Screening of cellular immunity in patients with rheumatoid arthritis by phytohaemagglutinin skin test

Phytohaemagglutinin (PHA) skin test was used for screening of non-specific cell-mediated immunity in 30 patients with rheumatoid arthritis (RA) and its results compared with those obtained in age- and sex-matched controls with non-inflammatory rheumatic diseases. Purified protein derivative (PPD) of M. tuberculosis was used for testing of specific cell-mediated immunity in the same two groups. The reactivity to both PHA and PPD was found to be significantly lower in patients with RA, indicating the decreased cell-mediated immunity in this disease, as compared to controls.