Soluble CD154 in rheumatoid arthritis: elevated plasma levels in cases with vasculitis.
OBJECTIVE
To determine the levels of soluble CD154 (sCD154) in the plasma of patients with rheumatoid arthritis (RA) and rheumatoid vasculitis (RV). and to examine the relationship between the levels of sCD154 in plasma and the clinical variables.


METHODS
Levels of sCD154 were quantified in 39 plasma samples from patients with RA, including 9 patients who were also diagnosed with RV, and compared with those of 20 healthy subjects. An ELISA was established and specificity of the ELISA was tested by control ELISA using isotype-matched IgG and preabsorption assay. The titers of IgM and IgG rheumatoid factor (IgM-RF, IgG-RF) for each patient were determined simultaneously, and values of other laboratory variables were also determined.


RESULTS
Levels of sCD 154 in plasma were higher in patients with RA than in the healthy subjects (p < 0.02). Compared with RA patients without vasculitis, patients with RV had significantly higher levels of sCD154 in their plasma (p < 0.001). Control ELISA and absorption assay of sCD154 indicated that our ELISA system was capable of measuring plasma sCD154 in RA patients. Levels of sCD154 in RA plasma correlated significantly with both IgM-RF and IgG-RF titers (r = 0.64 and 0.61, respectively, both p < 0.001). The levels of sCD154 decreased after commencement of treatment for vasculitis in cases with RV.


CONCLUSIONS
We identified the presence of sCD154 in RA plasma, with especially high levels in cases with vasculitis. Correlation between sCD154 and RF titers indicates the CD154-CD40 pathway is likely related to pathogenic RF production.
Tamura
N
N
Department of Rheumatology, Juntendo University, School of Medicine, Tokyo, Japan. tnaoto@med.juntendo.ac.jp
Kobayashi
S
S
Kato
K
K
Bando
H
H
Haruta
K
K
Oyanagi
M
M
Kuriyama
M
M
Kipps
T J
TJ
Hashimoto
H
H
D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000276:immunology*; D023201:CD40 Ligand / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D012217:Rheumatoid Factor / Q000097:blood / Q000145:classification; D014657:Vasculitis / Q000150:complications / Q000276:immunology*
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D023201:CD40 Ligand; D012217:Rheumatoid Factor