A prospective immunofluorescence study of immune deposits in the skin of primary Sjögren's syndrome.

There are conflicting opinions concerning the epidermal immunofluorescence pattern in primary Sjögren's syndrome. In a prospective study of 12 patients we found a characteristic pattern of epidermal nuclear/cytoplasmic IgG deposits in 8 (67%). This pattern was associated with the presence of antibodies against SSA/Ro and SSB/La in the serum and was also found in 2 out of 5 LE patients with monospecific antibodies against SSA/Ro. There is a resemblance to the pattern of dust-like particles described in the diseased skin of patients with subacute cutaneous LE. In one patient with primary Sjögren's syndrome, IgG deposits were confined to epidermal cell nuclei (in vivo ANA). Instead of antibodies against SSA/Ro or SSB/La, this particular patient had nRNP-antibodies. From this study, we conclude that the epidermal IgG deposits in primary Sjögren's syndrome may represent antibody binding to the sites within epidermal cells where the respective antigens are located.