Human leukocyte antigen crossmatch testing is important for liver retransplantation.

Although human leukocyte antigen (HLA) crossmatching is often thought to be unnecessary for liver transplants (LTs), we provide evidence that for retransplants, it is essential. Sera from 139 retransplant patients who had received livers from deceased donors were retrospectively analyzed with single antigen beads on a Luminex platform for HLA antibodies. Each patient received at least 2 transplants and was followed up for at least 6 months from the second LT, which was deemed to have failed if the patient had a third LT or died. Second LT survival was calculated from the date of the second LT to the date of the third LT or death. Our study cohort consisted of 118 adult patients (> or = 18 years old) as well as 21 pediatric patients (<18 years old). Class I HLA antibodies were associated with significantly poorer regraft survival in adults [survival differences of 21.3% (P = 0.046), 22.1% (P = 0.042), and 23.7% (P = 0.033) at 1, 3, and 5 years, respectively]; however, the presence of these antibodies was not associated with significant survival differences in the pediatric population. A univariate analysis of the effect of class I antibodies on second LT survival in adults showed a hazard ratio of 2.0 (95% confidence interval = 1.0-3.8, P = 0.028). Graft survival in patients with and without HLA antibodies or class II antibodies was similar. Because class I antibodies have a deleterious effect on liver regraft survival, crossmatch testing should be performed before liver retransplantation.

The impact of immunogenetics and clinical factors on the outcome of unrelated cord blood transplantation: the Milano Cord Blood Bank data.

In this article we examined the role of HLA incompatibility, of KIR C1 and C2 ligands and of other clinical factors on 99 cord blood transplants performed using single units from Milano Cord Blood Bank (MICB). We analyzed the occurrence of rejection, overall patient survival (OS) and occurrence of acute GvHD >or= 2 grade (severe aGvHD). No correlation was found between the end points and the number of HLA-A,-B, -DRB1 and -DQB1 mismatches. Only HLA-C disparities are associated with the occurrence of rejection (P=0.03). Our results showed that the presence of the C1 ligand in the donor decreased the occurrence of aGvHD (grade >or= 2) in the recipient while recipients of donors expressing the C2 KIR ligand experienced more frequently aGvHD (P=0.03). The HLA-C1 ligand, therefore, proved to have a protective effect towards severe aGvHD. The probability of rejection increased in KIR epitope-mismatched recipient/donor pairs (P=0.01). Finally the stage of disease at transplantation and cell dose were important for patient survival (P=0.003, P=0.048 respectively).

A Microsphere-Based Suspension Array for Blood Group Molecular Typing: An Update.

SUMMARY: BACKGROUND: In a previous publication we described a method for Jk(a)/Jk(b), Fy(a)/Fy(b), S/s, K/k, Kp(a)/Kp(b), Js(a)/Js(b), Co(a)/Co(b), and Lu(a)/Lu(b) genotyping based on a microsphere suspension array. Here, an improved version of the assay is presented. METHODS: TWO MULTIPLEX POLYMERASE CHAIN REACTIONS (PCR) WERE DEVELOPED: one for amplification of samples routinely tested and the other for those systems that are tested less frequently. Each biotinylated PCR product is hybridized in a single multiplex assay. A total of 2,020 samples were analyzed, and the genotypes were compared to the blood group phenotypes. RESULTS: There have been no discrepancies with the serology results other than null and/or weak phenotypes. CONCLUSION: In its present form, the method presented here has the capacity to genotype hundreds of a samples in few hours with a high concordance rate with serology.

Long-term outcome of renal transplantation from older donors.

BACKGROUND: Long-term survival of kidney grafts from older donors is inferior to that of grafts from younger donors. We sought to determine whether selecting older kidneys according to their histologic characteristics before implantation would positively influence long-term outcome. METHODS: In a prospective cohort study, we assessed outcomes among 62 patients who received one or two histologically evaluated kidneys from donors older than 60 years of age. These outcomes were compared with outcomes among 248 matched recipients of single kidney grafts that had not been histologically evaluated and were either from donors 60 years of age or younger (124 positive-reference recipients who, according to available data, were expected to have an optimal outcome) or from those older than 60 years (124 negative-reference recipients, expected to have a worse outcome). The primary end point was graft survival. RESULTS: During a median period of 23 months, 4 recipients (6 percent) of histologically evaluated kidneys progressed to dialysis, as compared with 7 positive-reference recipients (6 percent) and 29 negative-reference recipients (23 percent). Graft survival in recipients of histologically evaluated kidneys did not differ significantly from that of grafts in positive-reference recipients but was superior to that of grafts in negative-reference recipients (hazard ratio for graft failure in the negative-reference recipients relative to the recipients of histologically evaluated kidneys, 3.68; 95 percent confidence interval, 1.29 to 10.52; P=0.02). The performance of preimplantation histologic evaluation predicted better survival both in the whole study group (P=0.02) and among recipients of kidneys from older donors (P=0.01). CONCLUSIONS: The long-term survival of single or dual kidney grafts from donors older than 60 years of age is excellent, provided that the grafts are evaluated histologically before implantation. This approach may help to expand the donor-organ pool for kidney transplantation.

Killer cell immunoglobulin-like receptor genotype and killer cell immunoglobulin-like receptor-human leukocyte antigen C ligand compatibility affect the severity of hepatitis C virus recurrence after liver transplantation.

In 20% to 30% of infected individuals, hepatitis C virus (HCV) can cause cirrhosis and hepatocellular carcinoma, for which liver transplantation is the best treatment available. HCV re-infection is universal, and hepatitis disease recurrence occurs in most cases with a 30% probability of progression to graft cirrhosis at 5 years post-transplant. The immunological response to HCV involves natural killer (NK) cells and killer cell immunoglobulin-like receptors (KIRs), which specifically recognize human leukocyte antigen (HLA) class I antigens present on target cells. The effector functions of NK cells are influenced by inhibitory KIR interaction with self-HLA class I ligands, with HLA-C being the most predominant. This study examines the roles of KIR genotypes and their HLA ligands in both HCV disease recurrence and its progression. A total of 151 patients were included in the cohort, and their clinical details were recorded. Liver biopsies were used to define the absence/presence of recurrent hepatitis, the degree of fibrosis, and the progression to cirrhosis over a 10-year period. Mismatching of KIR-HLA-C ligands between donor-recipient pairs was associated with the recurrence of hepatitis (P = 0.008). The presence of KIR2DL3 in the recipient correlated with progression to liver fibrosis (P = 0.04). The mismatching of HLA-KIR ligands favored the progression of the recurrent hepatitis to fibrosis only in the presence of KIR2DL3 (P = 0.04). These preliminary results indicate that the KIR genotype and KIR-HLA-C ligand compatibility play roles in the recurrence and progression of hepatitis C disease in liver transplant recipients.

Complete sequencing of the HLA-A*68020102 novel allele identified in two Caucasoid families.

We describe here the isolation and the full-length sequence of the coding region of the HLA new variant at the HLA-A locus officially named A*68020102. This variant shows an 11 base pairs deletion within the 5' UTR region. The exon sequence is identical to that of A*6802 and the commercially available anti-A68 typing sera react with the antigen coded by the allele A*68020102. This variant was originally identified in two unrelated Caucasoid families because of discrepant HLA typing results between serology, Sequence Specific Oligonucleotide Probe (SSOP), and SBT. In fact, the A68 assigned by serology was undetectable with the molecular techniques. This has occurred because the deletion present in A*68020102 prevents specific amplification of HLA-A locus by some commercially available typing kits.

Luminex technology for anti-HLA antibody screening: evaluation of performance and of impact on laboratory routine.

The recent introduction of new technologies such as Luminex has provided alternative methods to the Complement Dependent Cytotoxicity (CDC) test for HLA specific antibody detection. In this study we compared the results obtained with CDC to those obtained using a Luminex method with the aim of evaluating the impact of this new technology on antibody screening policies in our transplant setting.A total of 1,421 sera, acquired from patients on the waiting list for a kidney transplant or following transplantation, were tested by both methodologies. CDC was performed using a whole lymphocyte population comprising a panel of 52 cells. The percentage panel reactive antibodies (PRA) and antibody specificity were evaluated using Lambda Scan Analysis software. For the Luminex method sera screening and identification of antibody specificity were carried out using the LABScreen Mixed and LABScreen PRA respectively. The overall concordance between the results obtained using the CDC and the Luminex methods was 85%. HLA antibody specificity was confirmed in 96% of the sera which tested positive using the Luminex system and serum positivity corresponded with a previous sensitisation event in these individuals. Using the Luminex method 18% of patients on the waiting list were considered and managed as sensitised as compared to 7% when testing with CDC alone. The Luminex method was able to detect a number of antibody specificities significantly more frequently than the CDC method and in addition the CDC method failed to detect some of the antibody specificities detected by the Luminex system. Based on this comparison study we have incorporated the Luminex methodology into our screening strategy.

Kidney transplantation from anti-HBc+ donors: results from a retrospective Italian study.

BACKGROUND: The risk of transmitting a hepatitis B virus (HBV) infection from donor kidneys with a past HBV serological profile may be negligible. Data on HBV transmission to kidney transplant recipients from donor organs that were anti-HBc/HBsAg in Italy has not been previously reported. Anti-HBc testing in cadaver organ donors has been mandatory in Italy since 2002, when anti-HBc determinations were included in the National Guidelines for donor evaluation. Therefore, prior to that date kidney recipients from anti-HBc/HBsAg donors can be identified retrospectively where stored serum is available for testing. METHODS: The prevalence of anti-HBc Italian organ donors, the incidence of HBV transmission according to the recipients' HBV status (vaccinated, recovered, or naive), and the clinical impact (5-year graft and patient survival rates) in the North Italy Transplant program was evaluated by retrospectively screening for anti-HBc antibodies in the sera of cadaver kidney donors used in transplants from 1997 to 1999. RESULTS: Two hundred and ten donors were found to have been anti-HBc. At the time of the study, no active infection was observed in any of the 344 HBsAg recipients, but 4/140 (2.86%) of the vaccinated recipients were found to have been anti-HBc/HBsAg. None of these patients, however, had any biochemical or clinical history of HBV infection. Patient and graft survival rates of anti-HBc or anti-HBc kidney recipients did not differ statistically. CONCLUSION: Kidney grafts from anti-HBc donors should be considered in all recipients because the benefit obtained from the transplantation out weighs the negligible risk of HBV transmission.

Incidence of second primary cancer in transplanted patients.

BACKGROUND: Solid organ transplanted patients have a three- to fourfold higher lifetime risk of developing a cancer than the general population. However, the incidence of a second primary cancer in transplanted patients has never been studied, despite the fact that the presence of regular follow-ups and the increased survival of these patients make them a very attractive model. METHODS: We investigated the incidence of a second primary cancer (SPC) in 7,636 patients who underwent a kidney, liver, lung or heart transplant between 1970 and 2004, and were followed-up for 51,819 person-years. RESULTS: During the follow-up, 499 subjects developed a first cancer (annual incidence: 98.6 x 10,000 PY), and 22 of them developed a SPC (annual incidence: 3.9 x 10,000 PY). The annual incidence of a SPC in the transplanted patients who developed a first cancer was 107.8 x 10,000 PY, giving a standardized incidence ratio of 1.1 (95% CI: 0.83-1.41). CONCLUSIONS: This result shows that the incidence of the SPC was the same as the incidence of a first cancer. Our study does not indicate an increased risk of SPC in transplanted subjects who already suffered a first malignancy.

Pharmacokinetic of cyclosporine microemulsion in pediatric kidney recipients receiving A quadruple immunosuppressive regimen: the value of C2 blood levels.

BACKGROUND: The management of cyclosporine therapy in pediatric kidney-transplant recipients is largely based on single center's experience rather than on a univocal pharmacokinetic approach based on therapeutic drug monitoring. A prospective multicenter trial was designed to address the question whether C2 blood level monitoring of cyclosporine microemulsion therapy is feasible in the pediatric setting. METHODS: Sixty-four pediatric kidney-transplant recipients receiving a triple immunosuppressive regimen based on cyclosporine microemulsion had their cyclosporine dose adjusted to the same protocol-defined C2 targets from the time of the transplant until 2 years posttransplant. The interim analyses after 1 year of enrollment is presented in this study. RESULTS: One-year patient and graft survival were 100% and 94.8%, respectively. One-year rejection rate was 15%. C2 management of cyclosporine did not affect graft function: 1-year serum creatinine and glomerular filtration rate were 1.3+/-1 mg/mL and 71.2+/-20 mL/min/1.73 m2, respectively. C2 was the best single-point predictor of the area under the concentration curve throughout the entire follow-up, with a mean coefficient of correlation of 0.97+/-0.01. CONCLUSIONS: C2 management of cyclosporine microemulsion therapy is effective and safe in pediatric kidney-transplant recipients given a combined immunosuppressive treatment.

Split-liver transplantation with pediatric donors: a multicenter experience.

BACKGROUND: Outcomes of split-liver transplantation (SLT) with pediatric donors have never been specifically reported. METHODS: A prospective multicenter study on SLT using donors younger than 15 years was conducted. Thirty-nine split-liver procedures generating a left lateral segment (LLS) and an extended right graft (ERG) were performed. In three cases, no recipient was found for ERG. In all but one case, the celiac trunk was maintained with LLS. Data were available for 67 grafts (90% of the total): 38 LLSs and 9 ERGs transplanted into 46 children and 20 ERGs transplanted into 20 adults. Sixty-two (93%) grafts were used for primary transplants and five (7%) for retransplantation. SLT were performed with 15 donors 10 years of age and less and with 24 between 11 and 15 years. RESULTS: Median follow-up was 24 months. Two-year patient and graft survival were 87% and 82%. Patient and graft survivals were not significantly different between pediatric and adult recipients, between recipients from donors 10 years of age and less and those between 11 and 15 years, and between recipients of LLS and ERG. Arterial complications occurred in 6% of cases (8% in the < or = 10 year donors group, 5% in the 11-15 year donors group). The incidence of other complications was similar between groups. CONCLUSIONS: SLT with pediatric donors, even younger than 10 years, provided results comparable with those achievable using adult donors. The similar incidence of arterial complications among patients receiving LLS or ERG suggests that maintenance of the celiac trunk with LLS is not detrimental for right-sided grafts.

Epidemiologic study on the origin of cancer after kidney transplantation.

BACKGROUND: Subjects who underwent solid organ transplantation are at higher risk for a wide variety of cancers. METHODS: The authors investigated the origin of cancer in a cohort of 2,526 patients followed up for 60.7 +/- 35.6 months after kidney transplantation between 1990 and 2000 in seven transplant centers. RESULTS: One hundred four of them developed cancer. All subjects who developed solid cancer within 6 months after transplantation (n=10) and a group of subjects who developed solid cancer after 6 months posttransplant (n=10) were selected. Short tandem repeat analysis was performed on paraffin-embedded biopsy specimens of tumors and on both donor and recipient pretransplant peripheral blood. Biologic material was obtained in 17 of the 20 selected patients (85.0%). The analysis showed that 16 of 17 tumors were genetically identical to the recipient. CONCLUSIONS: The authors' results suggest that donor transmission of solid cancer is an unlikely event in their population.

Islet transplantation improves vascular diabetic complications in patients with diabetes who underwent kidney transplantation: a comparison between kidney-pancreas and kidney-alone transplantation.

BACKGROUND: The aim of this study was to evaluate the effects of islet transplantation on patient survival and diabetic vascular complications. METHODS: Thirty-seven type 1 uremic diabetic kidney transplant patients underwent islet transplantation (KI group). Uremic type 1 diabetic kidney-pancreas (KP group, n=162), kidney-alone (KD group, n=42) transplant patients, and uremic type 1 diabetic patients still on hemodialysis (HD+DM group, n=196) constituted the control groups for survival and endothelial morphology. RESULTS: Patient survival was similar in the KI and KP groups and higher than in the HD+DM group (P<0.05). Patients experiencing long-term islet function (KI-successful [KI-s], n=24) showed a better survival (100%, 100%, and 90%) than those in the KI group who lost islet function (KI-unsuccessful [KI-u], n=13) (84%, 75%, and 45%) at 1, 4 and 7 years, respectively (P=0.02). The cardiovascular death rate for the KI group (18%) was similar to the KD group (19%) but lower when the KI-s group is considered alone (5%), and showed a cardiovascular death rate similar to the KP group (8%). The KI-s group showed a good metabolic profile, with reduction of exogenous insulin requirement and persistent C-peptide secretion, as compared with the KI-u group. The endothelial morphology was evaluated with a skin biopsy obtained in all groups. The KI-s and the KP groups demonstrated decreased signs of endothelial injury compared with the KI-u and HD+DM groups. The KI group showed a better atherothrombotic profile than the HD+DM group, with higher levels of natural anticoagulant protein. CONCLUSIONS: Successful islet transplantation improves survival, atherothrombotic profile, and endothelial morphology in uremic type 1 diabetic kidney transplant patients.

Incidence of cancer after kidney transplant: results from the North Italy transplant program.

BACKGROUND: Patients undergoing kidney transplantation demonstrate a higher risk of developing cancer as the result of immunosuppressive treatment and concurrent infections. METHODS: The incidence of cancer in a cohort of patients who underwent kidney transplantation between 1990 and 2000, and who survived the acute phase (10 days), was analyzed as part of the North Italy Transplant program. RESULTS: A total of 3,521 patients underwent transplantation during a 10-year period in 10 of 13 participating centers; the length of follow-up after kidney transplant was 67.7+/-36.0 months. During the follow-up, 172 patients developed cancer (39 with Kaposi sarcoma, 38 with lymphoproliferative diseases, and 95 with carcinomas [17 kidney, 11 non-basal cell carcinoma of the skin, 10 colorectal, 8 breast, 7 gastric, 7 lung, 6 bladder, and 3 mesothelioma]). The average time to cancer development after transplant was 40.1+/-33.4 months (range 0-134 months). Twenty-four patients developed cancer within 6 months from the transplant (10 with carcinomas, 7 with Kaposi sarcoma, and 7 with lymphoproliferative diseases). Three patients demonstrated a second primary cancer. The average cancer incidence was 4.9%. The incidence of cancer was 0.01 per year. Independent determinants of cancer development were age, gender, and immunosuppressive protocol including induction. Ten-year mortality was significantly higher in patients with cancer (33.1%) than among patients without cancer (5.3%). The relative risk of death in subjects with cancer was 5.5 (confidence interval 4.1-7.4). CONCLUSIONS: These preliminary data underline the importance of long-term surveillance of transplant recipients, choice of immunosuppressive treatment, and careful donor selection.

A comparative prospective study of two available solutions for kidney and liver preservation.

BACKGROUND: Viaspan (University of Wisconsin [UW]) solution is the gold standard for abdominal organ preservation. Celsior (CEL) is an extracellular-type, low-potassium, low-viscosity solution, initially used for heart and lung preservation. We have performed a prospective multicenter study to compare the role of these cold-storage solutions on kidney and liver recovery after transplantation. PATIENTS AND METHODS: From March 15, 2000 to December 31, 2001, 441 (172 CEL and 269 UW) renal transplants (RT) and 175 (79 CEL and 96 UW) liver transplants (LT) were included in the study. RESULTS: Perfusate volume used was significantly lower in the UW group, being 4,732 +/- 796 mL versus 5,826 + 834 mL in the CEL group (P < 0.001). In LT, median total bilirubin serum levels were significantly higher at 5 and 7 posttransplant days in the UW group (90.6 and 92.3 micromol/L, respectively) as compared with CEL (51.3 and 63.4 micromol/L, respectively). After LT, primary nonfunction (PNF) rates in the CEL and UW groups were 3.8% and 4.2% (P = NS) respectively, with 1-year graft and patient survival being 83.3% versus 85.4% (P = NS) and 89.9% versus 90.6% (P = NS). After RT, delayed graft function (DGF) rates were 23.2% and 22.7% (P = NS), respectively; PNF rates were 1.9% and 1.7% (P = NS) respectively, with 1-year graft and patient survival being 92.3% versus 94.2% (P = NS) and 99.4% versus 97.7% (P = NS). CONCLUSIONS: CEL solution was shown to be as effective as UW in both liver and kidney preservation. In LT patients, biliary function recovery is significantly better in the CEL group. CEL solution represents an efficacious option in multiorgan harvesting.

Genetic polymorphisms influencing therapy and susceptibility to rejection in organ allograft recipients.

Solid organ transplantation during the past 30 years has developed from an experimental procedure into routine clinical practice. The current repertoire of immunosuppressive agents has made a major contribution to transplant survival; however, problems in different areas still need to be overcome. Several gene polymorphisms are supposed to influence immunosuppressive therapy and susceptibility to rejection. Therefore, a priority of transplant biologists is to estimate individual patient risk and to characterise the genetic profile of patients in need of a transplant in order to optimise the use of a scarce resource such as organs from cadaver donors, and to avoid serious drug-induced adverse effects. Polymorphisms in genes encoding tumour necrosis factor-alpha (TNFalpha), interleukin (IL)-6, IL-10, interferon-gamma (IFNgamma), transforming growth factor-beta (TGFbeta) and thiopurine S-methyltransferase (TPMT) can have significant effects on an individual's risk of rejection, as well as their ability to tolerate immunosuppressive therapy. Genotyping of known polymorphisms in these genes may in the future contribute to our ability to individualise immunosuppressive therapy in organ transplant recipients.

Strategies for evaluation of suitable donors: Italian experience.

Italy was lacking standardised procedures for donor safety evaluation. We developed practice guidelines, while a panel of experts coordinated by the National Transplant Centre, is available 24 hours a day to support decisions in difficult cases. The guidelines identify five levels of risk and give recommendations for the utilization of donors with HBV and HCV infections as well as for malignancies with negligible or very low risk of transmission. In conclusion we aim to standardize the process of donor evaluation across Italy, to increase the pool of utilised donors and to reduce the risk of communicable disease transmission.

Alloantibody and autoantibody monitoring predicts islet transplantation outcome in human type 1 diabetes.

Long-term clinical outcome of islet transplantation is hampered by the rejection and recurrence of autoimmunity. Accurate monitoring may allow for early detection and treatment of these potentially compromising immune events. Islet transplant outcome was analyzed in 59 consecutive pancreatic islet recipients in whom baseline and de novo posttransplant autoantibodies (GAD antibody, insulinoma-associated protein 2 antigen, zinc transporter type 8 antigen) and donor-specific alloantibodies (DSA) were quantified. Thirty-nine recipients (66%) showed DSA or autoantibody increases (de novo expression or titer increase) after islet transplantation. Recipients who had a posttransplant antibody increase showed similar initial performance but significantly lower graft survival than patients without an increase (islet autoantibodies P < 0.001, DSA P < 0.001). Posttransplant DSA or autoantibody increases were associated with HLA-DR mismatches (P = 0.008), induction with antithymocyte globulin (P = 0.0001), and pretransplant panel reactive alloantibody >15% in either class I or class II (P = 0.024) as independent risk factors and with rapamycin as protective (P = 0.006) against antibody increases. DSA or autoantibody increases after islet transplantation are important prognostic markers, and their identification could potentially lead to improved islet cell transplant outcomes.

Description and molecular modeling of a novel human leukocyte antigen allele: A*32:22.

We describe here the sequence and the molecular modeling of a new variant of HLA-A*32 allele officially named A*32:22. This novel allele has been detected in an Italian cord blood sample by sequence-based typing (SBT). The mutation (CAT →CGT), which has occurred at codon 151, at nucleotide position 524, implies an amino acidic change from Histidine to Arginine. Residue 151 is located on top of the molecule inside the region contacted by T cell receptor (TCR) and it is possibly involved in docking TCR. A positively charged residue is maintained on this position determining a slight change of electrostatic potential on the molecular surface. This suggests a limited functional relevance of the amino acid substitution encoded by A*32:22.