Thrombotic thrombocytopenic purpura

DIAGNOSIS

Clinical pentad, present in fewer than 30% of cases:

consumptive thrombocytopenia,

microangiopathic hemolytic anemia,

fever,

renal dysfunction,

fluctuating neurologic deficits

Thrombocytopenia and microangiopathic hemolytic anemia are sufficient to make the diagnosis in the absence of other causes.

LABS – No definitive test

CBC - anemia and thrombocytopenia

low haptoglobin

elevated lactate dehydrogenase and indirect bilirubin

BUN, Cr - renal insufficiency

peripheral smear reveals – schistocytes

Coagulation studies usually are normal

MANAGEMENT

a medical emergency that requires immediate hospitalization, usually in an ICU

Plasma exchange (1.0 plasma volume qd) is the mainstay of therapy.

Remission rates are as high as 90% when plasma exchange is initiated without delay.

Addition of glucocorticoids (methylprednisolone, 200 mg IV qd)

Antiplatelet agents (aspirin, 325 mg PO qd, and dipyridamole, 100 mg PO q6h) are included in some regimens

Platelet transfusions, however, are relatively contraindicated

RBCs as needed

The end point of therapy is not well defined, but plasma exchange should be continued for at least 5 days or for 2 days after normalization of the platelet count and lactate dehydrogenase, resolution of neurologic signs, and improvement in microangiopathy. Renal failure may be slower to improve, and persistent azotemia does not necessarily indicate treatment failure.

2^nd Step a trial of plasma exchange with cryosupernatant in place of fresh frozen plasma (FFP).

3^rd step Splenectomy may salvage some patients with TTP that is refractory to plasma exchange or may reduce the frequency of relapses in patients who experience recurrent episodes

Relapse occurs most commonly within a month.