Recent studies suggest that platelet transfusions are harmful in patients with thrombotic thrombocytopenic purpura, an entity of thrombotic microangiopathies. As the typical or Shiga toxin-producing Escherichia coli-induced hemolytic uremic syndrome (STEC-HUS) is also classified as thrombotic microangiopathy, we complement these data with an analysis of 250 patients from the German O104:H4 STEC-HUS outbreak. The effect of platelet transfusion in 44 patients who received platelet transfusions vs 206 control patients was investigated. Criteria for both groups were severe thrombocytopenia less than 50/nL, severe hemolysis with administration of packed red blood cells, and a complicated clinical course with admission to intensive care units. Readouts were clinical complications and changes in routine clinical chemistry and whole blood count. Chemistry values at admission and demographic parameters were comparable. Platelet transfusions were administered in 44 cases a median of 7 (interquartile range, 6-9) days after diarrhea onset. After platelet transfusion, we observed a transient and slight increase in inflammation parameters. No significant difference in major complications such as seizures, or requirement for ventilation or renal replacement therapy could be observed. Thrombotic events such as thrombosis or embolism were comparably rare in both groups (2.3% in platelet transfused vs 4.4% in controls, P=not significant). The mortality was not significantly different (0% vs 2.6%, P=not significant) in our study cohort, but overall in the outbreak, 6 of 711 STEC-HUS patients in Germany died of a procedural-related bleeding complications. In conclusion, platelet transfusions seem comparably safe in adult STEC-HUS patients, considering both the possible necessity for invasive procedures and potential risk for severe bleeding.
