ATG induction therapy: long-term effects on Th1 but not on Th2 responses

Antithymocyte globulin (ATG) induction therapy is associated with an increased long-term risk of infection- and cancer-related death. To analyze long-term effects of ATG induction on lymphocyte function, we prospectively assessed CD4 helper function, B-cell/monocyte and cytokine responses in 84 renal transplant recipients (ATG, n = 44) up to 1 year post-transplant. A PWM-driven allogeneic coculture system was used to assess helper function of CD4+ T cells and T-cell-dependent B-cell responses. SAC I was used for T-cell-independent stimulation of B-cell cultures. In vitro cytokine secretion and serum soluble CD30 (sCD30) were determined by enzyme-linked immunosorbent assay (ELISA). ATG induced a persistent decrease of peripheral blood lymphocyte counts compared with non-ATG treatment because of a predominant decrease of CD4+ T cells (4 months, 1 year; P < 0.0005) which was associated with a decreased CD28 expression (1 year, P = 0.02) and CD4 cell interleukin 2 (IL-2) response (4 months, P < 0.0005). However, Th2 responses (CD4 help, CD4 cell IL-4 and IL-10 responses, sCD30), which proved to be predictive of graft outcome, were not affected, and neither was the secretion of the lymphoma growth factors IL-6 and IL-10 by B cells and monocytes. Our data show that ATG induction therapy in immunological high-risk patients induces a profound long-term decrease in cell counts and Th1 but not Th2 responses of CD4+ T cells which may explain long-term effects on infection and post-transplant lymphoproliferative disease (PTLD) incidence because of inadequate T-cell control.     

Evidence for IFN-gamma up- and IL-4 downregulation late post-transplant in patients with good kidney graft outcome

Abstract:  We found recently that patients with good graft outcome showed higher IFN-γ and IL-2, and lower IL-10 plasma levels late post-transplant than early post-transplant. In this retrospective study, we compared cytokine plasma levels in 33 symptom-free outpatients with those of 33 renal transplant recipients with early acute rejection (EAR), 29 with chronic rejection (CR), and 34 healthy controls (HC) to assess whether there is evidence for Th1 activation late post-transplant in patients with good graft outcome. Cytokines were measured pre-transplant, one wk, one month, six months, one yr, and two yr after transplantation. Twelve and 24 months post-transplant, IFN-γ plasma levels were significantly higher (p = 0.001; p = 0.001, respectively) and IL-4 plasma levels significantly lower (p = 0.028; p = 0.003, respectively) in patients with stable graft function than those in controls. Six, 12, and 24 months post-transplant, patients with stable graft function had similar IFN-γ and IL-4 plasma levels as patients with successfully treated EAR (p = n.s.), and higher IFN-γ (p = 0.013; p = 0.001; p = 0.0005, respectively) and lower IL-4 (p = 0.007; p = 0.417; p = 0.0001, respectively) plasma levels than patients with CR. These data suggest that increased plasma IFN-γ and decreased plasma IL-4 late post-transplant might be involved in the induction of mechanisms that facilitate good long-term graft outcome.     

Th17/Treg cell balance in stable liver transplant recipients

BackgroundImmune monitoring of transplanted patients may provide a reliable basis for the individualization of immunosuppressive therapy. In addition, it might be applied for realizing the early and non-invasive diagnosis of acute allograft rejection.MethodsPercentages of TCD4 + IL-17+ (Th17) and TCD4 + CD25 + CD127^dim/− (Treg) cells, as well as serum levels of interleukin (IL)-17 and transforming growth factor (TGF)-β1, were evaluated in 30 stable patients using flow cytometry and ELISA techniques before and six months after liver transplantation. Besides, the same cells and cytokines were quantified in 10 recipients with acute allograft rejection.ResultsSix months post-transplant, the percentage of Th17 and Treg cells in the peripheral blood of stable liver transplant recipients reduced significantly, but the Th17/Treg ratios were comparable to the pre-transplant period (1.24 vs. 1.56); however, Th17/Treg ratios in the rejection group was significantly higher than in the stable recipients (4.06 vs. 1.56, P-value = 0.001). Stable patients showed decreased amounts of serum IL-17 which was remarkably lower than in the rejection group (P-value = 0.01). Moreover, there was a significant correlation between the serum level of IL-17 and the percentage of Th17 cells (P-value <0.001). Th17 frequency was negatively associated with the liver allograft function. Notably, TGF-β1 levels differed neither between pre-and post-transplant samplings nor between stable and rejection groups.ConclusionSix months after liver transplantation, the mean Th17/Treg ratio in stable recipients remained comparable to the pre-transplant values; however, it was significantly elevated in patients with acute allograft rejection, suggesting the Th17/Treg ratio as a probable predictor of acute rejection.     

Influence of Th1, Th2, and Th3 cytokines during the early phase after liver transplantation

To investigate the change of Th1, Th2, Th3 cytokines during early liver transplantation. IFN-r, IL-4, TGF-beta production by CD4+ T cells were determined by fluorescence activated cell sorter analysis. Comparing the acute rejection with the non-acute rejection groups on the 7th, 14th, and 28th day showed that high interferon-gamma production associated with acute rejection in the early posttransplant period. There was no evidence of significant changes in interleukin-4 and transforming growth factor beta (TGF-beta) levels between non-acute rejection groups with acute rejection groups. Th1 cytokine high production is significantly associated with acute rejection in liver transplant recipients.     

Differential early posttransplant cytokine responses in living and cadaver donor renal allografts

BACKGROUND: Differences in early posttransplant immunologic responses between living donor (LDT) and cadaver donor transplant (CDT) recipients have not been thoroughly studied. This is the first study comparing lymphocyte subpopulations and plasma levels of different cytokines, soluble cytokine receptors, cytokine receptor antagonists, and neopterin during the first 2 posttransplant weeks. PATIENTS AND METHODS: Lymphocyte subpopulations (CD3, CD4, CD8, CD16, CD19, and CD25) and plasma levels of soluble (s) interleukin(IL)-1 receptor antagonist (RA), IL-2, sIL-2R, IL-3, IL-4, IL-6, sIL-6R, IL-8, IL-10, transforming growth factor-beta(2), tumor necrosis factor-alpha, interferon-gamma, and neopterin were studied in 52 CDT and 33 LDT recipients 1 to 2, 4 to 6, and 8 to 10 days after transplantation. RESULTS: The most impressive finding was a consistently higher neopterin plasma level in CDT than LDT recipients. Although plasma neopterin decreased during the second posttransplant week in both groups (CDT, P = 0.0001; LDT, P = 0.001), the difference in plasma neopterin levels 8-10 days after transplantation was highly significant (P = 0.005). In contrast, LDT had consistently higher sIL-1RA plasma levels during the first 2 posttransplant weeks. Whereas sIL-1RA plasma levels decreased in both groups during the first posttransplant week (CDT, P = 0.001; LDT, P = 0.005), they increased during the second posttransplant week in LDT (P = 0.02) but remained stable and low in CDT recipients. Eight to ten days after transplantation, the difference was highly significant (P = 0.002). CONCLUSION: These data suggest that transplantation of CDT is associated with strong monocyte-macrophage activation with consistently high neopterin plasma levels, whereas the effect of inflammatory cytokines seems to be down-regulated in LDT recipients by an increased release of antiinflammatory sIL-1RA.     

Analysis of AHG-PRA and ELISA-PRA in kidney transplant patients with acute rejection episodes

Many centers determined a significant correlation between post-transplant anti-HLA antibodies production and clinical outcome. In order to confirm this correlation and ascertain the sequential appearance of anti-HLA antibodies, we compared the ELISA (ELISA-PRA) and the anti-human globulin enhanced complement-dependent lymphocytotoxicity panel-reactive antibodies test (AHG-PRA) with the occurrence of acute rejection episodes. Thirty patients who underwent kidney transplantation between December 1998 and October 1999 were assayed. One pre-transplant and 10 post-transplant serum samples were tested from each recipient except from one of them who lost his graft on the 1 week post-transplant. The diagnosis of acute rejection episode was based on classical criteria (fever, graft swelling and tenderness, oliguria, weight gain) and a rapid rise in serum creatinine levels, confirmed by an allograft biopsy graded by the Banff working classification. The 322 pre- and post-transplant serum specimens were tested by AHG-PRA methodology and 298 of them by the ELISA-PRA. The agreement coefficient (kappa) for both methodologies was 0.63. There were 27 acute rejection episodes in 19 patients. AHG-PRA results were significantly correlated (Hazard ratio=10.06; P=0.006) with this occurrence. These data were not confirmed with the ELISA-PRA procedure. Our results suggest that a routine post-transplant AHG-PRA test offers an early risk assessment of acute rejection episodes and may be a useful method for monitoring the kidney transplant evolution.     

Observational support for an immunoregulatory role of CD3+CD4+CD25+IFN-gamma+ blood lymphocytes in kidney transplant recipients with good long-term graft outcome.

There is evidence that interferon-gamma (IFN-gamma)-dependent interactions of dendritic cell (DC), T regulatory (Treg), and T suppressor (Ts) subpopulations contribute to allograft acceptance. We measured DC subsets, CD3+CD4+CD25+ (Treg phenotype) and CD3+CD8+CD28(-) (Ts phenotype) peripheral blood lymphocytes (PBL) expressing Foxp3, Th1 or Th2 cytokines, peripheral T- and B-cell counts, and plasma cytokines in 33 kidney transplant recipients with a serum creatinine of < or =1.8 mg/dl and 32 recipients with a serum creatinine of > or =2.0 mg/dl more than 100 days post-transplant. Cell subsets were measured in whole blood using four-color flow cytometry. Patients with increased creatinine had less frequently detectable CD3+CD4+CD25+IFN-gamma+ PBL than patients with good graft function (P = 0.017). In patients with good graft function, CD3+CD4+CD25+IFN-gamma+ PBL were associated with high Foxp3+, IL-2+, IL-12+, IL-4+, and IL-10+ CD3+CD4+CD25+ T PBL (P < 0.001), low CD3+CD8+CD28(-)Foxp3+ (P = 0.002), CD3+CD4+DR+ (P = 0.002), CD3+CD8+DR+ T (P = 0.005) and CD19+ B PBL (P = 0.005), and low lineage(-)HLA-DR+CD11c+CD123(-) DC1 (P = 0.006). Patients with impaired graft function did not show these associations. Additional flow cytometric analysis confirmed strong co-expression of IFN-gamma and Foxp3 by CD4+CD25+ PBL particularly in patients with good graft function. Our data support an immunoregulatory role of CD3+CD4+CD25+Foxp3+IFN-gamma+ cells in a subgroup of transplant recipients with good graft acceptance.     

Association of circulating interleukin (IL)-12- and IL-10-producing dendritic cells with time posttransplant, dose of immunosuppression, and plasma cytokines in renal-transplant recipients

BACKGROUND: Interleukin (IL)-12-producing dendritic cells (IL-12+DC) polarize T helper (Th) differentiation toward Th1, whereas IL-10+DC induce Th differentiation toward Th2. We investigated DC and plasma cytokine patterns early and late after transplantation. METHODS: Twenty-five hospitalized renal-transplant recipients without acute rejection or infection early (<40 days) posttransplant, 32 symptom-free outpatients with long-term functioning transplants (2,762+/-2,423 days posttransplant), and 17 healthy controls were studied. The intracellular production of IL-12 and IL-10 in CD11c+ CD83+ CD40+ DC was measured in freshly obtained whole blood using four-color fluorescence flow cytometry. In addition, plasma cytokine levels were investigated. RESULTS: Early and late posttransplant patients had significantly lower proportions of IL-12+DC (early: P=0.001; late: P=0.034) and lower ratios of IL-12+/IL-10+DC (early: P=0.0001; late: P<0.0001) than healthy controls. IL-10+DC (P=0.0004) and IL-12+DC (P=0.002) increased with time posttransplant in association with dose reductions of cyclosporine (IL-10+DC: P=0.003; IL-12+DC: P=0.005), methylprednisolone (IL-10+DC: P<0.0001; IL-12+DC: P=0.001) and mycophenolate mofetil (IL-10+DC: P<0.0001; IL-12+DC: P=0.004). Both IL-10+DC and IL-12+DC were associated with low plasma IL-10 (IL-10+DC: P=0.010; IL-12+DC: P=0.011) and high plasma IL-6 (IL-10+DC: P=0.001; IL-12+DC: P=0.009). IL-10+DC were also associated with high plasma levels of IL-3 (P=0.003), interferon (IFN)-gamma (P=0.014), and IL-2 (P=0.058). CONCLUSION: IL-10+DC and IL-12+DC in peripheral blood are associated with time after transplantation and dosage of immunosuppression. IL-10+DC dominate late posttransplant in the presence of Th1 plasma cytokines (high IFN-gamma and IL-2), high IL-3, and low IL-10. These findings could be a reflection of immunoregulatory processes favoring long-term allograft acceptance.     

Changes of NK cell subsets with time post-transplant in peripheral blood of renal transplant recipients

BackgroundThere is evidence that NK cells with low cytotoxicity but strong immunoregulatory characteristics contribute to good graft outcome. We attempted to investigate which NK cell subsets increase post-transplant and might affect graft function.MethodLymphocyte and NK cell subsets were determined in whole blood using eight-colour-fluorescence flow cytometry in patients pre-transplant and post-transplant. In total, 31 transplant recipients were studied.ResultsWhen cell numbers were compared in 9 patients pre- and 6 months post-transplant, post-transplant CD56dimCD16+ (p = 0.011) NK cells with the phenotype CD158a+ (p = 0.008), CD158e+ (p = 0.038), NKG2A+ (p = 0.008), NKG2D+ (p = 0.011), IFNyR+ (p = 0.008), perforin+ (p = 0.008), granzymeB+ (p = 0.008), perforin+granzymeB+ (p = 0.008) and perforin-granzymeB- (p = 0.021) were lower than those pre-transplant, indicating a post-transplant reduction of cytotoxic NK cells. In 28 patients NK cell subsets were analyzed with respect to time post-transplant (median 888 days post-transplant). CD56dimCD16+ NK cells co-expressing CD158a (p = 0.014), NKG2D (p = 0.047), IL4R (p = 0.038), IL10R (p = 0.008) and IFNy (p = 0.036) as well as CD56bright NK cells with the phenotype TGFß+ (p = 0.017), TGFR+ (p = 0.035), CD158a+ (p = 0.042) and perforin-granzymeB- (p = 0.048) increased with time post-transplant.ConclusionPost-transplant, cytotoxic NK cells were lower than pre-transplant and remained low, whereas NK cell subsets with potentially immunoregulatory properties increased.     

Pre-Transplant IFN-γ ELISPOTs Are Associated with Post-Transplant Renal Function in African American Renal Transplant Recipients

Final crossmatch testing is routinely used to assess the risk of antibody-mediated graft injury/rejection post-transplant. Analogously, we postulated that quantitative measurements of anti-donor effector/memory T cells pre-transplant would independently assess post-transplant risk. To address this hypothesis, we determined the frequencies of pre-transplant, donor-specific interferon-gamma (IFN-gamma) enzyme-linked immunosorbent spots (ELISPOTs) and correlated the results with post-transplant outcomes in 37 African American recipients of deceased donor kidney transplants treated with tacrolimus- and sirolimus-based immunosuppression. A positive ELISPOT test (>25 spots/300,000 cells) was detected in 14 (38%) of 37 patients. The incidence of biopsy-proven acute rejection was 50% (7/14) in ELISPOT-positive versus 17% (4/23) in ELISPOT-negative patients (p=0.036). Calculated glomerular filtration rate (MDRD) at 12 months was 37+/-16 mL/min in ELISPOT-positive versus 55+/-20 mL/min in ELISPOT-negative patients (p=0.01). ELISPOT status remained a correlate of allograft function at 12 months by linear regression analysis (p=0.001), independent of rejection and other contributing variables. Pre-transplant donor-directed IFN-gamma ELISPOT assessment of anti-donor cellular immunity may function as a 'cellular crossmatch' and independently correlates with renal allograft function in African Americans receiving tacrolimus- and sirolimus-based immunosuppression.     

Evaluation of airway inflammation by quantitative Th1/Th2 cytokine mRNA measurement in sputum of asthma patients

BACKGROUND: Asthma is a chronic inflammatory disorder of the airways driven by T cell activation. Th2 cells and their cytokines are thought to play a role in the pathophysiology of allergic as well as non-allergic asthma. METHODS: Airway cells were obtained by sputum induction from 15 healthy and 39 asthmatic individuals and the airway T cell cytokine profiles (interleukin (IL)-4, IL-5, IL-13, IL-10 and interferon (IFN)-gamma) at the mRNA level were studied by real time RT-PCR. RESULTS: Asthma patients had increased expression of IL-5 (p = 0.001) and IL-13 (p = 0.03) mRNA in sputum compared with non-asthmatic controls. IL-4 mRNA and IFN-gamma mRNA were detectable in the sputum of 44% and 21% of patients, respectively, but not in controls. Sputum IL-10 mRNA levels did not differ significantly between patients and controls. Sputum mRNA expression levels of IL-4, IL-5, and IL-13 were significantly correlated with the percentage of eosinophils and were higher in subjects with allergic asthma than in those with non-allergic asthma (p = 0.03, p = 0.02 and p = 0.0002, respectively); they did not differ between mild asthmatic subjects and those with moderate to severe asthma. In contrast, IFN-gamma mRNA expression was higher in non-allergic than in allergic patients (p = 0.04) and higher in patients with moderate to severe asthma than in those with mild asthma (p<0.01). Sputum IL-5 mRNA levels (but not the other cytokine mRNA levels) were also correlated with exhaled nitric oxide (eNO) and with bronchial hyperreactivity expressed as the histamine concentration resulting in a 20% decrease in forced expiratory volume in 1 second. CONCLUSION: Real time RT-PCR analysis of mRNA in induced sputum confirms a predominance of Th2 cytokines in both allergic and non-allergic asthma. IL-5 levels reflect eosinophil infiltration as well as eNO levels and hyperreactivity, and levels of the Th1 cytokine IFN-gamma indicate asthma severity. The technique is a promising tool for use in further studies of asthma severity and disease activity.     

肝移植急性排斥反应者外周血CD4+CD25+Foxp3+调节性T淋巴细胞的变化

目的 探讨良性终末期肝病患者肝移植术后外周血CD4+CD25+叉状头螺旋转录因子(Foxp3)+调节性T淋巴细胞在急性排斥反应期的变化及意义.方法 2004年12月至2008年1月间,符合入选条件的良性终末期肝病患者共55例,按照术后是否发生急性排斥反应分为排斥组(14例)和无排斥组(41例).肝移植术前用流式细胞仪检测患者外周血CD4+CD25+Foxp3+T淋巴细胞占CD4+T淋巴细胞的百分率(简称CD4+CD25+Foxp3+T细胞百分率),出院后1年内每隔3～6个月复查;发生急性排斥反应时,于治疗前和治疗缓解后(3～6个月)复查.比较两组患者外周血CD4+CD25+Foxp3+T细胞百分率的变化,对排斥组发生急性排斥反应时外周血CD4+CD25+Foxr3+T细胞百分率与排斥反应活动指数(RAI的相关性进行统计学分析.结果 肝移植术前,排斥组与无排斥组外周血CD4+CD25+Foxp3+T细胞百分率的差异无统计学意义(P＞0.05).排斥组患者发生急性排斥反应时外周血CD4+CD25+Foxp3+T细胞百分率为(2.23±0.54)%,低于无排斥组的(2.99±0.86)%,差异有统计学意义(P＜0.01).排斥组中,患者发生急性排斥反应时外周血CD4+CD25+Foxp3+T细胞百分率低于未发生急性排斥反应时的(3.67±0.70)%,差异有统计学意义(P＜0.01).排斥组患者发生急性排斥反应时外周血CD4+CD25+Foxp3+T细胞百分率与RAI呈负相关(r=-0.80,P＜0.01).结论 监测肝移植受者外周血CD4+CD25+Foxp3+调节性T淋巴细胞的变化,可辅助诊断急性排斥反应及判断其严重程度.

Abstract：

Objective To investigate the expression of peripheral blood (PB) CD4+ CD25+ Foxp3+ regulatory T cells (Tregs) in patients with benign end-stage liver disease after liver transplantation and the relationship between levels of PB Tregs and acute rejection. Methods A prospective analysis was performed on 55 consecutive patients who underwent liver transplantation.Fourteen out of 55 cases suffered from acute rejection after liver transplantation were defined as rejection group,while the rest patients were classified into no acute rejection group. PB was obtained from liver transplant patients at different time points longitudinally: pre-transplant, post-transplant within one year and acute rejection. The circulating CD4+ CD25+ Foxp3+ Tregs in PB were measured by flow cytometry. Blood samples were drawn during acute rejection, at the same time, liver biopsies were performed. The circulating CD4+ CD25+ Foxp3+ Tregs were compared between two groups.Results There was no difference between two groups in levels of circulating CD4+ CD25+ Foxp3 + Tregs cells pre-transplant. However, the levels of circulating CD4+ CD25+ Foxp3+ Tregs in rejection group were decreased significantly as compared with no-rejection group (2. 23 % ± 0. 54 % vs. 2. 99 % ±0. 86 %,P＜0.01). The frequency of CD4+ CD25+ Foxp3+ T cells was negatively correlated with rejection activity index (RAI) (r = - 0. 80, P＜0. 01 ). Conclusion Monitoring PB CD4+ CD25+ Foxp3+ Tregs levels may be helpful in evaluating the immune state and act as a more sensitive marker for acute rejection diagnosis in the patients following liver transplantation.     

A retrospective study of the prognostic impact of cytokine secretion in mixed lymphocyte culture on long-term graft function following allogeneic renal transplantation

We have previously shown that in vitro measurement of cytokine production prior to renal transplantation can provide predictive information on the risk of acute rejection. Our earlier studies demonstrated that patients who secreted high levels of interferon-gamma (IFN-gamma) in OKT3-stimulated or mixed lymphocyte culture had a significantly increased risk of acute rejection compared with patients who secreted lower levels. In this study, we performed a retrospective analysis of the same cohort of patients in order to determine the prognostic value of cytokine profiles and other variables on long-term graft function. Our results show that high levels of IFN-gamma in pretransplant mixed lymphocyte culture are a highly significant predictor of poorer creatinine levels at 18, 24 and 36 months post-transplant.     

Enhanced Donor-Specific Alloreactivity Occurs Independently of Immunosuppression in Children with Early Liver Rejection

To determine whether early acute cellular rejection (ACR) is associated with sub-optimal immunosuppression in children with liver transplants (LTx). METHODS: Twenty-five children with primary LTx after pre-transplant rabbit anti-thymocyte globulin (rATG), and steroid-free tacrolimus (TAC) were evaluated. Mitogen-stimulated T- and B-cell responses and mixed lymphocyte response to donor and third-party antigens were performed at several time points between two consecutive TAC doses. TAC concentrations (C) associated with half-maximal effect (EC(50)) on lymphocytes was determined by pharmacodynamic equations. RESULTS: Mean age was 7.2 +/- 6.2 years, mean time to lymphocyte function studies was 25 +/- 19 days. Acute rejection occurred at a mean interval of 31 +/- 19 days after LTx. Rejectors (n = 16) demonstrated significantly higher EC(50) of TAC for the intra-cellular IFN-gamma in T cells (p = 0.005) and its CD8+ sub-population (p = 0.027) as well as the co-stimulatory/activation receptor CD54 on B cells (p = 0.0001). The response of recipient lymphocytes to donor antigen was significantly higher in rejectors, compared with non-rejectors (p = 0.015). The patient groups demonstrated no differences in third-party MLR, or in C of TAC. CONCLUSIONs: Independent of the amount of immunosuppressant, ACR of liver allografts in children is associated with enhanced donor-specific alloreactivity. This is accompanied by a cytotoxic T-cell sub-population with increased requirement for TAC.     

Influence of hypercholesterolemia on patient and graft survival in recipients of kidney transplants

AIM: The aim of this retrospective, single centre study, was to study the effect of pre- and post-transplant serum total cholesterol (TC) on patient and graft survival. We also sought to see whether patients who had very high TC (>8 mmol/L) had a higher incidence of graft failure and patient mortality compared with those whose cholesterol was only moderately elevated. METHODS: Records of 935 cadaver kidney transplants between 1984 and 1998 were examined. Patients were placed into three groups based on TC level: <5.5 mmol/L (group 1), 5.5-8 mmol/L (group 2) and >8 mmol/L (group 3). The mean TC value from the first five post-transplant years was taken to seek a correlation between TC and post-transplant events. RESULTS: The mean graft follow-up was 66.9 +/- 50.1 months, ranging from 0.1 to 191 months, while mean patient follow-up was 83.8 +/- 50.1 months, ranging from 0.5 to 191.6 months. Pre-transplant TC was available in 201 patients (21.5%), and post-transplant data was available (for first 5 yr) in 655 patients (70%). During the study period, 220 patients (23.5%) had died, 285 (30.5%) of the grafts had failed during the follow-up, while 129 (13.8%) of the patients died with a functioning graft. We found significantly longer survival of patients having a pre-transplant TC below 5.5 mmol/L vs. patients whose pre-transplant TC was above 5.6 mmol/L (p = 0.02). We also compared patients who had very high pre-transplant TC (>8 mmol/L) level with those whose TC was moderately elevated (5.5-8 mmol/L) and found that there was no higher incidence of graft failure (p = 0.77) nor patient mortality (p = 0.83). No difference could be found in graft survival based on pre-transplant TC. We also did not find a detrimental influence of post-transplant TC on the patient or graft survival. Diabetes mellitus (p = 0.006) and age over 50 yr (p = 0.007) affected patient survival, while low cyclosporine levels (p = 0.02) and acute rejection episodes (p = 0.009) affected graft survival. The mode of dialysis and time on dialysis prior to transplantation did not affect patient and graft survival. CONCLUSIONS: We found significantly greater survival of patients having a pre-transplant TC below 5.5 mmol/L. No difference could be found in graft survival based on pre-transplant TC. Post-transplant TC did not adversely affect patient or graft survival.     

Contribution of CD4+ and CD8+ T cells and interferon-gamma to the progress of chronic rejection of kidney allografts: the Th1 response mediates both acute and chronic rejection

T cells mediating chronic rejection (CR) of human kidney allografts were characterized by comparing them with those mediating acute rejection (AR). Two lines of analysis were performed using biopsy specimens (23 CR and 8 AR). First, the extent of infiltration of CD4+ and CD8+ T cells into allografts was assessed from mRNA expression of CD4 and CD8. The group of CR specimens was not significantly different from the group of AR specimens in terms of the extent of CD4+ and CD8+ T cell infiltration, underlining the importance of the immunological contribution to the progress of CR. Second, Th1/Th2 polarization in infiltrating T cells was investigated by measuring mRNA expression of interferon gamma (IFN-gamma; a Th1 cytokine) and interleukin 4 (IL-4; a Th2 cytokine). IFN-gamma expression was detected in most CR specimens, and was not significantly different between the group of CR specimens and the group of AR specimens. On the other hand, IL-4 expression was detected in only two CR specimens and one AR specimen; from its pathological features, the AR in this last case was concomitant with CR. These results suggest that most cases of CR and of AR are mediated by Th1 mechanisms, although some cases of CR show features of both Th1 and Th2.     

Dynamic changes in Th1, Th17, and FoxP3+ T cells in patients with acute cellular rejection after cardiac transplantation

Previously, studies suggest that CD4(+) effector T-cell subsets participate in allograft rejection. However, the dynamic changes and relative roles of these CD4(+) effector T-cell subsets, especially Th17 cells, have not been systemically examined in patients with acute rejection after cardiac transplantation. In this study, we have studied and compared these CD4(+) T-cell subsets in peripheral blood and endomyocardial biopsies (EMB) in patients with stable-graft and acute cellular rejection. We observed that the gene expressions including T-bet, IFN-γ, RORγt, IL-17, IL-23, and FoxP3, the functional marker of Th1, Th17, and FoxP3(+) CD4(+) T cells, were elevated in EMB samples from patients with acute graft rejection. Accordingly, the percentages of circulating Th1, Th17, and FoxP3(+) CD4(+) T cells were also significantly increased. The data suggest that Th1, Th17, and FoxP3(+) CD4(+) T cells are associated with acute graft rejection in patients with cardiac transplantation.     

The Effects of Different Induction Regimes on Serial Lymphocyte Subsets in Kidney Transplant Recipients: A Single Tertiary Center Experience

BackgroundImmunosuppressive therapy is the backbone of kidney transplantation in preventing acute rejection. T-cell depletion after doses of thymoglobulin is dose-dependent, as are their side effects. At the same time, basiliximab and other maintenance immunosuppressive drugs act at different signals on T lymphocytes. Therefore, studying the pattern of lymphocyte subset depletion depending on the induction regime given at transplantation could be an added tool in managing post-transplant recipients.MethodologyThis prospective observational study recruited kidney transplant recipients from August 2019 through April 2021 at the University of Malaya Medical Centre. Blood tests for lymphocyte subsets were taken at pre-transplant, 1 week, 1 month, 3 months, and 6 months post-transplantation. At transplantation, recipients received either basiliximab, low-dose thymoglobulin (cumulative dose: 1.5 mg/kg), or standard-dose thymoglobulin (cumulative dose: 5 mg/kg).ResultsA total of 39 patients were recruited: 38.5% received basiliximab (15 of 39), 15.4% received low-dose thymoglobulin (6 of 39), and 46.2% received standard-dose thymoglobulin (18 of 39). Absolute lymphocyte counts 1 week post-transplantation were 1.5 ± 0.84 × 10⁹/L for basiliximab, 0.7 ± 0.57 × 10⁹/L for low-dose thymoglobulin, and 0.1 ± 0.08 × 10⁹/L for standard-dose thymoglobulin (P < .001). The CD4+ and CD8+ counts were severely depleted in the standard-dose thymoglobulin group, with a statistically significant differenceup to 6 months post-transplantation. In the low-dose thymoglobulin group, the CD4+ and CD8+ counts were depleted at 1 week post-transplantation and recovered at 1 month post-transplantation. There was no difference in allograft function and incidence of allograft rejection across groups.ConclusionsThe effects on lymphocyte counts, CD4+ and CD8+, vary depending on the type and dose of induction immunosuppression. This could be a guiding tool in managing immunosuppression post-transplantation depending on the patient's immunologic risk.     

Evaluation of cytokines and cytokine-induced secondary messages in sera of patients after liver transplantation

The study objective was first to investigate serum levels of tumor necrosis factor alpha, interleukin 1 beta, interferon gamma, interferon alpha, interleukin 2, beta-2-microglobulin (B2M), and urinary neopterin in patients after orthotopic liver transplantation; and second to relate their levels to clinical complications. The design used was the prospective observation study, and the setting used was the transplant unit of a university medical center. Serum samples were collected from 20 patients every alternate day from transplantation until discharge. The measurements and main results were as follows: concentrations of cytokines, B2M, and neopterin were performed using commercially available radioimmuno-assays. In seven out of nine patients with acute cellular rejections, elevated levels of TNF-alpha, IFN-gamma, IL-1, B2M, and neopterin were detected. The highest absolute levels of TNF-alpha were observed in patients with CMV disease. Increments in bacterial infections were comparable to those seen in the above-mentioned groups with the exception of IFN-gamma, which remained stable. IL-1 serum levels showed a different pattern with peak concentrations measured in sera before transplant and during rejection, while in the case of CMV disease levels gradually decreased. No detectable levels of IFN-alpha or IL-2 were observed. Our results indicate that enhanced endogenous production of TNF-alpha and IFN-gamma accompanied by elevated levels of B2M and neopterin represent a regular feature of inflammatory complications after liver transplantation. Serum cytokine levels however were not useful in distinguishing between rejection and infection. Evaluation of neopterin was more sensitive than cytokine or B2M measurement for the detection of inflammatory complications.