title: Systemic lupus erythematosus and the crithidia luciliae immunofluorescent test. A comparative study with an adapted Farr radioimmunoassay.
abstract: A comparative study of the Crithidia luciliae immunofluorescence (CL-IF) assay and an adapted Farr radioimmunoassay (RIA), for the measurement of antibodies to native deoxyribonucleic acid, was performed using forty-two sera from patients with systemic lupus erythematosus (SLE) and another forty-two from patients with rheumatoid arthritis. Both assays were specific for SLE. The CL-IF assay was statistically significantly more sensitive than the adapted RIA assay. This significant difference was due to greater sensitivity of the CL-IF assay in the cases of sera from patients with SLE of slight activity. Additional advantages of the CL-IF assay were its use to classify the immunoglobulin types of the antibodies (most commonly IgG or IgM) and to measure complement-fixing antibodies to native deoxyribonucleic acid; it affords a simple method of selecting and following SLE patients at risk of developing severe renal disease. These advantages plus the simplicity and inexpensiveness of the CL-IF assay make it a useful tool, especially for use in small laboratories, for the study of antibodies to native deoxyribonucleic acid in patients with SLE.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000032:analysis*; D001172:Arthritis, Rheumatoid / Q000276:immunology; D003168:Complement Fixation Tests; D003421:Crithidia; D004247:DNA / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D000974:Antibodies, Antinuclear; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D004247:DNA