Serum Blocking Factors in Tumor Bearing Hosts: The Value of Extended Plasma Exchange on In Vitro Immune Parameters of Patients with Advanced Cancer

Abstract

Experimental and clinical studies (reviewed in Ref. 1) indicate that serum blocking factors may alter immunological and inflammatory responses promoting tumor growth. In recent years, many plasma components including as yet undefined soluble factors especially glyco-proteins have been described as inhibitory in in vitro and in vivo bio-assays. It is still controversial if these factors are tumor products or if they are consequent to a tumor induced host response. In the present study, we investigated the possibility of reducing or eliminating such factors by large volume plasma-exchange with the aim of modulating the host tumor response.