Elevated serum Cu in Hodgkin's disease and inhibitory effects of ceruloplasmin on lymphocyte response in vitro

Abstract

Ceruloplasmin (CP) a constituent of normal serum, and serum copper were measured and found elevated in patients with Hodgkin's disease. The ratio between serum copper and serum CP was found to be relatively constant indicating that about 90% of the total serum copper is bound to CP in all stages of the disease and that this is not significantly different from normal. Patients with Hodgkin's disease usually have decreased immunoreactivity, it was therefore investigated whether the high CP content found in serum from these patients would be immunosuppressive. In the present study, CP was found to markedly inhibit the in vitro proliferative response of normal human peripheral blood lymphocytes stimulated with phytohemagglutinin (PHA), concanavalin A (con A) and purified protein derivative (PPD), and to inhibit the mixed lymphocyte culture response. Generation of cytotoxic killer cells during mixed lymphocyte cultures was likewise inhibited whereas killing by preformed cytotoxic T cells was not influenced. It was concluded that increased serum CP which was found in 36% of the Hodgkin sera may act immunosuppressive but the extent of such effects in vivo can only be suggestively evaluated by means of measurements of the lymphocyte response in vitro.