Quantitation of T-lymphocyte Subsets Using the CELL-DYN Sapphire Automated Haematology Analyser / 임상검사와정도관리

BACKGROUND: Quantitative analysis of T-lymphocyte subsets is used to assess immune competency. Traditionally, T-lymphocyte subset analysis has been performed using flow cytometry, which requires complex instrumentation and relatively skilled manual operation. We evaluated the performance of an automated haematology analyser, the CELL-DYN Sapphire (CD Sapphire; Abbott Laboratories, USA) for T-lymphocyte subset analysis. METHODS: The precision and linearity obtained using the CD Sapphire was evaluated. T-lymphocyte subsets in blood samples from 120 patients were quantified using CD Sapphire and flow cytometry (Cytomics FC 500; Beckman-Coulter, France). The time required for complete T cell subset analysis using both methods was also evaluated. RESULTS: Results of CD Sapphire-based quantitation of CD3+, CD3+CD4+, and CD3+CD8+ cells showed intra-assay CV of less than 5% for precision and displayed linearity in the ranges of 84 to 5364, 41 to 2615, and 44 to 2800 cells/microL, respectively. There was good correlation among the CD3+, CD3+CD4+, and CD3+CD8+ cell counts as well as in the CD4/CD8 ratio (r=0.987, 0.982, 0.982, and 0.980, respectively) using CD Sapphire and flow cytometry. The mean turnaround time for the CD Sapphire (10.0+/-0.5 minutes) was significantly less than that for flow cytometry (111.8+/-8.4 minutes, P<0.001). CONCLUSIONS: T cell subset analysis using the CD Sapphire gives excellent performance and consistent results that correlate well with those obtained by flow cytometry. We conclude that this time-efficient method can replace conventional flow cytometric methods used for measuring T cell subsets.

Elevated Levels of T Helper 17 Cells Are Associated with Disease Activity in Patients with Rheumatoid Arthritis

BACKGROUND: Interleukin-17 (IL-17)-producing T helper (Th) 17 cells are considered as a new subset of cells critical to the development of rheumatoid arthritis (RA). We aimed to investigate the distribution of Th1 and Th17 cells and their association with disease activity, and determine the Th17-related cytokine levels in the peripheral blood of RA patients. METHODS: Peripheral blood mononuclear cells from 55 RA and 20 osteoarthritis (OA) patients were stimulated with mitogen, and the distributions of CD4+Interferon (INF)+IL-17- (Th1 cells) and CD4+INF-IL-17+ (Th17 cells) were examined by flow cytometry. Serum levels of IL-6, IL-17, IL-21, IL-23, and tumor necrosis factor (TNF)-alpha were measured by ELISA. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were recorded. The 28-joint disease activity score (DAS28) was also assessed. RESULTS: The median percentage of Th17 cells was higher in RA patients than in OA patients (P=0.04), and in active than in inactive RA (P=0.03), whereas that of Th1 cells was similar in both groups. Similarly, the levels of IL-17, IL-21, and IL-23 were detected in a significantly higher proportion of RA patients than OA patients and the frequencies of detectable IL-6, IL-17, and IL-21 were higher in active RA than in inactive RA group. The percentage of Th17 cells positively correlated with the DAS28, ESR, and CRP levels. CONCLUSIONS: These observations suggest that Th17 cells and Th17-related cytokines play an important role in RA pathogenesis and that the level of Th17 cells in peripheral blood is associated with disease activity in RA.