Giant cell (temporal) arteritis and hypereosinophilic syndrome: a non-fortuitous association.

Giant cell arteritis is a T-cell dependent auto-immune vasculitis that invo lves a T-helper 1 (Th1) cell response. We report the unusual case of a woma n who developed successively a biopsy-proven temporal arteritis without tis sue eosinophilia at age 65, an isolated blood eosinophilia at age 69 and an hypereosinophilic syndrome at age 71, while still taking corticosteroids a t the dose bf 3mg/day. Considering this temporal relationship, some charact eristics of her hypereosinophilic syndrome pointing to a Th2-dependent dise ase (absence of definite signs of myeloproliferative syndrome, elevated IgE levels and quick normalisation of eosinophil counts under corticosteroid t herapy) and die existence of an unexplained blood inflammatory response at the time of HES onset, we postulate that an unbalanced T helper response le d in this exceptional case to both diseases.