Interleukin 10 (IL-10) influences autoimmune response in primary Sjögren's syndrome and is linked to IL-10 gene polymorphism.
OBJECTIVE
To investigate the association between serum levels of interleukin 10 (IL-10), the synthesis of autoantibodies, salivary gland disease activity, clinical manifestations, and IL-10 microsatellite polymorphism in patients with primary Sjögren's syndrome (pSS).


METHODS
Serum IL-10 and autoantibody levels [IgG anti-Ro and anti-La, total and IgA rheumatoid factor (RF)] were measured by ELISA. A minor salivary gland (MSG) biopsy was performed in all patients and the focus score was determined as a measure of salivary gland disease activity. In addition, IL-10 microsatellite typing was performed by polymerase chain reaction technique.


RESULTS
IL-10 concentration was higher in patients (n = 39) than in controls (n = 15) (21.4 +/- 6.7 vs 2.5 +/- 3.5 pg/ml; p = 0.001). We found a significant positive correlation between IL-10 levels and titers of IgA RF, anti-Ro, and anti-La antibodies, as well as focus score. In comparison with patients with low IL-10 production (< 9.5 pg/ml), patients producing high IL-10 had significantly more episodes of cutaneous vasculitis and a higher proportion of them carried the IL-10.G9 allele.


CONCLUSIONS
Autoimmune response in pSS patients as well as salivary gland disease activity and cutaneous involvement appears to be mediated by IL-10 levels; in turn, there is a linkage with IL-10 gene polymorphism.
Anaya
Juan-Manuel
JM
Corporación para Investigaciones Biológicas, Clínica Universitaria Bolivariana, School of Medicine, Universidad Pontificia Bolivariana, Medellin, Colombia. jmanaya@epm.net.co
Correa
Paula A
PA
Herrera
Mónica
M
Eskdale
Joyce
J
Gallagher
Grant
G
D000328:Adult; D001323:Autoantibodies / Q000032:analysis; D015551:Autoimmunity / Q000502:physiology*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000097:blood* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011336:Probability; D011379:Prognosis; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012859:Sjogren's Syndrome / Q000235:genetics* / Q000276:immunology*; D018709:Statistics, Nonparametric
D001323:Autoantibodies; D016753:Interleukin-10