Increased concanavalin A-induced suppressor cell activity in humans with occupational lead exposure

E-rosette-forming cells (E-RFC), mitogen-induced blast transformation, OKT4⁺, OKT8⁺ cells, and their ratio were found to be normal in 10 subjects chronically exposed to lead with blood levels of 40-51 μg%. However, concanavalin A (Con A)-induced suppressor cell activity (SCA) in these subjects was significantly greater than in normal matched controls. The clinical relevance of this observation is not clear, but it may have some bearing on the various immunologic defects described in lead exposure.