Fig. 1.

Combined effect of intravenous immunoglobulin (IVIg) and phytohaemagglutinin (PHA) concentrations on Jurkat T cell activation. (a) Jurkat T cells were activated with 0·5 µg/ml of PHA in the presence of increasing concentrations of IVIg (0–20 mg/ml) and cultured for 24 h prior to evaluation of interleukin (IL)-2 secretion by enzyme-linked immunosorbent assay (ELISA). Results shown are the mean [± standard deviation (s.d.)] of three independent experiments. (b) Jurkat T cells were activated with increasing concentrations of PHA (0·25–4 µg/ml) in the presence or not of IVIg (10 mg/ml), for 24 h prior to IL-2 determination. Results shown are the mean (± s.d.) of four independent experiments. **P < 0·01; ***P < 0·001 [one-way analysis of variance (anova)] followed by Bonferroni's post-test).