Homogeneous immunoglobulins in the sera of lung carcinoma patients receiving cytotoxic chemotherapy--detection with the use of isoelectric focusing and immunoblotting.

Using isoelectric focusing (IEF) with immunoblotting, we have analysed serum immunoglobulins of 15 lung cancer patients on cytotoxic chemotherapy. In five of the patients homogeneous immunoglobulins were found which appeared between 9 and 18 months after beginning of treatment and were monoclonal in two and oligoclonal in three cases. These abnormalities were only partially shown by zonal electrophoresis with immunofixation and not detected by immune electrophoresis. Examination of 10 normal and 10 myeloma sera by the three techniques in parallel confirmed the competence and sensitivity of IEF with immunoblotting in detecting homogeneous immunoglobulins. Thus, this method provides a valuable tool for investigating an abnormal regulation of the immunoglobulin synthesis.