Rheumatoid factor, antinuclear antibodies, and non-organ specific antibodies may be present in the serum.
The skin is from a person with systemic lupus erythematosus and shows IgG deposits at two different places: The first is a bandlike deposit along the epidermal basement membrane ("lupus band test" is positive); the second is within the nuclei of the epidermal cells (antinuclear antibodies are present).