Cell-mediated immunity in systemic lupus erythematosus: alterations with advancing age.

Cell-mediated immunity (CMI) was tested in young patients with systemic lupus erythematosus (SLE) (mean age 30.9 years), in elderly patients with SLE (mean age 70.8 years), and in young and elderly control subjects. Pre-existing CMI as evaluated by skin test response to PPD and mumps antigens and the response of peripheral blood lymphocytes in culture to the mitogen phytohemagglutinin was not significantly different in thefour groups. However, the mean area of induration to Candida antigen was significantly less in both groups of elderly patients, suggesting a diminution of CMI with advancing age. Elderly control subjects and elderly patients with SLE had a significant decrease in incidence and severity of skin-test response when sensitized with 2-4-dinitrochlorobenzene (DNCB), suggesting that the capacity to respond to a new antigen is impaired in the elderly, with and without SLE. Young SLE patients were easily sensitized to DNCB and developed strong skin-test responses to Candida antigen suggesting normal CMI in the young SLE group. SLE is a milder disease in the elderly. If, as seems likely, cell-mediated immune injury is of importance in the pathogenesis of SLE, then these data are consistent with the possibility that an altered state of CMI in the elderly modifies the clinical expression of SLE.