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Tolerance induction through simultaneous hematopoietic stem cell and renal transplantation has shown promising results, but it is hampered by the toxicity of preconditioning therapies and graft-versus-host disease (GVHD). Moreover, renal function has never been compared to conventionally transplanted patients, thus, whether donor-specific tolerance results in improved outcomes remains unanswered. We collected follow-up data of published cases of renal transplantations after hematopoietic stem cell transplantation from the same donor and compared patient and transplant kidney survival as well as function with caliper-matched living-donor renal transplantations from the Austrian dialysis and transplant registry. Overall, 22 tolerant and 20 control patients were included (median observation period 10 years [range 11 months to 26 years]). In the tolerant group, no renal allograft loss was reported, whereas 3 were lost in the control group. Median creatinine levels were 85 μmol/l (interquartile range [IQR] 72-99) in the tolerant cohort and 118 μmol/l (IQR 99-143) in the control group. Mixed linear-model showed around 29% lower average creatinine levels throughout follow-up in the tolerant group (P < .01). Our data clearly show stable renal graft function without long-term immunosuppression for many years, suggesting permanent donor-specific tolerance. Thus sequential transplantation might be an alternative approach for future studies targeting tolerance induction in renal allograft recipients., (© 2018 The Authors American Journal of Transplantation published by Wiley Periodicals, Inc. on behalf of The American Society of Transplantation and the American Society of Transplant Surgeons.)

Background: Hematopoietic stem-cell transplant (HSCT) is associated with many risk factors for life-threatening complications. Post-transplant critical illness often requires admission to the pediatric intensive care unit (PICU)., Methods: A retrospective analysis was made on the risk factors associated with PICU admission and mortality of all HSCT patients at Helen DeVos Children's Hospital from October 1998 to November 2008., Results: One hundred and twenty-four patients underwent HSCT, with 19 (15.3%) requiring 29 PICU admissions. Fifty patients received autologous, 38 matched sibling, and 36 matched un-related donor HSCT, with 10%, 13% and 25% of these patients requiring PICU admission, respectively (P=0.01). Among the HSCT patients, those who were admitted to the PICU were more likely to have renal involvement by either malignancy requiring nephrectomy or a post transplant complication increasing the likelihood of decreased renal function (21.1% vs. 4.8%, P=0.03). PICU admissions were also more likely to receive pre-transplant total body irradiation (52.6% vs. 27.6%, P=0.03). Among 29 patients with PICU admission, 3 died on day 1 after admission, and 5 within 30 days (a mortality rate of 17%). Thirty days after PICU admission, non-survivors had a higher incidence of respiratory failure and septic shock on admission compared with survivors (80% vs. 16.7%, P=0.01 and 80% vs. 4.2%, respectively, P=0.001). Two survivors with chronic renal failure underwent renal transplantation successfully., Conclusions: Total body irradiation and renal involvement are associated with higher risk for PICU admissions after HSCT in pediatric patients, while septic shock upon admission and post-admission respiratory failure are associated with mortality.

Idiopathic pneumonia syndrome (IPS) is a frequently fatal complication after allogeneic stem cell transplantation (allo-SCT) that responds poorly to standard immunosuppressive therapy. The pathophysiology of IPS involves the secretion of inflammatory cytokines including IFN-gamma and TNF-alpha along with the recruitment of donor T cells to the lung. CXCR3 is a chemokine receptor that is expressed on activated Th1/Tc1 T cell subsets and the expression of its ligands CXCL9 (monokine induced by IFN-gamma (Mig)) and CXCL10 (IFN-gamma-inducible protein 10 (IP-10)) can be induced in a variety of cell types by IFN-gamma alone or in combination with TNF-alpha. We used a lethally irradiated murine SCT model (B6 --> bm1) to evaluate the role of CXCR3 receptor:ligand interactions in the development of IPS. We found that Mig and IP-10 protein levels were significantly elevated in the bronchoalveolar lavage fluid of allo-SCT recipients compared with syngeneic controls and correlated with the infiltration of IFN-gamma-secreting CXCR3(+) donor T cells into the lung. The in vivo neutralization of either Mig or IP-10 significantly reduced the severity of IPS compared with control-treated animals, and an additive effect was observed when both ligands were blocked simultaneously. Complementary experiments using CXCR3(-/-) mice as SCT donors also resulted in a significant decrease in IPS. These data demonstrate that interactions involving CXCR3 and its primary ligands Mig and IP-10 significantly contribute to donor T cell recruitment to the lung after allo-SCT. Therefore, approaches focusing on the abrogation of these interactions may prove successful in preventing or treating lung injury that occurs in this setting.