Markedly high eosinophilia and an elevated serum IL-5 level in an infant with cow milk allergy.

BACKGROUND

Interleukin-5 (IL-5) promotes the production and function of eosinophils, and an increase in the serum soluble CD23 (sCD23) level is suggestive of enhanced type-2 helper T-cell activity. The secretion of a large amount of the proinflammatory cytokine, tumor necrosis factor alpha (TNF-a), has been reported to alter the intestinal barrier capacity.

OBJECTIVE

To determine whether or not distinct profiles of cytokine production were involved in the marked peripheral eosinophilia of as high as 20,000/mm3 and the gastrointestinal symptoms seen in an infant with cow milk allergy.

METHODS

The levels of IL-5, sCD23, and TNF-alpha in serum and the culture supernatants of mononuclear cells were compared with those in infants with anaphylaxis to cow milk and nonallergic infants.

RESULTS

Interleukin-5 was detected in the serum (19 pg/mL) but became undetectable after 2 weeks on a milk-free diet together with clinical remission. A kinetic decrease in the serum sCD23 level was also observed during the administration of a milk-free diet with improvement of the eosinophilia in 2 months. The TNF-alpha produced in vitro after stimulation with cow milk protein was not different from in controls.

CONCLUSION

It seems likely that the allergic inflammation due to cow milk can induce marked eosinophilia with an associated increase in IL-5 production.