Abstract
Objective: To review the literature on obtaining universal blood, aiming to clarify the need for the practice in the current context and to demonstrate the advances and challenges for the success of the process. Literature review: This study analyzes blood conversion methods, the camouflage of blood cell antigens (PEG) and the enzymatic. Both proved to be unfeasible, with the enzymatic being the most promising. The PEG method demonstrated some impasses that make it questionable: the possibility of PEG becoming immunogenic and the lack of knowledge about the succession of coated red cells in the long term. The enzymatic conversion, however, presents incompatible pH and remaining antigens as difficulties. Although a recent study demonstrated greater efficacy with enzymes extracted from the bacterium Flavonifractor plautii, further tests are still needed to confirm the absence of variability in humans. Final considerations: Even though modern studies show good results, the area still needs a lot of research so that the practice becomes economically viable and does not cause harm to the patient.