Expression of CXCR-1 and CXCR-2 chemokine receptors on synovial neutrophils in inflammatory arthritides: does persistent or increasing expression of CXCR-2 contribute to the chronic inflammation or erosive changes?
OBJECTIVE
To analyze the CXCR-1 and CXCR-2 chemokine receptor expression on peripheral blood neutrophils (PBN) and synovial fluid neutrophils (SFN) of patients with rheumatoid arthritis (RA) and Behçet's disease (BD) (characterized by erosive and non-erosive arthritis, respectively), and to compare them with those of patients with osteoarthritis (OA).


METHODS
We used flow cytometry to investigate the expression of CXCR-1 and CXCR-2 chemokine receptors on PBN and SFN of fifty-five (22 RA, 22 BD and 11 OA) age and sex-matched patients.


RESULTS
In respect to chemokine receptor expression on neutrophils isolated from patients with RA, mean fluorescein intensity (MFI) of CXCR-1 chemokine receptors on PBN from active and inactive RA patients, and SFN from patients with RA were 151 (90-395), 129 (81-539) and 136 (64-220), respectively, and there were not statistically significant difference each other. But MFI of CXCR-2 chemokine receptors on SFN of patients with RA was 18 (10-32), and significantly higher than PBN of active and inactive RA patients (MFI: 10 (6-15) and 12 (7-16), P=0.002 and 0.037, respectively). In respect to chemokine receptor expression on neutrophils isolated from patients with BD, MFI of CXCR-1 chemokine receptors on PBN of active BD patients was 245 (97-844), and higher than PBN of active RA patients and SFN of BD patients (MFI: 151 (90-395) and 134 (61-231), P=0.047 and 0.017, respectively). MFI of CXCR-2 chemokine receptors on PBN of active and inactive BD patients, and SFN of patients BD were 10 (6-14), 10 (2-16), and 12 (8-24), respectively, there were not statistically significant difference each other. MFI of CXCR-1 chemokine receptors on SFN from patients with RA, BD, and OA were 136 (64-220), 134 (61-231), and 114 (60-180), respectively, and there was no difference between the study groups. MFI of CXCR-2 chemokine receptors on SFN of patients with RA was 18 (10-32), and higher than patients with BD and OA (MFI: 12 (8-24) and 11 (9-18), P=0.037 and 0.005, respectively), though there was no difference between last two groups.


CONCLUSIONS
Our study points that CXCR-1 and CXCR-2 chemokine receptors of SFN may have diverse functions in the course of inflammatory arthritides. These results indicate that CXCR-2 chemokine receptor might play more critical role in long lasting accumulation of neutrophils within the synovial fluid of patients with RA.
Pay
Salih
S
Division of Rheumatology of Department of Medicine, Gülhane Military School of Medicine, Etlik/Ankara 06018 Turkey. salihp@yahoo.com
Musabak
Ugur
U
Simşek
Ismail
I
Pekel
Aysel
A
Erdem
Hakan
H
Dinç
Ayhan
A
Sengül
Ali
A
D001172:Arthritis, Rheumatoid / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D001528:Behcet Syndrome / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D002908:Chronic Disease; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D010003:Osteoarthritis / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D023062:Receptors, Interleukin-8A / Q000378:metabolism*; D023063:Receptors, Interleukin-8B / Q000378:metabolism*; D013582:Synovial Fluid / Q000276:immunology / Q000378:metabolism; D013583:Synovial Membrane / Q000276:immunology* / Q000378:metabolism / Q000473:pathology
D023062:Receptors, Interleukin-8A; D023063:Receptors, Interleukin-8B