemoglobin Predicts Outcomes in Acute VTE: Low Hb Linked to Higher Bleeding, Ischemia and Mortality Risk
-
Aug 13, 2025, 04:13Lindsey George on Gene Therapy Transforming Hemophilia Care
-
Aug 13, 2025, 02:26Case Report Alert: Basilar Artery Occlusion in IgA-APS
-
Aug 12, 2025, 20:23Behnood Bikdeli on Comparative Effectiveness Research Examples in Thrombosis
-
Jul 28, 2025, 14:55HORIBA Decoding High Efficiency in Hematology Lab: Free Online Workshop
-
Jul 26, 2025, 17:56HIPEITHO Trial Achieves Remarkable Enrollment Milestone Across 72 Sites in the US and Europe
-
Jul 16, 2025, 15:04Toward Hemophilia Gene Therapy for All? Insights from Prof. Flora Peyvandi in Blood Advances
-
Jul 14, 2025, 16:39Dr. Philipp Bücke: MRI Proven as No.1 Choice for Accurate TIA Diagnosis
-
Jul 13, 2025, 16:05EMA and HMA Mark a Key Step with 1st AI Observatory Report
-
Aug 11, 2025, 05:16Andreas Calatzis: Any Information on Soviet Thrombelastographs?
-
Aug 9, 2025, 15:36NBCA: Blood Clot Survivor Runs 2025 NYC Marathon with Team Stop the Clot
-
Aug 8, 2025, 18:33Hemophilia Alliance during Tennessee Hemophilia and Bleeding Disorders Foundation Annual Meeting 2025
-
Aug 7, 2025, 14:49JAMA+AI Conversations: David Rhew's Journey from Clinical Practice to Technology Leadership
-
Aug 6, 2025, 16:47My Clot Story: Birth Control and A Life-threatening Pulmonary Embolism