BackgroundThe adoptive transfer of allogeneic antiviral T lymphocytes derived from seropositive donors can safely and effectively reduce or prevent the clinical manifestation of viral infections or reactivations in immunocompromised recipients after hematopoietic stem cell (HSCT) or solid organ transplantation (SOT). Allogeneic third party T-cell donors offer an alternative option for patients receiving an allogeneic cord blood transplant or a transplant from a virus-seronegative donor and since donor blood is generally not available for solid organ recipients. Therefore we established a registry of potential third-party T-cell donors (allogeneic cell registry, alloCELL) providing detailed data on the assessment of a specific individual memory T-cell repertoire in response to antigens of cytomegalovirus (CMV), Epstein-Barr virus (EBV), adenovirus (ADV), and human herpesvirus (HHV) 6.MethodsTo obtain a manufacturing license according to the German Medicinal Products Act, the enrichment of clinical-grade CMV-specific T cells from three healthy CMV-seropositive donors was performed aseptically under GMP conditions using the CliniMACS cytokine capture system (CCS) after restimulation with an overlapping peptide pool of the immunodominant CMVpp65 antigen. Potential T-cell donors were selected from alloCELL and defined as eligible for clinical-grade antiviral T-cell generation if the peripheral fraction of IFN-γ+ T cells exceeded 0.03% of CD3+ lymphocytes as determined by IFN-γ cytokine secretion assay.ResultsStarting with low concentration of IFN-γ+ T cells (0.07-1.11%) we achieved 81.2%, 19.2%, and 63.1% IFN-γ+CD3+ T cells (1.42 × 106, 0.05 × 106, and 1.15 × 106) after enrichment. Using the CMVpp65 peptide pool for restimulation resulted in the activation of more CMV-specific CD8+ than CD4+ memory T cells, both of which were effectively enriched to a total of 81.0% CD8+IFN-γ+ and 38.4% CD4+IFN-γ+ T cells. In addition to T cells and NKT cells, all preparations contained acceptably low percentages of contaminating B cells, granulocytes, monocytes, and NK cells. The enriched T-cell products were stable over 72 h with respect to viability and ratio of T lymphocytes.ConclusionsThe generation of antiviral CD4+ and CD8+ T cells by CliniMACS CCS can be extended to a broad spectrum of common pathogen-derived peptide pools in single or multiple applications to facilitate and enhance the efficacy of adoptive T-cell immunotherapy.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-014-0336-5) contains supplementary material, which is available to authorized users.

No abstract

During the last decade, hepatocyte transplantation has been suggested as a safe and potentially effective clinical option for the treatment of acute or decompensating chronic liver failure as well as for hereditary liver disease. Currently, one of the major limiting factors for clinical application is the insufficient access to suitable liver cell preparations. In cooperation with the German and Catalane organ procurement organizations, a routine procedure for the isolation of hepatocytes from donor organs rejected for transplantation (n = 117) has been established. The process is performed according to the current EC Guidelines for Good Manufacturing Practice (cGMP) and all corresponding national laws and regulations concerning donor organ and tissue procurement. In about 50% of the cases (n = 58) the three-step perfusion procedure has been completed with an average total cell yield of 5.9 × 10 9 cells per organ, the cell preparations displaying a mean viability of 64%. The mean specific yield was 3.6 × 10 6 total and 2.6 × 10 6 viable cells per gram liver tissue, respectively. Specific cell yields from three infantile donor livers were considerably higher. No correlation between isolation efficiency and cold ischemia time or donor age was found within the adult organ donors. In contrast, organs with a severe steatosis generally did not result in successful cell isolation. Results of sterility and endotoxin determination are also presented. In summary, a standardized and cGMP conform method of hepatocyte isolation from nontransplantable liver organs was established, which reproducibly yields large amounts of hepatocytes suitable for therapeutic application.

BackgroundThe aim of this study is to identify independent pre-transplant cancer risk factors after kidney transplantation and to assess the utility of G-chart analysis for clinical process control. This may contribute to the improvement of cancer surveillance processes in individual transplant centers.Patients and Methods1655 patients after kidney transplantation at our institution with a total of 9,425 person-years of follow-up were compared retrospectively to the general German population using site-specific standardized-incidence-ratios (SIRs) of observed malignancies. Risk-adjusted multivariable Cox regression was used to identify independent pre-transplant cancer risk factors. G-chart analysis was applied to determine relevant differences in the frequency of cancer occurrences.ResultsCancer incidence rates were almost three times higher as compared to the matched general population (SIR = 2.75; 95%-CI: 2.33–3.21). Significantly increased SIRs were observed for renal cell carcinoma (SIR = 22.46), post-transplant lymphoproliferative disorder (SIR = 8.36), prostate cancer (SIR = 2.22), bladder cancer (SIR = 3.24), thyroid cancer (SIR = 10.13) and melanoma (SIR = 3.08). Independent pre-transplant risk factors for cancer-free survival were age <52.3 years (p = 0.007, Hazard ratio (HR): 0.82), age >62.6 years (p = 0.001, HR: 1.29), polycystic kidney disease other than autosomal dominant polycystic kidney disease (ADPKD) (p = 0.001, HR: 0.68), high body mass index in kg/m2 (p<0.001, HR: 1.04), ADPKD (p = 0.008, HR: 1.26) and diabetic nephropathy (p = 0.004, HR = 1.51). G-chart analysis identified relevant changes in the detection rates of cancer during aftercare with no significant relation to identified risk factors for cancer-free survival (p<0.05).ConclusionsRisk-adapted cancer surveillance combined with prospective G-chart analysis likely improves cancer surveillance schemes by adapting processes to identified risk factors and by using G-chart alarm signals to trigger Kaizen events and audits for root-cause analysis of relevant detection rate changes. Further, comparative G-chart analysis would enable benchmarking of cancer surveillance processes between centers.

Liver cell transplantation (LCT) is a very promising method for the use in pediatric patients. It is significantly less invasive than whole organ transplantation, but has the potential to cure or at least to substantially improve severe disorders like inborn errors of metabolism or acute liver failure. Prior to a widespread use of the technique in children, some important issues regarding safety and efficacy must be addressed. We developed a mathematical model to estimate total hepatocyte counts in relation to bodyweight to make possible more appropriate dose calculations. Different liver cell suspensions were studied at different flow rates and different catheter sizes to determine mechanical damage of cells by shear forces. At moderate flow rates, no significant loss of viability was observed even at a catheter diameter of 4.2F. Addition of heparin to the cell suspension is favored, which is in contrast to previous animal experiments. Mitochondrial function of the hepatocytes was determined with the WST-1 assay and was not substantially altered by cryopreservation. We conclude that especially with the use of small catheters, human LCT should be safe and efficient even in small infants and neonates.

The BAR-score performed below accepted thresholds for potentially useful clinical prognostic models. Prognostic models with better predictive ability with AUROCs>0.700, concordance>70% and larger summary measures are required for the prediction of 90-day post-transplant mortality to enable donor organ allocation with reliable weighing of urgency versus utility.

No abstract

BackgroundModel of end-stage liver disease (MELD)-score and diverse variants are widely used for prognosis on liver transplant waiting-lists.Methods818 consecutive patients on the liver transplant waiting-list included to calculate the MELD, MESO Index, MELD-Na, UKELD, iMELD, refitMELD, refitMELD-Na, upMELD and PELD-scores. Prognostic abilities for 90-day mortality were investigated applying Receiver-operating-characteristic-curve analysis. Independent risk factors for 90-day mortality were identified with multivariable binary logistic regression modelling. Methodological quality of the underlying development studies was assessed with a systematic assessment tool.Results74 patients (9%) died on the liver transplant waiting list within 90 days after listing. All but one scores, refitMELD-Na, had acceptable prognostic performance with areas under the ROC-curves (AUROCs)>0.700. The iMELD performed best (AUROC = 0.798). In pediatric cases, the PELD-score just failed to reach the acceptable threshold with an AUROC = 0.699. All scores reached a mean quality score of 72.3%. Highest quality scores could be achieved by the UKELD and PELD-scores. Studies specifically lack statistical validity and model evaluation.ConclusionsInferior quality assessment of prognostic models does not necessarily imply inferior prognostic abilities. The iMELD might be a more reliable tool representing urgency of transplantation than the MELD-score. PELD-score is assumedly not accurate enough to allow graft allocation decision in pediatric liver transplantation.