Primary Treatment for Thrombotic Thrombocytopenic Purpura (TTP)
Immediate therapeutic plasma exchange (TPE) is the mandatory, life-saving treatment for TTP and must be initiated urgently when TTP is suspected, as untreated TTP has a mortality rate exceeding 90%. 1
Critical Distinction: TTP is NOT ITP
The evidence provided primarily addresses Immune Thrombocytopenic Purpura (ITP), which is a completely different disease from Thrombotic Thrombocytopenic Purpura (TTP). These conditions require fundamentally different treatments:
- TTP is caused by severe ADAMTS13 deficiency leading to microthrombi formation and requires plasma exchange 1
- ITP is an autoimmune platelet destruction disorder treated with corticosteroids and immunosuppression 2
Definitive Treatment Protocol for TTP
Immediate Therapeutic Plasma Exchange
- TPE must be started immediately upon clinical suspicion, without waiting for ADAMTS13 results, given the high mortality of untreated disease 1, 3
- Exchange 1-1.5 plasma volumes daily using fresh frozen plasma (FFP) as replacement fluid 4, 5
- Continue daily TPE until platelet count normalizes (>150 × 10⁹/L) and LDH normalizes, then taper slowly 4, 5
- Average treatment duration is 23 days with approximately 19 plasma exchange procedures per patient 5
Replacement Fluid Selection
- Fresh frozen plasma (FFP) is the standard replacement fluid 4, 6
- Cryoprecipitate-poor plasma (CPP) shows no superiority over FFP in prospective randomized trials 6
- Volume exchanged: 3600-4000 mL per procedure (1-1.5 plasma volumes) 5
Adjunctive Immunosuppression
- Corticosteroids (prednisone 0.75-1 mg/kg twice daily) should be initiated concurrently with TPE 1, 3
- Rituximab (anti-CD20 antibody) is effective for newly diagnosed cases, refractory cases, and relapse prevention 1
- Caplacizumab (anti-VWF nanobody) prevents microthrombi formation by inhibiting platelet-VWF binding 1
Expected Outcomes
Response Rates with TPE
- Overall response rate: 77-93% 4, 5
- Complete remission rate: 60-86% 4, 5
- Survival rate: approximately 80% with prompt treatment 6
- Mortality: 7-14% even with treatment, primarily in patients receiving fewer than 4 TPE procedures 5, 3
Prognostic Factors
- Presence of fever is a negative prognostic indicator requiring prolonged TPE treatment 4
- Primary (idiopathic) TTP responds better than secondary TTP (82.8% vs 29.4% complete response) 4
- Early initiation of TPE before severe organ damage occurs improves survival 3
Clinical Monitoring During Treatment
- Daily platelet counts and LDH levels to guide treatment duration 4, 5
- Monitor for neurological symptoms (present in 100% initially, should resolve with treatment) 3
- Assess renal function (impaired in 36-42% of patients at presentation) 5, 3
- Watch for hemolysis markers: hemoglobin, reticulocyte count, red cell fragmentation 3
Critical Pitfalls to Avoid
- Never delay TPE while awaiting ADAMTS13 results - the high mortality of untreated TTP mandates immediate empiric treatment 1
- Do not confuse TTP with ITP - corticosteroids alone are inadequate for TTP and will result in death 1
- Do not stop TPE prematurely - continue until complete normalization of platelets and LDH, then taper slowly to prevent relapse 4, 5
- Recognize that 10-30% of patients will relapse within months to years, requiring repeat TPE courses 5