BOF: Clotting (Thrombosis)

Which ONE of the following statements regarding thrombotic thrombocytopenic purpura (TTP) is true?

a) 90% of patients present with a form of neurological deficit

b) In those with severe deficiency of ADAMTS 13, 50% of patients who respond to initial treatment will relapse

c) It is more common in male patients

d) Mortality rates are estimated to be approximately 50%

e) The direct antiglobulin test is usually positive

Answer:

b) In those with severe deficiency of ADAMTS 13, 50% of patients who respond to initial treatment will relapse

Explanation:

Approximately 50%-65% of patients with TTP present with neurological deficit. Blood tests show fragmented red cells and polychromasia on the blood film. LDH is raised and the direct antiglobulin test is negative. TTP is more common in females, black patients and those with obesity. Treatment with urgent plasma exchange has been shown to have superior outcomes compared to FFP alone with response rates of 80%. Relapses are infrequent. However in those with severe deficiency of ADAMTS 13, 50% of patients who respond to initial treatment will relapse. Mortality prior to plasma exchange was in excess of 90%, but is now reported at between 10-30%.

Reference:

Scully, M., & Goodship, T. (2014). How I treat thrombotic thrombocytopenic purpura and atypical haemolytic uraemic syndrome. British Journal of Haematology, 164(6), 759–766. http://doi.org/10.1111/bjh.12718