Antibody clustering helps refine lupus prognosis.
OBJECTIVE
Our aim was to investigate a possible association between patterns of anti-dsDNA antibody isotypes (IgG, IgM, and IgA), rheumatoid factor (RF) isotypes (IgG, IgM, IgA), and IgG anti-C reactive protein (CRP) and systemic lupus erythematosus (SLE) disease activity (SLEDAI).


METHODS
Our study group included 98 patients, 86 women and 12 men, with a mean SLEDAI score of 7.9 +/- 4.1. We divided the patients into 4 groups by the serum anti-dsDNA antibody isotype intensity level.


RESULTS
We found that patients in group 1 (IgG > IgM, 42 patients) had a statistically significantly higher SLEDAI score than group 2 (IgG < IgM, 13 patients) (10.57 +/- 4.62 versus 5.6 +/- 4, P = 0.0012), group 3 (IgG = IgM, 8 patients) (10.57 +/- 4.62 versus 6.2 +/- 1.98, P = 0.04), and group 4 (none, 35 patients) (10.57 +/- 4.62 versus 6 +/- 1.5, P = 0.0001). SLE patients with IgG RF or IgM RF isotype present had a significantly higher SLEDAI score compared with those without IgG RF or IgM RF (10.57 +/- 4.8 versus 7.6 +/- 4.1, P = 0.03, 10.6 +/- 5 versus 7.6 +/- 3.9, P = 0.046). The presence of IgA RF isotype was not associated with a higher SLEDAI score. IgG anti-CRP did not correlate differentially with SLEDAI scores.


CONCLUSIONS
A combination of high-titer IgG anti-dsDNA with a positive RF of IgM isotype may serve as a marker for more active SLE.
Division of Clinical Immunology, Bnai Zion Medical Center, Rappaport Faculty of Medicine, Technion, Haifa 31048, Israel.
Aharon
A
Kessel
Itzhak
I
Rosner
Kathy
K
Halasz
Galia
G
Grushko
Yehuda
Y
Shoenfeld
Dafna
D
Paran
Elias
E
Toubi
D000293:Adolescent; D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D004247:DNA / Q000276:immunology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012217:Rheumatoid Factor / Q000097:blood; D012720:Severity of Illness Index; D055815:Young Adult
D000974:Antibodies, Antinuclear; D015415:Biomarkers; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D002097:C-Reactive Protein; D004247:DNA; D012217:Rheumatoid Factor