Prognostic value of inhibitory anti-ADAMTS13 antibodies in adult-acquired thrombotic thrombocytopenic purpura.
In order to assess the prognostic value of inhibitory anti-ADAMTS13 antibodies in thrombotic thrombocytopenic purpura (TTP), we performed a multicentre prospective study of 33 adult patients with idiopathic acquired TTP. Patients were treated with high-dose plasma infusion and therapeutic plasma exchange. Patients without (group 1, n = 12) and with (group 2, n = 21) detectable inhibitory anti-ADAMTS13 antibodies were compared for clinical presentation, treatment and outcome. Both groups were comparable for clinical presentation. All patients in group 1 achieved a sustained complete remission within a median of 7 d [95% confidence interval (CI), 4-18], which required a median plasma volume of 235 ml/kg (range, 131-1251). In group 2, 17 patients achieved a durable complete remission within a median of 23 d (95% CI, 11-32) (P = 0.001). Median plasma volume was 718 ml/kg (range, 219-3107) (P = 0.02). In group 2, there was a trend for more episodes of flare-up than in group 1 (13 vs. 3, respectively, P = 0.07). Four patients, all from group 2, died (P = not significant). The relapse rate was comparable between both groups. We suggest that TTP with detectable inhibitory anti-ADAMTS13 antibodies displays a worse prognosis, relative to a delayed platelet count recovery, a higher plasma volume requirement to achieve complete remission, and a trend for more frequent episodes of flare-up.
Coppo
P
P
Service d'Hématologie et de Thérapie Cellulaire, Faculté de Médecine Paris VI, Hôpital Saint-Antoine, Paris. paulcoppo@aol.com
Wolf
M
M
Veyradier
A
A
Bussel
A
A
Malot
S
S
Millot
G A
GA
Daubin
C
C
Bordessoule
D
D
Pène
F
F
Mira
J P
JP
Heshmati
F
F
Maury
E
E
Guidet
B
B
Boulanger
E
E
Galicier
L
L
Parquet
N
N
Vernant
J P
JP
Rondeau
E
E
Azoulay
E
E
Schlemmer
B
B
D051722:ADAM Proteins / Q000276:immunology*; D000071120:ADAMTS13 Protein; D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010951:Plasma Exchange; D010976:Platelet Count; D011379:Prognosis; D011446:Prospective Studies; D011697:Purpura, Thrombotic Thrombocytopenic / Q000097:blood / Q000276:immunology / Q000628:therapy*; D012008:Recurrence; D012074:Remission Induction; D016896:Treatment Outcome
D001323:Autoantibodies; D015415:Biomarkers; D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human