Serum interleukin-2-receptor in rheumatoid arthritis: a prognostic indicator of disease activity?
Interleukin-2 (IL-2) is an important growth factor for T lymphocytes. Its effects are mediated by cell surface receptors (IL-2 R) expressed on activated T cells. Receptor protein can be shed from cell membranes and the soluble form (sIL-2 R) is detectable by enzyme linked immunosorbent assay (ELISA). We have studied serial levels of sIL-2 R in the sera of patients with rheumatoid arthritis (RA). In 13 patients with active disease, the mean serum level of sIL-2 R was raised compared to age-matched healthy controls. In 48 samples taken at different times from 13 patients, serum sIL-2 R correlated significantly with Ritchie joint index, duration of early morning stiffness, patient pain score, physician's assessment, erythrocyte sedimentation rate (ESR) and platelet count. In individual patients, serial sIL-2 R serum levels fell with treatment preceding clinical improvement. In four patients where serum sIL-2 R levels fell and clinical improvement occurred, subsequent spontaneous increases of serum sIL-2 R level preceded increased clinical disease activity by up to 2 weeks. Serum sIL-2 R level in RA probably reflects activation of underlying immunopathogenic mechanisms and appears to be an excellent monitor of clinical disease activity. More importantly, a rising level may also predict exacerbation of disease activity.
Wood
N C
NC
University Department of Medicine, R.D.U., Northern General Hospital, Edinburgh.
Symons
J A
JA
Duff
G W
GW
D000328:Adult; D000368:Aged; D001171:Arthritis, Juvenile / Q000097:blood; D001172:Arthritis, Rheumatoid / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015375:Receptors, Interleukin-2 / Q000032:analysis*
D015415:Biomarkers; D015375:Receptors, Interleukin-2