Associations of seroreactivity against crystallin proteins with disease activity and cataract in patients with uveitis.

PURPOSE: betaB1-crystallin is a putative target of an autoantibody observed in a subset of patients with uveitis. The purpose of this study was to determine whether seroreactivity against betaB1 or other specific purified crystallin proteins is observed in patients with uveitis and whether this reactivity is associated with either cataract or active intraocular inflammation. METHODS: Sera from patients with uveitis were tested for IgG antibodies with reactivity against alphaA-, alphaB-, betaB1-, or betaB2-crystallin proteins using a modified slot-blot protocol. Ophthalmic evaluations included analysis of the degree of intraocular inflammation and assessment of lens opacity by the Lens Opacities Classification System (LOCS) III. Positive anti-crystallin reactivity was defined as greater than the mean + 2 SD of the reactivity of a commercially available control serum panel. Statistical analysis was performed with the Fisher exact test, Kruskal-Wallis test, and Student's t-test. RESULTS: IgG antibodies against alphaA-, alphaB-, or betaB1-crystallin were identified in 70% of 39 subjects; in contrast, only 30% of the control sera exhibited reactivity against one or more of these crystallin proteins (P

BetaB1-crystallin: identification of a candidate ciliary body uveitis antigen.

PURPOSE: Perineuclear anti-neutrophil cytoplasmic antibody (pANCA), a marker antibody present in 12% of patients with anterior uveitis, recognizes cytoplasmic antigens in the nonpigmented ciliary body epithelium, a probable site of immunologic reactivity in this inflammatory disease. In this study, a recombinantly isolated pANCA monoclonal antibody was used to identify the corresponding antigenic target(s) in the ciliary body. METHODS: Proteins from microdissected eye bank ocular ciliary body tissue were used to identify the corresponding ANCA antigen. Parallel two-dimensional protein gels were used for simultaneous identification of candidate antigenic protein spots by Western blot analysis and as a source of material for proteomic analysis. Multiple independent methods including Western blot analysis, confocal microscopy, and RT-PCR were used to provide additional characterization of the candidate protein. RESULTS: Proteomic analysis suggested that beta B1 (betaB1)-crystallin is the primary ciliary body antigen. The presence of betaB1-crystallin in the human ciliary body was confirmed by Western blot with a betaB1 specific anti-peptide antibody. Confocal microscopy revealed colocalization of the antigenic reactivity of both anti-betaB1 antibody and monoclonal pANCA. RT-PCR confirmed the presence of betaB1-crystallin RNA in the ciliary body tissues. CONCLUSIONS: This study identified betaB1-crystallin as a new cytoplasmic ciliary body antigenic target of a marker autoantibody associated with uveitis. This characterization of betaB1-crystallin outside the lens raises questions about its extralenticular expression, intracellular role, and potential target of inflammation in uveitis.