```html

Thrombotic Thrombocytopenic Purpura (TTP)

Overview

Thrombotic Thrombocytopenic Purpura (TTP) is a rare, life‑threatening blood disorder characterized by the formation of small blood clots (thrombi) throughout the body’s microvasculature. These clots use up platelets, leading to a low platelet count (thrombocytopenia) and cause damage to red blood cells, kidneys, brain, and other organs.

There are two main forms:

• Acquired (immune‑mediated) TTP – caused by auto‑antibodies that inhibit the enzyme ADAMTS13.
• Hereditary (congenital) TTP – due to inherited mutations in the ADAMTS13 gene.

Who it affects: TTP can occur at any age but has a peak incidence in adults 30–50 years old. Women are affected slightly more often than men (≈60 % of cases). The congenital form is present from birth, though symptoms may not appear until later in life.

Prevalence: In the United States, the incidence is about 3–4 cases per 1 million people per year, translating to roughly 10,000 new cases worldwide annually (CDC, Mayo Clinic).

Symptoms

The classic clinical picture is described by the “pentad” of TTP, although many patients present with only a few features.

1. Thrombocytopenia (low platelets)

• Easy bruising, petechiae (tiny red spots), or spontaneous bleeding (nose, gums).

2. Microangiopathic hemolytic anemia (MAHA)

• Fatigue, pallor, shortness of breath.
• Dark urine (due to hemoglobinuria) and jaundice from breakdown of red cells.

3. Neurologic symptoms

• Headache, confusion, seizures, focal weakness, or visual disturbances.
• Sudden changes in mental status are a red flag for rapid disease progression.

4. Renal involvement

• Hematuria, proteinuria, or decreased urine output.
• Kidney pain is less common than in hemolytic‑uremic syndrome (HUS) but can occur.

5. Fever

• Low‑grade or high fever, often accompanying the inflammatory response.

Other possible findings

• Abdominal pain or nausea (due to mesenteric ischemia).
• Cardiac ischemia or chest pain – rare but documented.
• Pregnancy‑related TTP – can mimic pre‑eclampsia; careful evaluation needed.

Causes and Risk Factors

Immune‑mediated (acquired) TTP

• ADAMTS13 auto‑antibodies – Inhibit the von Willebrand factor–cleaving protease, leading to ultra‑large von Willebrand multimers that precipitate platelet aggregation.
• Triggers:
  • Infections (especially HIV, influenza, COVID‑19)
  • Medications (quinine, cyclosporine, ticlopidine, thienopyridines, and certain antibiotics)
  • Autoimmune diseases (systemic lupus erythematosus, Sjögren’s)
  • Pregnancy and the postpartum period

Congenital (hereditary) TTP

• Mutations in the ADAMTS13 gene result in reduced enzyme activity from birth.
• Often presents after a physiological stress (infection, surgery, pregnancy) that raises von Willebrand factor levels.

Risk factors

• Female gender (particularly for acquired form)
• Age 30‑50 for acquired TTP
• History of prior TTP episode (relapse risk ≈30 % within 2 years)
• Underlying autoimmune disease
• Recent exposure to high‑dose quinine (e.g., tonic water) or certain antiplatelet drugs

Diagnosis

Because TTP progresses rapidly, diagnosis is often clinical and then confirmed with laboratory testing.

Step‑wise approach

1. Complete blood count (CBC) – shows thrombocytopenia (<150 × 10⁹/L) and anemia.
2. Peripheral blood smear – identifies schistocytes (fragmented RBCs), a hallmark of MAHA.
3. Lactate dehydrogenase (LDH) – elevated due to cell destruction; haptoglobin is low.
4. Creatinine & urinalysis – assess renal involvement.
5. ADAMTS13 activity assay – activity <10 % strongly supports TTP; results may take days, so treatment should not wait.
6. Coagulation profile – PT, aPTT are usually normal (helps differentiate from DIC).

Scoring tools

The PLASMIC score (Platelets, combined hemolysis, no active cancer, no transplant, MCV, INR, Creatinine) predicts the likelihood of severe ADAMTS13 deficiency and guides urgent therapy (JAMA 2016).

Treatment Options

Immediate therapy is essential. Modern management combines plasma exchange, immunosuppression, and newer targeted agents.

Plasma Exchange (PEX)

• First‑line: daily therapeutic plasma exchange (1–1.5 × plasma volume) replaces deficient ADAMTS13 and removes auto‑antibodies.
• Typical course: 5–7 days until platelets >150 × 10⁹/L and LDH normalizes, then taper.

Immunosuppressive therapy

• Corticosteroids – methylprednisolone 1 mg/kg IV daily, then taper.
• Rituximab – anti‑CD20 monoclonal antibody; 375 mg/m² weekly for 4 weeks reduces relapse rates (≈50 % lower vs. PEX alone) (NEJM 2015).
• Caplacizumab – nanobody that blocks von Willebrand factor‑platelet interaction; approved in the US/EU (2020). Reduces time to platelet normalization and mortality.
• Other agents (in refractory disease): cyclophosphamide, mycophenolate, vincristine.

Supportive care

• Red blood cell transfusions for symptomatic anemia.
• Avoid platelet transfusions unless life‑threatening hemorrhage.
• Renal protection: monitor fluid balance, avoid nephrotoxic drugs.
• Antibiotic prophylaxis during prolonged immunosuppression.

Long‑term management

• Maintenance rituximab (every 6‑12 months) in patients with low ADAMTS13 activity.
• Regular follow‑up labs: platelet count, LDH, creatinine, and ADAMTS13 activity.
• Vaccination (influenza, pneumococcal, COVID‑19) to reduce infection‑triggered relapses.

Living with Thrombotic Thrombocytopenic Purpura

Daily management tips

• Medication adherence – never miss rituximab or caplacizumab doses; keep a medication calendar.
• Hydration – drink adequate fluids (unless contraindicated by heart/kidney disease) to support renal perfusion.
• Bleeding precautions – use soft toothbrushes, avoid NSAIDs and aspirin unless directed by a physician.
• Monitoring – weekly CBC and LDH during the first 3 months, then monthly if stable.
• Pregnancy planning – discuss with a hematologist; TTP can flare during pregnancy, requiring close multidisciplinary care.
• Psychosocial support – connect with patient advocacy groups (e.g., TTP Foundation) for counseling and peer support.

When to call your doctor

• New bruising, petechiae, or bleeding.
• Sudden headache, visual change, confusion, or weakness.
• Persistent fever or unexplained chills.
• Drop in urine output or swelling in legs.

Prevention

Because TTP can be triggered by external factors, risk reduction focuses on avoidance and early detection.

• Avoid known drug triggers – quinine, certain antiplatelet agents, and high‑dose statins (rare).
• Infection control – keep vaccinations up‑to‑date; seek prompt treatment for flu, COVID‑19, or urinary infections.
• Manage autoimmune disease – maintain control of lupus or other conditions with rheumatology follow‑up.
• Pregnancy monitoring – early obstetric referral for women with a prior TTP episode.
• Regular laboratory surveillance for patients with a history of TTP; a drop in ADAMTS13 activity can precede clinical relapse.

Complications

If untreated or delayed, TTP can cause permanent organ damage or death.

• Neurologic deficits – stroke, seizures, chronic cognitive impairment.
• Renal failure – may require dialysis.
• Cardiac injury – myocardial infarction from microvascular thrombosis.
• Hemorrhagic complications – intracranial bleeding due to severe thrombocytopenia.
• Relapse – up to 30‑40 % experience at least one recurrence; each episode adds cumulative risk.
• Mortality – before plasma exchange, mortality exceeded 90 %; today, with early treatment, 5‑year survival >80 % (Cleveland Clinic).

When to Seek Emergency Care

References

• Mayo Clinic. Thrombotic Thrombocytopenic Purpura (TTP). Accessed June 2026.
• CDC. Rare Blood Disorders. 2023.
• JAMA. Scully M et al. “PLASMIC Score for Predicting Severe ADAMTS13 Deficiency.” 2016.
• NEJM. H. S. Scully et al. “Rituximab in Acquired TTP.” 2015.
• World Health Organization. “Guidelines for Diagnosis and Management of TTP.” 2022.
• Cleveland Clinic. “Thrombotic Thrombocytopenic Purpura – Treatment & Prognosis.” 2024.

```