Diverse clinical outcomes of eosinophilic patients with T-cell receptor gene rearrangements: The emerging diagnostic importance of molecular genetics testing

Abnormal clones of clusters of differentiation (CD)3-CD4+ or CD3+CD4-CD8- phenotypically abnormal lymphocytes have been identified in some patients who have the idiopathic hypereosinophilic syndrome. This report illustrates the disparate clinical courses of six eosinophilic patients with evidence of abnormal T-cell clones based on the finding of a T-cell receptor gene rearrangement. The data suggest that molecular genetics testing for T-cell receptor gene rearrangements should be included in the routine work-up of patients with idiopathic eosinophilia.