Rheumatoid factors in systemic lupus erythematosus: association with clinical and laboratory parameters. SLE study group.
The prevalence and clinical and laboratory associations of IgM, IgG and IgA rheumatoid factors (RF) were determined in 352 patients with systemic lupus erythematosus (SLE). IgM, IgG, and IgA class RF were detected in 17.9%, 20.5%, and 20.5% of the sera, respectively. RF were associated with sicca syndrome, hypergammaglobulinemia, high titer of antinuclear antibodies, anemia, SSA- and SSB-antibodies, and with the presence of HLA-DR3. RF correlated negatively with nephritis and livedo racemosa. Moreover, we observed an association of RF and parameters of inflammatory activity such as elevated erythrocyte sedimentation rate (ESR) and leukopenia. Analysis of immunoglobulin classes revealed that laboratory parameters of inflammatory activity, SSA- and SSB-antibodies and HLA-DR3 correlated with IgA RF only. IgA RF define a subgroup of SLE patients characterized by distinct autoimmune phenomena and high disease activity in the absence of nephritis.
Witte
T
T
Abteilung Klinische Immunologie, Medizinische Hochschule Hannover, Germany. witte.torsten@mh-hannover.de
Hartung
K
K
Sachse
C
C
Matthias
T
T
Fricke
M
M
Kalden
J R
JR
Lakomek
H J
HJ
Peter
H H
HH
Schmidt
R E
RE
D000974:Antibodies, Antinuclear / Q000097:blood; D015331:Cohort Studies; D004797:Enzyme-Linked Immunosorbent Assay; D015803:HLA-DR3 Antigen / Q000097:blood; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000235:genetics; D011933:Reagent Kits, Diagnostic; D012217:Rheumatoid Factor / Q000097:blood*; D012859:Sjogren's Syndrome / Q000097:blood / Q000235:genetics
D000974:Antibodies, Antinuclear; D015803:HLA-DR3 Antigen; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011933:Reagent Kits, Diagnostic; C035356:SS-A antibodies; C035357:SS-B antibodies; D012217:Rheumatoid Factor