10
Treatment
Statement 2
➤ We did not systematically search and review the evidence on
different clinical or laboratory approaches for diagnostic workup of
a patient with suspected TTP. However, initial laboratory evaluation
of presumptive TTP should include a complete blood count (CBC)
with careful review of a peripheral blood film for lack of platelets
and presence of fragmented red blood cells (or schistocytes), serum
lactate dehydrogenase (LDH) and creatinine, testing to demonstrate
hemolysis (e.g., low haptoglobin and increased indirect bilirubin),
coagulation testing (which is expected to be relatively normal in
TTP unless severe disease and there is a concomitant disseminated
intravascular coagulation (DIC), and a direct Coombs test (which is
expected to be negative in TTP, but not in autoimmune hemolytic
anemia). Troponin I and electrocardiogram are systematically
performed to identify subclinical cardiac involvement. Computerized
tomography/magnetic resonance imaging (CT/MRI) of the brain
may also be included in the initial evaluation for TTP if there are
symptoms of brain injury.
Statement 3
➤ If the index of suspicion for TTP is high, clinicians should consider
the emergency initiation of therapeutic plasma exchange (TPE). Due
to the severity and instability of their illness, and the foundational
role of TPE in the treatment of TTP, patients experiencing an acute
event of TTP are usually urgently transferred to a facility that can
perform TPE, ideally overseen by a clinician who has expertise in the
management of TTP. Most of these patients (>95%) if confirmed with
severe ADAMTS13 deficiency are immune TTP (or iTTP).
➤ For suspected iTTP, a blood sample should be obtained for plasma
ADAMTS13 testing (e.g., activity and inhibitors) prior to the initiation
of TPE. Daily TPE is generally initiated as soon as possible with fresh
frozen plasma, cryopoor plasma, or solvent detergent treated plasma
as the replacement fluid. The volume of replacement fluid is usually
1.0 to 1.5 times of patient's plasma volume (i.e., 40-60 ml/kg) every
24 hours until normalization of platelet counts and LDH.
➤ Patients with a suspected or confirmed hereditary or congenital TTP
(cTTP) are generally treated with plasma infusion with a volume of 10-
15 mL/kg at a frequency of every 1-3 weeks for maintenance therapy
or daily for symptomatic patients until symptoms resolve.
