Identification of Trigger Factors Initiating an Acute TTP Episode in 68 Patients.

Recent research efforts have provided significant insight into the pathogenesis of thrombotic thrombocytopenic purpura (TTP). However, the low incidence of the disease hampers the identification of trigger factors initiating an acute TTP episode. In the present work data from 68 TTP patients were analyzed. The patients were asked by a questionnaire to provide data concerning age, gender, medical history, underlying and concomitant diseases and potential triggers. Additional laboratory and clinical data from onset of disease and remission phase were obtained by a second questionnaire completed by the physicians. Our study showed that long term abuse of nicotine is a predisposing factor with an OR of 3.19. The OR for obesity and development of TTP was 2.01. The influence of nicotine abuse has not yet been described whereas the association between obesity and development of TTP is already known. The intake of oral contraceptives (13 of 46 women/28%) of Tamoxifen, of Fluvastatin, of Ticlopidine and of Quinine was identified to be potential triggers. 55% (34 patients) of the patients reported infections and inflammations as triggers (mostly influenza (n=16) and gastroenteritis (n=14)). The relation of female and male patients was 3:1. The mean age, in which the initial TTP episode occurred, was significantly lower in female patients compared with the male patients (33.8 versus 43.8 years). Severe ADAMTS-13 deficiency was found in 91% in all investigated episodes of the patients. Inhibitory activity was associated with severe ADAMTS-13 deficiency in 81% of the cases. The comparison of patients during remission with and without relapses of TTP revealed a significant lower ADAMTS-13 activity in patients with relapsing TTP compared to patients without a relapse of TTP. This result suggests that ADAMTS-13 activity has prognostic value with respect to the occurrence of relapse.