Diagnosis of exlusion.
Platelets >450 for a prolonged period of time.
All patients need ASA, and high risk (over 60 or platelets >1000) need hydroxyurea.
Typically associated with increased red cell mass or elevated hemoglobin. Also often associated with both thrombocytosis and leukocytosis.
Presence of JAK2 V616F mutation or other functionally similar JAK2 mutation.
Often accompanied by splenomegaly and low erythropoietin levels.
Chronic Myelogeous Leukemia
Presents with splenomegaly, leukocytosis, with or without thrombocytosis.
Diagnosed by the presence of the Philadelphia chromosome and/or the presence of BCR-ABL1 fusion product.
X-chromosome inactivation in early embryogenesis.
Hemophilia: Clinical Severity
An indication of MAHA. Broken fragments of red blood cells.
Laboratory Testing for MAHA
1. Schistocytes on PBS
2. Anemia and thrombocytopenia in CBS
3. Negative DAT
4. Increased LDH
5. Increased bilirubin
6. Decreased haptoglobin
Thrombotic Thrombocytopenic Purpura (TTP)
Normally, ADAMTS-13 cleaves unusually large multimers of VWF.
In patients with TTP, adhesion and aggregation of platelets to the large multimers of VWF renders ADAMTS-13 unable to cleave them. This results in MAHA, thrombocytopenia, acute kidney injury, neurologic deficits, and fever.
In the lab, you will see anemia, schistocytes, increased LDH, increased bilirubin, decreased haptoglobin, thrombocytopenia, increased creatinine, and decreased ADAMTS13.
TTP is a hematological emergency with a 90% fatality rate if untreated. Patients need a daily plasma exchange until platelets >150 and LDH is normal and will need steroids/immunosuppressive therapy if acquired TTP.
Hemolytic Uremic Syndrome (HUS)
Is caused by a systemic ADAMTS-13 deficiency. Shigatoxin from E. coli disables the enzyme which results in similar symptoms to TTP.
Antibiotic use is avoided unless the patient is septic as it may cause further toxin release. Hemodialysis may be required as kidney failure is more common.
Disseminated Intravascular Coagulation (DIC)
1. Excess TF release activating F7/extrinsic pathway
2. Excessive thrombin production and defective anticoagulant mechanisms
3. Suppression of fibrin clot degradation
When to Transfuse Platelets
Hemolysis, elevated liver enzymes, and low platelets.
Seen between 28-36 weeks gestation.
Delivery is the only effective treatment.
A "line" that needs to be crossed to develop thrombosis. It increases with age always but can be influenced by genetic risk and transient (or environmental) factors.
Cancer and surgery can increase it.
1. Venous stasis
2. Hypercoagulable state
3. Vessel injury or abnormalities
Protein C and Protein S
Downregulate F8 and F5
Downregulates F2 and F10
Classical Symptoms of DVT
Classical Symptoms of PE
2. Chest pain
6. Syncope (loss of consciousness)
7. Sudden death
Best used for a negative predictive value for a blood clot.
CT Pulmonary Angiography (CTPA)
95% sensitivity and specificty when used in conjunction with D-dimer. Very good at detecting PE.
Mimics antithrombin and inhibits Factor 10a and Factor 2.
Safe in pregnancy.
May cause Heparin-Induced Thrombocytopenia in 1-5% of people.
Occurs with Heparin sometimes.
Antibodies form against the complex of heparin and platelets, which causes their destruction. Stop heparin and switch to an alternative anticoagulant.
Therapeautic INR of Warfarin
Between 2.0 and 3.0
For mechanical heart valves between 2.5 and 3.5