Expression of K2P5.1 potassium channels on CD4+ T lymphocytes correlates with disease activity in rheumatoid arthritis patients.

Abstract

INTRODUCTION:

CD4+ T cells express K(2P)5.1 (TWIK-related acid-sensitive potassium channel 2 (TASK2); KCNK5), a member of the two-pore domain potassium channel family, which has been shown to influence T cell effector functions. Recently, it was shown that K(2P)5.1 is upregulated upon (autoimmune) T cell stimulation. The aim of this study was to correlate expression levels of K(2P)5.1 on T cells from patients with rheumatoid arthritis (RA) to disease activity in these patients.

METHODS:

Expression levels of K(2P)5.1 were measured by RT-PCR in the peripheral blood of 58 patients with RA and correlated with disease activity parameters (C-reactive protein levels, erythrocyte sedimentation rates, disease activity score (DAS28) scores). Twenty patients undergoing therapy change were followed-up for six months. Additionally, synovial fluid and synovial biopsies were investigated for T lymphocytes expressing K(2P)5.1.

RESULTS:

K(2P)5.1 expression levels in CD4+ T cells show a strong correlation to DAS28 scores in RA patients. Similar correlations were found for serological inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein). In addition, K(2P)5.1 expression levels of synovial fluid-derived T cells are higher compared to peripheral blood T cells. Prospective data in individual patients show a parallel behaviour of K(2P)5.1 expression to disease activity parameters during a longitudinal follow-up for six months.

CONCLUSIONS:

Disease activity in RA patients correlates strongly with K(2P)5.1 expression levels in CD4+ T lymphocytes in the peripheral blood in cross-sectional as well as in longitudinal observations. Further studies are needed to investigate the exact pathophysiological mechanisms and to evaluate the possible use of K(2P)5.1 as a potential biomarker for disease activity and differential diagnosis.

• Authors: Stefan Bittner, Nicole Bobak, Martin Feuchtenberger, Alexander M Herrmann, Kerstin Göbel, Raimund W Kinne, Anker J Hansen, Thomas Budde, Christoph Kleinschnitz, Oliver Frey, Hans-Peter Tony, Heinz Wiendl, Sven G Meuth
• Journal: Arthritis research & therapy (Arthritis Res Ther) Vol. 13 Issue 1 Pg. R21 (Feb 11 2011) ISSN: 1478-6362 [Electronic] England
• PMID: 21314928 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• KCNK5 protein, human
• Potassium Channels, Tandem Pore Domain

Topics

• Arthritis, Rheumatoid (immunology, metabolism, physiopathology)
• Blotting, Western
• CD4-Positive T-Lymphocytes (metabolism)
• Cell Separation
• Female
• Flow Cytometry
• Fluorescent Antibody Technique
• Humans
• Male
• Potassium Channels, Tandem Pore Domain (biosynthesis)
• Real-Time Polymerase Chain Reaction
• Reverse Transcriptase Polymerase Chain Reaction