VARIATIONS IN SERUM SCD23 IN CONDITIONS WITH EITHER ENHANCED HUMORAL OR CELL-MEDIATED-IMMUNITY

Soluble CD23 (sCD23) is increased by interleukin-4 (IL-4) and decrease d by interferon-gamma (IFN-gamma). On the basis of cytokine profiles T -helper (Th) cells may be functionally divided into IL-2- and IFN-gamm a-secreting Th1 cells, which are involved in cell-mediated immunity (C MI), and IL-4- and IL-5-producing Th2 cells, which arc involved in hum oral immunity. Compared with sex-matched controls (median 8.5) we foun d significantly elevated levels of serum sCD23 in patients with rheuma toid arthritis (median 22.7, P < 0.0002), with the highest levels dete cted in patients fulfilling an increasing number of the American Assoc iation revised criteria for rheumatoid arthritis. Soluble CD23 levels were also significantly raised in autoimmune thyroiditis (median 11.7, P < 0.02) and myasthenia gravis (median 10.4, P < 0.05). In contrast patients with either coeliac (median 6.5) or Crohn's disease (median 5 .8) had reduced levels of sCD23 compared to appropriate controls (medi an 11.8), in both cases significant at P < 0.01. Variations in sCD23 m ay, therefore, reflect enhanced Th1 activity in the two latter conditi ons in contrast to heightened Th2 activity within the three classical autoimmune conditions.