Applications of Therapeutic Apheresis in Patients with Malignant Disease.

Therapeutic apheresis (TA) provides the means for the removal of blood components that are abnormal or that circulate in excessive amounts and have a defined pathogenetic role, or are thought to have one. Multiple disease processes have been treated with TA at one time or another, but scientific assessment of the therapeutic effects of the procedure has lagged behind application of the technology. This led the American Medical Association and the American Society for Apheresis to publish position papers on the proper applications of TA. In the field of oncology, therapeutic plasma exchange (TPE) and related procedures may be the treatment of choice for some conditions (e.g., TPE for thrombotic thrombocytopenic purpura, therapeutic leukapheresis for extreme leukocytosis in acute myelogenous leukemia, etc.), or may represent a promising therapeutic modality whose efficacy needs to be established by randomized controlled trials in the future (e.g., photopheresis for the treatment of cutaneous graft-versus-host disease). Some applications should be considered strictly investigational, and should be offered to patients only if they are part of an approved research protocol (e.g., extracorporeal immunoadsorption with staphylococcal protein A for non-hematologic cancer). Routine use of TA should be restricted to conditions where the benefit has been established by controlled studies or the best available evidence.