Circulating soluble interleukin-2 receptor level predicts remission in very early reactive arthritis.
OBJECTIVE
To assess the predictive value of serum soluble interleukin-2 receptor (sIL-2R) levels in patients with acute reactive arthritis (ReA).


METHODS
The study includes 26 patients with acute ReA who had participated in a prospective population-based cohort study of very early arthritis. The patients had had arthritis of at least one joint with a maximum duration of 3 months. They were assessed by a rheumatologist on presentation and 6 months later. Serum sIL-2R levels on presentation were measured by the Immulite automated immunoassay analyser. Remission at 6 months, defined by the absence of swollen and tender joints, was related to the baseline sIL-2R level using a permutation test with general scores. Bootstrap estimation was used to derive the 95% confidence interval (CI).


RESULTS
A total of 17 patients (65%) were in remission at 6 months and nine patients (35%) still had joint symptoms. In patients reaching remission within 6 months, the mean baseline sIL-2R level, 891 U/mL (95% CI: 658 to 1123), was higher than in patients not reaching remission, 501 U/mL (95% CI: 436 to 566), p = 0.022.


CONCLUSIONS
A high serum sIL-2R level at baseline is a predictor of remission in patients with acute ReA.
Kuuliala
A
A
Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland. antti.kuuliala@helsinki.fi
Söderlin
M
M
Kautiainen
H
H
Repo
H
H
Leirisalo-Repo
M
M
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016918:Arthritis, Reactive / Q000097:blood* / Q000175:diagnosis* / Q000276:immunology / Q000628:therapy; D015415:Biomarkers / Q000097:blood*; D015331:Cohort Studies; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D000091402:Prohibitins; D015375:Receptors, Interleukin-2 / Q000097:blood* / Q000276:immunology; D012074:Remission Induction; D012995:Solubility
D015415:Biomarkers; C000717331:PHB2 protein, human; D000091402:Prohibitins; D015375:Receptors, Interleukin-2