RT Journal Article
SR Electronic
T1 Serum Amyloid A and C-Reactive Protein Concentrations Are Differently Associated with Markers of Autoimmunity in Patients with Primary Sjögren’s Syndrome
JF The Journal of Rheumatology
JO J Rheumatol
FD The Journal of Rheumatology
SP 2487
OP 2490
DO 10.3899/jrheum.090300
VO 36
IS 11
A1 MARJA PERTOVAARA
A1 JUULIA JYLHÄVÄ
A1 HANNU UUSITALO
A1 JUHANI PUKANDER
A1 HEIKKI HELIN
A1 MIKKO HURME
YR 2009
UL http://www.jrheum.org/content/36/11/2487.abstract
AB Objective. Primary Sjögren’s syndrome (pSS) is an autoimmune disease in which the concentration of the acute-phase protein serum C-reactive protein (CRP) is low. We investigated whether levels of another acute-phase protein, serum amyloid A (SAA), are increased in patients with pSS and whether the immunological markers in patients with pSS are associated with variation in SAA levels. Methods. Serum SAA concentrations were measured by ELISA in 74 patients with pSS and in 56 control subjects with sicca symptoms. Results. Median SAA levels did not differ significantly between patients with pSS and subjects with sicca symptoms. In patients with pSS SAA concentrations correlated significantly with age, leukocyte count, CRP, interleukin 6, and C4. Unlike CRP, there was a significant inverse correlation between SAA and serum IgG levels and anti-SSA antibody titers, as well as a trend towards an inverse correlation between SAA and antinuclear antibody and rheumatoid factor titers. Conclusion. Our data imply that high SAA production could constitute a protective element in pSS: high SAA levels inhibit in particular various signs of B cell hyperreactivity, i.e., IgG and autoantibody production.