Bleeding Disorders & Hemostasis – Clinical Scenarios with Lab Data
You will be presented with 8 clinical scenarios of children with suspected bleeding disorders.
For each, interpret the lab data and provide: 1) Diagnosis, 2) Any other test, 3) What to do next, 4) Follow-up plan.
Hemophilia A: ↓FVIII, ↑PTT, normal PTVWD: ↓VWF:Ag, ↓VWF:RCo, ↓FVIIIFactor XIII: normal PT/PTT, clot solubility abnormalInhibitor: ↑PTT, mixing study no correction
Case 1
A 3-year-old boy with recurrent swellihg of the right knee and easy bruising since infancy. No family history of bleeding.
PT
13 sec (normal 10-13)
PTT
65 sec (normal 25-35)
Platelet Count
280,000/µL (normal)
Factor IX Assay
95% (normal)
Blood Pressure
105/68 mm Hg
1️⃣ Diagnosis: (Write your answer below)
2️⃣ Any other test: (Write your answer below)
3️⃣ What to do next: (Write your answer below)
4️⃣ Follow-up plan: (Write your answer below)
✅ Model Answer:
• Diagnosis: Severe hemophilia A (factor VIII deficiency) – X-linked bleeding disorder.
• Any other test: Factor VIII assey, Factor VIII inhibitor (Bethesda assay) to rule out inhibitor; genetic testing (F8 gene, intron 22 inversion).
• What to do next: Factor VIII replacement (recombinant or plasma-derived) 25-40 IU/kg IV for bleeding. Consider starting prophylaxis (25-40 IU/kg 3x/week) to prevent hemarthrosis.
• Follow-up plan: Monitor factor VIII trough levels, joint function, and inhibitor development (Bethesda assay every 3-6 months). Physical therapy for joint health. Avoid NSAIDs. Family counseling and genetic testing for carrier status.
Case 2
A 12-year-old girl presents with heavy menstrual bleeding, she has history of easy bruising, and epistaxis since childhood.
PT
13 sec (normal)
PTT
42 sec (mildly prolonged, normal 25-35)
Platelet Count
250,000/µL (normal)
Factor VIII
25 IU/dL (low)
Blood Pressure
115/72 mm Hg
1️⃣ Diagnosis: (Write your answer below)
2️⃣ Any other test: (Write your answer below)
3️⃣ What to do next: (Write your answer below)
4️⃣ Follow-up plan: (Write your answer below)
✅ Model Answer:
• Diagnosis: Von Willebrand disease (VWD) type 1 – quantitative deficiency of VWF.
• Any other test: VWF:Ag, VWF:RCo, VWF multimer analysis, bleeding time (PFA-100), and von Willebrand factor propeptide (to assess clearance).
• What to do next: Desmopressin (DDAVP) 0.3 mcg/kg IV or intranasal (Stimate) for bleeding/ menorrhagia. For severe bleeding or DDAVP failure: VWF-containing concentrate (Humate-P). Tranexamic acid for mucosal bleeding.
• Follow-up plan: Monitor VWF levels and response to DDAVP. Manage menorrhagia with oral contraceptives or tranexamic acid. Avoid aspirin/NSAIDs. If future surgery, DDAVP test dose and factor level monitoring.
Case 3
A 6-year-old with prolonged bleeding after circumcision and delayed umbilical stump bleeding.
PT
12 sec (normal)
PTT
30 sec (normal)
Platelet Count
280,000/µL (normal)
Factor VIII
95% (normal)
Factor IX
100% (normal)
Blood Pressure
110/70 mm Hg
1️⃣ Diagnosis: (Write your answer below)
2️⃣ Any other test: (Write your answer below)
3️⃣ What to do next: (Write your answer below)
4️⃣ Follow-up plan: (Write your answer below)
✅ Model Answer:
• Diagnosis: Factor XIII deficiency – normal PT/PTT with abnormal clot solubility test.
• Any other test: Clot Solubility (5M Urea), Factor XIII assay (quantitative) to confirm deficiency; genetic testing (F13A1 or F13B gene).
• What to do next: Factor XIII concentrate (20-40 U/kg) or cryoprecipitate (1 unit/10 kg) for acute bleeding. For major surgery or prophylaxis, FXIII concentrate every 4-6 weeks.
• Follow-up plan: Prophylaxis with FXIII concentrate 20-40 U/kg every 4-6 weeks for severe deficiency to prevent intracranial hemorrhage. Monitor trough FXIII levels. Genetic counseling for family members.
Case 4
A 10-year-old with severe hemophilia A on factor VIII prophylaxis develops a knee hemarthrosis.
PT
13 sec (normal)
PTT
68 sec (prolonged)
Platelet Count
250,000/µL (normal)
Factor VIII
5% (low)
Mixing Study
PTT does NOT correct with 1:1 normal plasma
Blood Pressure
115/75 mm Hg
1️⃣ Diagnosis: (Write your answer below)
2️⃣ Any other test: (Write your answer below)
3️⃣ What to do next: (Write your answer below)
4️⃣ Follow-up plan: (Write your answer below)
✅ Model Answer:
• Diagnosis: Hemophilia A with high-titer inhibitor (acquired factor VIII inhibitor).
• Any other test: Bethesda Assay, Emicizumab (if not already on it), factor VIII inhibitor titer monitoring, Nijmegen-Bethesda assay.
• What to do next: For acute bleeding: bypassing agent – rFVIIa 90-120 mcg/kg q2-3h or aPCC 50-100 U/kg q6h. For prophylaxis: start emicizumab (bispecific antibody) if not already on it. Avoid high-dose factor VIII (ineffective with high-titer inhibitor).
• Follow-up plan: Continue emicizumab prophylaxis. Monitor Bethesda titers. Consider immune tolerance induction (ITI) with daily high-dose factor VIII for inhibitor eradication. Monitor for thrombosis with aPCC.
Case 5
A 14-year-old with history of prolonged bleeding after dental extractions. PTT is prolonged, PT normal. Family history of bleeding in a sibling.
PT
13 sec (normal)
PTT
58 sec (prolonged)
Platelet Count
260,000/µL (normal)
Factor VIII
100% (normal)
Factor IX
95% (normal)
Blood Pressure
120/78 mm Hg
1️⃣ Diagnosis: (Write your answer below)
2️⃣ Any other test: (Write your answer below)
3️⃣ What to do next: (Write your answer below)
4️⃣ Follow-up plan: (Write your answer below)
✅ Model Answer:
• Diagnosis: Factor XI deficiency (rare, autosomal recessive, common in Ashkenazi Jews).
• Any other test: Factor XI, Genetic testing (F11 gene), factor XI inhibitor (Bethesda assay) if poor response to replacement.
• What to do next: For bleeding or surgery: fresh frozen plasma (FFP) 15-25 mL/kg or factor XI concentrate (if available). For minor procedures: tranexamic acid (antifibrinolytic).
• Follow-up plan: Avoid aspirin/NSAIDs. Preoperative planning: factor XI level and antifibrinolytic therapy. Genetic counseling for family members.
Case 6
A 5-year-old with easy bruising, and epistaxis.
PT
20 sec (prolonged, normal 10-13)
PTT
32 sec (normal)
Platelet Count
280,000/µL (normal)
Factor VIII
95% (normal)
Factor IX
100% (normal)
Blood Pressure
110/68 mm Hg
1️⃣ Diagnosis: (Write your answer below)
2️⃣ Any other test: (Write your answer below)
3️⃣ What to do next: (Write your answer below)
4️⃣ Follow-up plan: (Write your answer below)
✅ Model Answer:
• Diagnosis: Factor VII deficiency (isolated prolonged PT, normal PTT).
• Any other test: Factor VII Assay, Genetic testing (F7 gene), factor VII inhibitor (Bethesda assay) if poor response.
• What to do next: For bleeding: recombinant factor VIIa (rFVIIa) 15-30 mcg/kg q4-6h. For major surgery: FFP or rFVIIa. For minor procedures: tranexamic acid.
• Follow-up plan: Monitor factor VII levels. Avoid aspirin/NSAIDs. If severe deficiency, consider prophylaxis with rFVIIa or FFP for major surgeries. Genetic counseling.
Case 7
A 15-year-old with thrombocytopenia (platelets 15,000) and microangiopathic hemolytic anemia . Fever and confusion.
PT
14 sec (normal)
PTT
30 sec (normal)
Platelet Count
15,000/µL (low)
Hemoglobin
8.5 g/dL (low)
LDH
1200 U/L (elevated)
Haptoglobin
<10 mg/dL (low)
Peripheral Smear
Schistocytes present
Blood Pressure
125/80 mm Hg
1️⃣ Diagnosis: (Write your answer below)
2️⃣ Any other test: (Write your answer below)
3️⃣ What to do next: (Write your answer below)
4️⃣ Follow-up plan: (Write your answer below)
✅ Model Answer:
• Diagnosis: Thrombotic thrombocytopenic purpura (TTP) – ADAMTS13 deficiency <10%.
• Any other test: ADAMTS13 Activity, ADAMTS13 inhibitor (autoantibody) to differentiate acquired vs congenital; complement studies (if atypical HUS considered).
• What to do next: Emergency: Start daily plasma exchange (PLEX) and corticosteroids (methylprednisolone 1g/day). Avoid platelet transfusion (unless life-threatening bleeding).
• Follow-up plan: Continue PLEX daily until platelet count normalizes and LDH improves. If refractory, add rituximab (anti-CD20) or caplacizumab. Monitor for relapse. If congenital TTP (Upshaw-Schülman), prophylactic plasma infusions.
Case 8
A 4-year-old with history of Frequent nosebleeds, bleeding gums, easy bruising.
PT
13 sec (normal)
PTT
32 sec (normal)
Platelet Count
300,000/µL
Flow Cytometry
↓CD42b (GPIb)
Blood Pressure
110/70 mm Hg
1️⃣ Diagnosis: (Write your answer below)
2️⃣ Any other test: (Write your answer below)
3️⃣ What to do next: (Write your answer below)
4️⃣ Follow-up plan: (Write your answer below)
✅ Model Answer:
• Diagnosis: Bernard-Soulier syndrome – giant platelets, defective ristocetin-induced aggregation (GPIb/IX/V deficiency).
• Any other test:Peripheral Smear of platelets Giant platelets , Normal Platelet Aggregation (ADP, Collagen), Absent Platelet Aggregation (Ristocetin), Genetic testing (GP1BA, GP1BB, GP9), platelet adhesion studies, vWF levels.
• What to do next: For bleeding: platelet transfusion (risk of alloimmunization). Avoid desmopressin (ineffective). Consider rFVIIa for severe bleeding. Avoid antiplatelet agents.
• Follow-up plan: Monitor for platelet alloimmunization. For major surgery, use HLA-matched platelets. Consider hematopoietic stem cell transplant for severe disease. Genetic counseling.