Genetic polymorphisms in IL‐2, IL‐10, TGF‐β1, and IL‐2RB and acute rejection in renal transplant patients

Acute rejection (AR) remains a concern for kidney transplantation. Cytokines are key mediators in the induction and effector phases of all immune and inflammatory responses. Single nucleotide polymorphisms (SNPs) in cytokines and their receptors may relate to AR. We investigated the relation between AR and SNPs in the genes encoding for IL‐2(–330G>T), IL‐10(?592C>A and ?1082G>A), TGF‐β1(915G>C), and IL‐2RB(rs228942 C>A and rs228953 C>T) in 325 renal transplant patients during the first year after transplantation. The overall incidence of AR was 15.4%. In multivariate analysis, only the use of induction therapy was correlated with AR (odds ratio 1.9; 95% confidence interval 1.1–3.7; p = 0.04). No statistically significant associations between the SNPs studied and AR were observed. SNPs in the investigated cytokines and their receptors were not associated with the risk of AR. Genotyping patients for these SNPs is unlikely to aid the clinician in adjusting the immunosuppressive therapy for individual patients.     

The influence of CTLA‐4 single nucleotide polymorphisms on acute kidney allograft rejection in Turkish patients

Cytotoxic T‐lymphocyte antigen‐4 (CTLA‐4) is a cell surface protein, which down‐regulates the immune response at CTLA‐4/CD28/B7 pathway. We aimed to investigate the influence of the ?318C/T, +49A/G, ?1661A/G and CT60A/G, and CTLA‐4 gene polymorphisms on acute rejection of kidney allograft in Turkish patients. The study design was a case–control study that consists of three groups: Group 1 (n = 34) represented the kidney transplant (Ktx) recipients who experienced acute rejection, Group 2 (n = 47) was randomly assigned Ktx recipients without acute rejection, and Group 3 (n = 50) consisting of healthy volunteers to evaluate the normal genomic distribution. The polymerase chain reaction–restriction fragment length polymorphism technique was used to determine the polymorphisms. Genotype and allele frequencies among three groups denoted similar distributions for +49A/G, ?1661A/G, and CT60A/G. Conversely, ?318C/T genotype was three times more frequent in the acute rejection group than in the non‐rejection group (OR = 3.45; 95%CI = 1.18–10.1, p = 0.015) and two times more frequent than the healthy control group (OR = 2.45; 95% CI = 0.98 – 6.11, p = 0.047). Additionally, having a T allele at ?318 position was significantly associated with acute rejection (0.147 vs. 0.043, OR = 3.45; 95% CI = 1.13–10.56, p = 0.02). 318C/T gene polymorphism and T allelic variant were found to be associated with increased acute rejection risk in Turkish kidney allograft recipients.     

Impact of donor and recipient cytokine genotypes on renal allograft outcome

Allelic differences in gene promoter or codifying regions have been described to affect regulation of gene expression, consequently increasing or decreasing cytokine production and signal transduction responses to a given stimulus. This observation has been reported for interleukin (IL)-10 (-1082 A/G; -819/-592 CT/CA), transforming growth factor (TGF)-beta (codon 10 C/T, codon 25 G/C), tumor necrosis factor (TNF)-alpha (-308 G/A), TNF-beta (+252 A/G), interferon (IFN)-gamma (+874 T/A), IL-6 (-174 G/C), and IL-4R alpha (+1902 G/A). To evaluate the influence of these cytokine genotypes on the development of acute or chronic rejection, we correlated the genotypes of both kidney graft recipients and cadaver donors with the clinical outcome. Kidney recipients had 5 years follow-up, at least 2 HLA-DRB compatibilities, and a maximum of 25% anti-HLA pretransplantation sensitization. The clinical outcomes were grouped as follows: stable functioning graft (NR, n = 35); acute rejection episodes (AR, n = 31); and chronic rejection (CR, n = 31). The cytokine genotype polymorphisms were defined using PCR-SSP typing. A statistical analysis showed a significant prevalence of recipient IL-10 -819/-592 genotype among CR individuals; whereas among donors, the TGF-beta codon 10 CT genotype was significantly associated with the AR cohort and the IL-6 -174 CC genotype with CR. Other albeit not significant observations included a strong predisposition of recipient TGF-beta codon 10 CT genotype with CR, and TNF-beta 252 AA with AR. A low frequency of TNF-alpha -308 AA genotype also was observed among recipients and donors who showed poor allograft outcomes.     

Relationships between tumour necrosis factor-α, interleukin-12B and interleukin-10 gene polymorphisms and hepatitis B in Chinese Han haemodialysis patients

Aim: To investigate the possible association of gene polymorphisms of tumour necrosis factor (TNF)‐α (‐238 and ‐308), interleukin (IL)‐10 (‐592 and ‐819) and 3′ untranslated region (3′UTR) of the IL12B (‐1188) and hepatitis B in Chinese Han haemodialysis (HD) patients. Methods: The genotyping of TNF‐α ‐238 and ‐308, IL‐10 ‐592 and ‐819 and 3′UTR of the IL12B were performed by polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method. Results: The TNF‐α‐238 A allele, the IL12B 3′UTR C/C, C/A genotypes were associated with decreased susceptibility to hepatitis B viral infection (P = 0.047, P= 0.003 and P = 0.001 respectively). The frequencies of IL‐10–592 A/A genotype, IL‐10–819 T/T genotype were lower in the HBV persistence group (P = 0.029 and P = 0.019) than those in the virus clearance group. Conclusions: TNF‐α and IL12B 3′UTR gene polymorphisms may be associated with HBV susceptibility and IL‐10 gene polymorphisms may be related to the HBV persistence infection in Chinese Han HD patients.     

Subcutaneous administration of a neutralizing IL‐1β antibody prolongs limb allograft survival

Cytokine‐expression profiles revealed IL‐1ß highly upregulated in rejecting skin of limb allografts. We investigate the effect of intragraft treatment with a neutralizing IL‐1β antibody in limb transplantation. Following allogenic hind‐limb transplantation, Lewis rats were either left untreated 1 or treated with anti‐lymphocyte serum + tacrolimus (baseline) 2 ; baseline immunosuppression + anti‐IL‐1β (1 mg/kg once/week, 6‐8 subcutaneous injections) into the transplanted 3 or contralateral 4 limb. Endpoint was rejection grade III or day 100. Graft rejection was assessed by histology, immunohistochemistry, flow cytometry phenotyping of immune cells, and monitoring cytokine expression. Anti‐IL‐1β injections into the allograft or contralateral limb resulted in a significant delay of rejection onset (controls: 58.60 ± 0.60; group 3: 75.80 ± 10.87, P = .044; group 4: 73.00 ± 6.49, P = .008) and prolongation of graft survival (controls: 64.60 ± 0.87; group 3: 86.60 ± 5.33, P = .002; group 4: 93.20 ± 3.82, P = .002), compared to controls. Although the phenotype of the graft infiltrating immune cells did not differ between groups, significantly decreased skin protein levels of IL‐1β, IL‐4, IL‐13, IP‐10, MCP‐1, and MCP‐3 in long‐term‐survivors indicate an overall decrease of chemoattraction and infiltration of immune cells as the immunosuppressive mechanism of anti‐IL‐1β. Inhibition of IL‐1β with short‐term systemic immunosuppression prolongs limb allograft survival and represents a promising target for immunosuppression in extremity transplantation.     

Association between interleukin-10 gene polymorphism -592 (A/C) and peritoneal transport in patients undergoing peritoneal dialysis

Aim: The aim of this analysis was to know whether these three cytokine polymorphisms, including interleukin‐6 (IL‐6; ?572 G/C), tumour necrosis factor‐α (TNF‐α; ?308 G/A), and IL‐10 (–592 A/C) have an effect on baseline peritoneal transport property and longitudinal evolution of peritoneal function. Methods: A total of 141 stable peritoneal dialysis (PD) patients with mean treatment duration of 84.4 ± 34.2 months were enrolled. We genotyped these three cytokine polymorphisms, together with clinical parameters that were included as factors affecting longitudinal change of property of peritoneal transport over the first 3 year period after commencing therapy. Results: There was no significant association between genotypes and baseline peritoneal transport property. The ?592 A/C polymorphism of IL‐10 was associated with longitudinal change of peritoneal transport. The ratio of D/P creatinine was significantly higher in patients with AA than those with CC/CA genotypes at 12 months (0.65 ± 0.11 vs 0.62 ± 0.09, P = 0.048) and 24 months (0.64 ± 0.12 vs 0.59 ± 0.09, P = 0.018). In addition, patients with increased peritoneal transport have greater frequency distribution of AA genotype and A allele. Logistic regression analysis revealed that ?592 A allele was an independent predictor for the increase in D/P creatinine over the first 12 month period (odds ratio: 2.482, P = 0.017). There was no correlation between either polymorphism of IL‐6 ?572 (G/C) or TNF‐α?308 (G/A) and longitudinal change of peritoneal function. Conclusions: Single nucleotide polymorphism of IL‐10 ?592 (A/C) was associated with longitudinal evolution of peritoneal transport rate in PD patients rather than the baseline peritoneal characteristics.     

Cytokine polymorphisms do not influence acute rejection in renal transplantation under tacrolimus-based immunosuppression

INTRODUCTION: Acute rejection remains an important cause of graft loss after renal transplantation. It has been suggested that cytokine genotyping may play a predictive role in identifying individuals who are at higher risk of acute rejection with a view to individualizing their immunosuppression. The aim of this study was to investigate any possible associations between acute rejection and certain cytokine polymorphisms. METHODS: We genotyped 91 cadaveric renal transplant recipients on tacrolimus-based immunosuppression and 84 of their donors. The cytokine polymorphisms studied were the following: tumor necrosis factor (TNF)-alpha-1032 T/C, TNF-alpha-865 C/A, TNF-alpha-859 G/A, interleukin (IL)1-R1-970 C/T, IL-10 haplotype [-1082, -819, -592], and IL-6-174 C/G. RESULTS: We found no association between any polymorphism and the incidence of acute rejection. This was true for both the recipient and donor population. CONCLUSION: Cytokine polymorphisms did not influence acute rejection in our study. We conclude that in the modern era of immunosuppression cytokine genotyping is not a significant predictor of acute rejection in renal transplantation.     

A comparison of long‐term outcomes of portal versus systemic venous drainage in pancreatic transplantation: a systematic review and meta‐analysis

Pancreas transplantation venous effluent can be drained via the portal vein or the systemic circulation; however, no recommendation exists for the ideal technique. A systematic review of the literature from 1989 through 2014 using PubMed, CINHAL, and Cochrane Library for portal versus systemic venous drainage was undertaken. Only studies on humans and published in English were considered. Measures of glycemic control and total cholesterol were synthesized for meta‐analysis utilizing random‐effects models. Of 166 articles retrieved, 15 articles were included for meta‐analysis. Patient and graft survival were comparable in a large database study as well as in the only randomized control study. No differences in complications were seen when exocrine drainage was enteric for the systemic venous group. Fasting insulin (?34.13 pmol/mL, p < 0.001) was significantly lower within the portal drained group; however, fasting blood glucose levels (?3.4 mg/dL, p = 0.32) and hemoglobin A1C levels (mean difference 0.124%, p = 0.25) were comparable. Total cholesterol levels (?3.62 mg/dL, p = 0.447), as well as other measures of lipids, showed no difference. Based on this systematic review and meta‐analysis, there is no evidence of differences in outcomes or metabolic control in patients undergoing pancreatic transplant with portal venous drainage compared to the systemic venous drainage.     

B cell–derived IL‐1β and IL‐6 drive T cell reconstitution following lymphoablation

Understanding the mechanisms of T cell homeostatic expansion is crucial for clinical applications of lymphoablative therapies. We previously established that T cell recovery in mouse heart allograft recipients treated with anti‐thymocyte globulin (mATG) critically depends on B cells and is mediated by B cell–derived soluble factors. B cell production of interleukin (IL)‐1β and IL‐6 is markedly upregulated after heart allotransplantation and lymphoablation. Neutralizing IL‐1β or IL‐6 with mAb or the use of recipients lacking mature IL‐1β, IL‐6, IL‐1R, MyD88, or IL‐6R impair CD4⁺ and CD8⁺ T cell recovery and significantly enhance the graft‐prolonging efficacy of lymphoablation. Adoptive co‐transfer experiments demonstrate a direct effect of IL‐6 but not IL‐1β on T lymphocytes. Furthermore, B cells incapable of IL‐1β or IL‐6 production have diminished capacity to mediate T cell reconstitution and initiate heart allograft rejection upon adoptive transfer into mATG treated B cell deficient recipients. These findings reveal the essential role of B cell–derived IL‐1β and IL‐6 during homeostatic T cell expansion in a clinically relevant model of lymphoablation.     

Therapeutic doses of neostigmine,depolarising neuromuscular blockade and muscle weakness in awake volunteers: a double‐blind,placebo‐controlled,randomised volunteer study

Neostigmine reverses non‐depolarising neuromuscular blockade, but may cause muscle weakness when administered after full recovery of neuromuscular function. We hypothesised that neostigmine in therapeutic doses impairs muscle strength and respiratory function in awake healthy volunteers. Twenty‐one volunteers were randomised to receive two doses of either intravenous (i.v.) neostigmine 2.5 mg with glycopyrrolate 450 μg (neostigmine group, n = 14) or normal saline 0.9% (placebo group, n = 7). The first dose was administered immediately after obtaining baseline measurements, and the second dose was administered 15 min later. All 14 volunteers in the neostigmine group received the first dose, mean (SD) 35 (5.8) μg.kg^?1, but only nine of these volunteers agreed to receive the second dose, 34 (3.5) ?g.kg^‐1. The primary outcome was hand grip strength. Secondary outcomes were train‐of‐four ratio, single twitch height, forced expiratory volume in 1 s, forced vital capacity, forced expiratory volume in 1 s/forced vital capacity ratio, oxygen saturation, heart rate and mean arterial pressure. The first dose of intravenous neostigmine with glycopyrrolate resulted in reduced grip strength compared with placebo, ?20 (20) % vs. +4.3 (9.9) %, p = 0.0016; depolarising neuromuscular blockade with decreased single twitch height, ?14 (11) % vs. ?3.8 (5.6) %, p = 0.0077; a restrictive spirometry pattern with decreased predicted forced expiratory volume in 1 s, ?15 (12) % vs. ?0.47 (3.4) %, p = 0.0011; and predicted forced vital capacity, ?20 (12) % vs. ?0.59 (3.2) %, p < 0.0001 at 5 min after administration. The second dose of neostigmine with glycopyrrolate further decreased grip strength mean (SD) ?41 (23) % vs. +1.0 (15) %, p = 0.0004; single twitch height ?25 (15) % vs. ?2.5 (6.6) %, p = 0.0030; predicted forced expiratory volume in 1 s ?23 (24) % vs. ?0.7 (4.4) %, p = 0.0063; and predicted forced vital capacity, ?27.1 (22.0) % vs. ?0.66 (3.9) %, p = 0.0010. Train‐of‐four ratio remained unchanged (p = 0.22). In healthy volunteers, therapeutic doses of neostigmine induced significant and dose‐dependent muscle weakness, demonstrated by a decrease in maximum voluntary hand grip strength and a restrictive spirometry pattern secondary to depolarising neuromuscular blockade.     

Cytokine gene polymorphisms and risks of acute rejection and delayed graft function after kidney transplantation

BACKGROUND: Pretransplantation identification of patients at an increased risk for adverse events would allow more individualized treatment strategies possibly improving long-term outcome. We studied cytokine gene polymorphisms of kidney allograft recipients and their donors to identify factors predisposing for acute rejection (AR) and delayed graft function (DGF). METHODS: A total of 291 adult cadaver kidney recipients transplanted at a single transplantation centre between 1999 and 2002 were investigated. Recipients and donors were typed for TNF-alpha(-308G/A), TGF-beta1(codon 10T/C, codon 25C/G), IL-10(-1082G/A, -819C/T, -592C/A), IL-6(-174C/G), and IFN-gamma(+874T/A) polymorphisms using a SSP-PCR kit. An AR episode was defined based on clinical and histological findings (Banff criteria). RESULTS.: The incidence of AR was 17%. In univariate statistical analyses recipients with TNF-alpha -308AA-genotype were found to be at a significantly increased risk for rejection (odds ratio [OR] 5.0, 95% CI 3.0-8.3, P = 0.003). The association was independent from the patient-donor HLA-mismatch status. In addition, patients with IL-10 ACCACC, ATAATA, GCCATA (-1082A/G, -819C/T, -592C/A, respectively) haplotypes were predisposed to rejection (OR 1.9, 95% CI 1.1-3.1, P = 0.016). Further, the combination of recipient TGF-beta1 25GG-genotype and donor IL-10 -819T-allele was associated with rejection (OR 1.8, 95% CI 1.1-3.0, P = 0.027). These variables remained significant risk factors also in a multivariate logistic regression analysis. The incidence of DGF was 22%. The risk was increased by a donor TNF-alpha -308GA-genotype (OR 1.6, 95% CI 1.1-2.6, P = 0.040). CONCLUSIONS: Our results confirm that cytokine gene polymorphisms influence the outcome of kidney transplantation. Our data especially identify the TNF-alpha -308AA-genotype as a factor predisposing for AR episodes.     

Relationship of semen hyperviscosity with IL‐6, TNF‐α, IL‐10 and ROS production in seminal plasma of infertile patients with prostatitis and prostato‐vesiculitis

Changes in levels of oxidative damage products in semen and their relationship to seminal fluid viscosity (SFV) have recently received increasing research interest. We analysed whether SFV was associated with ROS generation, levels of cytokines TNF‐alpha (TNF‐α), IL‐6 and IL‐10 and seminal leucocyte concentration, and whether ROS production was related to the extent of infections/inflammations at one (prostatitis) or two (prostato‐vesiculitis) male accessory glands. We studied 169 infertile patients, with chronic bacterial prostatitis (PR, n = 74) and/or bilateral prostato‐vesiculitis (PV, n = 95), as diagnosed by the ultrasound (US) criteria. Healthy fertile men (n = 42) served as controls. In the PV patient group, SFV, semen characteristics and ROS production had median values that were significantly higher than those found in PR patients and controls, although other sperm variables had values significantly lower than those found in PR patients or controls. In PV infertile patients, ROS generation and pro‐inflammatory cytokines levels were higher than those found in PR infertile patients and controls, although seminal IL‐10 levels in PV and PR patients were lower than those found in the controls. In PR patients, the levels of SFV were positively related to TNF‐α (r = 0.67; P < 0.01), fMLP‐stimulated ROS production in the 45% Percoll fraction (r = 0.687, P < 0.01) and the 90% Percoll fraction in basal condition (r = 0.695, P < 0.01), and after fMLP‐stimulation (r = 0.688, P < 0.01). Thus, our data indicated that seminal hyperviscosity is associated with increased oxidative stress in infertile men and increased pro‐inflammatory interleukins in patients with male accessory gland infection, more when the infection was extended to the seminal vesicles.     

IL‐17 Expression by Tubular Epithelial Cells in Renal Transplant Recipients with Acute Antibody‐Mediated Rejection

Acute rejection is still a common complication of kidney transplantation. IL‐17 is known to be associated with allograft rejection but the cellular source and the role of this cytokine remains unclear. We investigated IL‐17 graft expression in renal transplant recipients with acute antibody‐mediated rejection (ABMR), acute T‐cell‐mediated rejection (TCMR), interstitial fibrosis and tubular atrophy (IFTA) and acute tubular damage due to calcineurin‐inhibitor toxicity (CNI). In acute ABMR, tubular IL‐17 protein expression was significantly increased compared to TCMR, where most of the IL‐17⁺cells were CD4⁺graft infiltrating lymphocytes, IFTA and CNI control groups. The tubular expression of IL‐17 in acute ABMR colocalized with JAK2 phosphorylation and peritubular capillaries C4d deposition. In addition, IL‐17 tubular expression was directly and significantly correlated with the extension of C4d deposits. In cultured proximal tubular cells, C3a induced IL‐17 gene and protein expression along with an increased in JAK2 phosphorylation. The inhibition of JAK2 abolished C3a‐induced IL‐17 expression. The use of steroids and monoclonal antibodies reduced IL‐17 expression, JAK2 phosphorylation and C4d deposition in acute ABMR patients. Our data suggest that tubular cells represent a significant source of IL‐17 in ABMR and this event might be mediated by the complement system activation featuring this condition.     

Expression of Inflammatory Cytokines (TNF‐αα, IL‐1, IL‐6 and IL‐8) in Colon of Pigs Naturally Infected with Salmonella typhimurium and S. choleraesuis

The expression of mRNA encoding tumour necrosis factor‐α (TNF‐α), interleukin‐1 (IL‐1), IL‐6 and IL‐8 was studied, by in situ hybridization with a non‐radioactive digoxigenin‐labelled probe, in formalin‐fixed, paraffin wax‐embedded colonic tissue from pigs naturally infected with Salmonella typhimurium and S. choleraesuis. By in situ hybridization, a distinct positive signal for TNF‐α, IL‐1, IL‐6 and IL‐8 was detected in colon from all 12 infected pigs. Hybridization signals for all four inflammatory cytokines were detected primarily inflammatory cells infiltrating the lamina propria and submucosa. In comparison, expression of all four inflammatory cytokines was minimal in non‐lesional colon of infected pigs and in normal colon from control pigs. The results suggest that these cytokines play an important role in the pathophysiological processes in porcine salmonellosis.     

Protective role of IL‐1β against post‐arthroplasty Staphylococcus aureus infection

MyD88 is an adapter molecule that is used by both IL‐1R and TLR family members to initiate downstream signaling and promote immune responses. Given that IL‐1β is induced after Staphylococcus aureus infections and TLR2 is activated by S. aureus lipopeptides, we hypothesized that IL‐1β and TLR2 contribute to MyD88‐dependent protective immune responses against post‐arthroplasty S. aureus infections. To test this hypothesis, we used a mouse model of a post‐arthroplasty S. aureus infection to compare the bacterial burden, biofilm formation and neutrophil recruitment in IL‐1β‐deficient, TLR2‐deficient and wild‐type (wt) mice. By using in vivo bioluminescence imaging, we found that the bacterial burden in IL‐1β‐deficient mice was 26‐fold higher at 1 day after infection and remained 3‐ to 10‐fold greater than wt mice through day 42. In contrast, the bacterial burden in TLR2‐deficient mice did not differ from wt mice. In addition, implants harvested from IL‐1β‐deficient mice had more biofilm formation and 14‐fold higher adherent bacteria compared with those from wt mice. Finally, IL‐1β‐deficient mice had ～50% decreased neutrophil recruitment to the infected postoperative joints than wt mice. Taken together, these findings suggest a mechanism by which IL‐1β induces neutrophil recruitment to help control the bacterial burden and the ensuing biofilm formation in a post‐surgical joint. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 1621–1626, 2011     

LCPT once‐daily extended‐release tacrolimus tablets versus twice‐daily capsules: a pooled analysis of two phase 3 trials in important de novo and stable kidney transplant recipient subgroups

African‐American and elderly kidney transplant recipients (KTR) have increased risk for poor clinical outcomes post‐transplant. Management of immunosuppression may be challenging in these patients and contribute to worse outcomes. A novel once‐daily formulation of tacrolimus (LCPT) has demonstrated noninferiority, similar safety, improved bioavailability, a consistent concentration time profile, and less peak and peak‐trough fluctuations vs. tacrolimus twice‐daily (Tac BID). This pooled analysis of two phase 3 randomized, controlled trials, including 861 (LCPT N = 428; Tac BID N = 433; 38% of patients were stable KTR, and 62% were de novo KTR) patients, examined the efficacy of LCPT in KTR subgroups (blacks, females, and age ≥65). Overall, treatment failure [death, graft failure, centrally read biopsy‐proven acute rejection (BPAR), or lost to follow‐up] at 12 months was as follows: LCPT: 11.9%, BID Tac: 13.4% [?1.48% (?5.95%, 2.99%)]. BPAR rates were as follows: LCPT: 8.2%, Tac BID: 9.5% [?1.29% (?5.14%, 2.55%)]. Numerically, fewer treatment failure events with LCPT were found in the majority of subgroups, with significantly less treatment failure associated with LCPT among black KTR [?13.82% (?27.22%, ?0.31%)] and KTR ≥65 [?13.46% (?25.27%, ?0.78%)]. This pooled analysis suggests numerically lower efficacy failure rates associated with LCPT among high‐risk subgroups, in particular black KTR and KTR ≥65 years old.     

Potential pathological role of pro‐inflammatory cytokines (IL‐6, TNF‐α, and IL‐17) in xenotransplantation

The major limitation of organ transplantation is the shortage of available organs from deceased human donors which leads to the deaths of thousands of patients each year. Xenotransplantation is considered to be an effective way to resolve the problem. Immune rejection and coagulation dysfunction are two major hurdles for the successful survival of pig xenografts in primate recipients. Pro‐inflammatory cytokines, such as IL‐6, TNF‐α, and IL‐17, play important roles in many diseases and in allotransplantation. However, the pathological roles of these pro‐inflammatory cytokines in xenotransplantation remain unclear. Here, we briefly review the signaling transduction and expression regulation of IL‐6, TNF‐α, and IL‐17 and evaluate their potential pathological roles in in vitro and in vivo models of xenotransplantation. We found that IL‐6, TNF‐α, and IL‐17 were induced in most in vitro or in vivo xenotransplantation model. Blockade of these cytokines using gene modification, antibody, or inhibitor had different effects in xenotransplantation. Inhibition of IL‐6 signaling with tocilizumab decreased CRP but did not increase xenograft survival. The one possible reason is that tocilizumab can not suppress IL‐6 signaling in porcine cells or organs. Other drugs which inhibit IL‐6 signaling need to be investigated in xenotransplantation model. Inhibition of TNF‐α was beneficial for the survival of xenografts in pig‐to‐mouse, rat, or NHP models. Blockade of IL‐17 using a neutralizing antibody also increased xenograft survival in several animal models. However, the role of IL‐17 in the pig‐to‐NHP xenotransplantation model remains unclear and needs to be further investigated. Moreover, blockade of TNF‐α and IL‐6 together has got a better effect in pig‐to‐baboon kidney xenotransplantation. Blockade two or even more cytokines together might get better effect in suppressing xenograft rejection. Better understanding the role of these cytokines in xenotransplantation will be beneficial for choosing better immunosuppressive strategy or producing genetic modification pig.     

Complement Dependence of Murine Costimulatory Blockade‐Resistant Cellular Cardiac Allograft Rejection

Building on studies showing that ischemia–reperfusion‐(I/R)‐injury is complement dependent, we tested links among complement activation, transplantation‐associated I/R injury, and murine cardiac allograft rejection. We transplanted BALB/c hearts subjected to 8‐h cold ischemic storage (CIS) into cytotoxic T‐lymphocyte associated protein 4 (CTLA4)Ig‐treated wild‐type (WT) or c3^?/? B6 recipients. Whereas allografts subjected to 8‐h CIS rejected in WT recipients with a median survival time (MST) of 37 days, identically treated hearts survived >60 days in c3^?/? mice (p < 0.05, n = 4–6/group). Mechanistic studies showed recipient C3 deficiency prevented induction of intragraft and serum chemokines/cytokines and blunted the priming, expansion, and graft infiltration of interferon‐γ–producing, donor‐reactive T cells. MST of hearts subjected to 8‐h CIS was >60 days in mannose binding lectin (mbl1^?/?mbl2^?/?) recipients and 42 days in factor B (cfb^?/?) recipients (n = 4–6/group, p < 0.05, mbl1^?/?mbl2^?/? vs. cfb^?/?), implicating the MBL (not alternative) pathway. To pharmacologically target MBL‐initiated complement activation, we transplanted BALB/c hearts subjected to 8‐h CIS into CTLA4Ig‐treated WT B6 recipients with or without C1 inhibitor (C1‐INH). Remarkably, peritransplantation administration of C1‐INH prolonged graft survival (MST >60 days, p < 0.05 vs. controls, n = 6) and prevented CI‐induced increases in donor‐reactive, IFNγ‐producing spleen cells (p < 0.05). These new findings link donor I/R injury to T cell–mediated rejection through MBL‐initiated, complement activation and support testing C1‐INH administration to prevent CTLA4Ig‐resistant rejection of deceased donor allografts in human transplant patients.     

Renal Transplantation With Final Allocation Based on the Virtual Crossmatch

Solid phase immunoassays (SPI) are now routinely used to detect HLA antibodies. However, the flow cytometric crossmatch (FCXM) remains the established method for assessing final donor–recipient compatibility. Since 2005 we have followed a protocol whereby the final allocation decision for renal transplantation is based on SPI (not the FCXM). Here we report long‐term graft outcomes for 508 consecutive kidney transplants using this protocol. All recipients were negative for donor‐specific antibody by SPI. Primary outcomes are graft survival and incidence of acute rejection within 1 year (AR <1 year) for FCXM+ (n = 54) and FCXM? (n = 454) recipients. Median follow‐up is 7.1 years. FCXM+ recipients were significantly different from FCXM? recipients for the following risk factors: living donor (24% vs. 39%, p = 0.03), duration of dialysis (31.0 months vs. 13.5 months, p = 0.008), retransplants (17% vs. 7.3%, p = 0.04), % sensitized (63% vs. 19%, p = 0.001), and PRA >80% (20% vs. 4.8%, p = 0.001). Despite these differences, 5‐year actual graft survival rates are 87% and 84%, respectively. AR <1 year occurred in 13% FCXM+ and 12% FCXM? recipients. Crossmatch status was not associated with graft outcomes in any univariate or multivariate model. Renal transplantation can be performed successfully, using SPI as the definitive test for donor–recipient compatibility.