Multivariate statistical comparison of autoantibody-repertoires (western blots) by discriminant analysis.

A procedure for the quantification and comparison of complex (auto-) antibody repertoires of many individuals is described. It is based on multivariate statistical analyses of densitometric data of individual staining patterns, in this case Western blots. Implementation of algorithms can be based on standard software and hardware components. This procedure allows (i) the quantitative assessment of the reproducibility and reliability of any electrophoretic procedure, such as for the production of the immunological substrate, (ii) the statistical comparison of any group of staining patterns, e.g., derived from patients with autoimmune diseases or normal controls, (iii) the identification of the bands that contribute most to the differences between such groups, and (iv) the determination whether an unknown individual sample belongs to a known group. A statistical analysis of autoantibody repertoires has important possible applications: it detects spontaneous or therapeutically induced changes of repertoires, it identifies regions of interest, it supports the isolation of relevant antigens, and it will also be helpful in the diagnosis of autoimmune diseases.