The present disclosure is directed to isolated or recombinant proteins, such as antibodies, which bind to, and inhibit or reduce the function of, midkine (MK) and their use as therapeutic and/or diagnostic agents for midkine-related disorders. The present disclosure is also related to nucleic acid sequences which encode said proteins and their expression in recombinant host cells. In particular, the present disclosure is directed towards humanized antibodies derived from murine antibody IP14 which specifically bind to human MK.L'invention concerne des protéines isolées ou recombinantes, telles que des anticorps, qui se lient à la midkine (MK) et inhibent ou réduisent sa fonction, et leur utilisation comme agents thérapeutiques et/ou diagnostiques contre des troubles liés à la midkine. Elle concerne également des séquences d'acides nucléiques codant lesdites protéines, et leur expression dans des cellules hôtes recombinantes. Elle concerne en particulier des anticorps humanisés issus de l'anticorps murin IP14, qui se lie de manière spécifique à la MK humaine.
