Removing Parathyroid Hormone by Immunoadsorption at Kidney Dialysis
The restoration of normal parathyroid hormone (PTH) §levels for kidney failure patients has to date §proven to be a very challenging clinical problem. §Middle molecular weight toxins such as PTH are §poorly dialyzed, and drug therapies require weeks to §months to lower serum PTH levels. Based on the §characteristic of high specific affinity between §antigen and antibody, a chromatographic column with §packing coated by monoclonal antibody placed in §series with a conventional hemodialyzer has been §designed to reduce PTH levels to normal within one §dialysis session. A mathematical model of the §modified dialysis circuit of the form of a single §delay differential equation, whose approximately §analytical solution was obtained emoplying a Padé §approximation, was developed which reproduces an in §vitro experiment with high accuracy, and indicates §that the immunosorptive column will be efficacious §in lowering PTH levels when scaled up to clinical §scenarios. Process intensification of the modified §dialyzer circuit was also investigated by §functionalizing the lumenal surfaces of the dialyzer §cartridge itself.