Importance of human leukocyte antigen antibodies and leukocyte antigen/killer-cell immunoglobulin-like receptor genes in liver transplantation

Many mechanisms have been proposed to explain the hypothetical state of hepatic tolerance, which is described by eventual imbalances or deregulation in the balance of cytokines, mediators, effectors, and regulatory cells in the complex milieu of the liver. In this section, we will comment on the importance of donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA) as well as the compatibility and pairings of HLA and killer-cell immunoglobulin-like receptor (KIR) genotypes in the evolution of liver transplantation. Thus, HLA compatibility, viral infections, and HLA-C/KIR combinations have all been linked to liver transplant rejection and survival. There have been reports of increased risk of acute and chronic rejection with ductopenia, faster graft fibrosis, biliary problems, poorer survival, and even de novo autoimmune hepatitis when DSAs are present in the recipient. Higher mean fluorescence intensity (MFI) values of the DSAs and smaller graft size were associated with poorer patient outcomes, implying that high-risk patients with preformed DSAs should be considered for selecting the graft placed and desensitization methods, according to the investigators. Similarly, in a combined kidney-liver transplant, a pretransplant with a visible expression of several DSAs revealed that these antibodies were resistant to treatment. The renal graft was lost owing to antibody-mediated rejection (AMR). The HLA antigens expressed by the transplanted liver graft influenced antibody elimination. Pathologists are increasingly diagnosing AMR in liver transplants, and desensitization therapy has even been employed in situations of AMR, particularly in patients with DSAs in kidney-hepatic transplants and high-class II MFI due to Luminex. In conclusion, after revealing the negative impacts of DSAs with high MFI, pretransplant virtual crossmatch techniques may be appropriate to improve evolution; however, they may extend cold ischemia periods by requiring the donor to be typed.     

Impact of human leukocyte antigen mismatching on outcomes of liver transplantation: A meta-analysis

AIM:To assess the effect of human leukocyte antigen(HLA) mismatching on liver graft outcome and acute rejection from a meta-analysis of available cohort studies.METHODS:Articles in PubMed/MEDLINE,EMBASE and the Cochrane database from January 1970 to June 2009,including non-English literature identified in these databases,were searched.Only studies comparing HLA or sub-phenotype matching with mismatching were extracted.The percentage of graft survival was extracted by "Engauge Digitizer" from survival curves...     

Impact of donor-specific antibodies on long-term graft survival with pediatric liver transplantation

BACKGROUNDIn a previous paper, we reported a high prevalence of donor-specific antibody (DSA) in pediatric patients with chronic rejection and expressed the need for confirmation of these findings in a larger cohort.AIMTo clarify the importance of DSAs on long-term graft survival in a larger cohort of pediatric patients.METHODSWe performed a retrospective analysis of 123 pediatric liver transplantation (LT) recipients who participated in yearly follow-ups including Luminex testing for DSA at our center. The cohort was split into two groups according to the DSA status (DSA-positive n = 54, DSA-negative n = 69). Groups were compared with regard to liver function, biopsy findings, graft survival, need for re-LT and immunosuppressive medication.RESULTSDSA-positive pediatric patients showed a higher prevalence of chronic rejection (P = 0.01), fibrosis (P < 0.001) and re-transplantation (P = 0.018) than DSA-negative patients. Class II DSAs particularly influenced graft survival. Alleles DQ2, DQ7, DQ8 and DQ9 might serve as indicators for the risk of chronic rejection and/or allograft fibrosis. Mean fluorescence intensity levels and DSA number did not impact graft survival. Previous episodes of chronic rejection might lead to DSA development.CONCLUSIONDSA prevalence significantly affected long-term liver allograft performance and liver allograft survival in our cohort of pediatric LT. Screening for class II DSAs in combination with assessment of protocol liver biopsies for chronic antibody-mediated rejection improved early identification of patients at risk of graft loss.     

High tacrolimus intra-patient variability is associated with graft rejection,and de novo donor-specific antibodies occurrence after liver transplantation

AIM To investigate the role of tacrolimus intra-patient variability(IPV) in adult liver-transplant recipients.METHODS We retrospectively assessed tacrolimus variability in a cohort of liver-transplant recipients and analyzed its effect on the occurrence of graft rejection and de novo donor-specific antibodies(dn DSAs), as well as graft survival during the first 2 years posttransplantation. Between 02/08 and 06/2015, 116 patients that received tacrolimus plus mycophenolate mofetil(with or without steroids) were included. RESULTS Twenty-two patients(18.5%) experienced at least one acute-rejection episode(BPAR). Predictive factors for a BPAR were a tacrolimus IPV of 35% [OR = 3.07 95%CI(1.14-8.24), P = 0.03] or 40% [OR = 4.16(1.38-12.50), P = 0.01), and a tacrolimus trough level of 5 ng/mL [OR=3.68(1.3-10.4), P =0.014]. Thirteen patients(11.2%) developed at least one dn DSA during the follow-up. Tacrolimus IPV [coded as a continuous variable: OR = 1.1, 95%CI(1.0-1.12), P = 0.006] of 35% [OR = 4.83, 95%CI(1.39-16.72), P = 0.01] and 40% [OR = 9.73, 95%CI(2.65-35.76), P = 0.001] were identified as predictors to detect dn DSAs. IPV did not impact on patient-or graft-survival rates during the follow-up. CONCLUSION Tacrolimus-IPV could be a useful tool to identify patients with a greater risk of graft rejection and of developing a de novo DSA after liver transplantation     

Early plasmapheresis and rituximab for acute humoral rejection after ABO-compatible liver transplantation

Acute humoral rejection （AHR） is uncommon after ABO- compatible liver transplantation. Herein, we report two cases of AHR treated with plasmapheresis and rituximab in two ABO-compatible liver-transplant patients with preformed anti-human leukocyte antigen donor-specific antibodies. Patient 1 experienced a biopsy-proven AHR at day 10 post-transplant. She was treated by steroid pulses, and OKT3. Because of persisting signs of biopsy-proven AHR at day 26, she was treated by plasmapheresis and rituximab. Uver enzyme levels did not improve, and she died on day 41. Patient 2 experienced a biopsy-proven AHR on day 10 post-transplant. She was treated by steroid pulses, plasmapheresis, and rituximab. Liver enzymes returned to within normal range 18 d after diagnosis. Uver biopsies, at 3 and 9 mo post-transplant, showed complete resolution of AHR. We conclude that plasmapheresis should be started as soon as AHR is diagnosed, and be associated with a B-cell depleting agent. Rituximab may be considered as a first-line therapy.     

Association of cytomegalovirus infection with human leukocyte antigen genotypes in recipients after allogeneic liver transplantation

BACKGROUND: Cytomegalovirus (CMV) infection is the important cause affecting the survival rate and function of the transplanted organ after transplantation. The occurrence of CMV infection after liver transplantation (LT) is associated with many factors. Lots of studies suggest that genetic mutation between hosts and CMV may play a role in the occurrence and development of CMV infection. CMV exists in an incubative state, affect or destroy the expression of human leukocyte antigen (HLA) molecules in the host cell surface, and interfere antigen's submission. This mechanism is the key of CMV to avoid immune defense mechanism of the host. To detect HLA and CMV antibody (CMV-Ab), CMV antigen (CMV-Ag) of transplantation recipients, we evaluated the association of CMV infection and the particular HLA genotypes in recipients after LT. METHODS: 277 blood samples were collected from 39 LT recipients. CMV antibody and antigen were detected by ELISA or immunohistochemical methods. The HLA types of the recipients were determined by PCR. To analyze the association of HLA alleles and the occurrence of CMV antigenemia in the patients, relative risk degree (RR) was used as the parameter for the Chi-square test. RESULTS: The LT recipients were serum CMV IgG positive (100%), but none of them was CMV IgM positive (0%). Thirty-three LT recipients (84.6%) were CMV antigenic positive with 1-50 positive leukocytes per 50000 leukocytes in extent and 7.2±4.2 positive leukocytes per 50000 leukocytes on average. Thirteen patients developed CMV pneumonia, with CMV antigenic positive (100%) and 17.7±5.5 positive leukocytes per 50000 leukocytes on average. Some HIA alleles were associated with the occurrence and extent of CMV antigenemia. HLA-A2 was the higher frequency allele for patients with antigenemia (P<0.05), and 7 patients carrying HLA-DR11 allele developed antigenemia (P<0.05). In the lower antigenemia group, HLA-A11 was higher in frequency than others (P<0.05). Besides, none of the patients carrying HLA-B16 allele developed clinical symptoms of CMV infection (P<0.05). CONCLUSIONS: The variability of HLA alleles might modulate immune response to CMV infection. HLA examination before transplantation should be made for prevention and treatment of CMV infection aider operation.     

Living donor liver transplantation for patients immunized against human leukocyte antigen

Background/purpose

The clinical features and perioperative management of liver transplant recipients who are already sensitized against human leukocyte antigen (HLA) prior to transplantation are not yet clear.

Materials and methods

Medical records of living donor liver transplant recipients were reviewed and clinical features of the patients possessing anti-HLA antibodies were studied.

Results

Among the 470 consecutive living donor liver transplant recipients, 6 patients (1.3%) had preformed anti-HLA antibodies. A review of the postoperative courses of these patients revealed that the problems included platelet transfusion refractoriness (PTR) due to immune-mediated destruction of platelet and thrombotic microangiopathy (TMA). PTR was observed in patients with anti-HLA class I antibodies and only HLA-matched platelet concentrate (HLA-matched PC) relieved thrombocytopenia. Intravenous gammaglobulin had an additive effect to HLA-matched PC in some cases, and platelet transfusion from close relatives might be a substitute for HLA-matched PC in life-threatening situations. Although the etiology of TMA is unremarkable, the incidence was high (67%, 4/6) compared with that in patients who were not sensitized against HLA (5.6%, 26/464; p < 0.01). Of the four patients, three were complicated with late-onset TMA.

Conclusions

Considering these clinical features, careful preparation and postoperative management are needed for liver transplant candidates with anti-HLA antibodies.     

HLA variants related to primary sclerosing cholangitis influence rejection after liver transplantation

AIM:To investigate influence of human leukocyte antigen(HLA)and killer immunoglobuline-like receptor(KIR)genotypes on risks of acute rejection(AR)after liver transplantation(LTX).METHODS:In this retrospective study we included143 adult donor-recipient pairs with a minimum of 6mo follow-up after LTX for whom DNA was available from both donor and recipients.Clinical data,all early complications including episodes and severity of AR and graft/patient survival were registered.The diagnosis of AR was based on clinical,biochemical and histological criteria.All suspected episodes of AR were biopsy confirmed.Key classical HLA loci(HLA-A,HLA-B,HLA-C and HLA-DRB1)were genotyped using Sanger sequencing.16 KIR genes were genotyped using a novel real time PCR approach which allows for determination of the diploid copy number of each KIR gene.Immunohistochemical staining for T(CD3),B(CD20)and natural killer(NK)cells(CD56 and CD57)were performed on liver biopsies from 3 different patient groups[primary sclerosing cholangitis(PSC),primary biliary cirrhosis and non-autoimmune liver disease],10 in each group,with similar grade of AR.RESULTS:Fourty-four(31%)patients were transplanted on the basis of PSC,40%of them had AR vs 24%in the non-PSC group(P=0.04).No significant impact of donor-recipient matching for HLA and KIR genotypes was detected.In the overall recipient population an increased risk of AR was detected for HLA-B*08(P=0.002,OR=2.5;95%CI:1.4-4.6),HLA-C*07(P=0.001,OR=2.4;95%CI:1.4-4.0)and HLA-DRB1*03(P=0.03,OR=1.9;95%CI:1.0-3.3)and a decreased risk for HLA-DRB1*04(P=0.001,OR=0.2;95%CI:0.1-0.5).For HLA-B*08,HLA-C*07 and DRB1*04 the associations remained evident in a subgroup analysis of non-PSC recipients(P=0.04,P=0.003 and P=0.02,respectively).In PSC recipients corresponding P values were 0.002,0.17 and 0.01 for HLA-B*08,HLA-C*07and DRB1*04,respectively.A dosage effect of AR prevalence according to the PSC associated HLA alleles was also notable in the total recipient population.For HLA-B*08 the frequency of AR was 56%in HLA-B*08homozygous recipients,39%in heterozygous recipients and 21%in recipients lacking HLA-B*08(P=0.02).The same was observed for the HLA-C*07 allele with AR in 57%,27%and 18%in recipients being homozygous,heterozygous and lacking HLA-C*07 respectively(P=0.003).Immunohistochemical analysis showed similar infiltration of T,B and NK cells in biopsies with AR in all three groups.CONCLUSION:We found significant associations between the PSC-associated HLA-B*08,HLA-C*07,HLADRB1*03 and HLA-DRB1*04 alleles and risk of AR in liver transplant recipients.     

Detection of human leukocyte antigen compatibility and antibodies in liver transplantation in China

BACKGROUND:The exact roles of human leukocyte antigen(HLA)compatibility,HLA antibodies and underlying diseases in acute rejection of liver transplants are not clear.Moreover,cytomegalovirus(CMV)infection one of the most common infections after transplantation,is related to HLA genotype and the incidence of acute rejection METHODS:Since there are controversial reports,we analyzed the impact of HLA matching,HLA antibodies and underlying diseases in 38 liver transplant recipients in China and assessed the asso...     

Impact of human leukocyte antigen matching on hepatitis B virus recurrence after liver transplantation

BACKGROUND:Liver transplantation(LT)is an effective therapy for end-stage hepatitis B virus(HBV)infection. Recurrence of HBV is one of the frequent complications.In the present study,we investigated whether human leukocyte antigen(HLA)matching influences the incidence of HBV recurrence,and the time point of HBV recurrence after LT. METHODS:One hundred and two recipients of LT with end-stage chronic HBV infection were reviewed.The triple- drug immunosuppression regimen consisted of tacrolimus,mycophenolate,a...     

Risk of recurrence of primary sclerosing cholangitis after liver transplantation is associated with de novo inflammatory bowel disease

AIM To evaluate risk factors for primary sclerosing cholangitis(PSC) recurrence(rPSC) after orthotopic liver transplantation(OLT) in patients with well-preserved colons. METHODS We retrospectively evaluated the medical records of all patients transplanted for PSC in our center between July 1994 and May 2015 and selected 47 with followup of at least 60 mo for further analysis based on strict inclusion and exclusion criteria. rPSC was confirmed by magnetic resonance or endoscopic retrograde cholangiopancreatography and liver biopsy. All patients were evaluated by protocolary pre-OLT colonoscopy with randomized mucosal biopsies. Colonoscopy was repeated annually after OLT. Both organ donors and recipients were human leukocyte antigen(HLA) typed by serological and/or DNA methods. All input data were thoroughly analyzed employing relevant statistical methods.RESULTS Altogether, 31 men and 16 women with a median(range) age of 36(15-68) years at the time of OLT and a median follow-up of 122(60-249) mo were included. rPSC was confirmed in 21/47(44.7%) of patients, a median 63(12-180) mo after transplantation. De novo colitis [rPSC in 11/12, P ≤ 0.05, hazard ratio(HR): 4.02, 95% confidence interval(CI): 1.58-10.98] and history of acute cellular rejection(rPSC in 14/25, P ≤ 0.05; HR: 2.66, 95%CI: 1.03-7.86) showed strong positive associations with rPSC. According to the univariate analysis, overlapping features of autoimmune hepatitis(r PSC in 5/5, P ≤ 0.05) and HLA-DRB1*07 in the donor(r PSC in 10/15, P ≤ 0.05) represent other potential risk factors for rPSC, while the HLA-DRB1*04(rPSC in 0/6, P ≤ 0.05), HLA-DQB1*03(rPSC in 1/11, P ≤ 0.05), and HLA-DQB1*07(rPSC in 0/7, P ≤ 0.05) recipient alleles may have protective roles.CONCLUSION De novo colitis and acute cellular rejection are clinical conditions significantly predisposed towards recurrence of PSC after liver transplantation.     

肝移植急性排斥反应的生化诊断

目的　总结肝移植术后急性排斥反应 (AR)的诊断经验。方法　回顾性分析 70例肝移植患者术后AR的发生率 ;分析AR组、保存 再灌注损伤 (PRI)组移植肝活检前患者生化检测值。结果　 42例次移植肝活检 ,17次发生AR ,2 2次为PRI ;3次为药物中毒。生化检测AR组 ,随发病进展 ,ALT、AST逐渐增高 ,成正相关 (P <0 .0 5 ) ;PRI组随发病进展 ,ALT、AST逐渐降低 ,成负相关 (P <0 .0 5 )。结论　移植肝活检及活检前生化检测对于AR的诊断与鉴别诊断有重要意义。     

细胞黏附分子表达对人肝移植急性排斥反应的诊断价值

急性排斥反应是肝移植术后最常见的并发症,肝穿刺活组织检查是对此进行鉴别诊断的有效手段之一.但多种并发症的病理表现时有重叠,给病理诊断带来了极大的干扰,因此,单纯的组织形态学诊断仍具有一定的局限性,探索特异的诊断指标已成为当前肝移植病理诊断研究的热点.     

Capillary C4d and Kidney Allograft Outcome in Relation to Morphologic Lesions Suggestive of Antibody-Mediated Rejection

Background and objectives

Recent studies highlighting a role of C4d− antibody-mediated rejection (ABMR) have debated whether C4d staining has independent value as a rejection marker. Considering the presumed role of complement as an important effector of graft injury, this study hypothesized that capillary C4d, a footprint of antibody-triggered complement activation, indicates a particularly severe manifestation of ABMR.

Design, setting, participants, & measurements

This large retrospective clinicopathologic study sought to assess the clinical predictive value of C4d staining in relation to ABMR morphology. Overall, 885 renal allograft recipients who underwent transplantation between 1999 and 2006 (median duration of follow-up, 63.3 [interquartile range, 40.6–93.5] months; 206 graft losses) were included if they had had one or more indication biopsies. A total of 1976 biopsy specimens were reevaluated for capillary C4d staining (C4d data were available for 825 patients) and distinct morphologic lesions suggestive of ABMR, including glomerulitis, peritubular capillaritis, capillary microthrombi, transplant glomerulopathy, and severe intimal arteritis.

Results

C4d+ patients, with or without ABMR features, had worse death-censored 8-year graft survival (53% or 67%) than C4d− patients (66% or 81%; P<0.001). In Cox regression analysis, C4d was associated with a risk of graft loss independently of baseline confounders and ABMR morphology (hazard ratio, 1.85 [95% confidence interval, 1.34 to 2.57]; P<0.001). The risk was higher than that observed for C4d− patients, a finding that reached statistical significance in patients showing fewer than two different ABMR lesions. Moreover, in a mixed model, C4d was independently associated with a steeper decline of eGFR (slope per year, −8.23±3.97 ml/min per 1.73 m²; P<0.001).

Conclusions

These results suggest that detection of intragraft complement activation has strong independent value as an additional indicator of ABMR associated with adverse kidney transplant outcomes.     

Evidence of a Genetic Basis for the Different Geographic Occurrences of Liver/Kidney Microsomal Antibody Type 1 in Hepatitis C

Antibodies to liver/kidney microsome type 1 occur in Italian patients with hepatitis C, but rarely develop in North American patients. Our goals were to compare the frequencies of the HLA markers associated with autoimmune expression in Italian and North American patients with chronic hepatitis C and to determine genetic bases for regional differences in antibody production. HLA B8, DR3, DR4, DR7, DR11, DR13, DQ2, and the B8-DR3-DQ2 haplotype were determined by microlymphocytotoxicity and polymerase chain reaction in 105 Italian patients (50 with microsomal antibodies), 100 North American patients (none with microsomal antibodies), and Italian and North American healthy control subjects. Italian patients with microsomal antibodies differed from North American patients without these antibodies by having a higher frequency of HLA DR7 (54% vs. 27%, P=0.002). HLA DR7 occurred more frequently in seropositive Italian patients than in seronegative counterparts (54% vs. 11% P < 0.0001), Italian healthy control subjects (54% vs. 29%, P=0.0009), and North American healthy control subjects (54% vs. 19%, P < 0.0001). The frequency of HLA DR7 was similar in North American patients and controls (27% vs. 19%, P=0.2), but it was lower than in Italian controls (19% vs. 29%, P=0.059). Seropositive Italian patients had a lower frequency of HLA DR11 than seronegative Italian patients and Italian controls (18% vs. 34%, P=0.07, and 18% vs. 35%, P=0.02, respectively). In contrast to seropositive Italian patients, North American patients had HLA DR4 (30% vs. 12%, P=0.02), HLA DR13 (29% vs. 10%, P=0.01), and the B8-DR3-DQ2 haplotype (23% vs. 6%, P=0.01) more often. Similarly, HLA DR4 and the B8-DR3-DQ2 phenotype were more frequent in North American patients than in Italian controls (30% vs. 16%, P=0.005, and 23% vs. 7%, P=0.00002, respectively). HLA DR7 is associated with the development of microsomal antibodies in Italian patients with chronic hepatitis C. The lower frequency of HLA DR7 in North America could contribute to the rarity of these antibodies in this region. HLA DR11 may be protective against the development of microsomal antibodies in Italian patients, whereas HLA DR4, HLA DR13, and the B8-DR3-DQ2 haplotype may be protective in North American patients.     

肝硬化患者人类白细胞抗原-DRB1和DPB1基因多态性的临床意义

目的 探讨人类白细胞抗原(HLA)-DRB1和DPB1基因多态性与肝硬化易感性的关联.方法 收集肝硬化患者168例作为研究组,其生物学父母作为对照组.运用聚合酶链反应扩增及单核苷酸多态性的分子生物学技术,检测HLA-DRB1和DPB1基因rs24755213、rs202176660基因多态性,进行肝硬化与HLA-DRB1和DPB1基因多态性的关联分析和单体型相对风险率分析.哈迪温伯格吻合度检验进行群体分析,P＜ 0.05为差异有统计学意义. 结果 HLA-DRB1单核苷酸多态性基因(SNP)位点rs24755213为A/G两种基因型,HLA-DPB1基因SNP位点rs202176660为C/T两种基因型,Hardy-Weinberg平衡检验结果表明吻合度良好;HLA-DRBI和DPB1基因SNP位点rs24755213与肝硬化相关联(P=0.014),其中等位基因A为危险因素(Z=2.33),G是保护因素(Z=-2.33);rs202176660等位基因多态性与肝硬化相关联(P=0.026),其中等位基因C是保护因素(Z=-2.06),T为危险因素(Z=2.06).rs24755213、-rs202176660单体型的G/T、A/C与肝硬化相关联(Z值分别为-2.12、2.09,P值分别为0.037、0.002). 结论 HLA-DRB1和DPB1基因的单核苷酸表型差异与肝硬化的发生和发展关系密切.     

Role of liver transplantation in human immunodeficiency virus positive patients

End-stage liver disease(ESLD) is a leading cause of morbidity and mortality amongst human immunodeficiency virus(HIV)-positive individuals. Chronic hepatitis B and hepatitis C virus(HCV) infection,drug-induced hepatotoxicity related to combined antiretro-viral therapy,alcohol related liver disease and non-alcohol related fatty liver disease appear to be the leading causes. It is therefore,anticipated that more HIV-positive patients with ESLD will present as potential transplant candidates. HIV infection is no longer a contraindication to liver transplantation. Key transplantation outcomes such as rejection and infection rates as well as medium term graft and patient survival match those seen in the non-HIV infected patients in the absence of co-existing HCV infection. HIV disease does not seem to be negatively impacted by transplantation. However,HIV-HCV coinfection transplant outcomes remain suboptimal due to recurrence. In this article,we review the key challenges faced by this patient cohort in the pre- and posttransplant period.     

Donor-specific antibodies in liver transplantation

Despite unique immunoregulatory properties pointing toward tolerance, the liver allograft can be negatively impacted by humoral alloreactivity, with immediate as well as long-term harmful consequences. With regard to the unmet need of long-term outcomes improvement after liver transplantation, donor-specific antibodies have recently been the matter of intense study in this context. We review here recent advances regarding the understanding of the impact of preformed as well as de novo anti-human leukocyte antigen donor-specific antibodies in liver transplantation and discuss potential strategies to overcome this problem.