Patients with thrombotic thrombocytopenic purpura (TTP) undergoing therapeutic plasma exchange (TPE) may require more treatments if they do not have type O blood, according to an article published in Thrombosis Research.

Some data suggest that patients with ADAMTS13 deficiency are more likely than others to respond to TPE. Response is also linked to removal of von Willebrand factor ultra large multimers (VWF UL-multimers).

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The relationships between blood types, specifically type O, and ADAMTS13 deficiency-related TTP are currently unclear. However, some research suggests that VWF in patients with type O blood is more susceptible to ADAMTS13 degradation and, consequently, that people with type O blood are at greater risk for TTP.

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In this study, researchers evaluated whether patients with type O blood require a different number of TPE procedures to reach normal platelet counts. Of 70 included patients with suspected TTP, 41 had ADAMTS13 deficiency. Among patients in this subgroup, 20 had type O blood, 11 had type A blood, and 10 had type B blood.

Among the 41 patients with ADAMTS13 deficiency, nontype O patients received a mean of 21.2 TPE procedures, whereas patients who were type O received a mean of 14.5 procedures (P =.039). Furthermore, all patients with ADAMTS13 deficiency, regardless of blood type, underwent more TPE procedures compared with patients without ADAMTS13 deficiency (mean, 17.9 vs 6.4; P =.0000002). ADAMTS13-deficient patients also demonstrated a greater rate of obesity compared with that seen in the general population.

Further research is needed to determine “with greater certainty” whether blood type influences the number of TPE procedures required by patients with ADAMTS13 deficiency, the researchers wrote.


1.     Behtaj M, Zhu ML, Bittencourt CE, Ha JP, Maitta RW. Non-O blood group thrombotic thrombocytopenic purpura patients take longer to recover as measured by number of therapeutic plasma exchanges needed for platelet recovery [published online November 20, 2019]. Thromb Res. doi:10.1016/j.thromres.2019.11.022