Adverse transfusion reactions in recipients with anti-vitamin K treatment

Objective: 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.

Methods: 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.

Results: 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%).

Conclusions: 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.