Cytokine concentrations and regulatory T cells in living donor and deceased donor liver transplant recipients

Outcomes of pediatric liver transplantation have constantly improved in the last decade. Living‐related liver transplantation does not seem to improve long‐term outcomes following liver transplantation, but few studies have evaluated immunological parameters of the alloimmune response after living vs. deceased donor organ transplantation. We analyzed numbers of regulatory T cells, lymphocyte subsets, and serum cytokine concentrations in 12 pediatric recipients of living‐related liver transplants and in 28 pediatric recipients of deceased donor organs during their annual follow‐ups. Transplant recipients who underwent living donor organ transplantation had significantly higher numbers of regulatory T cells and IL‐4 serum concentrations than recipients of deceased donor organs; both of these factors are associated with beneficial outcomes and transplantation tolerance. Living‐related liver transplantation may have potentially beneficial immunological aspects, although long‐term outcomes do not seem to be better in recipients of living donor organs than in recipients of deceased donor organs. Further studies are needed to compare immunological aspects of the two transplant procedures.     

CD4+CD25(high) Treg cells in peripheral blood during remission and exacerbation of allergic asthma in children

Aim: To determine the percentage of CD4⁺CD25^high Treg cells in peripheral blood CD4⁺ T cells of allergic asthmatic children during disease remission and exacerbation. Methods: Peripheral blood mononuclear cells (PBMC) and serum samples were collected from 6‐ to 11‐year‐old children with mild‐to‐moderate allergic asthma (n = 34) and from healthy controls (n = 15). CD4⁺CD25^high T cells in PBMC were detected by flow cytometry. Total and specific IgE in serum were analysed by enzyme‐amplified chemiluminescence, and IL‐2 was measured by ELISA. Results: There was no significant difference in CD4⁺CD25^high T‐cell proportions between asthmatic children in exacerbation and remission as compared with controls. CD4⁺CD25^high T‐cell percentages were not correlated with total and specific IgE. IL‐2 was elevated in both disease remission and exacerbation but did not correlate significantly with CD4⁺CD25^high T‐cell percentages. Conclusion: CD4⁺CD25^high T‐cell proportion in the peripheral blood of total CD4⁺ T cells is not reduced in children with allergic IgE‐mediated asthma and does not differ between disease remission and exacerbation.     

Increased levels of PD‐1 expression on CD8 T cells in patients post‐renal transplant irrespective of chronic high EBV viral load

Studies have identified solid organ transplant recipients who remain asymptomatic despite maintaining CHL. Factors which determine the CHL state remain poorly understood but are likely to involve immunological control of the viral infection. We monitored expression of PD‐1, a marker of T‐cell exhaustion and viral persistence, on CD8 T cells in patients who resolved EBV infection as determined by undetectable EBV DNA (REI) and CHL patients. PD‐1 expression on CD8 T cells was increased in the first year post‐transplant irrespective of EBV outcome, and most CD8 T cells continued to express PD‐1 for up to three yr post‐transplant. Although all patient groups showed similar frequencies of EBV‐specific CD8+ T cells, PD‐1 expression on these cells increased in the post‐transplant groups compared with the pretransplant patients. Functional studies of EBV‐specific CD8+ T cells stimulated with BZLF or LMP2 peptide pools revealed monofunctional IFN‐γ responses. Our results indicate that PD‐1 expression on CD8 T cells post‐transplant may result from factors other than antigenic stimulation.     

Enhanced production of IL4 but not of IFNλ and IL10 by peripheral blood mononuclear cells from atopic children in response to CD2 plus CD28 stimulation

Peripheral blood mononuclear cells from 16 children with atopic disease (range of IgE levels: 33 - 2892 kU/l) and 12 age matched controls were stimulated either with mAbs specific for CD3, CD2, CD3 plus CD28, CD2 plus CD28, with Tetanus Toxoid, SEA, or PHA plus PMA and their cell proliferation was determined. In addition, their cytokine production (IL2, IL4, ILIO, IFNλ) following selected stimuli was measured. We found that the cells from atopies proliferated significantly better in response to CD2 stimulation than control cells, with no difference in response to CD3 or SEA stimulation. Furthermore, cells from atopies produced significantly higher amounts of IL4 than cells from controls, a difference most pronounced following CD2 plus CD28 stimulation. No differential production was found for IL 10 and IFNλ. We conclude that in atopic children with moderately elevated IgE a hyperreactivity of the CD2 pathway of stimulation and a clear elevation of IL4 but not of IL 10 or IENλ production can be demonstrated.