Histopathology of delayed hypersensitivity reacitons in the guinea pig uveal tract.

Two distinct patterns of delayed-onset, cell-mediated hypersensitivity have been induced in the guinea pig eye with the same soluble protein antigen and two different methods of immunization. The predominant histologic feature of these reactions was the large number of eosinophils which infiltrated the uveal tract and the limbus. Skin test reactions in the same animals contained very few eosinophils and were typical of cutaneous basophil hypersensitivity or classic delayed hypersensitivity of the tuberculin type. It is suggested that local factors play a role in determining the character of immune expression in different tissues.