Restoration of immunosuppression in lung cancer by normal sera

The ConA and PWM responses of blood lymphocytes from lung cancer patients (LC) was found to be diminished in comparison to normal. LC sera inhibited the blastogenic response of normal human and rat lymphocytes, suggesting that there is a common inhibitory mechanism. Addition of normal serum to lung cancer blood lymphocytes allows a restoration of the diminished proliferative responses to normal or near normal levels, except to high ConA concentrations. Possible explanations for this finding are discussed.