The invention describes a method to treat an extracorporeally body fluid. The body fluid can include, for example, blood, cerebral spinal fluid and lymph. A first stage of the method applies a treatment to the extracorporeal body fluid. The treatment comprises combining at least one antibody with a CA antigen to produce an antibody-CA antigen moiety. A second stage of the method substantially removes the antibody-CA antigen moiety from the extracorporeal body fluid.
