EFFECTS OF CHROMIUM ON LYMPHOCYTE SUBSETS AND IMMUNOGLOBULINS FROM NORMAL POPULATION AND EXPOSED WORKERS

Blood lymphocyte subsets and serum immunoglobulins were studied in 15 men (mean age: 35 years), not exposed to toxic agents, and in 15 healt hy men, exposed to dust containing several compounds (including lead c hromate), working in a factory producing plastic materials. Worker blo od lead and urine chromium (Cr) levels were significantly higher than controls, while serum Cr concentration was unchanged. In the worker bl ood, CD4+ helper-inducer (mainly CD4+-CD45RO- ''virgin''), CD5--CD19B, CD3--CD25+ activated B and CD3--HLA-DR+ activated B and natural kil ler (NK) lymphocytes were significantly reduced (about 30-50 %). The i nvestigated workers were exposed to hexavalent Cr, as lead chromate, w hereas normal population (control group) was mainly exposed to trivale nt Cr. In the control group, urinary Cr showed a significant positive correlation with CD16+-56+ NK, CD5+-CD19+ B and HLA-DR+ activated T, B and NK lymphocytes and a negative correlation with serum IgA immunogl obuins; moreover, serum Cr was significantly correlated with all blood lymphocytes and HLA-DR+, CD3--HLA-DR+ and CD3--CD25+ lymphocyte subse ts. These data suggest that trivalent Cr may be involved in mechanisms regulating the immune response in humans.