Considering only the notifications sent to Anvisa, this study found that the main diagnosis was FNHTR, followed by an allergic reaction, similar to what was demonstrated in some studies that evaluated the ATR frequency.34, 35, 36 However, it is worth noting that the pathophysiology regarding the allergic reaction is related to the presence of anti-IgE antibodies in the receptor, or in rare cases, to IgA deficiency with the formation of anti-IgA5 antibodies, with no indication for the use of leukoreduction for preventing this type of reaction. The gene discussed is IGHE; the disease is selective IgA deficiency disease.