Serum IgE elevation correlates with blood lead levels in battery manufacturing workers

Lead (Pb), an occupational and environmental toxicant, is known to induce immunomodulatory effects resulting in lowered resistance to infectious micro-organisms and altered levels of immunoglobulins in humans. Preferential activation of type-2 helper T cells and inhibition of type-1 T-cell activation is considered a cellular mechanism for the Pb-induced immune alteration, which has not been investigated well in humans. Lead's influence on in vivo balance between type-1 and type-2 activities was assessed among workers exposed to Pb through battery manufacturing in Korea. Serum IgE levels were significantly higher in the workers with a blood Pb level (PbB) of greater than or equal to30 mug/dL than in the workers with a PbB of <30 mu g/dL. Furthermore, the serum IgE concentrations significantly correlated with PbB although no significant relationship between PbB and serum interleukin-4 or interferon gamma levels was observed. The present study indicates that elevation of IgE levels may be an immunologic index for Pb-induced in vivo toxicities, potentially involved with progression of various allergic diseases in humans.