Oxidative DNA damage in reconstituting T cells is associated with relapse and inferior survival after allo-SCT.

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is the only curative treatment option for a number of hematologic malignancies. Its therapeutic potential relies on the potency of donor T cells to eliminate residual malignant cells, the so-called graft-versus-leukemia (GVL) effect. Disease relapse remains the most frequent treatment failure and is associated with poor outcome. Therefore, it is inevitable to decipher mechanisms that weaken GVL. In recent years, studies of tumor biology have revealed that metabolic remodeling of the micromilieu can critically regulate immune responses. Accumulation of reactive oxygen species leads to a metabolic condition known as oxidative stress, which can severely hamper T cells. Currently, only a few studies, mainly using preclinical models, have demonstrated the occurrence of oxidative stress after allo-SCTs. Therefore, we sought to investigate oxidative stress in a well-characterized group of patients who underwent allo-SCT and its impact on reconstituting T cells. We identified high concentrations of serum 8-hydroxydeoxyguanosine (8-OHdG) as an established biomarker for oxidative stress. 8-OHdG is one of the major products of DNA oxidation, which is normally rapidly removed. After allo-SCT, T cells accumulated oxidative DNA damage. High cellular 8-OHdG content (8-OHdGhi) was associated not only with signs of enhanced T-cell activation but also premature exhaustion. The inability of 8-OHdGhi T cells to efficiently target malignant cells or produce cytotoxic granzyme B and interferon gamma was associated with a significantly increased relapse risk and a shorter overall survival. Taken together, our novel findings could give reason to focus on bolstering DNA repair in reconstituting T cells as a means to improve GVL efficacy.

Allogeneic donor split skin grafts for treatment of refractory ulcers in cutaneous chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation-a retrospective analysis on seven patients.

Refractory skin ulcers due to severe chronic graft-versus-host disease (cGVHD) remain to be associated with significant morbidity and mortality.We performed an allogeneic donor skin transplantation in seven adult patients after allogeneic hematopoietic stem cell transplantation for cGVHD-associated refractory skin ulcers. While four patients received a split skin graft (SSG), in one patient, a full thickness skin graft for two small refractory ulcers of the ankle was performed, and one patient received in vitro expanded donor keratinocyte grafts derived from hair roots of the original unrelated donor. In one additional patient, a large deep fascial defect of the lower leg was covered with an autologous greater omentum free graft before coverage with an allogeneic SSG. An additional patient was treated with an autologous scrotal skin graft for a refractory ulcer associated with deep sclerosis of cGVHD after unrelated donor transplantation.All skin grafts engrafted and resulted in permanent coverage of the grafted ulcers without any signs of immunological mediated damage. In the patient receiving in vitro expanded keratinocyte grafts, two localized ulcers were permanently covered by donor skin while this approach failed to cover extensive circular ulcers of the lower legs.Allogeneic donor skin grafts are a valuable treatment option in refractory ulcers due to cGVHD but are restricted mainly to related donors while keratinocyte grafts from unrelated donors remain experimental. In male patients lacking a related donor, autologous scrotal skin graft may be an alternative option.

Reference point insensitive molecular data analysis.

MOTIVATION: In biomedicine, every molecular measurement is relative to a reference point, like a fixed aliquot of RNA extracted from a tissue, a defined number of blood cells, or a defined volume of biofluid. Reference points are often chosen for practical reasons. For example, we might want to assess the metabolome of a diseased organ but can only measure metabolites in blood or urine. In this case, the observable data only indirectly reflects the disease state. The statistical implications of these discrepancies in reference points have not yet been discussed. RESULTS: Here, we show that reference point discrepancies compromise the performance of regression models like the LASSO. As an alternative, we suggest zero-sum regression for a reference point insensitive analysis. We show that zero-sum regression is superior to the LASSO in case of a poor choice of reference point both in simulations and in an application that integrates intestinal microbiome analysis with metabolomics. Moreover, we describe a novel coordinate descent based algorithm to fit zero-sum elastic nets. AVAILABILITY AND IMPLEMENTATION: The R-package "zeroSum" can be downloaded at https://github.com/rehbergT/zeroSum Moreover, we provide all R-scripts and data used to produce the results of this manuscript as Supplementary Material CONTACT: Michael.Altenbuchinger@ukr.de, Thorsten.Rehberg@ukr.de and Rainer.Spang@ukr.deSupplementary information: Supplementary material is available at Bioinformatics online.

[Tauopathies : From molecule to therapy]. / Tauopathien : Vom Molekül zur Therapie.

BACKGROUND: The microtubule-associated tau protein is the defining denominator of a group of neurodegenerative diseases termed tauopathies. OBJECTIVE: Provide a timely state of the art review on recent scientific advances in the field of tauopathies. MATERIAL AND METHODS: Systematic review of the literature from the past 10 years. RESULTS: Tau proteins are increasingly being recognized as a highly variable protein, underlying and defining a spectrum of molecularly defined diseases, with a clinical spectrum ranging from dementia to hypokinetic movement disorders. Genetic variation at the tau locus can trigger disease or modify disease risk. Tau protein alterations can damage nerve cells and propagate pathologies through the brain. Thus, tau proteins may serve both as a serological and imaging biomarker. Tau proteins also provide a broad spectrum of rational therapeutic interventions to prevent disease progression. This knowledge has led to modern clinical trials. CONCLUSION: The field of tauopathies is in a state of dynamic and rapid progress, requiring close interdisciplinary collaboration.

Altered immune reconstitution of B and T cells precedes the onset of clinical symptoms of chronic graft-versus-host disease and is influenced by the type of onset.

We analyzed lymphocyte subpopulations and cytokines 3 months after allogeneic hematopoietic stem cell transplantation aiming to identify predictive cellular and serum markers for chronic graft-versus-host disease (cGVHD). Samples of 49 patients (pts) (no cGVHD (n = 14), subsequent quiescent onset (n = 16), de novo onset of cGVHD (n = 19)) were analyzed in the absence of active GVHD by flow cytometry and enzyme-linked immunosorbent assay. All mean absolute cell counts are presented as cells per microliter; relative cell counts are presented as percentage of lymphocytes. Pts with subsequent de novo cGVHD had significantly higher relative and absolute counts of CD4+ T cells including higher absolute counts of CD4+ memory T cells (22.36%; 206.55/µl; 136/µl, respectively) compared to pts with subsequent quiescent onset of cGVHD (12.41%; 83.42/µl; 54.3/µl) and pts without cGVHD (10.55%) with regard to relative counts of CD4+ T cells. Similarly, significantly more relative and absolute regulatory T cell numbers (CD4+FOXP3+) were detected in pts with de novo onset of cGVHD (3.08% and 24.63/µl) compared to those in pts without (1.25% and 9.06/µl) or with quiescent onset of cGVHD (1.15% and 6.91/µl). Finally, relative B cell counts, including naïve and memory B cells, were also significantly decreased in pts developing quiescent cGVHD (0.85, 0.73, 0.12% resp.) when compared to pts with de novo onset (5.61, 5.24, 0.38%). The results demonstrate that alterations in immune reconstitution are already present before onset of clinical symptoms and differ between de novo and quiescent onset of disease.

Mesenchymal Stromal Cells Protect Endothelial Cells from Cytotoxic T Lymphocyte-Induced Lysis.

The integrity of the vasculature plays an important role in the success of allogeneic organ and haematopoietic stem cell transplantation. Endothelial cells (EC) have previously been shown to be the target of activated cytotoxic T lymphocytes (CTL) resulting in extensive cell lysis. Mesenchymal stromal cells (MSC) are multipotent cells which can be isolated from multiple sites, each demonstrating immunomodulatory capabilities. They are explored herein for their potential to protect EC from CTL-targeted lysis. CD8(+) T cells isolated from human PBMC were stimulated with mitotically inactive cells of a human microvascular endothelial cell line (CDC/EU.HMEC-1, further referred to as HMEC) for 7 days. Target HMEC were cultured in the presence or absence of MSC for 24 h before exposure to activated allogeneic CTL for 4 h. EC were then analysed for cytotoxic lysis by flow cytometry. Culture of HMEC with MSC in the efferent immune phase (24 h before the assay) led to a decrease in HMEC lysis. This lysis was determined to be MHC Class I restricted linked and further analysis suggested that MSC contact is important in abrogation of lysis, as protection is reduced where MSC are separated in transwell experiments. The efficacy of multiple sources of MSC was also confirmed, and the collaborative effect of MSC and the endothelium protective drug defibrotide were determined, with defibrotide enhancing the protection provided by MSC. These results support the use of MSC as an adjuvant cellular therapeutic in transplant medicine, alone or in conjunction with EC protective agents such as defibrotide.

Impact of genomic risk factors on survival after haematopoietic stem cell transplantation for patients with acute leukaemia.

The EBMT risk score is an established tool successfully used in the prognosis of survival post-HSCT and is applicable for a range of haematological disorders. One of its main advantages is that score generation involves summation of clinical parameters that are available pretransplant. However, the EBMT risk score is recognized as not being optimal. Previous analyses, involving patients with various diagnoses, have shown that non-HLA gene polymorphisms influence outcome after allogeneic HSCT. This study is novel as it focuses only on patients having acute leukaemia (N = 458) and attempts to demonstrate how non-HLA gene polymorphisms can be added to the EBMT risk score in a Cox regression model to improve prognostic ability for overall survival. The results of the study found that three genetic factors improved EBMT risk score. The presence of MAL (rs8177374) allele T in the patient, absence of glucocorticoid receptor haplotype (consisting of rs6198, rs33389 and rs33388) ACT in the patient and absence of heat-shock protein 70-hom (+2437) (rs2227956) allele C in the patient were associated with decreased survival time. When compared to the EBMT risk score, the scores combining EBMT risk score with the genetic factors had an improved correlation with clinical outcome and better separation of risk groups. A bootstrapping technique, involving repeated testing of a model using multiple validation sets, also revealed that the newly proposed model had improved predictive value when compared to the EBMT risk score alone. Results support the view that non-HLA polymorphisms could be useful for pretransplant clinical assessment and provide evidence that polymorphisms in the recipient genotype may influence incoming donor cells, suppressing the initiation of the graft versus leukaemia effect and reducing survival.

Retrospective genome-oriented analysis reveals low transmission rate of multidrug-resistant Pseudomonas aeruginosa from contaminated toilets at a bone marrow transplant unit.

BACKGROUND: Prevention of toilet-to-patient transmission of multidrug-resistant Pseudomonas aeruginosa (MDR PA) poses management-related challenges at many bone marrow transplant units (BMTUs). AIM: To conduct a longitudinal retrospective analysis of the toilet-to-patient transmission rate for MDR PA under existing infection control (IC) measures at a BMTU with persistent MDR PA toilet colonization. METHODS: The local IC bundle comprised: (1) patient education regarding IC; (2) routine patient screening; (3) toilet flushing volume of 9 L; (4) bromination of toilet water tanks, and (5) toilet decontamination using hydrogen peroxide. Toilet water was sampled periodically between 2016 and 2021 (minimum every three months: 26 intervals). Upon MDR PA detection, disinfection and re-sampling were repeated until ≤3 cfu/100 mL was reached. Whole-genome sequencing (WGS) was performed retrospectively on all available MDR PA isolates (90 out of 117 positive environmental samples, 10 out of 14 patients, including nine nosocomial). FINDINGS: WGS of patient isolates identified six sequence types (STs), with ST235/CT1352/FIM-1 and ST309/CT3049/no-carbapenemase being predominant (three isolates each). Environmental sampling consistently identified MDR PA ST235 (65.5% ST235/CT1352/FIM-1), showing low genetic diversity (difference of ≤29 alleles by core-genome multi-locus sequence typing (cgMLST)). This indicates that direct toilet-to-patient transmission was infrequent although MDR PA was widespread (detection on 79 occasions, detection in every toilet). Only three MDR PA patient isolates can be attributed to the ST235/CT1352/FIM-1 toilet MRD PA population over six years. CONCLUSION: Stringent targeted toilet disinfection can reduce the potential risk for MDR PA acquisition by patients.

Vaccination against pandemic H1N1 (2009) in patients after allogeneic hematopoietic stem cell transplantation: a retrospective analysis.

PURPOSE: Limited data are available on immunologic responses to primary pandemic H1N1 (2009) vaccination in recipients of allogeneic hematopoietic stem cell transplantation (HSCT) recipients. In 2009 serologic responses to either pandemic H1N1 (2009) vaccine (n = 36) or pandemic H1N1 (2009) infection (n = 2) were studied in 38 HSCT recipients. METHODS: Responses were measured with a standard hemagglutination-inhibition assay. Fourteen patients had active chronic graft-versus-host disease (cGvHD) at the time of vaccination/infection and seven patients had cGvHD in remission; 11 patients had no immunosuppressive therapy, and 27 patients were on immunosuppressive therapy. Nineteen patients (53%) responded to pandemic H1N1 (2009) vaccination. Two patients had pandemic H1N1 (2009) infection without prior vaccination, and one patient had severe pandemic H1N1 (2009) infection with acute respiratory distress syndrome despite prior single vaccination. RESULTS: Non-responders to pandemic H1N1 (2009) vaccination more often had cGvHD (65 vs. 53%) and received second- or third-line therapy (53 vs. 11%), while responders mostly had first-line therapy for cGvHD. While vaccine responders had no or single agent immunosuppressive therapy, non-responders frequently received moderate or intense immunosuppressive therapy. All vaccine recipients previously treated with rituximab were non-responders. CONCLUSIONS: In summary, the overall response to pandemic H1N1 (2009) vaccination in HSCT recipients was modest. Patients receiving combined immunosuppressive therapy for steroid-refractory cGvHD barely responded to pandemic H1N1 (2009) vaccination.

MIP-3α expression in macrophages is NOD dependent.

BACKGROUND: The first identified susceptibility gene for Crohn's disease, NOD2, acts as a sensor for the bacterial-wall peptidoglycan fragment muramyl dipeptide (MDP) and activates the transcription factor nuclear factor-κB (NF-κB). Upon NF-κB activation, intestinal macrophages (IMACs) induce expression of macrophage inflammatory protein (MIP)-3α to attract memory T lymphocytes. We therefore investigated the influence of NOD2 ligation of IMAC differentiation and functional MIP-3α induction. METHODS: Human embryonal kidney HEK293 cells were transfected with NOD2 wild-type (NOD2(WT)) and the NOD2 SNP13 variant (NOD2(L1007fsinsC)) and stimulated with MDP. Recruitment of CD45R0+ and Th17 cells was determined by immunohistochemistry. RESULTS: Endogenous NOD2 stimulation was followed by a dose-dependent increase in MIP-3α secretion in MONO-MAC-6 (MM6) cells. MIP-3α mRNA was also significantly (*p < 0.05) induced in HEK293 transfected with NOD2(WT) via MDP ligation. In vivo cell-cell contacts between IMACs and CD45R0+ memory T cells as well as recruitment of Th17 cells in patients of NOD2 variants were unchanged as compared to wild-type patients. CONCLUSION: Our data demonstrate a dose-dependent increase in MIP-3α secretion in the human myeloid cell line MM6 upon MDP. However, MIP-3α-driven recruitment of Th17 cells or CD45R0+ memory T lymphocytes is not affected in patients carrying heterozygous NOD2 variants.

Human leukocyte antigen distribution in German Caucasians with advanced Ewing's sarcoma.

BACKGROUND: Risk stratification criteria for patients with Ewing's sarcoma family of tumors (ESFT) are still limited. We hypothesized divergent human leukocyte antigen (HLA) patterns in ESFT patients and compared HLA-A, -B and -DR phenotype frequencies of patients with advanced ESFT with those of healthy controls. PATIENTS: HLA types of all German Caucasian patients with advanced ESFT and available HLA-A, -B and -DR data registered in the European Group for Blood and Marrow Transplantation, Paediatric Registry for Stem Cell Transplantation and the MetaEICESS data bases (study group, n=30) were retrospectively compared with HLA types of healthy German stem cell donors (control group, n=8 862 for single HLA frequencies and n=8 839 for allele combinations). Study group patients had been immuno-typed due to eligibility for allogeneic stem cell transplantation for high risk of treatment failure, and thus constituted a selected subgroup of ESFT patients. RESULTS: After Bonferroni correction for multiple testing (PC), phenotype frequencies of HLA-A24 remained significantly higher in the study group compared to controls (PC<0.05). Furthermore, several HLA combinations were significantly more frequent in the study group compared to controls (all PC<0.05). CONCLUSION: We report an increased incidence of circumscribed HLA patterns in German Caucasians with advanced ESFT. The possible clinical significance of this observation has to be re-assessed in prospective trials comprising larger ESFT patient numbers of all risk groups.

No improvement of survival with reduced- versus high-intensity conditioning for allogeneic stem cell transplants in Ewing tumor patients.

BACKGROUND: Outcomes of Ewing tumor (ET) patients treated with allogeneic stem cell transplantation (allo-SCT) were compared regarding the use of reduced-intensity conditioning (RIC) and high-intensity conditioning (HIC) regimens as well as human leukocyte antigen (HLA)-matched and HLA-mismatched grafts. PATIENTS AND METHODS: We retrospectively analyzed data of 87 ET patients from the European Group for Blood and Marrow Transplantation, Pediatric Registry for Stem Cell Transplantations, Asia Pacific Blood and Marrow Transplantation and MetaEICESS registries treated with allo-SCT. Fifty patients received RIC (group A) and 37 patients received HIC (group B). Twenty-four patients received HLA-mismatched grafts and 63 received HLA-matched grafts. RESULTS: Median overall survival was 7.9 months [±1.24, 95% confidence interval (CI) 5.44-10.31] for group A and 4.4 months (±1.06, 95% CI 2.29-6.43) for group B patients (P = 1.3). Death of complications (DOC) occurred in 4 of 50 (0.08) and death of disease (DOD) in 33 of 50 (0.66) group A and in 16 of 37 (0.43) and 17 of 37 (0.46) group B patients, respectively. DOC incidence was decreased (P < 0.01) and DOD/relapse increased (P < 0.01) in group A compared with group B. HLA mismatch was not generally associated with graft-versus-Ewing tumor effect (GvETE). CONCLUSIONS: There was no improvement of survival with RIC compared with HIC due to increased DOD/relapse incidence after RIC despite less DOC incidence. This implicates general absence of a clinically relevant GvETE with current protocols.

Isolated cerebral manifestation of Epstein-Barr virus-associated post-transplant lymphoproliferative disorder after allogeneic hematopoietic stem cell transplantation: a case of clinical and diagnostic challenges.

We present the case of a 49-year-old male patient with Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disorder (PTLD) limited to the brain that occurred 6 months after allogeneic hematopoietic stem cell transplantation (HSCT). Clinical symptoms included mental confusion, ataxia, and diplopia. Magnetic resonance imaging (MRI) revealed cerebellar and periventricular lesions consistent with an inflammatory process. Cerebrospinal fluid (CSF) analysis, but not peripheral blood, was positive for EBV-DNA, but no malignant cells were found. Brain biopsy was not feasible because of low platelet counts. As we considered a diagnosis of either EBV-associated encephalitis or PTLD, the patient was treated with rituximab combined with antiviral therapy. However, the cerebral lesions progressed and follow-up CSF testing revealed immunoglobulin H clonality as evidence of a malignant process. Subsequent treatment attempts included 2 donor lymphocyte infusions (DLI). Despite treatment, the patient died from autopsy-proven PTLD within 8 weeks of the onset of symptoms. This case demonstrates the clinical and diagnostic challenges of primary cerebral PTLD in a patient following allogeneic HSCT.

Clinical experience with posaconazole prophylaxis--a retrospective analysis in a haematological unit.

Invasive fungal infections (IFI) are major causes of death in high-risk haematological patients receiving induction therapy for acute leukaemia or intensified immunosuppression due to acute or chronic graft-vs.-host disease (GvHD) following allogeneic stem cell transplantation (SCT). Recently, two randomised studies showed the efficacy of a posaconazole prophylaxis (PP) in these patients to prevent IFI. This prompted the strong recommendation for the use of PP in national and international guidelines. As we started PP in our leukaemia and transplantation unit in summer 2007, we retrospectively analysed the impact of PP on the incidence of possible, probable or proven IFI in this group of patients. Incidence of IFI according to the revised EORTC criteria, published in 2008, was reviewed retrospectively in a group of high-risk patients treated in our unit 1 year before the start of PP compared with the same group in the following year with PP. First analysis was performed on an intention-to-treat basis comparing patients during 1 year of PP with the same group of patients in the year before the start of PP. In a second, deeper analysis, patients were grouped for fluconazole or posaconazole irrespective of the time period the prophylaxis was given. In a first intent-to-treat analysis, 56 patients were analysed in the period without PP (noPP) compared with 34 patients in the period with PP. Overall IFI rates (possible, probable and proven IFI) were reduced from 47% (noPP group) to 35% (PP group). In a second analysis, only patients receiving either fluconazole or PP were analysed, resulting in 29 patients in the noPP group and 36 patients in the PP group. There was a reduction in overall IFI in the PP group especially in the acute myeloid leukaemia (AML) induction patients, but this does not reach statistical significance because of low patient numbers. However, initiation of antifungal therapy was significantly less frequent in AML induction patients in the PP group compared with the noPP group. Unfortunately, this does not result in reduced mortality rates, as mortality in the PP group is higher (15% vs. 7%) than in noPP patients because of double the number of patients with severe GvHD in the PP group. Both breakthrough infections were documented in this subgroup of patients. Our data, collected in every day clinical practice, add further evidence to the advantage of a PP strategy in this group of high-risk patients. However, more data are urgently needed to assess the impact of PP on the incidence and pattern of fungal infections and the strategies to be used in patients with persisting fever and pulmonary infiltrates receiving PP, especially in the setting of SCT and GvHD.

[Graft-versus-host disease (GvHD) - an update. Part 2: prognosis and therapy of GvHD]. / Graft-versus-Host-Disease (GvHD) - ein Update. Teil 2: Prognose und Therapie der GvHD.

Graft-versus-host disease (GvHD) remains one of the major complications after allogeneic stem cell transplantation (SCT) and is responsible for morbidity, mortality and decrease in quality of life of patients after SCT. The most important preventive approach is the selection of a donor with best possible HLA compatibility between donor and recipient. Basic prophylaxis of acute GvHD begins already prior to transplantation and usually consists of cyclosporine with or without methotrexate. In the past few years, many new therapies have been introduced for the treatment of acute and chronic GvHD. Extracorporeal photopheresis (ECP), for example, represents a promising treatment option for acute and chronic GvHD with very few side effects. For chronic GvHD mTOR inhibitors (sirolimus, everolimus) may replace calcineurin-inhibitors with the advantage of not inducing malignant skin tumors. Guidelines are available ort he management of acute and chronic GvHD. While pathophysiology, classification and skin manifestations of GvHD have been already presented in the first part of this article, this second part covers the prognosis, prevention and treatment of GvHD.

[Graft-versus-Host Disease (GvHD) - an update : Part 1: Pathophysiology, clinical features and classification of GvHD]. / Graft-versus-Host-Disease (GvHD) - ein Update : Teil 1: Pathophysiologie, Klinik und Stadieneinteilung der GvHD.

GvHD remains associated with significant morbidity and mortality despite new techniques for allogeneic stem cell transplantation (SCT), such as optimized conditioning regimens. Within the past ten years, the incidence of acute GvHD has remained unchanged and the incidence of chronic GvHD has even increased. The traditional classification of GvHD according to the time of clinical manifestation is now out-dated. Acute GvHD symptoms may even occur after 100 days; vice versa, primary chronic GvHD may already be observed one month after stem cell transplantation. The current classification introduced by the National Institutes of Health includes classic acute GvHD (up to 100 days), late-onset acute GvHD (after 100 days), as well as an overlap syndrome showing features of acute and chronic GvHD and classic chronic GvHD without any time limit. Diagnosis of GvHD of the skin remains difficult because of histological similarities to drug eruptions and viral exanthems. In this first part of the article the pathophysiology, classification, skin manifestations of acute and chronic GvHD and the histopathology will be presented. In a second part the prognosis, prophylaxis and therapy of GvHD will be discussed.

Recipient NOD2/CARD15 status affects cellular infiltrates in human intestinal graft-versus-host disease.

Nucleotide-binding oligomerization domain 2/caspase recruitment domain 15 (NOD2/CARD15) polymorphisms have been identified as risk factors of both Crohn's disease and graft-versus-host disease (GVHD) following allogeneic stem cell transplantation. However, the role of these receptors of innate immunity in the pathophysiology of gastrointestinal GVHD is still poorly defined. Immunohistological features of intestinal GVHD were analysed in gastrointestinal biopsies from 58 patients obtained at the time of first onset of intestinal symptoms. The observed changes were correlated with concomitant risk factors and the presence of polymorphisms within the pathogen recognition receptor gene NOD2/CARD15. Intestinal GVHD was associated with a stage-dependent decrease in CD4 T cell infiltrates and an increase in CD8 T cells in the lamina propria; CD8 infiltrates correlated with extent of apoptosis and consecutive epithelial proliferation. The presence of NOD2/CARD15 variants in the recipient was associated with a significant loss of CD4 T cells: in a semiquantitative analysis, the median CD4 score for patients with wild-type NOD2/CARD15 was 1.1 (range 3), but only 0.4 (range 2) for patients with variants (P = 0.002). This observation was independent from severity of GVHD in multivariate analyses and could not be explained by the loss of forkhead box P3(+) T cells. Our results suggest a loss of protective CD4 T cells in intestinal GVHD which is enhanced further by the presence of NOD2/CARD15 variants. Our study might help to identify more selective therapeutic strategies in the future.

Interleukin-10 promotes NK cell killing of autologous macrophages by stimulating expression of NKG2D ligands.

Under inflammatory conditions, the pleiotropic cytokine interleukin-10 (IL-10) is released in many tissues. It mediates anti-inflammatory effects in particular by inhibiting the release of T helper type 1 (Th1) cytokines. In contrast, we show here that NK cell cytotoxicity against autologous macrophages is elevated if both cell types are cultured with IL-10. The expression of most activatory NK receptors is increased after culture in the presence of IL-10. On the other hand, macrophages cultured in the presence of IL-10 show elevated expression of the NKG2D ligands major histocompatibility complex (MHC) class 1-like molecules (MIC) - A and - B, as well as UL-16 binding proteins (ULBP) - ULBP-1, ULBP-2 and ULBP-3. By masking the interaction of NK cells with macrophages through interruption of the NKG2D receptor with its ligands, we could reverse the IL-10-induced lysis of macrophages. Our data therefore reveal that IL-10 may exert a novel immunomodulatory role by stimulating NKG2D ligand expression on macrophages, thereby rendering them susceptible to NK cell elimination. This suggests that NK cells would delete macrophages and potentially other immature antigen-presenting cells (APC) or their precursors under inflammatory conditions as a feedback mechanism to shut off uncontrolled immune responses.

Successful treatment of Scedosporium apiospermum soft tissue abscess with caspofungin and voriconazole in a severely immunocompromised patient with acute myeloid leukemia.

We report the case of a 53-year-old female patient with refractory acute myeloid leukemia developing a necrotic, soft tissue abscess on the right forearm caused by Scedosporium apiospermum during prolonged severe neutropenia (absolute white blood cell count <500/µL for 49 days). In the context of the severely immunocompromised state of the patient and her need for allogeneic hematopoietic stem cell transplantation (HSCT), surgical treatment options were not favored. Therefore, combined antifungal therapy with voriconazole and caspofungin was started, based on the results of the in vitro testing (minimum inhibitory concentrations of voriconazole, posaconazole, and amphotericin B: 1, 4, and >2mg/L, respectively). The local site of infection slowly improved clinically and no spread of S. apiospermum infection to other sites was observed. After HSCT, the soft tissue abscess resolved completely and the patient has remained free of S. apiospermum infection since then. We successfully demonstrate that the use of combined antifungal therapy with voriconazole and casopfungin may further improve the clinical course and provides a promising therapeutic option to treat Scedosporium infections in such patients.

Chemokine and chemokine receptor expression analysis in target organs of acute graft-versus-host disease.

Acute graft-versus-host disease (aGVHD) is a major complication after allogeneic bone marrow transplantation (allo-BMT), and infiltration of donor leukocytes into aGVHD target organs is partially orchestrated by chemokines. Using a murine BMT model, the expression of 30 chemokines or chemokine receptors in the lung, liver, gut and tongue was analyzed using real-time PCR at 1, 2, 3 and 6 weeks after BMT during the development of clinical aGVHD and target organ histopathology. CXCL9-11 expression was linked to elevated expression of CXCR3 in the gut, lung and tongue. In contrast, hepatic CXCR3 expression was not changed, whereas a clear association was seen for CXCL16 and CXCR6 expression. An elevated intestinal CCL3 expression 1 week after allo-BMT was associated with an increased expression of CCR5 but not CCR1 or CCR3, and in the lung and liver CCL3-CCL5 expression was associated with increases in CCR1 and CCR5. Overexpression of CCL2, CCL8, CCL12 and their receptor CCR2 was found in the liver and lung, but not in the gut and tongue. On the basis of the differences in kinetics and organ distribution, more studies are required to better characterize specific targets within this network, as this will allow the development of novel preventive and therapeutic approaches by using single or multiple targeting reagents.