Uveitis in a patient treated with Bacille-Calmette-Guérin: possible antigenic mimicry of mycobacterial and retinal antigens.

Purpose: To investigate the cellular immune response in uveitis developing after intravesical Bacille-Calmette-Guérin (BCG) applications.

Design: Experimental study.

Participants: A 72-year-old HLA-B27-negative patient with bilateral granulomatous anterior uveitis that developed during the third cycle of intravesical BCG applications she was receiving for treatment of bladder carcinoma.

Methods: The patient's peripheral T cell reactivity to ocular autoantigens was compared with the response to purified protein derivative (PPD) from Mycobacterium tuberculosis. T-cell proliferation and cytokine and chemokine secretion were measured in vitro.

Main Outcome Measures: Anterior uveitis was treated successfully with topical corticosteroids and cycloplegics.

Results: The following were demonstrated: proliferation to PPD, interphotoreceptor retinoid-binding protein (IRBP), and IRBP-peptide R16, as well as secretion of proinflammatory cytokines in response to PPD, retinal soluble antigen (S-Ag), IRBP, cellular retinal-binding protein (CRALBP), and some S-Ag and IRBP peptides.

Conclusions: These data indicate the generation of a polyclonal autoimmune reaction elicited by BCG. Amino acid sequence alignments revealed homologies between proteins from M. tuberculosis, BCG, and retinal antigens, suggesting antigenic mimicry as a potential cause of uveitis in this patient.