[Adverse transfusion reactions in recipients with anti-vitamin K treatment]

Vitamin K antagonist treated patients are exposed to a risk of haemorrhage in case of overdose leading to a need for transfusion. In order to determine the incidence of adverse transfusion reactions in these patients, the reports indicating a vitamin K antagonist treatment were analyzed.

In the treated and transfused patient population, the diagnosis following the adverse transfusion reactions, the incidence, the degree of severity, the blood component involved and its imputability were evaluated.

From January 1st 2000 to December 31st 2014, 142 reports were notified in 141 patients. Haemorrhage was observed in 102 cases (71.8%). Overdose of anti-vitamin K was reported in 43 cases only (30.3%). The most frequent adverse transfusion reaction was the anti-erythrocyte alloimmunization (66 cases, 46.5%) followed by the febrile non-haemolytic reaction (37 cases, 26.1%). Most adverse reactions were non-severe (131 cases, 92.3%). The most involved blood component was the red blood cells concentrate (139 cases, 97.9%). The imputability of the blood product was certain in 39 cases only (27.5%).

In patients treated with vitamin K antagonists and transfused, the anti-erythrocyte alloimmunization was the most frequent adverse transfusion reaction. Overdose of the vitamin K antagonists was notified in approximately a third of cases.