Increased serum levels of macrophage migration inhibitory factor in patients with primary Sjögren's syndrome.
The objective of this study was to analyse levels of the proinflammatory cytokine macrophage migration inhibitory factor (MIF) in patients with primary Sjögren's syndrome (pSS) and to examine associations of MIF with clinical, serological and immunological variables. MIF was determined by ELISA in the sera of 76 patients with pSS. Further relevant cytokines (IL-1, IL-6, IL-10, IFN-gamma and TNF-alpha) secreted by peripheral blood mononuclear cells (PBMC) were determined by ELISPOT assay. Lymphocytes and monocytes were examined flow-cytometrically for the expression of activation markers. Results were correlated with clinical and laboratory findings as well as with the HLA-DR genotype. Healthy age- and sex-matched volunteers served as controls. We found that MIF was increased in patients with pSS compared with healthy controls (p < 0.01). In particular, increased levels of MIF were associated with hypergammaglobulinemia. Further, we found a negative correlation of MIF levels with the number of IL-10-secreting PBMC in pSS patients (r = -0.389, p < 0.01). Our data indicate that MIF might participate in the pathogenesis of primary Sjögren's syndrome. MIF may contribute to B-cell hyperactivity indicated by hypergammaglobulinemia. The inverse relationship of IL-10 and MIF suggests that IL-10 works as an antagonist of MIF in pSS.
Willeke
Peter
P
Department of Medicine B, Muenster University Hospital, Albert Schweitzer Strasse 33, 48129 Muenster, Germany. willeke.peter@uni-muenster.de
Gaubitz
Markus
M
Schotte
Heiko
H
Maaser
Christian
C
Domschke
Wolfram
W
Schlüter
Bernhard
B
Becker
Heidemarie
H
D016207:Cytokines / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000235:genetics; D006801:Humans; D016753:Interleukin-10 / Q000097:blood; D008213:Lymphocyte Activation / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D008263:Macrophage Migration-Inhibitory Factors / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012859:Sjogren's Syndrome / Q000097:blood* / Q000235:genetics / Q000503:physiopathology
D016207:Cytokines; D006684:HLA-DR Antigens; D008263:Macrophage Migration-Inhibitory Factors; D016753:Interleukin-10