Antinuclear antibodies as molecular and diagnostic probes.

Much progress has been made in the past decade in defining the specificities of antinuclear antibodies (ANA) that are present in the blood of patients with multi-system autoimmune rheumatic diseases, and ANA now have an important place in diagnostic immunology. Disease-specific ANA have been defined and the intracellular autoantigens against which they react have been characterized. ANA have also established an important place in cell biology. Their use as probes has enabled molecular biologists to isolate, purify and assay the function of the highly conserved molecules with which they react, revealing new insights into the role these molecules play in gene transcription and translation. Cloning of the genes encoding these molecules in addition to providing information on primary structure has also provided human recombinant proteins for use as pure substrates for the development of simple and highly sensitive diagnostic assays in rheumatology. Studies on the epitopes with binding sites for ANA should provide new knowledge on how the immune response to these molecules evolves, how it is maintained and what role ANA play in the pathogenesis of disease.