Is there a factor in sera from cancer patients that inhibits lymphocyte response to phytohaemagglutinin?

Abstract

Lymphocytes from patients with benign breast disease (used as controls), patients with early breast cancer, and patients with advanced breast cancer were stimulated by PHA in the presence of one of five types of serum: (a) autologous serum, (b) AB serum, (c) pooled serum from patients with advanced breast cancer, (d) pooled serum from patients with advanced colon cancer, (e) foetal calf serum. Control lymphocytes were significantly inhibited by sera from all of the four non-self groups (P < 0·001), whereas lymphocytes from early breast cancer patients were significantly inhibited by advanced colon cancer serum (P < 0·05), AB serum (P < 0·05), and foetal calf serum (P < 0·01). Lymphocytes from advanced breast cancer patients were inhibited by all the non-self sera but the inhibition was only significant with pooled advanced colon cancer serum (P < 0·05). The most likely explanation is that the inhibition produced is due to the non-self serum rather than to a specific inhibitory factor. However, it is possible that there may be such a factor in the serum of advanced colon cancer patients.