Interleukin-6, soluble interleukin-2 receptor and soluble interleukin-6 receptor in the sera of patients with different histological patterns of rheumatoid synovitis.
OBJECTIVE
The present study was conducted to investigate whether the serum levels of interleukin 6 (IL-6), soluble IL-2 receptor (sIL-2R) and sIL-6R are associated with the morphological appearance of rheumatoid arthritis (RA).


METHODS
Using the ELISA technique we measured the IL-6, sIL-2R and sIL-6R concentrations in the serum of 34 patients with RA and 28 patients with osteoarthritis (OA). Histological analysis of synovial samples distinguished 2 types of rheumatoid synovitis. Twenty-one RA specimens presented diffuse infiltrates of mononuclear cells without any specific microanatomical organization. In remaining 13 samples the formation of lymphocytic follicles with germinal center-like structures was found.


RESULTS
Serum levels of IL-6, sIL-2R and sIL-6R were elevated in patients with RA compared to the OA control group (p < 0.001, p < 0.001 and p < 0.05 respectively). Concentrations of IL-6 and sIL-2R were highest in the serum of RA patients with follicular synovitis in comparison to patients with diffuse synovitis (p < 0.001 and p < 0.01 respectively) and could distinguish RA patients with these two histological variants of the disease. Serum levels of IL-6 and sIL-2R correlated with markers of disease activity such as ESR and CRP levels. In addition, the clinical data suggest a more severe disease among RA patients with follicular synovitis.


CONCLUSIONS
Distinct histological types of rheumatoid synovitis associated with unique serum concentrations of IL-6 and sIL-2R reflect levels of disease activity and confirm the concept of RA heterogeneity.
Klimiuk
P A
PA
Department of Rheumatology and Internal Diseases, Medical University of Bialystok, Bialystok, Poland. klimp@amb.edu.pl
Sierakowski
S
S
Latosiewicz
R
R
Cylwik
J P
JP
Cylwik
B
B
Skowronski
J
J
Chwiecko
J
J
D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000150:complications / Q000473:pathology; D015415:Biomarkers / Q000097:blood; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000097:blood / Q000150:complications / Q000473:pathology; D015375:Receptors, Interleukin-2 / Q000097:blood*; D019947:Receptors, Interleukin-6 / Q000097:blood*; D013585:Synovitis / Q000097:blood* / Q000209:etiology / Q000473:pathology
D015415:Biomarkers; D015850:Interleukin-6; D015375:Receptors, Interleukin-2; D019947:Receptors, Interleukin-6; D002097:C-Reactive Protein