Investigation on reference intervals and regional differences of platelet indices in healthy Chinese Han adults.

BACKGROUND: Reference intervals are important for interpretation of clinical laboratory tests. The platelet (PLT) indices such as the mean platelet volume (MPV) and platelet distribution width (PDW) are newer hematological parameters, which have been recently reported as clinically valuable biomarkers. However, there are not many studies that have estimated the reference intervals for these parameters in healthy Chinese Han adults. OBJECTIVE: The objectives of this study were to establish reference values of PLT indices [including PLT count, MPV, PDW, platelet-large cell ratio (P-LCR), and plateletcrit (Pct)] for healthy Chinese Han adults. We also aimed to determine the region-based differences of PLT indices in China. METHODS: A total of 4,642 volunteers with a mean age of 43 were recruited from six regions of China. PLT indices were performed on Sysmex XE-2100 hematology analyzers, whose traceability was well verified. RESULTS: There were significant region-based differences for all PLT indices. Reference people in Chengdu had the lowest mean PLT count and Pct, but the highest MPV, PDW, and P-LCR among the six regions. Therefore, we derived the reference intervals in Chinese Han population excluding Chengdu reference people for PLT indices as PLT count: (127-341) × 10(9)/l; MPV: (9.20-13.30) fl; PDW: 9.90-19.00%; P-LCR: 18.10-52.00%; Pct: 16.00-41.00%. CONCLUSIONS: Region-specific reference intervals are essential as there were statistically significant region-related differences in the PLT parameters. The reference intervals established in this study differed from the existing reference values. Chengdu region may need proper specific reference ranges, which apply to their people, for all PLT parameters.

Abnormal Fas/FasL and caspase-3-mediated apoptotic signaling pathways of T lymphocyte subset in patients with systemic lupus erythematosus.

OBJECTIVES: To explore the relationships between Fas-FasL-mediated signaling pathway and apoptosis disturbance of T lymphocyte subset in patients with SLE. METHODS: Flow cytometry was used to determine the percentage of apoptotic lymphocytes and necrotic lymphocytes by AnnexinV-FITC/PI double staining. Cell surface expression rates of Fas, FasL, and intracellular expression rates of activated caspase-3 were evaluated by two-color flow cytometry analysis in peripheral T lymphocyte subsets of SLE patients with inactive disease (n=22) and with active disease (n=17). The serum concentration of anti-nucleosome antibodies in SLE patients were assayed by ELISA immunoassay methods. Health volunteers (n=13) served as controls. RESULTS: The percentage of early apoptotic cells was enhanced in patients with active disease (P=0.001, vs. control) and in patients with inactive disease (P=0.004, vs. control). Compared with health control, the percentage of necrotic cells was significant higher in patients with active disease (P=0.001). The percentages of CD4(+)T cells expressing Fas (P=0.023, vs. control) and FasL (P=0.001, vs. control) were increased in patients with active disease. But there were no obvious differences of expression rates of Fas and FasL on T cell subset between two disease groups (P>0.05). In patients with active disease the percentage of CD4(+)T cells or CD8(+)T cells expressing intracellular activated caspase-3 significantly increased compared to inactive disease patients (P=0.018, P=0.027, respectively) and health controls (P=0.001, P=0.001, respectively). The serum concentration of anti-nucleosome antibodies was strikingly higher in patients with active disease (P=0.002, vs. patients with inactive disease; P=0.001, vs. control, respectively), however, the serum concentration of anti-nucleosome antibodies was not obviously different between patients with inactive disease and health control group (P=0.473). The percentage of apoptotic cells correlated with the serum concentration of anti-nucleosome antibodies in SLE patients (r(s)=0.350, P=0.031). CONCLUSIONS: Apoptosis of T lymphocyte subset in SLE patients increases. CD4(+)T cells are a state of active apoptosis. Fas/FasL-mediated apoptotic pathways are especially important for CD4(+)T cells undergoing apoptosis in SLE patients with active disease. Increased Fas expression results in a higher susceptibility to Fas-mediated apoptosis, which contributes to the increased levels of intracellular activated caspase-3 and accelerates apoptosis of T lymphocytes. The degree of lymphocytic apoptosis disturbance correlates with the level of anti-nucleosome antibodies in the circulation. Acceleration of lymphocytic apoptosis plays important roles in immune pathologic injury and immune regulation dysfunction.