Immunological markers of the subsets of systemic scleroderma and its overlap.
The studies performed repeatedly in 298 cases of systemic scleroderma (SSc) disclosed high prevalence of antinuclear antibody (in about 95% of the cases) with the use of HEp-2 cells as the substrate for indirect immunofluorescence method. Anticentromere antibody (ACA) was found in 25% of acrosclerosis cases, but in 50% of patients with cutaneous involvement limited to the digits, i.e. almost without cutaneous indurations. The visceral involvement was comparable in cases positive and negative for ACA, and a follow-up of these patients showed that the course, although protracted, was not always mild as previously believed. Scl 70 antibody proved to be a most characteristic marker of SSc, appearing in about 87% of diffuse variety and in above 50% of acrosclerosis cases. The most important finding was the detection of the coexistence of ACA and Scl 70 antibody in 10 of 180 cases studied by three methods: indirect immunofluorescence, double immunodiffusion, (for Scl 70) and immunoblotting with recombinant kinetochore antigen for ACA and recombinant Topoisomerase I antigen for Scl 70 antibody. These antibodies, believed to be mutually exclusive, are most often missed due to masking effect on HEp-2 cells by the stronger antibody, usually Scl 70. Its detection proved to be possible by evaluation of different serum dilutions and several cell mitoses, and confirmed by immunoblotting with recombinant antigens. Of practical significance are the clinical correlations between Pm-Scl antibodies, showing homogeneous nucleolar staining on HEp-2 cells, and overlap or atypical SSc cases with concomitant muscle involvement. This antibody was found to have a surprisingly high association with atypical SSc or scleromyositis of children.
Jabłońska
S
S
Department of Dermatology, Warsaw School of Medicine, Poland.
Błaszczyk
M
M
Jarzabek-Chorzelska
M
M
Chorzelski
T
T
Kołacińska-Strasz
Z
Z
D000974:Antibodies, Antinuclear / Q000097:blood; D001324:Autoantigens; D015415:Biomarkers; D002503:Centromere / Q000276:immunology; D004264:DNA Topoisomerases, Type I; D005455:Fluorescent Antibody Technique; D006801:Humans; D009687:Nuclear Proteins / Q000276:immunology; D012595:Scleroderma, Systemic / Q000145:classification* / Q000276:immunology*
D000974:Antibodies, Antinuclear; D001324:Autoantigens; D015415:Biomarkers; D009687:Nuclear Proteins; C048100:Scl 70 antigen, human; D004264:DNA Topoisomerases, Type I