Serum levels of sCD23, interleukin-10 and interferon-gamma in patients with coeliac disease.

The role of cellular and humoral immunity coeliac disease was investigated by the measurement of serum levels of interleukin-10 (IL-10), interferon-gamma (IFN-gamma) and soluble CD23 (sCD23). Coeliac disease was diagnosed by duodenal biopsy and response to a gluten-free diet (GFD). The results were compared with age and sex-matched patients with non-specific upper gastrointestinal symptoms and normal duodenal histology. While the levels of serum IL-10 were significantly elevated (P < 0.01) in patients with coeliac disease taken as a whole, the levels of serum IFN-gamma were normal and sCD23 significantly decreased (P < 0.002). The median serum sCD23 was significantly lower in the coeliac disease patients not on a GFD compared with those asymptomatic on a GFD (P < 0.03) and the control group (P < 0.0004). The coeliac disease patients on a GFD also had significantly lower serum sCD23 and higher IL-10 compared with the control group (P < 0.01 and P < 0.015). There was no significant difference in the serum IL-10 between the coeliac disease patients on a GFD and those not on a GFD and between the latter and the control group. The low levels of serum sCD23 in coeliac disease suggest diminished humoral immunity and, conversely, exaggerated cellular immunity. The aetiology of the raised levels of IL-10 in coeliac disease is unclear and similar to that observed in patients with inflammatory bowel disease. However, this may represent a regulatory response to the elevated levels of proinflammatory cytokines described in coeliac disease. A combination of diminished sCD23 and raised IL-10 is clearly unusual as both are associated with Th2-type functions. The possible causes of this finding are discussed.