Cytokine production and serum levels in systemic sclerosis.
Serum levels of various cytokines, tumor necrosis factor-alpha (TNF-alpha), interleukin 1-beta (IL1-beta), and interleukin 2 (IL2), and of soluble IL2 receptors (sIL2R) were determined in 30 patients with definite systemic sclerosis (SSc). Spontaneous and lipopolysaccharide-or mitogen-induced production of the cytokines, TNF-alpha, IL1-beta, and IFN-gamma, by peripheral blood mononuclear cells (PBMNC) of these SSc patients was measured by immunoassays. The patients were divided into three groups: 12 with limited cutaneous disease (lcSSc), 7 with diffuse cutaneous disease (dcSSc) < 3 years duration, and 11 with dcSSc > 3 years duration. None were treated with cytotoxic drugs or biologic response modifiers. Sera of patients with SSc had elevated sIL2R levels, and only low levels of IL2 (1-2 U/ml) were detected in 10/29 sera tested. Spontaneous production of TNF-alpha and IL1-beta by PBMNC of patients with SSc (829 pg/ml +/- 215 SEM and 728 pg/ml +/- 186, respectively) was significantly higher than that by normal PBMNC obtained from 30 volunteers (25 +/- 10 and 34 +/- 6 pg/ml, respectively) and tested at the same time as patients' PBMNC. The largest increases in spontaneous release of TNF-alpha or IL1-beta were seen in patients with early dcSSc. No significant difference in spontaneous IFN-gamma production by patient or control PBMNC was detected. On the other hand, the mean level of mitogen-induced IFN-gamma production by PBMNC was significantly depressed in patients with SSc (103 U/ml +/- 18 vs 255 +/- 33 U/ml in controls). In vitro-induced production of TNF-alpha or IL1-beta by patients' PBMNC was comparable to that of normal PBMNC. These data indicate that in vivo-activated PBMNC of patients with SSc spontaneously secrete excessive amounts of fibrogenic cytokines, which are involved in modulation of connective tissue synthesis.
Kantor
T V
TV
Department of Medicine, University of Pittsburgh School of Medicine, Pennsylvania.
Friberg
D
D
Medsger
T A
TA
Buckingham
R B
RB
Whiteside
T L
TL
D016207:Cytokines / Q000096:biosynthesis / Q000097:blood*; D006801:Humans; D066298:In Vitro Techniques; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D015375:Receptors, Interleukin-2 / Q000737:chemistry / Q000378:metabolism*; D012595:Scleroderma, Systemic / Q000097:blood* / Q000188:drug therapy; D012995:Solubility
D016207:Cytokines; D015375:Receptors, Interleukin-2