Inclusion-bearing cells in industrial workers exposed to lead

Histochemical and microscopic studies have shown that a characteristic renal response to lead exposure is the formation of discrete, dense, staining intranuclear inclusion bodies in renal tubular epithelial cells. Cytologic examination of urinary sediment showed that four of 19 (21%) lead workers had exfoliated inclusion-bearing cells of proximal renal tubular origin. These lead-induced inclusion-bearing cells appeared distinctly different from viral-induced inclusions, degenerative or nonspecific intranuclear inclusions seen with tubular necrosis, or macronucleoli seen in reparative renal tubular epithelium. While their presence indicates cytologic evidence of tubular injury, the clinical significance of these cells and their application to medical monitoring is not clearly understood.