Thrombotic thrombocytopenic purpura (TTP) is a rare condition, which has a very high risk of death if not recognised and given immediate treatment. TTP is caused by a very low level of an enzyme in the body, called ADAMTS13. A lack of ADAMTS13 causes multiple small clots to form around the body which can disrupt the blood flow to important organs. Although survival has improved significantly, it is now being recognised that patients with TTP may suffer with longer term complications as a result of their condition; literature from the USA reports higher rates of major depression and also poor memory and reduced concentration in patients with TTP. The investigators aim to improve the understanding of the long-term complications and review, for the first time, forward-looking data at multiple time points in patients with TTP in the UK. Both patients with a new diagnosis and patients with a known diagnosis of TTP identified in NHS hospitals will be included, over a minimum duration of 2 years. This will be a questionnaire based study with both doctor led and participant led questionnaires at pre-determined points in time. By improving the understanding and comparing symptoms to that of the general population, the investigators hope to improve the support and tailor the treatments which can be offered to patients with TTP.

Inclusion Criteria:

1.Acute episode TTP:

• Adult male or female patient ≥18 years of age at the time of signing the consent form, with a confirmed diagnosis of TTP (initial or relapse) based on ADAMTS13 <10% 2. Known diagnosis of TTP:
• Adult male or female patient ≥ 18 years of age at time of signing the consent form, with a historical confirmed diagnosis of TTP (based on ADAMTS13 at initial presentation <10%) 3. Healthy control:
• Non-blood relative / friend / carer of patients under the care of Haematology clinics at the Royal Liverpool University hospital or other participating centres.

Exclusion Criteria:

1. Acute episode of TTP:

   • Participants less than 18 years old at the time of signing the consent form
   • Patient with ADAMTS13 greater than 10%
   • Patient with cancer or transplant associated MAHA will not be included
   • Patient (or NOK, where patient does not have capacity) not wishing to consent to trial

2. Known diagnosis of TTP:

   • Participants less than 18 years old at the time of signing the consent form
   • Patient with ADAMTS13 greater than 10%
   • Patient with cancer or transplant associated MAHA will not be included
   • Patient (or NOK, where patient does not have capacity) not wishing to consent to trial

3. For healthy control:

   • Participants less than 18 years old at the time of signing the consent form
   • Participant not wishing to consent to trial
   • Any personal or family history of thrombotic microangiopathy

Adult patients diagnosed with thrombotic thrombocytopenic purpura in the United Kingdom