Delayed sample processing leads to marked decreases in measured plasma IL-7 levels

NCI-Frederick, Фредерик, Maryland, United States
JAIDS Journal of Acquired Immune Deficiency Syndromes (Impact Factor: 4.39). 09/2006; 42(4):511-2. DOI: 10.1097/
Source: PubMed
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Elevated serum interleukin 7 (IL-7) levels are observed in lymphopenic conditions, including idiopathic CD4 lymphopenia (ICL), which is characterized by CD4 lymphopenia in the absence of human immunodeficiency virus infection or other known immunodeficiency. To test whether defective IL-7 signaling could be an etiologic or contributing factor in ICL, peripheral blood mononuclear cells from patients with ICL (median CD4 T-cell count, 160 cells/μL) and healthy controls (median CD4 T-cell count, 582 cells/μL) were evaluated for expression of IL-7Rα chain (CD127) and intracellular phosphorylated STAT-5 (a marker of γc cytokine signaling) after cytokine stimulation. Gene expression was analyzed by real-time polymerase chain reaction following IL-7 stimulation. The percentage of CD4+CD127+ T cells was lower in patients with ICL, compared with controls (P < .001). Lower levels of STAT-5 phosphorylation after IL-7 stimulation were observed in both CD4 and CD8 T cells from patients with ICL, compared with controls (P < .001 and P = .017, respectively), that inversely correlated in CD4 T cells with serum IL-7 levels (r = -0.734, P = .013). Destabilization of p27(kip1), a critical step for IL-7-induced T-cell cycling, was decreased in patients with ICL, compared with controls (P = .004), after IL-7 stimulation. These data suggest that diminished responsiveness to IL-7 in CD4 and CD8 T cells during ICL may be contributing to the dysregulation of T-cell homeostasis.
    The Journal of Infectious Diseases 03/2012; 205(9):1382-90. DOI:10.1093/infdis/jis219 · 5.78 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Flexibility in sample processing may improve test utility of the quantitative antigen-specific T cell assay (T-SPOT.TB). We investigated whether delayed sample processing with and without the use of T-Cell Xtend, a proprietary reagent, impacted upon test accuracy. Blood samples obtained from 363 sequentially recruited tuberculosis suspects or treated patients were processed immediately (day 0) and at different times after receipt of the sample [approximately 24-h (day 1) or approximately 32-h (day 2)] with and without adding T-Cell Xtend. T-Cell-Xtend-independent median ELISPOT counts (spot forming cells per million peripheral blood mononuclear cells) were significantly higher at day 1 versus day 0 (114 vs. 100; n=66; p=0.03); inter-time-point agreement between the results was 95.45% and the conversion/reversion rate was 4.55%. By contrast, counts on day 0 without T-Cell Xtend versus day 1 with T-Cell Xtend were similar (56 vs. 56; n=215), inter-time-point agreement between the results was 97.17%, and the conversion/reversion rate was 2.83%. Counts performed at day 2 with T-Cell Xtend were not significantly different from day 0. These findings were independent of HIV status. There was high agreement between results when samples were processed immediately and after a 24-h delay. However, although the use of T-Cell Xtend appeared to reduce the number of conversions/reversions this reduction was not statistically significant. Larger studies are required to clarify these findings.
    The Journal of infection 02/2010; 60(5):344-50. DOI:10.1016/j.jinf.2010.01.012 · 4.02 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: RA is a complex disease that develops as a series of events often referred to as disease continuum. RA would benefit from novel biomarker development for diagnosis where new biomarkers are still needed (even if progresses have been made with the inclusion of ACPA into the ACR/EULAR 2010 diagnostic criteria) and for prognostic notably in at risk of evolution patients with autoantibody-positive arthralgia. Risk biomarkers for rapid evolution or cardiovascular complications are also highly desirable. Monitoring biomarkers would be useful in predicting relapse. Finally, predictive biomarkers for therapy outcome would allow tailoring therapy to the individual. Increasing numbers of cytokines have been involved in RA pathology. Many have the potential as biomarkers in RA especially as their clinical utility is already established in other diseases and could be easily transferable to rheumatology. We will review the current knowledge's relation to cytokine used as biomarker in RA. However, given the complexity and heterogeneous nature of RA, it is unlikely that a single cytokine may provide sufficient discrimination; therefore multiple biomarker signatures may represent more realistic approach for the future of personalised medicine in RA.
    Mediators of Inflammation 03/2014; 2014:545493. DOI:10.1155/2014/545493 · 2.42 Impact Factor