The incidence of thrombotic thrombocytopenic purpura‐hemolytic uremic syndrome: all patients, idiopathic patients, and patients with severe ADAMTS‐13 deficiency

Abstract

Summary. Background: Accurate estimates of the incidence of thrombotic thrombocytopenic purpura (TTP) are important to assess the resources required for current treatments as well as to anticipate the need to develop new treatments. Previous estimates have been indirect and have not reported data on patients with ADAMTS‐13 deficiency. Objective: To determine the incidence of patients with TTP‐hemolytic uremic syndrome (HUS) in three categories: all patients with clinically suspected TTP‐HUS, patients with idiopathic TTP‐HUS, and patients with severe ADAMTS‐13 deficiency. Methods: Incidence rates were estimated from the Oklahoma TTP‐HUS Registry, analyzing all 206 consecutive patients from January 1, 1996 to June 30, 2004 who were treated with plasma exchange for their initial episode of clinically suspected TTP‐HUS. ADAMTS‐13 activity was measured in 186 (90%) of the 206 patients. Results: The age–sex–race standardized annual incidence rates were 11.29 × 106 (95% CI: 9.70–12.88) for all patients with clinically suspected TTP‐HUS; 4.46 × 106 (95% CI: 3.43–5.50) for patients with idiopathic TTP‐HUS; and 1.74 × 106 (95% CI: 1.06–2.41) for patients with severe ADAMTS‐13 deficiency (<5% activity). In all three categories, the incidence rates were greater for women and for blacks. For patients with severe ADAMTS‐13 deficiency, the age–sex standardized incidence rate ratio of blacks to non‐blacks was 9.29 (95% CI: 4.33–19.93). Conclusions: Accurate incidence rate estimates for all patients with clinically suspected TTP‐HUS, idiopathic TTP‐HUS, and TTP associated with severe ADAMTS‐13 deficiency have been determined. The greater incidence among women and blacks is comparable with their increased risk for other autoimmune disorders.

Thrombotic Thrombocytopenic Purpura: A Thrombotic Disorder Caused by ADAMTS13 Deficiency

“…HIV was present in approximately 50% of the TTP cases at a major urban center [57], in 39% of our non-referral cases, and in 4% of the Oklahoma registry cases [44]. The use of ticlopidine may increase the risk of TTP by 50-200-folds [58;59].…”

Use of the ADAMTS13 Activity Assay Improved the Accuracy and Efficiency of the Diagnosis and Treatment of Suspected Acquired Thrombotic Thrombocytopenic Purpura

“…3,4 Despite the rarity of this disease, A-TTP is a significant cause of microangiopathic hemolytic anemia (MAHA) requiring rapid diagnosis and treatment. 5 The disease is the result of a circulating inhibitor against the von Willebrand factor-cleaving protease, ADAMTS13.…”

“…This is especially true in the pediatric population, in which hemolytic uremic syndrome is a more common diagnosis with predominantly indistinguishable clinical presentation. 5 In the past decade, the ADAMTS13 activity assay has improved to become an important contributor in the diagnosis of A-TTP, providing clinicians with additional certainty of the diagnosis before starting treatment with TPE. 17 Unfortunately, many hospital labs are not equipped to perform the ADAMTS13 activity assay.…”

Microangiopatía trombótica en Lupus Eritematoso Sistémico: a propósito de tres casos

“…Al parecer, también la inmunosupresión de estos pacientes puede retardar las manifestaciones clínicas de PTT en LES (8). En el 2008 en la Universidad de Louisiana (9) fue realizado un análisis retrospectivo de 114 pacientes con exacerbaciones LES, algunos de ellos cursaron con anemia hemolítica microangiopática y fueron comparados con los que no.…”