Investigations on immune parameters in welders

The aim of the present investigation was to study the effects of welding fumes on the human immune system. Thirty male subjects who had regularly welded and 16 control persons without occupational exposure were examined. Cellular immunity was evaluated by phenotyping of peripheral leucocytes, measurement of mitogenic T cell response and T cell stimulation in a heterologous mixed lymphocyte reaction. Non-specific immune reactions were quantified by oxidative burst of granulocytes and monocytes and the cytotoxicity of lymphokine-activated killer (LAK) cells. Serum immunoglobulin levels and immunoglobulin production by stimulated B cells served to demonstrate humoral immune reactions. Welding fumes retarded the kinetics of DNA synthesis after phytohaemagglutinin stimulation of T cells and reduced the cytotoxic activity of LAK cells. No effects on lymphocytic subpopulations, mixed lymphocyte reaction, the phagocytosis of leucocytes or the production of immunoglobulins were observed. Several welders reported on recurrent respiratory infections or bronchitis, a few on allergic skin reactions and one worker was affected by asthmatic symptoms. With the exception of a reduced activity of LAK cells, these effects could not be related to any impairment of immune reactions as they were measured by the immunotoxicity tests applied.