Circulating levels of interleukin 1 beta and of interleukin 1 receptor antagonist in systemic juvenile chronic arthritis.
OBJECTIVE
To measure circulating interleukin 1 beta (IL-1 beta) and IL-1 receptor antagonist (IL-1Ra) levels in patients with systemic juvenile chronic arthritis (JCA) and to evaluate their correlation with disease activity.


METHODS
IL-1 beta and IL-1Ra levels were measured by ELISA in 45 patients with JCA (20 systemic, 10 polyarticular and 15 pauciarticular) and in 15 healthy controls.


RESULTS
Plasma IL-1 beta levels were undetectable in the majority of patients with systemic JCA, and detectable levels were not associated with different treatments or with parameters of disease severity. Serum IL-1Ra levels were markedly increased in patients with systemic JCA and significantly correlated with the persistence of systemic features, the extent and severity of joint involvement, and with C-reactive protein concentrations. Serum IL-1Ra levels were also significantly correlated with IL-6 levels.


CONCLUSIONS
These results argue against a relevant role of IL-1 in systemic JCA. The increase in IL-1Ra levels does not appear to reflect an increase in IL-1 production, but may rather be induced by IL-6.
De Benedetti
F
F
Clinica Pediatrica, Università degli Studi di Pavia, Italy.
Pignatti
P
P
Massa
M
M
Sartirana
P
P
Ravelli
A
A
Martini
A
A
D000293:Adolescent; D001171:Arthritis, Juvenile / Q000188:drug therapy / Q000276:immunology*; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D005340:Fibrinogen / Q000032:analysis; D006403:Hematologic Tests; D006801:Humans; D007375:Interleukin-1 / Q000097:blood* / Q000276:immunology; D015850:Interleukin-6 / Q000097:blood; D007958:Leukocyte Count; D010976:Platelet Count; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors* / Q000097:blood / Q000276:immunology
D007375:Interleukin-1; D015850:Interleukin-6; D017472:Receptors, Interleukin-1; D005340:Fibrinogen; D002097:C-Reactive Protein