Treatment of Thrombotic Thrombocytopenic Purpura (TTP)
Immediately initiate therapeutic plasma exchange (TPE) at 1-1.5 times plasma volume daily using fresh frozen plasma as replacement fluid upon clinical suspicion of TTP, without waiting for ADAMTS13 results, as delay increases mortality. 1
Immediate Management Algorithm
First-Line Treatment (Start Simultaneously)
Begin daily TPE immediately at 1-1.5 times plasma volume using fresh frozen plasma (FFP) as replacement fluid, continuing daily until platelet count exceeds 150,000/mm³ and LDH normalizes, then taper slowly 1, 2
Administer high-dose corticosteroids concurrently with methylprednisolone 1g IV daily for 3 days, followed by prednisone 1-2 mg/kg/day 1, 3
Consider adding caplacizumab for acquired TTP in combination with TPE and immunosuppression, as this represents the most recent therapeutic advance 1, 3
Critical Diagnostic Tests (Order Urgently, Do Not Delay Treatment)
Send ADAMTS13 activity level and inhibitor titer to distinguish TTP from other thrombotic microangiopathies, but do not wait for results before starting TPE 1
Examine peripheral blood smear for schistocytes, which confirms microangiopathic hemolytic anemia 1
Check hemolysis markers: LDH (elevated), haptoglobin (reduced), indirect bilirubin (elevated), reticulocyte count (elevated), and direct Coombs test (negative) 1, 3
Screen for secondary causes: HIV, HCV, H. pylori, malignancy, drug exposure, pregnancy/postpartum state, and antiphospholipid syndrome 1
Refractory or Unresponsive TTP
When patients fail to respond to initial TPE and corticosteroids after several days:
Add rituximab 375 mg/m² weekly for 3-4 weeks as the preferred second-line immunomodulator 1, 3
Consider escalating to twice-daily plasma exchange for more intensive therapy 3
Alternative immunosuppressive options include pulses of cyclophosphamide, vincristine, or cyclosporine A 3
Salvage splenectomy may be considered in truly refractory cases 3
Supportive Care and Monitoring
Transfusion Management
Transfuse red blood cells conservatively, targeting hemoglobin 7-8 g/dL in stable patients to relieve symptoms only 1
Avoid platelet transfusions unless life-threatening bleeding is present, as they may worsen thrombosis 1
Monitoring Parameters
Monitor platelet count and LDH daily to guide TPE duration and tapering 1, 2
Provide folic acid 1 mg daily supplementation to support erythropoiesis 1
Monitor hemoglobin weekly during corticosteroid taper 1
Use continuous cardiac monitoring if concurrent myocarditis is suspected 1
Special Populations
Pregnant Patients
TPE remains first-line treatment in pregnancy, with corticosteroids used concurrently 1
The same aggressive approach applies, as TTP carries high maternal and fetal mortality without treatment 1
Evidence Quality and Nuances
The evidence strongly supports TPE as life-saving therapy, with historical mortality rates exceeding 90% before TPE availability, now reduced to 10-20% with prompt treatment 3, 2. Multiple retrospective studies demonstrate complete response rates of 60-85% with TPE 2, 4.
A critical pitfall is delaying TPE while awaiting ADAMTS13 results—the clinical diagnosis of thrombocytopenia plus microangiopathic hemolytic anemia is sufficient to start treatment 1, 2. One prospective randomized trial found no difference between FFP and cryoprecipitate-poor plasma as replacement fluid, so FFP (which is more readily available) is appropriate 5.
The addition of corticosteroids to TPE showed mortality benefit in one large retrospective study (3% vs 14% mortality) 2, supporting their routine use despite lack of randomized data. Caplacizumab represents the newest evidence-based addition, though specific dosing protocols require hematology consultation 1, 3.
High-dose plasma infusion (25-30 mL/kg/day) may be used only when TPE is unavailable, but 42% of patients required switching to TPE due to fluid overload or inadequate response 6. This should be viewed as a temporizing measure only while arranging transfer to a facility with TPE capability.