ORIGINAL ARTICLE

Decreased numbers of signal-joint T cell receptor excision circle-containing CD4+ and CD8+ cells in systemic lupus erythematosus patients

Authors

Daitaro Kurosaka¹, Jun Yasuda¹, Hiroko Ikeshima-Kataoka², Yoshinori Ozawa¹, Ken Yoshida¹, Chiho Yasuda¹, Isamu Kingetsu¹, Saburo Saito² and Akio Yamada¹

1. Division of Rhuematology, Department of Internal Medicine, Jikei University School of Medicine, 3-25-8 Nishishinbashi, Minato-ku, Tokyo 105-8461, Japan
2. Department of Molecular Immunology, Institute of DNA Medicine, Jikei University School of Medicine, Tokyo, Japan

Received:

08 November 2006

Accepted:

06 March 2007

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Abstract

Systemic lupus erythematosus (SLE) patients have a decreased number of peripheral blood T cells containing signal-joint T cell receptor excision circles (Sj TRECs), which are considered an indicator of thymic output. The objective of this study was to investigate the mechanism of the decrease in such T cells. Peripheral blood T cells from SLE patients were classified into CD4+ and CD8+ cells. Sj TREC levels were measured by real-time PCR. Telomerase activity was determined by the telomeric repeat amplification protocol assay. The numbers of Sj TREC containing CD4+ and CD8+ cells were lower in the peripheral blood of SLE patients than in the controls. A correlation was found between the numbers of Sj TREC-positive CD4+ and CD8+ cells. The level of TRECs is influenced by an increase in cell division. To examine this increase, telomerase activity as an indicator of cell division was measured simultaneously; however, there was no correlation between the Sj TREC level and telomerase activity. These results suggest that decreased thymic output occurs in SLE patients.

Key words

CD4 - CD8 - SLE - Telomerase - T lymphocyte - T cell receptor excision circles (TRECs)