The Pattern of Epidermal Immune Deposits in Patients with High - Titer Anti - Ro Positive Lupus Erythematosus

Lee, Chang Woo; Jun, Jae Hong

Abstract

BACKGROUND: Antibodies to Bo antigen are present in most patients with subacute cutaneous lupus erythematosus and in about 50% of Korean patients with systemic lupus erythematosus (LE). However, the pattern of in vivo epidermal deposits of anti Ro antibodies has not been widely recognized.
OBJECTIVE
The purpose of thjs study was to define characteristic findings of direct and indirect immunofluorescence(IF) in patients with high-titer anti-Ro or anti-Ro/La positive LE.
METHODS
Lupus band test (riirect IF with normal appearing forearm skin specimens) and indi- rect IF with normal skin substr ates were performed with 3 patients of systemic LE who have high titers( >1: 640) of anti-Ro or anti-Ro/La antibodies but have no antibodies against other nuclear antigens such as nDNA/Sm/nRNP/Scl-70.
RESULTS
An identical pattern of immune deposits was observed in the epidermis in all 3 pa- tients through direct and indirect, IF examinations. The characteristic pattern recognized was "fine speckling" of IgG (or IgG/IgM) mainly at the nuclei on the basal keratinocytes or keratinocytes throught the epidermis. In the immunoblot assay performed with one patient, IgG anti-Ro/La anti- bodies were identified to recognize the 52/42kD antigens (probably, the Ro/La antigens) in the cultured keratinocyte extracts.
CONCLUSION
Most direct IF studies in patients with systemic LE(lupus band test) have shown granular depositions of immunoglabulins and complement components along the dermoepidermal junction, however, the staining patterns as observed in this study may have been overlooked. The recognizable fine speckled patteen of immune deposits at the epidermal keratinocytes could he taken into account as a positivi. finding in the broad category of "lupus band", seen with the normal appearing skin in patient s with systemic LE, especially, who have high titers of anti-Ro/ La antibodies.