TY - JOUR T1 - Decreased Recent Thymus Emigrant Number Is Associated with Disease Activity in Systemic Lupus Erythematosus JF - The Journal of Rheumatology JO - J Rheumatol SP - 1762 LP - 1767 VL - 35 IS - 9 AU - QUEILA F. VIEIRA AU - CRISTIANE KAYSER AU - ESPER G. KALLAS AU - LUÍS EDUARDO C. ANDRADE Y1 - 2008/09/01 UR - http://www.jrheum.org/content/35/9/1762.abstract N2 - Objective T cell receptor excision circle (TREC) is produced during T cell maturation within the thymus, and the number of TREC-bearing cells reflects the proportion of recent thymic emigrants in the peripheral lymphocyte pool. We studied TREC levels in peripheral CD4+ and CD8+ lymphocytes in patients with systemic lupus erythematosus (SLE) with quiescent and with active disease and in age- and sex-matched healthy volunteers. Methods TREC levels in peripheral CD4+ and CD8+ lymphocytes were determined in 29 patients with quiescent SLE, in 22 with active disease, and in 31 age- and sex-matched healthy volunteers. The number of TREC/μg DNA was determined by real-time polymerase chain reaction gauged by a standard curve with known number of TREC-containing plasmids. Results TREC levels in CD4+ and CD8+ cells were lower in patients with active SLE (2.27 ± 2.05 × 104 and 4.14 ± 4.06 × 104 TREC/μg DNA, respectively) compared to quiescent SLE (5.83 ± 7.41 × 104 and 11.24 ± 15.06 × 104 TREC/μg DNA; p = 0.03, p = 0.02, respectively). Patients with active SLE had lower TREC levels in CD4+ T cells than controls (2.27 ± 2.05 × 104 vs 5.64 ± 4.99 × 104 TREC/μg DNA; p = 0.03), but this difference did not reach statistical significance for CD8+ cells (4.14 ± 4.06 × 104 vs 8.77 ± 8.78 × 104 TREC/μg DNA; p = 0.1). Patients with quiescent SLE presented TREC levels similar to controls in CD4+ and CD8+ cells (p = 0.49, p = 0.3, respectively). Conclusion Our results reveal decreased TREC levels in the peripheral blood of patients with active but not in patients with quiescent SLE. These data suggest that TREC levels are affected by disease activity in SLE. ER -