Patients with thrombotic thrombocytopenic purpura (TTP) who experience remission may face an increased risk for stroke in association with lower levels of ADAMTS13 enzymatic activity, according to research published in Blood.

“TTP survivors have a high rate of stroke even after recovery from their acute TTP episode, which is independent of TTP recurrence,” wrote the study authors.

In this study conducted at Johns Hopkins Hospital in Baltimore, Maryland, records of past patients were analyzed in combination with data collected from new patients who were prospectively examined on enrollment between 2014 and 2018.

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From these data, the researchers analyzed levels of ADAMTS13 activity measured during remission following an acute TTP event and at a minimum of 3 months after the acute TTP event. The threshold the researchers used to define normal ADAMTS13 activity was a level of greater than 70%.

Among 137 patients who were followed over a median duration of 3.08 years, 13.1% experienced stroke. The study authors reported that this occurred at a rate significantly higher than the rate of 2.6% in a reference population that was matched by age and sex (P =.002).

There were 52 patients with ADAMTS13 activity data available from a period of remission from acute TTP. Patients’ levels of ADAMTS13 activity during remission ranged from greater than 70% activity in 44.2% of the patients to less than 10% in 7.7% of the patients.

There was a significant association between incidence of stroke and ADAMTS13 activity level during remission from acute TTP. None of the 22 patients with normal ADAMTS13 activity experienced stroke, whereas stroke occurred in 27.6% of the 29 patients with ADAMTS13 activity below 70% (P =.007).

“Incomplete recovery of ADAMTS13 after an acute episode of TTP is associated with an increased risk of stroke,” the authors wrote. They recommended closely monitoring patients following episodes of acute TTP.

Reference

  1. Upreti H, Kasmani J, Dane K, et al. Reduced ADAMTS13 activity during TTP remission is associated with stroke in TTP survivors [published online August 20, 2019]. Blood. doi:10.1182/blood.2019001056