ADAMTS13 activity and autoantibodies classes and subclasses as prognostic predictors in acquired thrombotic thrombocytopenic purpura.
J Thromb Haemost. 2012 Jun 5;
Authors: Bettoni G, Palla R, Valsecchi C, Consonni D, Lotta LA, Trisolini SM, Mancini I, Musallam KM, Rosendaal FR, Peyvandi F
Abstract
Background:?Thrombotic thrombocytopenic purpura (TTP) is a rare life-threatening disease. Of surviving patients, 45% develops an exacerbation or a late recurrence. Severe ADAMTS13 deficiency, both during the acute episode and remission is a well-established predictor of recurrence. The predictive value of anti-ADAMTS13 antibodies, their inhibitory activity and Ig class subtype for disease recurrence is still to be established. Objectives:?To analyze ADAMTS13 related biomarkers (ADAMTS13 and anti-ADAMTS13 immunoglobulins, classes and subclasses) and their potential relationship with prognosis. Patients/Methods:?In 115 patients with TTP we assessed the association between levels of these biomarkersand the severity of acute episodes; we analysed also the hazard ratio and 95% confidence interval of recurrence in association with biomarkers levels retrieved at the previous acute episode or during remission, using Cox regression models. Results:?During the acute phase, higher IgA, IgG1 and IgG3 titres showed the strongest association with acute episode severity. In the survival analyses the only biomarker significantly associated with a high hazard of recurrence following an acute episode was presence of IgG. Conversly, low ADAMTS13 activity or antigen levels (<10%), presence of ADAMTS13 inhibitor or IgG during remission were all significantly associated with a higher hazard of recurrence. Conclusions: Both the Ig class and subclass are of predictive value for acute episode severity in patients with TTP. Although markers that could predict the risk of recurrence in the acute phase are limited, a thorough assessment of ADAMTS13 related parameters during remission is warranted. © 2012 International Society on Thrombosis and Haemostasis.
PMID: 22672482 [PubMed - as supplied by publisher]