title: Antinuclear antibodies measured by enzyme immunoassay in patients with systemic lupus erythematosus: relation to disease activity.
abstract: To evaluate the correlation between measurements of antinuclear antibodies serum levels by enzyme immunoassay (ANA-EIA), and the degree of systemic lupus erythematosus disease activity. To retest the performance of the test compared to measurement of antinuclear antibodies by immunofluorescence (ANA-IIF). Eighty-five sera from 71 patients with SLE were tested. Demographic, clinical, laboratory, and SLEDAI status were collected. The sera were tested for ANA-EIA and by ANA-IIF at 1:40 and 1:160 dilutions. Serum levels of ANA-EIA were compared to the overall SLEDAI score and to each of its components. A SLEDAI score of > or =6 was considered clinically significant. The sera of fifty-one healthy volunteers served as controls. Serum levels of ANA-EIA were significantly higher in patients with a SLEDAI score of > or =6 compared to the group of patients with a SLEDAI score of <6 (P = 0.004). High serum levels of ANA-EIA correlated significantly with elevated anti DS-DNA antibodies (P < 0.001), low C(3) or C(4) levels (P < 0.001), pyuria (P < 0.011), arthritis (P = 0.019), and new rash (P = 0.019). Levels of ANA-EIA were significantly higher in patients tested positive by IIF compared to those who tested negative. Higher serum levels of ANA-EIA correlated with clinically significant disease activity in patients with SLE. Higher serum levels of ANA-EIA also correlated with some single items of the SLEDAI. The results also reiterated the validity of ANA-EIA testing in patients with SLE. Further longitudinal studies are needed in order to test the hypothesis that serum ANA-EIA levels might reflect fluctuations in disease activity.
authors.affiliation: Department of Medicine D, Ha'Emek Medical Center, Afula 18101, Israel.
authors.forename: Ehud
authors.initials: E
authors.lastname: Paz
authors.forename: Muhammed
authors.initials: M
authors.lastname: Adawi
authors.forename: Idit
authors.initials: I
authors.lastname: Lavi
authors.forename: Yehuda
authors.initials: Y
authors.lastname: Mussel
authors.forename: Reuven
authors.initials: R
authors.lastname: Mader
mesh_terms: D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012720:Severity of Illness Index
chemical_list: D000974:Antibodies, Antinuclear; D015415:Biomarkers