Abstract: The invention relates to a blood treatment device configured to dephosphorylate extracellular adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP) and/or lipopolysaccharide (LPS) in the blood of a patient in need thereof in an extracorporeal blood circuit, wherein the device comprises a matrix having alkaline phosphatase (AP) immobilized thereon. The invention further relates to an extracorporeal blood circuit comprising a blood treatment device of the invention and to the blood treatment device for use as a medicament or to methods of treating an infection, preferably a blood or systemic infection, such as sepsis, and/or for the treatment of sepsis-associated acute kidney injury (AKI).