Abstract
Abstract: :
Purpose:Beta B1 crystallin was recently identified as a cognate antigen of the pANCA autoantibody, Fab 5-3. pANCA antibodies are expressed by a subset of uveitis patients, however their relevance is not yet understood. The goals of this study were to test whether patients with anterior uveitis have autoantibodies against beta B1 crystallin, determine if that reactivity is solely dependent on the ANCA antibody status, and identify other crystallin proteins as candidate antigens in uveitis. Methods:Total soluble lens protein extract and purified Beta B1, Beta B2, alpha-B crystallins were used as antigenic targets in these studies. A total of 100 serum samples were obtained from anterior uveitis patients, normal controls, and cataract controls (presence of cataracts, prior to intraocular surgery) were tested. Identification of the ANCA status was achieved using serum ELISA and immunofluorescence according to published methods (J. Clin Immunol. 1998 18:264) Reactivity against the lens crystallins was screened by ELISA and further analyzed by Western immunoblotting. Results:Serum IgG immunoreactivity, as judged by ELISA, against the total soluble lens extract or the individual crystallins was significantly greater in uveitis patients than either normal or cataract controls (p<0.0007). The strongest seroreactivity, as analyzed by Western blot, was specifically directed against the purified Beta B1 crystallin. Conclusion:Beta B1 crystallin was previously identified as a candidate autoantigen in uveitis. IgG seroreactivity against multiple lens crystallin proteins, with increased specificity against the Beta B1 crystallin, is demonstrated in an anterior uveitis population. Further study of the role of these proteins in the immunopathogenesis or the secondary complications of uveitis is merited.
Keywords: 612 uveitis-clinical/animal model • 327 autoimmune disease • 378 crystallins