Demographic and ADAMTS13 biomarker data as predictors of early recurrences of idiopathic thrombotic thrombocytopenic purpura.
OBJECTIVE
Approximately 40% of idiopathic thrombotic thrombocytopenic purpura (TTP) patients will suffer an exacerbation (recurrence of TTP within 30 d after their last plasma exchange (PE) procedure), but there are no data to predict who is at greater risk. We studied the clinical utility of demographic and ADAMTS13 biomarker data to predict the risk for exacerbation.


METHODS
Forty-four acute episodes of idiopathic TTP from 26 patients were studied.


METHODS
PE was performed plus either prednisone (1 mg/kg/d) or cyclosporin (2-3 mg/kg/d) as adjuncts. PE was continued daily until response (platelet count >150 000/microL and normalized lactate dehydrogenase) and tapered uniformly in all patients. ADAMTS13 biomarkers were studied prior to PE and after achieving a response, but within 7 d of the last PE.


RESULTS
African American race (AA) was associated with an increased risk for exacerbation (P = 0.046). ADAMTS13 at presentation was also significantly lower in patients experiencing an exacerbation (P = 0.0364). After adjusting for the race effect, ADAMTS13 remained marginally significant (P = 0.0569).


CONCLUSIONS
AA is significantly associated with an increased risk for exacerbations of TTP. These data also suggest that decreasing pretreatment ADAMTS13 activity was associated with an increased risk for exacerbation, even after accounting for the effect of race.
Cataland
Spero R
SR
Department of Medicine, Columbus, OH, USA. spero.cataland@osumc.edu
Yang
Shang-bin
SB
Witkoff
Leslie
L
Kraut
Eric H
EH
Lin
Shili
S
George
James N
JN
Wu
Haifeng M
HM
D051722:ADAM Proteins / Q000097:blood* / Q000276:immunology; D000071120:ADAMTS13 Protein; D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D001323:Autoantibodies / Q000097:blood; D001324:Autoantigens / Q000097:blood* / Q000276:immunology; D015415:Biomarkers; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010951:Plasma Exchange; D011697:Purpura, Thrombotic Thrombocytopenic / Q000453:epidemiology* / Q000276:immunology / Q000628:therapy; D012008:Recurrence; D015203:Reproducibility of Results; D012306:Risk; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D001323:Autoantibodies; D001324:Autoantigens; D015415:Biomarkers; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human