Anti-double stranded DNA antibodies in systemic lupus erythematosus: detection and clinical relevance of IgM-class antibodies.
We determined the discriminative value of the Farr assay in comparison to ELISA and Crithidia luciliae immunofluorescence assay (IFT) for detecting anti-dsDNA antibodies as a diagnostic tool for systemic lupus erythematosus (SLE). Special attention was paid to the diagnostic significance of IgM-class anti-dsDNA. Sera were analyzed from 74 patients with SLE, 257 patients with other auto-immune diseases, and 50 healthy controls. All sera were tested for anti-dsDNA using the IFT (anti-total immunoglobulin conjugate), ELISA (anti-IgG and anti-IgM conjugates), and the 125I Farr assay. Specificity and sensitivity for a diagnosis of SLE appeared to be highest for the Farr. All SLE sera with IgM-class anti-dsDNA without IgG-class anti-dsDNA as detected by ELISA, were positive when tested by the Farr assay. In contrast, most of the sera with IgM-class anti-dsDNA as detected by ELISA from patients with diseases other than SLE were negative when tested by Farr assay.
Bootsma
H
H
Department of Internal Medicine, University Hospital Groningen, The Netherlands.
Spronk
P E
PE
Hummel
E J
EJ
de Boer
G
G
ter Borg
E J
EJ
Limburg
P C
PC
Kallenberg
C G
CG
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000974:Antibodies, Antinuclear / Q000097:blood*; D001327:Autoimmune Diseases / Q000175:diagnosis / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood*; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015531:Radioimmunoprecipitation Assay; D012008:Recurrence; D012680:Sensitivity and Specificity
D000974:Antibodies, Antinuclear; D007074:Immunoglobulin G; D007075:Immunoglobulin M