Thymosin-inducible 'null' cells in atopic eczema.

Thirty children with atopic eczema were compared with an equal number of age-matched healthy children. The mean peripheral blood T-lymphocyte level was lower in the eczema group (mean 1,197/mm2 as against 1,702/mm3; P = 0 . 003). This difference was abolished in vitro by thymosin, a thymic hormone extract. Positive correlations were found between eczema severity and: eosinophilia; hyperimmunoglobulinaemia E; but not T lymphopaenia. Thymosin-inducible T-cell (Ti) counts correlated with plasma IgE levels, suggesting that these Ti cells may be immature suppressor T cells. If this T-cell deficiency represents inadequate suppression of IgE responses, then a trial of treatment with thymosin appears to be warranted.