Chlorinated dibenzo-P-dioxins and dibenzofurans and the human immune system: 3. Plasma immunoglobulins and cytokines of workers with quantified moderately-increased body burdens

The concentrations of immunoglobulins (IgA, IgD, IgG, IgM) and of several c ytokines were measured in the plasma of volunteers with clearly, but modera tely, increased body burdens of polychlorinated dibenzo-p-dioxins and diben zofurans (PCDD/PCDF), using monoclonal antibodies and an enzyme-linked immu no-sorbant assay. Two groups of workers with different body burdens of PCDD /PCDF were studied: (trial I) persons with mainly 2,3,7,8-tetrachlorodibenz o-p-dioxin (TCDD), and (trial II) persons with mainly penta- and hexachlori nated dibenzofurans (P5CDF/H6CDF) in their blood fat. Including the referen ce group, 158 volunteers were investigated. A slight but statistically sign ificant decrease was observed in the plasma concentration of IgG1 in person s exposed to TCDD, but not in persons exposed to P5CDF/H6CDF. When the data of both groups were pooled and a multiregression analysis against internat ional TCDD toxicity equivalencies (I-TEq, NATO/CCMS) was performed, taking several confounding factors into account, no influence of the dioxin exposu re could be revealed. There were no changes in the plasma concentrations of the other immunoglobulins studied In the same volunteers, no deviation fro m the reference range was found for the concentrations of the cytokines: IL -1 alpha, IL-1 beta, IL-6 and TNF alpha in blood plasma.