Title: objective documentation of neurologic injury in patients with idiopathic thrombotic thrombocytopenic purpura (TTP)
Abstract number: OC-WE-129
Cataland1 S.R., Paskavitz2 J., Maruff3 P., Witkoff1 L., Jin4 M., Gilbert5 J.C., Wu4 H.M.
11Medicine, Ohio State University, Columbus 22Perceptive Corp., Waltham, MA, USA 33Cogstate Corp., Melbourne, Australia 44Pathology, Ohio State University, Columbus 55Archemix Corp., Cambridge, MA, USA
How-to-cite Cataland SR, Paskavitz J, Maruff P, Witkoff L, Jin M, Gilbert JC, Wu HM. Title: objective documentation of neurologic injury in patients with idiopathic thrombotic thrombocytopenic purpura (TTP). Journal of Thrombosis and Haemostasis 2009; Volume 7, Supplement 2: Abstract OC-WE-129
Background: CNS injury is a common complication of TTP. It manifests acutely as stroke, coma, or seizures, but chronic neurocognitive deficits in patients have been reported. This study sought to determine the utility of a blood-based biomarker of CNS injury (S100β), MRI imaging, and a neurocognitive test battery (CogState¯) to objectively characterize the nature and extent of CNS injury in idiopathic TTP.
Patients: 12 TTP patients were evaluated at presentation with an acute episode (n = 2), during convalescence from a prior episode (n = 9), or both (n = 1). Additionally, 630 banked plasma samples from 57 acute episodes (33 patients) obtained at presentation and throughout longitudinal follow-up were studied to characterize changes in S100β over time.
Methods: In the acute and convalescent patients, S100β testing, cranial MRI imaging, and CogState¯ testing were performed. S100β was measured by ELISA, MRI's were acquired using T2, GRE, DWI, and FLAIR sequences, and CogState¯ testing was administered.
Results: S100β was acutely elevated (median peak ∼ 4xULN) in TTP patients independently of the presence of CNS symptoms. S100β peaked early (< 5 days) and then normalized in the majority of patients responsive to PEX, but in some patients dependent on PEX it remained elevated for weeks. Neurocognitive performance of convalescent TTP patients was diminished relative to age-matched population norms, and correlated with chronic elevations of S100β. MRI findings during an acute episode of TTP in one patient included new cortical microvascular lesions on FLAIR and DWI images which correlated with the patient's neurologic symptoms and S100β (peak 121.5 pg/mL).
Table for OC-WE-129
| | TTP +CNS s/s (n = 39) | TTP -CNS s/s (n = 17) | Normal Donors (n = 20) |
|---|
| Med.Peak S100β (pg/ml) | 61.5 | 57.4 | 19.2 |
| Range | <15.6–747.8 | <15.6–1371.6 | <15.6–20.3 |
Conclusions: Microvascular CNS injury in TTP patients can be quantified using the S100β biomarker which correlates well with abnormalities documented by neurocognitive testing.
Disclosure of interest: This study is supported by the Archemix Corp.
