15
Statement 16
➤ We did not systematically search and review the evidence on
cyclophosphamide for TTP patients. Patients with refractory TTP
unresponsive to standard treatments may be considered for other
immunosuppressive treatments with scant supporting evidence,
including cyclophosphamide. In these cases, cyclophosphamide is
usually administered at doses of 500 mg intravenously, once daily
over 2 hours. Typically, a single dose is used, as additional doses can
cause severe bone marrow suppression.
Statement 17
➤ We did not systematically search and review the evidence on
splenectomy for TTP patients. This procedure has been largely
superseded by other treatments such as rituximab. It is generally not
used, but may have a role in selected TTP patients as a prophylactic
strategy.
Statement 18
➤ We did not systematically search and review the evidence on
azathioprine for TTP patients. Clinicians sometimes consider
azathioprine to inhibit ADAMTS13 autoantibody production that leads
to normalization of plasma ADAMTS13 activity and prevents relapse
in patients with refractory TTP unresponsive to standard treatments.
Statement 19
➤ We did not systematically search and review the evidence on
antiplatelet agents for TTP patients. Antiplatelet agents were used
in nonpregnant patients with TTP, particularly in the setting of
macrothrombotic complications (e.g., ischemic stroke and myocardial
infarction). Otherwise, antiplatelets are not generally used in TTP;
their role in preventing relapse is not supported in the literature,
and they may be harmful in the acute phase of TTP when the platelet
count is <50 × 109/L. Input from cardiologists, neurologists, and/
or other vascular medicine specialists is usually sought if antiplatelet
agents are considered in the treatment of TTP complications.
Statement 20
➤ We did not systematically search and review the evidence on
eculizumab for TTP patients. Increased complement activation is
demonstrated in TTP. Therefore, clinicians sometimes consider
an anti-C5 monoclonal antibody (i.e. eculizumab) in very selected
TTP patients with refractory disease or unresponsive to all other
treatment options. This strategy should be pursued with caution.
