19
Statement 31
➤ We did not systematically search and review the evidence on the
effect of antithrombotic therapy in pregnant women with TTP.
Largely based on indirect evidence from other populations, pregnant
women with a history of TTP, and a history of venous thrombosis, are
usually offered low molecular weight heparin at prophylactic doses
throughout pregnancy, with the goal of preventing the formation
of placental microthrombi and insufficiency, as well as preventing
recurrent venous thrombosis. Offering antithrombotic therapy to
women with a history of TTP-associated pregnancy loss, but not
venous thrombosis, remains controversial.
Statement 32
➤ We did not systematically search and review the evidence on the
effect of hormonal preparations, particularly those containing
estrogen, as a potential trigger for relapse in women with TTP.
Women with a history of TTP are usually counselled that non-
hormonal methods of contraception and progestin only preparations
are preferred over estrogen containing preparations which may
promote production of autoantibodies against ADASMTS13.
SECTION V. Refusal of Blood Products
➤ The following statement pertains to care of TTP in patients who
refuse blood products.
Statement 33
➤ We did not systematically search and review the evidence on
alternatives to blood products in TTP patients. Patients with TTP
refusing blood products (e.g., Jehovah's Witnesses) generally will
not accept TPE with replacement of plasma. Clinicians should
explore the patient's values and preferences to determine if they
will accept albumin and other purified protein fractions, as these
products are sometimes acceptable. This strategy can, at minimum,
help remove ADAMTS13 autoantibodies and other potential harmful
inflammatory mediators. Clinicians may empirically consider the
use of corticosteroids, rituximab, and caplacizumab as well as
erythropoietin and folic acid (to promote erythropoiesis). If the
patient will accept plasma derivatives, factor VIII concentrates
containing sufficient amounts of ADAMTS13 may be considered
instead of plasma. If the patient will accept albumin, TPE with
albumin as the replacement fluid may be considered.
