Prognostic value of inhibitory anti‐ADAMTS13 antibodies in adult‐acquired thrombotic thrombocytopenic purpura

Abstract

Summary 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.

High versus standard dose methylprednisolone in the acute phase of idiopathic thrombotic thrombocytopenic purpura: a randomized study

“…However, contrasting results have been obtained by the few studies aimed at establishing whether ADAMTS13 testing during the acute episode helps to identify patients' prognosis and can be used to guide their management [17][18][19][20]. On this basis, there is general agreement that all patients in the acute phase have to receive the most effective treatment [21], and we suggest that, at least presently, the best option is represented by concomitant PE and high dose corticosteroids.…”

A phase 2 study of the safety and efficacy of rituximab with plasma exchange in acute acquired thrombotic thrombocytopenic purpura

“…14 The efficacy of PEX treatment is well established, 15 and patients with anti-ADAMTS13 antibodies require more PEX and therefore more plasma. 3 However, there are limited data clearly demonstrating the utility of other immunosuppressive therapies in the management of TTP. Several small patient series describe various therapies, such as vincristine, 16 cyclophosphamide, or splenectomy.…”

“…The mainstay of treatment remains plasma exchange (PEX) and steroids. 2 However, patients with acquired idiopathic autoimmune disease are more likely to take longer to achieve a normal platelet count and require more plasma therapy, 3 with a relapse rate of 30%-50%. 4,5 In such refractory/relapsing TTP patients, further immunosuppressive therapy may be required, such as Ciclosporin, cyclophosphamide, or vincristine.…”

Management of Concurrent Severe Preeclampsia and Thrombotic Thrombocytopenic Purpura (TTP)

“…Overall, we come to the conclusion that existence of anti ADAMTS 13 is associated with a worse prognosis [47][48][49][50][51]. Moreover there are some reports of a positive correlation between high inhibitor titers and severity of clinical manifestations, treatment refractoriness and the rate of deaths [48,52,53].…”