The advent of plasma exchange has led to a dramatic improvement in the survival of patients with thrombotic thrombocytopenic purpura (TTP), though approximately 10% of patients still die and a third suffer relapses. Clinical features that identify poor risk patients have not been clearly identified. We reviewed 100 patients who were treated for a first episode of TTP at the Cleveland Clinic between 2000 and 2012 to identify factors predictive of poor outcomes. On multivariate analysis, increasing age, especially age > 60 (RR: 7.08, 95% CI: 2.15-23.39, P = 0.002), severe neurological symptoms at presentation (RR: 18.37, 95% CI: I4.19-80.13, P < 0.001) and a persistently elevated LDH level after two plasma exchanges were predictive of mortality. Patients with ADAMTS13 activity above or below 5% did not differ in terms of clinical presentation or mortality and relapse rates, although ADAMTS13 activity > 5% was an independent predictor of adverse renal outcomes (need for dialysis and progression to chronic kidney disease). These variables may be useful for risk stratification and identification of patients who could potentially benefit from early institution of adjunctive therapy.
Copyright © 2013 Wiley Periodicals, Inc.