The autoantibody response to Ro/SSA in cutaneous lupus erythematosus.
METHODS
Seventeen patients with subacute cutaneous lupus erythematosus (SCLE) were compared with 15 patients with discoid lupus erythematosus (DLE) to evaluate the relationship of 60- and 52-kd Ro/SSA autoantibodies to the clinical diagnosis and to evaluate assays for anti-Ro/SSA.


RESULTS
All serum samples from patients with SCLE had precipitating anti-Ro/SSA antibodies in immunodiffusion, and all had high titer anti-60-kd Ro/SSA in enzyme-linked immunosorbent assay. Immunoblotting was inadequately sensitive for detecting anti-60-kd Ro/SSA. Fifteen patients with SCLE had anti-52-kd Ro/SSA (11 high titer, four low titer). Only one of the 15 patients with DLE had precipitating, high-titer anti-Ro/SSA. Nine other patients with DLE had low-titer anti-60-kd Ro/SSA, and four had low-titer anti-52-kd Ro-SSA. Low-titer anti-Ro/SSA did not confer an increased risk for photosensitivity in the DLE group.


CONCLUSIONS
High-titer, precipitating antibodies to Ro/SSA are typical of SCLE and unusual in DLE. Low-titer, nonprecipitating antibodies to Ro/SSA are common in DLE and could be an indication of pathogenic factors shared with SCLE. However, low titers of anti-Ro/SSA do not confer a significant risk for SCLE skin lesions. For the purpose of clinical evaluation of skin disease, immunodiffusion assays for anti-Ro/SSA are cost-effective and informative.
Lee
L A
LA
Department of Dermatology, University of Oklahoma Health Sciences Center, Oklahoma City.
Roberts
C M
CM
Frank
M B
MB
McCubbin
V R
VR
Reichlin
M
M
D001324:Autoantigens / Q000097:blood / Q000276:immunology*; D006801:Humans; D008178:Lupus Erythematosus, Cutaneous / Q000097:blood / Q000276:immunology*; D008179:Lupus Erythematosus, Discoid / Q000276:immunology; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins / Q000097:blood / Q000276:immunology*; D000099207:SS-A Antigen
D001324:Autoantigens; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins; D000099207:SS-A Antigen; C116006:RO60 protein, human