Anti-nuclear antibody (ANA) detection in culture supernatant of cloned B cells

Anti-nuclear antibodies (ANA) of individuals with SLE contribute to disease pathogenesis and tissue injury. Systematic analysis of the fine specificity of ANA produced by individual B cells has been limited, in part, to the low concentration of immunoglobulin in single B cell cultures. We modified single B cell culture methods and developed an ANA ELISA to detect ANA at very low levels (15.0 ng/ml) of IgM in the supernatant of clonally expanded B cell cultures. This approach allows for the analysis of ANA reactivity of the IgM produced by approximately 60% of the single sorted naive B cells expanded in culture and permits a relatively high throughput evaluation at the single cell level of the ANA reactivity of naive B cells of healthy individuals and patients with autoimmune diseases.