1.
Dynamics of virus-specific T cell immunity in pediatric liver transplant recipients.
Arasaratnam, RJ, Tzannou, I, Gray, T, Aguayo-Hiraldo, PI, Kuvalekar, M, Naik, S, Gaikwad, A, Liu, H, Miloh, T, Vera, JF, et al
American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2018;(9):2238-2249
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Abstract
Immunosuppression following solid organ transplantation (SOT) has a deleterious effect on cellular immunity leading to frequent and prolonged viral infections. To better understand the relationship between posttransplant immunosuppression and circulating virus-specific T cells, we prospectively monitored the frequency and function of T cells directed to a range of latent (CMV, EBV, HHV6, BK) and lytic (AdV) viruses in 16 children undergoing liver transplantation for up to 1 year posttransplant. Following transplant, there was an immediate decline in circulating virus-specific T cells, which recovered posttransplant, coincident with the introduction and subsequent routine tapering of immunosuppression. Furthermore, 12 of 14 infections/reactivations that occurred posttransplant were successfully controlled with immunosuppression reduction (and/or antiviral use) and in all cases we detected a temporal increase in the circulating frequency of virus-specific T cells directed against the infecting virus, which was absent in 2 cases where infections remained uncontrolled by the end of follow-up. Our study illustrates the dynamic changes in virus-specific T cells that occur in children following liver transplantation, driven both by active viral replication and modulation of immunosuppression.
2.
Longitudinal assessment of T cell inhibitory receptors in liver transplant recipients and their association with posttransplant infections.
Mysore, KR, Ghobrial, RM, Kannanganat, S, Minze, LJ, Graviss, EA, Nguyen, DT, Perez, KK, Li, XC
American journal of transplantation : official journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2018;(2):351-363
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Abstract
Current immunosuppression regimens in organ transplantation primarily inhibit T cells. However, T cells are also critical in protective immunity, especially in immune-compromised patients. In this study, we examined the association of T cell dysfunction, as marked by expression of T cell exhaustion molecules, and posttransplant infections in a cohort of liver transplant patients. We focused on Programmed Death 1 (PD-1) and T cell Ig- and mucin-domain molecule 3 (Tim-3), which are potent co-inhibitory receptors, and their persistent expression often leads to T cell dysfunction and compromised protective immunity. We found that patients with the highest expression of PD-1 +Tim-3+ T cells in the memory compartment before transplantation had increased incidence of infections after liver transplantation, especially within the first 90 days. Longitudinal analysis in the first year showed a strong association between variability of PD-1 and Tim-3 expression by T cells and infectious episodes in transplant patients. Furthermore, T cells that expressed PD-1 and Tim-3 had a significantly reduced capacity in producing interferon (IFN)-γ in vitro, and this reduced IFN-γ production could be partially reversed by blocking PD-1 and Tim-3. Interestingly, the percentage of Foxp3+ regulatory T cells in liver transplant patients was stable in the study period. We concluded that the functional status of T cells before and after liver transplantation, as shown by PD-1 and Tim-3 expression, may be valuable in prognosis and management of posttransplant infections.
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A retrospective study to compare the use of tacrolimus and cyclosporine in combination with adriamycin in post-transplant liver cancer patients.
Gu, L, Jin, W, Kan, L, Wang, X, Shan, C, Fan, H
Cell biochemistry and biophysics. 2015;(2):565-70
Abstract
The aim of this study was to compare the clinical effect of tacrolimus (TAC) versus cyclosporine (CycA) in post-transplant hepatic cancer patients undergoing adriamycin hydrochloride (ADM) chemotherapy. Patients with advanced hepatic cancer who underwent liver transplant and subsequent therapy between March 2007 and March 2009 in our hospital were selected for this study. All of these patients were treated with chemotherapeutic agent adriamycin, with respect to immunosuppressant, whereas they received either TAC or CycA, and hence represented two groups, TAC and controls, respectively. The short- and long-term outcomes of two therapies, ADM + TAC and ADM + CsA, were compared. The TAC group patients showed improved remission compared to the control group (40 cases with 46.0 % versus 32 cases with 31.1 % remission, respectively). The 5-year survival in TAC group was significantly prolonged (20.7 %) compared to that of the controls (8.7 %). The short-term outcomes, such as serum levels of calcium, biomarkers of cardiac toxicity/functioning, and regulatory T lymphocytes counts (markers of immune functioning), were found to be significantly more auspicious with TAC treatment than with CycA. Our study showed that use of TAC plus ADM resulted in improved patient survival, tolerance of the graft, and remission compared to CycA combined with ADM. The serum levels of various markers in the short follow-up analysis indicated a better cardiac and immune functioning with TAC than with CycA treatment.