Lymphocyte Cell-Cycle Inhibition by HLA-G Is Mediated by Phosphatase SHP-2 and Acts on the mTOR Pathway

Human leukocyte antigen G (HLA-G) is involved in regulating T-cell responses through its interaction with inhibitory receptors belonging to the immunoglobulin-like transcript family (ILT). In this context, we investigated the pathways involved in the control of cell-cycle entry of T cells following HLA-G interaction with its inhibitory receptor. We show that HLA-G acts through its interaction with the LILRB1 receptor expressed on T lymphocytes. Both HLA-G and LILRB1 antibodies block the inhibitory effect of HLA-G and restore T-cell proliferation. The interaction of HLA-G with T lymphocytes is associated with phosphorylation of SHP-2 phosphatase, but not SHP-1. In addition, in activated T cells, their incubation with HLA-G is not associated with a decrease in the TCR or CD28 downstream pathways, but is associated with dephosphorylation of the mTOR molecule and p70S6K. In contrast, Akt, which acts upstream of mTOR, is not affected by HLA-G. The inhibition of SHP-2 by NSC-87877(5 µM), a chemical inhibitor of SHP-2, or the use of siRNA, abrogates dephosphorylation of mTOR and impairs the overexpression of p27kip in the presence of HLA-G. Together, these results indicate that HLA-G is associated with activation of phosphatase SHP-2, which inhibits the mTOR pathway and favors the inhibition of the cell-cycle entry of human-activated T cells

Long-term, prolonged-release tacrolimus-based immunosuppression in de novo kidney transplant recipients: 5-year prospective follow-up of the ADHERE study patients.

The objectives of this study were to assess long-term graft survival, patient survival, renal function, and acute rejections in de novo kidney transplant recipients, treated with once-daily prolonged-release tacrolimus-based therapy. The study was a 5-year non-interventional prospective follow-up of patients from the ADHERE study, a Phase IV 12-month open-label assessment of patients randomized to receive prolonged-release tacrolimus in combination with mycophenolate mofetil (MMF) (Arm 1) or sirolimus (Arm 2). From 838 patients in the randomized study, 587 were included in the long-term follow-up, of whom 510 completed the study at year 5. At 1 year post-transplant, graft and patient survival rates were 93.0% and 97.8%, respectively, and at 5 years were 84.0% and 90.8%, respectively. Cox proportional hazards analysis showed no association between graft loss, initial randomized treatment arm, donor age, donor type, or sex. The 5-year acute rejection-free survival rate was 77.4%, and biopsy-confirmed acute rejection-free survival rate was 86.0%. Renal function remained stable over the follow-up period: mean ± SD eGFR 4-variable modification diet in renal disease formula (MDRD4) was 52.3 ± 21.6 ml/min/1.73 m2 at 6 months and 52.5 ± 23.0 ml/min/1.73 m2 at 5 years post-transplant. These findings support the role of long-term once-daily prolonged-release tacrolimus-based immunosuppression, in combination with sirolimus or MMF, for renal transplant recipients in routine clinical practice. ispartof: TRANSPLANT INTERNATIONAL vol:33 issue:2 pages:161-173 ispartof: location:England status: publishe

Acute respiratory failure in kidney transplant recipients: a multicenter study

International audienceINTRODUCTION: Data on pulmonary complications in renal transplant recipients are scarce. The aim of this study was to evaluate acute respiratory failure (ARF) in renal transplant recipients. METHODS: We conducted a retrospective observational study in nine transplant centers of consecutive kidney transplant recipients admitted to the intensive care unit (ICU) for ARF from 2000 to 2008. RESULTS: Of 6,819 kidney transplant recipients, 452 (6.6%) required ICU admission, including 200 admitted for ARF. Fifteen (7.5%) of these patients had combined kidney-pancreas transplantations. The most common causes of ARF were bacterial pneumonia (35.5%), cardiogenic pulmonary edema (24.5%) and extrapulmonary acute respiratory distress syndrome (ARDS) (15.5%). Pneumocystis pneumonia occurred in 11.5% of patients. Mechanical ventilation was used in 93 patients (46.5%), vasopressors were used in 82 patients (41%) and dialysis was administered in 104 patients (52%). Both the in-hospital and 90-day mortality rates were 22.5%. Among the 155 day 90 survivors, 115 patients (74.2%) were dialysis-free, including 75 patients (65.2%) who recovered prior renal function. Factors independently associated with in-hospital mortality were shock at admission (odds ratio (OR) 8.70, 95% confidence interval (95% CI) 3.25 to 23.29), opportunistic fungal infection (OR 7.08, 95% CI 2.32 to 21.60) and bacterial infection (OR 2.53, 95% CI 1.07 to 5.96). Five factors were independently associated with day 90 dialysis-free survival: renal Sequential Organ Failure Assessment (SOFA) score on day 1 (OR 0.68/SOFA point, 95% CI 0.52 to 0.88), bacterial infection (OR 0.43, 95% CI 0.21 to 0.90), three or four quadrants involved on chest X-ray (OR 0.44, 95% CI 0.21 to 0.91), time from hospital to ICU admission (OR 0.98/day, 95% CI 0.95 to 0.99) and oxygen flow at admission (OR 0.93/liter, 95% CI 0.86 to 0.99). CONCLUSIONS: In kidney transplant recipients, ARF is associated with high mortality and graft loss rates. Increased Pneumocystis and bacterial prophylaxis might improve these outcomes. Early ICU admission might prevent graft loss

Costimulation blockade with Belatacept in renal transplantation

Background: Renal transplantation is the standard of care for patients with end-stage renal disease. Although maintenance immunosuppression with calcineurin inhibitors yields excellent one-year survival, it is associated over the long term with high rates of death and graft loss, owing in part to the adverse renal, cardiovascular, and metabolic effects of these agents. The use of potentially less toxic agents, such as belatacept, a selective blocker of T-cell activation, may improve outcomes. Methods: We randomly assigned renal-transplant recipients to receive an intensive or a less-intensive regimen of belatacept or cyclosporine. All patients received induction therapy with basiliximab, mycophenolate mofetil, and corticosteroids. The primary objective was to demonstrate the noninferiority of belatacept over cyclosporine in the incidence of acute rejection at six months (with an upper bound of the 95 percent confidence interval around the treatment difference of less than 20 percent). Results: At six months, the incidence of acute rejection was similar among the groups: 7 percent for intensive belatacept, 6 percent for less-intensive belatacept, and 8 percent for cyclosporine. At 12 months, the glomerular filtration rate was significantly higher with both intensive and less-intensive belatacept than it was with cyclosporine (66.3, 62.1, and 53.5 ml per minute per 1.73 m2, respectively), and chronic allograft nephropathy was less common with both regimens of belatacept than with cyclosporine (29 percent, 20 percent, and 44 percent, respectively). Lipid levels and blood-pressure values were similar or slightly lower in the belatacept groups, despite the greater use of lipid-lowering and antihypertensive medications in the cyclosporine group. Conclusions: Belatacept, an investigational selective costimulation blocker, did not appear to be inferior to cyclosporine as a means of preventing acute rejection after renal transplantation. Belatacept may preserve the glomerular filtration rate and reduce the rate of chronic allograft nephropathy

Combined Liver-Kidney Transplantation With Preformed Anti-human Leukocyte Antigen Donor-Specific Antibodies

Introduction: the impact of preformed donor-specific anti-human leukocyte antigen (HLA) antibodies (pDSAs) after combined liver-kidney transplantation (CLKT) is still uncertain. Methods: we conducted a retrospective study in 8 European high-volume transplant centers and investigated the outcome of 166 consecutive CLKTs, including 46 patients with pDSAs. Results: patient survival was lower in those with pDSAs (5-year patient survival rate of 63% and 78% with or without pDSA, respectively; P = 0.04). The presence of pDSAs with a mean fluorescence intensity (MFI) ≥ 5000 (hazard ratio 4.96; 95% confidence interval: 2.3-10.9; P < 0.001) and the presence of 3 or more pDSAs (hazard ratio 6.5; 95% confidence interval: 2.5-18.8; P = 0.05) were independently associated with death. The death-censored liver graft survival was similar in patients with or without pDSAs. Kidney graft survival was comparable in both groups. (The 1- and 5-year death-censored graft survival rates were 91.6% and 79.5%, respectively, in patients with pDSAs and 93% and 88%, respectively, in the donor-specific antibody [DSA]-negative group, P = not significant). Despite a higher rate of kidney graft rejection in patients with pDSAs (5-year kidney graft survival rate without rejection of 87% and 97% with or without pDSAs, respectively; P = 0.04), kidney function did not statistically differ between both groups at 5 years post-transplantation (estimated glomerular filtration rate 45 ± 17 vs. 57 ± 29 ml/min per 1.73 m2, respectively, in patients with and without pDSAs). Five recipients with pDSAs (11.0%) experienced an antibody-mediated kidney rejection that led to graft loss in 1 patient. Conclusion: our results suggest that CLKT with pDSAs is associated with a lower patients' survival despite good recipients', liver and kidney grafts' outcome

Race-free estimated glomerular filtration rate equation in kidney transplant recipients:development and validation study

OBJECTIVE: To compare the performance of a newly developed race-free kidney recipient specific glomerular filtration rate (GFR) equation with the three current main equations for measuring GFR in kidney transplant recipients.DESIGN: Development and validation study SETTING: 17 cohorts in Europe, the United States, and Australia (14 transplant centres, three clinical trials).PARTICIPANTS: 15 489 adults (3622 in development cohort (Necker, Saint Louis, and Toulouse hospitals, France), 11 867 in multiple external validation cohorts) who received kidney transplants between 1 January 2000 and 1 January 2021.MAIN OUTCOME MEASURE: The main outcome measure was GFR, measured according to local practice. Performance of the GFR equations was assessed using P 30 (proportion of estimated GFR (eGFR) within 30% of measured GFR (mGFR)) and correct classification (agreement between eGFR and mGFR according to GFR stages). The race-free equation, based on creatinine level, age, and sex, was developed using additive and multiplicative linear regressions, and its performance was compared with the three current main GFR equations: Modification of Diet in Renal Disease (MDRD) equation, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) 2009 equation, and race-free CKD-EPI 2021 equation. RESULTS: The study included 15 489 participants, with 50 464 mGFR and eGFR values. The mean GFR was 53.18 mL/min/1.73m 2 (SD 17.23) in the development cohort and 55.90 mL/min/1.73m 2 (19.69) in the external validation cohorts. Among the current GFR equations, the race-free CKD-EPI 2021 equation showed the lowest performance compared with the MDRD and CKD-EPI 2009 equations. When race was included in the kidney recipient specific GFR equation, performance did not increase. The race-free kidney recipient specific GFR equation showed significantly improved performance compared with the race-free CKD-EPI 2021 equation and performed well in the external validation cohorts (P 30 ranging from 73.0% to 91.3%). The race-free kidney recipient specific GFR equation performed well in several subpopulations of kidney transplant recipients stratified by race (P 30 73.0-91.3%), sex (72.7-91.4%), age (70.3-92.0%), body mass index (64.5-100%), donor type (58.5-92.9%), donor age (68.3-94.3%), treatment (78.5-85.2%), creatinine level (72.8-91.3%), GFR measurement method (73.0-91.3%), and timing of GFR measurement post-transplant (72.9-95.5%). An online application was developed that estimates GFR based on recipient's creatinine level, age, and sex (https://transplant-prediction-system.shinyapps.io/eGFR_equation_KTX/). CONCLUSION: A new race-free kidney recipient specific GFR equation was developed and validated using multiple, large, international cohorts of kidney transplant recipients. The equation showed high accuracy and outperformed the race-free CKD-EPI 2021 equation that was developed in individuals with native kidneys.TRIAL REGISTRATION: ClinicalTrials.gov NCT05229939.</p

Report of depressive symptoms on waiting list and mortality after liver and kidney transplantation: a prospective cohort study

International audienceABSTRACT: BACKGROUND: Little research has explored pre-transplantation psychological factors as predictors of outcome after liver or kidney transplantation. Our objective is to determine whether report of depressive symptoms on waiting list predicts outcome of liver and kidney transplantation. METHODS: Patients on waiting list for liver or kidney transplantation were classified for report or non-report of depressive symptoms on waiting list. 339 were transplanted 6 months later on average, and followed prospectively. The main outcome measures were graft failure and mortality 18 months post-transplantation. RESULTS: Among the 339 patients, 51.6% reported depressive symptoms on waiting list, 16.5% had a graft failure and 7.4% died post-transplantation. Report of depressive symptoms on waiting list predicted a 3 to 4-fold decreased risk of graft failure and mortality 18-months post-transplantation, independently from age, gender, current cigarette smoking, anxiety symptoms, main primary diagnosis, UNOS score, number of comorbid diagnoses and history of transplantation. Data were consistent for liver and kidney transplantations. Other baseline predictive factors were: for graft failure, the main primary diagnosis and a shorter length since this diagnosis, and for mortality, older age, male gender and the main primary diagnosis. CONCLUSION: Further studies are needed to understand the underlying mechanisms of the association between report of depressive symptoms on waiting list and decreased risk of graft failure and mortality after transplantation

Long-Lasting Inhibitory Effects of Fetal Liver Mesenchymal Stem Cells on T-Lymphocyte Proliferation

Human bone marrow mesenchymal stem cells (BM-MSC) are multipotent progenitor cells that have transient immunomodulatory properties on Natural Killer (NK) cells, Dendritic Cells (DC), and T cells. This study compared the use of MSC isolated from bone marrow and fetal liver (FL-MSC) to determine which displayed the most efficient immunosuppressive effects on T cell activation. Although both types of MSC exhibit similar phenotype profile, FL-MSC displays a much more extended in vitro life-span and immunomodulatory properties. When co-cultured with CD3/CD28-stimulated T cells, both BM-MSC and FL-MSC affected T cell proliferation by inhibiting their entry into the cell cycle, by inducing the down-regulation of phospho-retinoblastoma (pRb), cyclins A and D1, as well as up-regulating p27kip1expression. The T cell inhibition by MSC was not due to the soluble HLA-G5 isoform, but to the surface expression of HLA-G1, as shown by the need of cell-cell contact and by the use of neutralizing anti-HLA-G antibodies. To note, in a HLA-G-mediated fashion, MSC facilitated the expansion of a CD4low/CD8low T subset that had decreased secretion of IFN-γ, and an induced secretion of the immunomodulatory cytokine IL-10. Because of their longer lasting in vitro immunosuppressive properties, mainly mediated by HLA-G, and their more efficient induction of IL-10 production and T cell apoptosis, fetal liver MSC could be considered a new tool for MSC therapy to prevent allograft rejection