Mario Scalamogna

Human skin-derived stem cells migrate throughout forebrain and differentiate into astrocytes after injection into adult mouse brain.

Recent evidence indicates that neural stem cell properties can be found among a mammalian skin‐derived multipotent population. A major barrier in the further characterization of the human skin‐derived neural progenitors is the inability to isolate this population based on expression of cell surface markers. Our work has been devoted to purified human skin‐derived stem cells that are capable of neural differentiation, based on the presence or absence of the AC133 cell surface marker. The enriched skin‐derived AC133+ cells express the CD34 and Thy‐1 antigens. These cells cultured in a growth medium containing epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) proliferate, forming spheres, and differentiate in vitro into neurons, astrocytes, and rarely into oligodendrocytes. Single cells from sphere cultures initiated from human purified AC133+ cells were replated as single cells and were able to generate new spheres, demonstrating the self‐renewing ability of these stem cell populations. Brain engraftment of cells obtained from human purified AC133+‐derived spheres generated different neural phenotypes: immature neurons and a most abundant population of well differentiated astrocytes. The AC133‐derived astrocytes assumed perivascular locations in the frontal cortex. No donor‐derived oligodendrocytes were found in the transplanted mouse brains. Several donor small, rounded cells that expressed endothelial markers were found close to the host vessel and near the subventricular zone. Thus, mammalian skin AC133‐derived cells behave as a multipotent population with the capacity to differentiate into neural lineages in vitro and, prevalently, endothelium and astrocytes in vivo, demonstrating the great plasticity of these cells and suggesting potential clinical application.

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.

Split and whole liver transplantation outcomes: A comparative cohort study

A specific split liver transplantation (SLT) program has been pursued in the North Italian Transplant program (NITp) since November 1997. After 5 yr, 1,449 liver transplants were performed in 7 transplant centers, using 1,304 cadaveric donors. Whole liver transplantation (WLT) and SLT were performed in 1,126 and 323 cases, respectively. SLTs were performed in situ as 147 left lateral segments (LLS), 154 right trisegment liver (RTL) grafts, and 22 modified split livers (MSL), used for couples of adult recipients. After a median posttransplant follow‐up of 22 months, SLTs achieved a 3‐yr patient and graft survival not significantly different from the entire series of transplants (79.4 and 72.2% vs. 80.6 and 74.9%, respectively). Recipients receiving a WLT or a LLS showed significantly better outcomes than patients receiving RTL and MSL (P < 0.03 for patients and P < 0.04 for graft survival). At the multivariate analysis, donor age of >60 yr, RTL transplant, <50 annual transplants volume, urgent transplantation (United Network for Organ Sharing (UNOS) status I and IIA), ischemia time of >7 hours, and retransplantation were factors independently related to graft failure and to significantly worst patient survival. Right grafts procured from RTL and either split procured as MSL had a similar outcome of marginal whole livers. In conclusion, in 5 yr, the increased number of pediatric transplants due to split liver donation reduced to 3% the in‐list children mortality, and a decrease in the adult patient dropout rate from 27.2 to 16.2% was observed. Such results justify a more widespread adoption of SLT protocols, organizational difficulties not being a limit for the application of such technique. Liver Transpl 12:402–410, 2006.

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.

Peculiar HLA polymorphisms in Italian patients with primary biliary cirrhosis.

BACKGROUND/AIMS Primary biliary cirrhosis (PBC) is an autoimmune cholestatic liver disease of unknown etiology with a highly variable progression rate and prevalence among different geographical areas. Data concerning human leukocyte antigen (HLA) polymorphisms in PBC come from a limited number of geographical areas, from which the association with the HLA-DRB1*08 allele has been consistently reported. METHODS To investigate whether HLA polymorphisms contribute toward disease susceptibility, we compared 186 well-defined Italian PBC patients with 558 healthy subjects matched by age, gender and geographical area (Northern, Central and Southern Italy). Patients and controls were HLA typed at low resolution by PCR-sequence specific oligonucleotides for the loci A and B; HLA-DRB1 alleles were typed by reverse line blot assay of PCR-amplified DNA. RESULTS HLA-DRB1*11 was associated with a markedly reduced risk of developing PBC (OR: 0.3; 95% CI: 0.2-0.5). No association was found with HLA-DRB1*08. The B*15 (2.5; 1.3-4.6), B*41 (12.0; 2.7-72.1), B*55 (2.9; 1.1-7.5) and B*58 alleles (6.8; 1.1-46.3) were more frequent in PBC. The frequency of HLA polymorphisms was similar in PBC patients with progressive or non-progressive disease, and in those with or without anti-mitochondrial antibodies. CONCLUSIONS Our data on a large series of Italian patients suggest that PBC may have a peculiar genetic background in the Mediterranean area.

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.

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 μmol/L, respectively) as compared with CEL (51.3 and 63.4 μmol/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.

Tackling the shortage of donor kidneys: How to use the best that we have

Shortage of kidney donor is still a major limitation for renal transplantation programs. This review focuses on the emerging practices, adopted to increase transplant activities, of expanding the criteria for donor and recipient selection without exposing the recipient to the drawbacks of a graft with inadequate nephron mass. Expanding the donor pool inevitably led to consideration for kidney transplantation of organs from older donors or from donors with hypertension, diabetes or other renal diseases. To fit the reduced performance of these suboptimal organs with the renal requirement of the recipient, selection of recipients with reduced metabolic requirements or increase of nephron mass by simultaneous transplantation of two suboptimal kidneys in the same recipient have been pursued. However, a critical aspect of both approaches is to quantify functioning nephron mass provided to the recipient by pre-transplant kidney biopsies. Morphological parameters assessed on kidney biopsies at the time of donor evaluation may serve to quantify the preserved tissue and to discriminate chronic irreversible lesions from acute changes that may account for a transiently impaired renal function in the donor, but that may recover after transplant.

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 (≥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. Liver Transpl 16:308–313, 2010.

Heart transplantation with donor-specific antibodies directed toward denatured HLA-A*02:01: a case report.

The development of solid-phase assays for antibody detection has aided in the frequent detection of human leukocyte antigen (HLA) antibodies in nonalloimmunized males. Some scientists have reported that these HLA antibodies are produced to pathogens or allergens and the reactivity with HLA coated beads is the result of cross-reactive epitopes. These antibodies may also be directed toward cryptic epitopes exposed on the denatured beads. In this report, we describe the case of a heart transplanted patient who exhibited anti-HLA-A*02:01 donor-specific antibodies detected with a bead-based assay (Luminex) and undetected with the complement-dependent cytotoxicity (CDC) test. Posttransplant monitoring, carried out with CDC and with Luminex on sera from this patient collected at the 2nd, 4th, 8th, and 12th posttransplant weeks and at 1 year confirmed the presence of anti-HLA-A*02:01 in all serum samples. Additional tests carried out with denatured and intact HLA molecules using single antigen beads demonstrated that the antibody was directed toward a cryptic epitope. One year after transplantation the patient is doing well. No sign of antibody-mediated rejection was observed throughout the follow-up. A comprehensive evaluation of the anamnesis and of antibodies is critical to avoid needless exclusion of organ donors.