Experience with the mTOR Inhibitor Everolimus in Pediatric Liver Graft Recipients.

INTRODUCTION: Immunosuppression after pediatric liver transplantation remains a major challenge. MTOR inhibitors provide a promising therapeutic approach in combination with reduced CNI after transplantation. However, there are still few data regarding their use in children. PATIENTS: We analyzed 37 patients with a median age of 10 years, who received Everolimus for one or more of the following indications: I = chronic graft dysfunction (n = 22); II = progressive renal impairment (n = 5); III = non-tolerable side effects with previous immunosuppressive medication (n = 6); and IV = malignancies (n = 10). The median follow-up time was 36 months. RESULTS: Patient survival was 97%, and graft survival 84%, respectively. Stabilization of graft function was observed in 59% in subgroup 1, with 18.2% ultimately requiring retransplantation. No patient in subgroup IV developed recurrence of his primary tumor or PTLD by the endpoint of the study. Side effects were observed in 67.5% of the study patients, with infections being the most frequent (n = 20; 54.1%). There were no relevant effects on growth and development. CONCLUSION: Everolimus seems to be a treatment option in selected pediatric liver graft recipients for whom other regimens are not suitable. Overall, the efficacy was good and the side effect profile appeared to be acceptable.

Protocol Biopsies in Pediatric Liver Transplantation Recipients Improve Graft Histology and Personalize Immunosuppression.

OBJECTIVES: Protocol liver biopsies (PLBs) are part of the follow-up program at many pediatric liver transplant centers, but the impact on clinical decision-making and allograft histology following adjustments of immunosuppression (IS) after PLB has not been thoroughly analyzed. METHODS: Following our previous single-center cohort study, we have now evaluated histological findings of 178 PLBs of 118 pediatric patients transplanted at our center between 1998 and 2017. In particular, we focused on the changes in allograft histology in the follow-up biopsy of a subgroup of 22 patients, in which the histologic findings led to an adjustment of immunosuppressive therapy. All biopsies of this sub-study group were reevaluated by an experienced pathologist. RESULTS: The overall frequency and severity of fibrosis increased over time after orthotopic liver transplantation. Patients with donor-specific antibodies (DSAs) had a higher prevalence of fibrosis than DSA-negative patients. Graft inflammation decreased significantly after intensifying IS, but renal function needs to be monitored. A significant increase in fibrosis was detected in children with reduced IS. CONCLUSION: The adjustment of IS following PLBs has a significant impact on allograft histology. Since chronic inflammatory changes may lead to graft failure, adjustment of IS seems to be of major importance for the long-term outcome.

Progressive liver, kidney, and heart degeneration in children and adults affected by TULP3 mutations.

Organ fibrosis is a shared endpoint of many diseases, yet underlying mechanisms are not well understood. Several pathways governed by the primary cilium, a sensory antenna present on most vertebrate cells, have been linked with fibrosis. Ciliopathies usually start early in life and represent a considerable disease burden. We performed massively parallel sequencing by using cohorts of genetically unsolved individuals with unexplained liver and kidney failure and correlated this with clinical, imaging, and histopathological analyses. Mechanistic studies were conducted with a vertebrate model and primary cells. We detected bi-allelic deleterious variants in TULP3, encoding a critical adaptor protein for ciliary trafficking, in a total of 15 mostly adult individuals, originating from eight unrelated families, with progressive degenerative liver fibrosis, fibrocystic kidney disease, and hypertrophic cardiomyopathy with atypical fibrotic patterns on histopathology. We recapitulated the human phenotype in adult zebrafish and confirmed disruption of critical ciliary cargo composition in several primary cell lines derived from affected individuals. Further, we show interaction between TULP3 and the nuclear deacetylase SIRT1, with roles in DNA damage repair and fibrosis, and report increased DNA damage ex vivo. Transcriptomic studies demonstrated upregulation of profibrotic pathways with gene clusters for hypertrophic cardiomyopathy and WNT and TGF-ß signaling. These findings identify variants in TULP3 as a monogenic cause for progressive degenerative disease of major organs in which affected individuals benefit from early detection and improved clinical management. Elucidation of mechanisms crucial for DNA damage repair and tissue maintenance will guide novel therapeutic avenues for this and similar genetic and non-genomic diseases.

Psychosocial situation, adherence, and utilization of video consultation in young adult long-term pediatric liver transplant recipients during COVID-19 pandemic.

BACKGROUND: Young adults who underwent liver transplantation in childhood (YALTs) are highly vulnerable to non-adherent behavior and psychosocial problems. During the COVID-19 pandemic, special efforts may be necessary to maintain contact with these patients and offer support. This can be achieved through the use of telemedicine. The study's objective was to assess adherence and the psychosocial situation of YALTs during the COVID-19 pandemic in Germany and to evaluate the utilization of video consultations. METHODS: In May 2020, a questionnaire was sent to YALTs treated at the Hamburg University Transplant Center, accompanied by the offer of video appointments with the attending physician. The questionnaire included the Generalized Anxiety Disorder Scale 7, the Patient Health Questionnaire 2, and questions compiled by the authors. RESULTS: Of 98 YALTs, 12% used the video consultation, while 65% had an in-person appointment. The 56 patients who completed the questionnaire did not report reduced medication adherence during the pandemic, but 40% missed follow-up visits with their primary care physician or check-up laboratory tests. About 70% of YALTs were afraid to visit their physician and the transplant center, and 34% were afraid of a SARS-CoV-2 infection. Mental health and well-being were unimpaired. CONCLUSIONS: During the COVID-19 pandemic, YALTs in our study did not show an increased need for psychosocial support, but a majority were afraid to attend medical appointments, and 40% reported lower appointment adherence. Acceptance of video consultations was lower than expected. The reasons for this need to be further investigated in order to optimize care.

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

BACKGROUND: In 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. AIM: To clarify the importance of DSAs on long-term graft survival in a larger cohort of pediatric patients. METHODS: We 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. RESULTS: DSA-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. CONCLUSION: DSA 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.

Presence of donor specific HLA class 2 antibodies (DSA class 2) is associated with development of graft fibrosis more than 10 years after liver transplantation-a retrospective single center study.

Here the impact of donor specific human leukocyte antigen (HLA) class 2 antibodies (DSA cl 2) on long term outcome after liver transplantation (LT) was investigated. Altogether 156 (44 pediatric and 112 adult) LT recipients were included in the study. Graft fibrosis was assessed by liver elastography and biopsy. DSA cl 2 were determined by Luminex technology. 46% of LT recipients were positive for DSA cl 2 after a median follow-up of 15 years. In the multivariate analysis DSA cl 2 were significantly associated with immunosuppressive monotherapy (OR 5.42; 95% CI: 1.02-28.90; p = .048). Compared to DSA cl 2 negative patients, positive recipients had significantly more graft fibrosis based on the liver stiffness (mean 9.4 ± 9.0 kPa vs. 6.5 ± 6.3 kPa; p < .002) and fibrosis stages determined by liver elastography (p = .016) and the performed liver biopsies (p = .002). Also, a significantly higher incidence of chronic rejections (11% vs. 2%; p = .045) and graft losses (6% vs. 0%; p = .043) were found. In the multivariate regression analysis DSA cl 2 were significantly associated with graft fibrosis (OR 4.57; 95% CI 1.59-13.10; p = .005). So, these data suggest that development of DSA cl 2 occurs more often with immunosuppressive monotherapy and may ultimately result in chronic rejection and graft fibrosis.

Impact of hepatopathy in pediatric patients after surgery for complex congenital heart disease.

Patients undergoing complex pediatric cardiac surgery in early infancy are at risk of postoperative secondary end-organ dysfunction. The aim of this study was to determine specific risk factors promoting the development of peri- and postoperative hepatopathy after surgery for congenital heart disease. In this retrospective study, we identified 20 consecutive patients operated between 2011 and 2019 from our institutional cohort who developed significant postsurgical hepatic dysfunction. These patients were compared to a control group of 30 patients with comparable initial cardiac conditions and STS-EACTS risk score. Patients who developed hepatopathy in the intensive care unit have chronic cholestasis and decreased liver synthesis. The impact of postoperative hepatopathy on morbidity was marked. In six patients (30%), liver transplantation was executed as ultima ratio, and two (10%) were listed for liver transplantation. The overall mortality related to postoperative hepatopathy is high: We found nine patients (45%) having severe hepatopathy and mostly multiple organ dysfunction who died in the postoperative course. According to risk analysis, postoperative right and left heart dysfunction in combination with a postoperative anatomical residuum needing a re-operation or re-intervention in the postoperative period is associated with a high risk for the development of cardiac hepatopathy. Furthermore, postoperative complications (pleural effusion, heart rhythm disorders, etc.), postoperative infections, and the need for parenteral nutrition also raise the risk for cardiac hepatopathy. Further investigations are needed to reduce hepatic complications and improve the general prognosis of such complex patients.

Hydrogel increases diclofenac skin permeation and absorption.

PURPOSE: Topical nonsteroidal anti-inflammatory drug formulations are used commonly to treat musculoskeletal pain and inflammation. Drug properties and formulation composition are the primary determinants of the transdermal drug delivery rate. The ex vivo transdermal flux through human skin of three topical diclofenac formulations was compared. METHODS: The formulations tested were hydrogel 1% diclofenac sodium and two emulsion gels (1.16%/2.32% diclofenac diethylamine, equivalent to 1%/2% diclofenac sodium). Human abdominal skin obtained during unrelated surgical procedures was stored at -20 °C until use. Skin specimens were thawed, prepared and placed in Franz diffusion cells (stratum corneum facing donor cell). The test formulation (~200 mg) was applied to the donor cell skin surface, and the receptor compartment was periodically sampled over 48 hours. The drug concentration in the receptor medium was determined by a validated HPLC method. Raman spectral imaging was performed to visualize the location and distribution of diclofenac. RESULTS: After 5 hours, the cumulative amount of hydrogel diclofenac transiting the skin was about 10 times that of the emulsion gel 1.16% (P=0.0004) and about twice that of the emulsion gel 2.32% (P=0.022). Similar results were seen after 9 hours. Raman spectroscopy showed that the hydrogel formulation was a homogeneous mixture of its various components, including diclofenac. The emulsion gels were non-homogeneous, with diclofenac in close proximity to the lipophilic (paraffin) phase. CONCLUSIONS: The transdermal transit of diclofenac from the hydrogel demonstrated a faster onset and a greater absorption rate than either emulsion gel formulation, suggesting that the hydrogel formulation may have a faster onset of action in underlying tissues vs. the emulsion gel products.

Alloimmunity and Cholestasis After Liver Transplantation in Children With Progressive Familial Intrahepatic Cholestasis.

OBJECTIVES: Bile salt export pump (BSEP) deficiency is an important reason for chronic cholestasis leading to liver transplantation (LT) in early childhood. The underlying pathology is a dysfunction of BSEP due to various mutations in the ABCB11 gene. Cases of clinical recurrence after LT due to alloantibodies directed against BSEP (antibody-induced BSEP deficiency [AIBD]) have been reported. Most of these patients could be controlled by intensified immunosuppression. METHODS: We here report on 3 children with BSEP-deficiency and end-stage liver disease, which developed AIBD after LT refractory to extensive immunosuppressive and immunomodulatory treatments; retransplantation was necessary in all 3 patients. In 1 patient, a stem cell transplantation was performed successfully. RESULTS: AIBD seems to be induced by triggering factors such as initial impaired graft function or infections after LT. CONCLUSIONS: The underlying mutation may play a role in this process. Intensifying immunosuppression may be able to control AIBD, but some cases seem to be refractory to treatment and require retransplantation. Stem cell transplantation may provide a new therapeutic option for cases refractory to conservative treatment.

Revealing the spatial distribution of chemical species within latent fingermarks using vibrational spectroscopy.

Latent fingermarks are an important form of crime-scene trace evidence and their usefulness may be increased by a greater understanding of the effect of chemical distribution within fingermarks on the sensitivity and robustness of fingermark detection methods. Specifically, the relative abundance and micro-distribution of sebaceous (lipophilic) and eccrine (hydrophilic) material in fingermarks have long been debated in the field, yet direct visualisation of relative abundance and micro-distribution was rarely achieved. Such a visualisation is nonetheless essential to provide explanations for the variation in reproducibility or robustness of latent fingermark detection with existing methods, and to identify new strategies to increase detection capabilities. In this investigation, we have used SR-ATR-FTIR and confocal Raman microscopy to probe the spatial micro-distribution of the sebaceous and eccrine chemical components within latent fingermarks, deposited on non-porous surfaces. It was determined that fingermarks exhibit a complex spatial distribution, influenced by the ratio of lipophilic to aqueous components, and to a first approximation resemble a water-in-oil or oil-in-water emulsion. Detection of a substantial lipid component in "eccrine enriched fingermarks" (wherein hands are washed to remove lipids) is noteworthy, as it provides a potential explanation for several scenarios of unexpected fingermark detection using methods previously thought unsuitable for "eccrine deposits". Furthermore, the pronounced distribution of lipids observed in natural fingermark deposits was intriguing and agrees with recent discussion in this research field that natural fingermarks contain a much higher lipid content than previously thought.

Allogeneic haematopoietic stem cell transplantation eliminates alloreactive inhibitory antibodies after liver transplantation for bile salt export pump deficiency.

Progressive familial intrahepatic cholestasis 2 is an autosomal-recessive disorder caused by mutations in the ABCB11 gene, which encodes the bile salt export pump (BSEP). Recurrence of BSEP deficiency after liver transplantation is caused by the development of anti-BSEP antibodies. Antibody-induced BSEP deficiency is typically treated by increasing immunosuppressive therapy. We report, in a child, the first case of allogeneic haematopoietic stem cell transplantation for antibody-induced BSEP deficiency that was refractory to intensive pharmacological immunosuppression and immunoadsorption. After haematopoietic stem cell transplantation, anti-BSEP antibodies were cleared from the patient's serum and later from the canalicular space of the liver graft.

Hypereosinophilic Syndrome After Liver Transplantation: A Case Report and a Review of the Literature.

Persistently elevated eosinophil granulocytes in the peripheral blood in children is challenging because of a complex diagnosis especially after solid organ transplantation and can lead to difficulties in finding an underlying causative factor.We report a 12-year-old boy who developed severe hypereosinophilia 11 years after liver transplantation due to biliary atresia. Accompanying symptoms were recurrent fever, fatigue, elevated liver enzymes, abdominal pain, and significant weight loss. After exclusion of secondary causes of eosinophilia, an idiopathic hypereosinophilic syndrome (I-HES) was diagnosed. Treatment with prednisolone resulted in an immediate response with rapid reduction of eosinophils, normalization of liver enzymes, and amelioration of any clinical symptoms. A hypereosinophilic syndrome in patients after liver transplantation is rare, and a broad differential diagnosis has to be considered. Prednisolone may lead to a prompt amelioration of eosinophilia and associated symptoms.

Oncogenic features of the bone morphogenic protein 7 (BMP7) in pheochromocytoma.

BMP7 is a growth factor playing pro- or anti-oncogenic roles in cancer in a cell type-dependent manner. We previously reported that the BMP7 gene is overexpressed in pheochromocytomas (PCCs) developing in MENX-affected rats and human patients. Here, analyzing a large cohort of PCC patients, we found that 72% of cases showed elevated levels of the BMP7 protein. To elucidate the role of BMP7 in PCC, we modulated its levels in PCC cell lines (overexpression in PC12, knockdown in MPC and MTT cells) and conducted functional assays. Active BMP signaling promoted cell proliferation, migration, and invasion, and sustained survival of MENX rat primary PCC cells. In PCC, BMP7 signals through the PI3K/AKT/mTOR pathway and causes integrin ß1 up-regulation. Silencing integrin ß1 in PC12 cells suppressed BMP7-mediated oncogenic features. Treatment of MTT cells with DMH1, a novel BMP antagonist, suppressed proliferation and migration. To verify the clinical applicability of our findings, we evaluated a dual PI3K/mTOR inhibitor (NVP-BEZ235) in MENX-affected rats in vivo. PCCs treated with NVP-BEZ235 had decreased proliferation and integrin ß1 levels, and higher apoptosis. Altogether, BMP7 activates pro-oncogenic pathways in PCC. Downstream effectors of BMP7-mediated signaling may represent novel targets for treating progressive/inoperable PCC, still orphan of effective therapy.

Clinical-scale isolation of the total Aspergillus fumigatus-reactive T-helper cell repertoire for adoptive transfer.

BACKGROUND AIMS: Evidence of the criticality of the adaptive immune response for controlling invasive aspergillosis has been provided. This observation is supported by the fact that invasive aspergillosis, a grave complication of allogeneic stem cell transplantation, occurs long after myeloid reconstitution in patients with low T-cell engraftment and/or on immunosuppressants. Adoptive T-cell transfer might be beneficial, but idiosyncrasies of Aspergillus fumigatus and the anti-Aspergillus immune response render established selection technologies ineffective. METHODS: We developed a Good Manufacturing Practice (GMP)-compliant protocol for preparation of A. fumigatus-specific CD4+ cells by sequentially depleting regulatory and cytotoxic T cells, activating A. fumigatus-specific T-helper cells with GMP-grade A. fumigatus lysate, and immuno-magnetically isolating them via the transiently up-regulated activation marker, CD137. RESULTS: In 13 full-scale runs, we demonstrate robustness and feasibility of the approach. From 2 × 10(9) peripheral blood mononuclear cells, we isolated 27 × 10(3)-318 × 10(3)Aspergillus-specific T-helper cells. Frequency among total T cells was increased, on average, by 200-fold. Specific studies indicate specificity and functionality: After non-specific in vitro expansion and re-stimulation with different antigens, we observed strong cytokine responses to A. fumigatus and some other fungi including Candida albicans, but none to unrelated antigens. DISCUSSION: Our technology isolates naturally occurring Aspergillus-specific T-helper cells within 2 days of identifying the clinical indication. Rapid adoptive transfer of Aspergillus-specific T cells may be quite feasible; the clinical benefit remains to be demonstrated. A manufacturing license as an advanced-therapy medicinal product was received and a clinical trial in post-transplantation invasive aspergillosis patients approved. The product is dosed at 5 × 10E3/kg T cells (single intravenous injection), of which at least 10% must be A. fumigatus-specific.

Long-term Clinical Relevance of De Novo Donor-Specific Antibodies After Pediatric Liver Transplantation.

BACKGROUND: Anti-HLA antibodies and especially donor-specific antibodies (DSA) play a significant role in graft survival after solid organ transplantation. Their impact on long-term survival in adult liver transplantation (LT) is controversial, but they may be a risk factor. The effects of DSA after pediatric LT are still unclear. METHODS: We performed a retrospective evaluation of DSA in sera from 43 children who had received transplants at our tertiary center. Twenty-four patients had good long-term clinical and laboratory graft function (group 1), whereas 19 LT recipients suffered from histologically confirmed and clinically relevant chronic allograft rejection (group 2); 16 of these have already undergone retransplantation due to graft dysfunction. Inclusion criteria were availability of sera before the first LT to identify preformed antibodies in case of DSA positivity after LT and long-term follow-up at our institution. Sera were analyzed for anti-HLA antibodies using Luminex single antigen beads, where a mean fluorescence intensity value of more than 1500 was considered positive. RESULTS: The prevalence of DSA was 33% for group 1 and 68% for group 2. Antibodies were predominantly HLA class II. Values of mean fluorescence intensity were comparable in both groups. Only one of the DSA+ ve patients from group 1 exhibited preformed antibodies. In conclusion, pediatric patients with chronic rejection revealed a higher rate of de novo DSA, especially of HLA-class II DSA. Further studies are necessary to confirm these data with a larger pediatric cohort.

Developments in pediatric liver transplantation since implementation of the new allocation rules in Eurotransplant.

Liver allocation in the Eurotransplant (ET) region has changed from a waiting time to an urgency-based system using the model of end-stage liver disease (MELD) score in 2006. To allow timely transplantation, pediatric recipients are allocated by an assigned pediatric MELD independent of severity of illness. Consequences for children listed at our center were evaluated by retrospective analysis of all primary pediatric liver transplantation (LTX) from deceased donors between 2002 and 2010 (110 LTX before/50 LTX after new allocation). Of 50 children transplanted in the MELD era, 17 (34%) underwent LTX with a high-urgent status that was real in five patients (median lab MELD 22, waiting time five d) and assigned in 12 patients (lab MELD 7, waiting time 35 d). Thirty-three children received a liver by their assigned pediatric MELD (lab MELD 15, waiting time 255 d). Waiting time in the two periods was similar, whereas the wait-list mortality decreased (from about four children/yr to about one child/yr). One- and three-yr patient survival showed no significant difference (94.5/97.7%; p = 0.385) as did one- and three-yr graft survival (80.7/75.2%; and 86.5/82%; p = 0.436 before/after). Introduction of a MELD-based allocation system in ET with assignment of a granted score for pediatric recipients has led to a clear priorization of children resulting in a low wait-list mortality and good clinical outcome.

Outcome of liver re-transplantation in children--impact and special analysis of early re-transplantation.

In case of graft failure, re-LTX is the only life-saving option but it has been associated with inferior results. This study analyzes the outcome following pediatric re-LTX with a main focus on the timely relation between initial transplant and re-LTX. All pediatric LTX at our institution between 2000 and 2010 divided into patients with primary LTX and patients undergoing re-LTX early (≤30 days) or late (>30 days) after previous LTX were analyzed. Two hundred and ninety-eight primary LTX(79%), 33 early (9%), and 46 late (12%) re-LTX were performed. Patient/graft survival was significantly worse for children undergoing early re-LTX compared to primary LTX and late re-LTX (p = 0.024/0.001 and p = 0.015/0.03). One-/five-yr graft survival rates were 66%/49% for early re-LTX compared to 86%/76% for late re-LTX and 90%/74% for primary LTX. The inferior results in children undergoing early re-LTX were due to events occurring in the first six months with similar survival thereafter. No difference in outcome was evident after adjustment of the groups for high-urgency status. Outcome was excellent for primary LTX and late re-LTX, supporting late re-LTX in children. Early re-LTX takes an elevated risk of early graft loss and patient death; however, beyond the early postoperative period, the outcome was comparable.

Identification and characterization of circulating variants of CXCL12 from human plasma: effects on chemotaxis and mobilization of hematopoietic stem and progenitor cells.

Mobilization of hematopoietic stem and progenitor cells (HPCs) is induced by treatment with granulocyte-colony stimulating factor, chemotherapy, or irradiation. We observed that these treatments are accompanied by a release of chemotactic activity into the blood. This plasma activity is derived from the bone marrow, liver, and spleen and acts on HPCs via the chemokine receptor CXCR4. A human blood peptide library was used to characterize CXCR4-activating compounds. We identified CXCL12[22-88] and N-terminally truncated variants CXCL12[24-88], CXCL12[25-88], CXCL12[27-88], and CXCL12[29-88]. Only CXCL12[22-88] could effectively bind to CXCR4 and induce intracellular calcium flux and chemotactic migration of HPCs. CXCL12[25-88] and CXCL12[27-88] revealed neither agonistic nor antagonistic activities in vitro, whereas CXCL12[29-88] inhibited CXCL12[22-88]-induced chemotactic migration. Since binding to glycosaminoglycans (GAG) modulates the function of CXCL12, binding to heparin was analyzed. Surface plasmon resonance kinetic analysis showed that N-terminal truncation of Arg22-Pro23 increased the dissociation constant KD by one log10 stage ([22-88]: KD: 5.4 ± 2.6 µM; [24-88]: KD: 54 ± 22.4 µM). Further truncation of the N-terminus decreased the KD ([25-88] KD: 30 ± 4.8 µM; [27-88] KD: 23 ± 1.6 µM; [29-88] KD: 19 ± 5.4 µM), indicating increasing competition for heparin binding. Systemic in vivo application of CXCL12[22-88] as well as CXCL12[27-88] or CXCL12[29-88] induced a significant mobilization of HPCs in mice. Our findings indicate that plasma-derived CXCL12 variants may contribute to the regulation of HPC mobilization by modulating the binding of CXCL12[22-88] to GAGs rather than blocking the CXCR4 receptor and, therefore, may have a contributing role in HPC mobilization.

Long-term outcomes after liver transplantation for deoxyguanosine kinase deficiency: a single-center experience and a review of the literature.

Deoxyguanosine kinase (DGUOK) deficiency is a well-known cause of hepatocerebral mitochondrial DNA depletion syndromes, which include a broad spectrum of clinical presentations. Affected patients often develop life-threatening liver failure, but the benefits of liver transplantation (LT) are controversial because of the frequently severe neurological involvement due to the underlying mitochondrial disease. We describe the long-term clinical course of 2 patients from our institution and provide an update on their outcomes after LT with this condition. Another 12 pediatric patients were identified through a systematic search of the literature. All 14 reported patients underwent transplantation in infancy despite mild to moderate neurological impairment in some cases. The 2 DGUOK-deficient patients from our center displayed liver failure and mild to moderate neurological involvement. At the time of this writing, they had been followed for 5 and 8 years after LT, both patients were alive, and they had only mild neurological symptoms. Three of the 12 patients identified through the literature review survived for a long time (17, 12, and 23 years); 8 died during early follow-up; and for 1 patient, no follow-up information was available. The 1-year survival rate was 64%; 36% survived for more than 5 years. The long-term survivors had good quality of life. In conclusion, although survival after LT for DGUOK deficiency is lower than survival after LT for other indications, a significant proportion of patients benefit from LT with long-term survival and a stable neurological situation despite initial neurological abnormalities. Nevertheless, a decision to carry out LT for patients with DGUOK deficiency remains difficult because neurological symptoms may occur and worsen after LT despite their absence before transplantation.

Peripheral blood biomarkers for the characterization of alloimmune reactivity after pediatric liver transplantation.

Individualization of immunosuppressive medications is an important objective in transplantation medicine. Reliable biomarkers to distinguish between patients dependent from intensive immunosuppressive therapy and those where therapy can be minimized among pediatric transplant recipients receiving immunosuppressive medications are still not established. We evaluated the potential of cross-sectional quantification of regulatory T cells, lymphocyte subsets, and cytokine concentrations as biomarkers in 60 pediatric liver transplant recipients with AR, CR, or normal graft function and in 11 non-transplanted patients. Transplant recipients presenting with AR had significantly higher CD8+ T-cell counts, significantly higher concentrations of IL-2, and increased levels of IFN-γ compared with asymptomatic patients or controls. Regulatory T-cell numbers did not differ between children with rejection and children with good graft function. A tendency toward increased concentrations of IL-4 and TGF-ß was detected in transplant recipients with good graft function. Cross-sectional parameters of peripheral regulatory T cells in pediatric liver transplant recipients do not seem to be valuable biomarkers for individualizing immunosuppressive therapy prior to the weaning process. Lymphocyte subsets, IL-2, IFN-γ, IL-4, and TGF-ß serum concentrations may be helpful to identify children in whom immunosuppression can be reduced or discontinued.