Cellular immune reactivity in patients with rheumatoid arthritis and effects of levamisole.

Cellular immune reactivity was examined in control subjects and in 16 patients with rheumatoid arthritis before and after administration of levamisole. Prior to levamisole treatment, this population of patients with rheumatoid arthritis had diminished cellular immunity as measured by skin test reactivity, lymphocyte stimulation by antigen and by PHA, lymphocyte count and percentage and absolute numbers of long-incubation rosette-forming cells (RFC). Administration of levamisole caused enhancement of skin test reactivity and flares at dinitrochlorobenzene (DNCB) test sites which were not paralleled by an increase in lymphocyte stimulation by the same antigens in vitro or enhancement in the PHA response. The increase in lymphocyte count and RFC was borderline (p = .06). Of the 16 patients who received levamisole for three months, nine patients showed at least one physical sign of improvement, five patients remained unchanged, and two patients experienced progression of their disease.