outcomes
Caplacizumab blocks platelet binding to what molecule?
Von Willebrand factor.
What two findings define the classic hematologic presentation of iTTP?
MAHA and thrombocytopenia.
What ADAMTS13 activity level confirms TTP in the right clinical setting?
Less than 10%
Name one prediction score used to estimate likelihood of severe ADAMTS13 deficiency.
PLASMIC or FRENCH score.
What urgent treatment should start before ADAMTS13 results if suspicion is intermediate or high?
Therapeutic plasma exchange
What is the major adverse effect of caplacizumab?
Bleeding.
What platelet count is typical in iTTP?
Less than 30 × 10⁹/L.
Why should ADAMTS13 testing be drawn before plasma exchange?
Donor plasma can falsely increase ADAMTS13 activity.
What PLASMIC score threshold should prompt urgent hematology consultation?
5 or higher.
What two therapies are strongly recommended first-line by ISTH for acute iTTP?
Plasma exchange and corticosteroids.
What is an iTTP exacerbation?
Recurrence within 30 days of stopping plasma exchange or caplacizumab.
What is the most common symptom category at presentation?
Neurologic symptoms.
What smear finding supports MAHA?
Schistocytes.
The modified FRENCH score uses which lab values? platelet count?
Platelet count and Creatinine.
What does plasma exchange provide that the patient lacks?
Functional ADAMTS13 from donor plasma.
What ADAMTS13 activity threshold during remission commonly triggers preemptive rituximab?
Less than 20%
How often does the full TTP pentad appear at presentation?
Less than 10% of patients.
What should be done if ADAMTS13 activity is 10% to 20% but suspicion remains high?
Repeat testing and continue treatment if iTTP remains likely.
What coagulation pattern argues against classic iTTP and toward DIC?
Markedly abnormal coagulation tests, such as elevated INR/PT and D-dimer
What biologic therapy reduces anti-ADAMTS13 autoantibody production by depleting B cells?
Rituximab.
Name three factors associated with higher mortality in acute iTTP.
Neurologic features, age ≥60, LDH >10× ULN, elevated troponin, or GCS ≤14.
In iTTP, kidney injury is usually mild compared with what other TMA?
Complement-mediated TMA / atypical HUS.
Persistent ADAMTS13 activity below 10% in remission without detectable antibody suggests what diagnosis?
Congenital TTP.
What distinguishes severe vitamin B12 deficiency mimicking TMA from true TMA? Name 3.
Very high LDH, High MCV, Low ADAMST13, Low reticulocyte count.
What infection must be screened for before rituximab due to reactivation risk?
Hepatitis B.