Increased serum levels of interleukin 10 in Sjögren's syndrome; correlation with increased IgG1

J Rheumatol. 2000 Apr;27(4):935-9.


Objective: To determine levels of interleukin 10 (IL-10) and IgG subclasses in serum from 53 patients with primary Sjögren's syndrome (SS).

Methods: Serum levels of IL-10 were measured using specific sandwich ELISA in 25 patients with "definite" SS, 28 with "possible" SS, and 32 healthy controls. Interferon-gamma (IFN-gamma) and transforming growth factor-beta1 (TGF-beta1) were also measured by immunoassays. Immunoglobulin classes, IgG subclasses, and C-reactive protein were measured by nephelometry.

Results: Circulating IL-10 was elevated in 25 patients. The increase reached significance in the group with possible SS (p = 0.03) versus controls. In the group with definite SS, IL-10 level was correlated with IgG1 level (p = 0.01, r = 0.67) and with focus score (p = 0.01). IFN-gamma was undetectable in most patients. TGF-beta1 was higher (not significantly) in possible SS than in definite SS.

Conclusion: IL-10 is increased in SS and may account for the overproduction of IgG1 in the syndrome. High IL-10 in the absence of increased IgG1 in possible SS suggests that IL-10 may be necessary but not sufficient for IgG1 overproduction and that other factors are involved. Whereas the correlation of IL-10 level with focus score was expected, it is intriguing that IL-10 was more frequently increased in the incomplete (possible) form of SS than the complete (definite) form. Elevated IL-10 may characterize the lower stage of eccrine dysfunction and perhaps contributes to limiting its severity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Female
  • Humans
  • Immunoglobulin A / blood
  • Immunoglobulin G / blood*
  • Immunoglobulin M / blood
  • Interferon-gamma / blood
  • Interleukin-10 / blood*
  • Male
  • Middle Aged
  • Sjogren's Syndrome / blood
  • Sjogren's Syndrome / immunology*
  • Transforming Growth Factor beta / blood


  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin M
  • Transforming Growth Factor beta
  • Interleukin-10
  • Interferon-gamma