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Background Maintaining gastrointestinal (GI) microbiome diversity plays a key role during allogeneic stem cell transplantation (ASCT), and loss of diversity correlates with acute GI graft versus host disease (GvHD) and poor outcomes. Methods In this retrospective analysis of 161 ASCT patients, we used serial analyses of urinary 3-indoxyl sulfate (3-IS) levels and GI microbiome parameters within the first 10 days after ASCT to identify potential commensal microbiota–sparing antibiotics. Based on antibiotic activity, we formed 3 subgroups (Rifaximin without systemic antibiotics, Rifaximin with systemic antibiotics, and Ciprofloxacin/Metronidazole with/without systemic antibiotics). Results Mono-antibiosis with Rifaximin revealed higher 3-IS levels (P < .001), higher Clostridium cluster XIVa (CCXIVa) abundance (P = .004), and higher Shannon indices (P = .01) compared to Ciprofloxacin/Metronidazole with/without systemic antibiotics. Rifaximin followed by systemic antibiotics maintained microbiome diversity compared to Ciprofloxacin/Metronidazole with/without systemic antibiotics, as these patients showed still higher 3-IS levels (P = .04), higher CCXIVa copy numbers (P = .01), and higher Shannon indexes (P = .01). Even for this larger cohort of patients, the outcome was superior with regard to GI GvHD (P = .05) and lower transplant-related mortality (P < .001) for patients receiving Rifaximin plus systemic antibiotics compared to other types of systemic antibiotic treatment. Antibiosis with Ciprofloxacin/Metronidazole (n = 12, P = .01), Piperacillin/Tazobactam (n = 52, P = .01), Meropenem/Vancomycin (n = 16, P = .003), Ceftazidime (n = 10, P = .03), or multiple systemic antibiotics (n = 53, P = .001) showed significantly lower 3-IS levels compared to mono-antibiosis with Rifaximin (n = 14) or intravenous Vancomycin (n = 4, not statistically significant). Conclusions Different types of antibiotic treatments show different impacts on markers of microbiome diversity. The identification of antibiotics sparing commensal bacteria remains an ongoing challenge. However, Rifaximin allowed a higher intestinal microbiome diversity, even in the presence of systemic broad-spectrum antibiotics.

Acute gastrointestinal (GI) graft-versus-host disease (GvHD) is a life-threating complication in patients after allogeneic stem cell transplantation (ASCT). In 60 sonographic analyses, a novel scoring system for non-invasive diagnosis of severe GI GvHD was developed. The score comprised morphological and vascular changes using B-mode and color-coded Doppler sonography, changes of mural stiffness using compound elastography, and dynamic microvascularisation using contrast-enhanced ultrasound (CEUS). Furthermore, inflammatory parameters such as CRP, Calprotectin, and regenerating islet-derived protein 3α (Reg3α) were obtained. ROC curve analysis of our novel GvHD sum score revealed an area under the curve of 1.0 (95% CI: 0.99-1.00) in diagnosing GI GvHD and 0.88 (95% CI: 0.79-0.96) for severe GI GvHD. A sum score above 5 correlated with GI GvHD with a sensitivity of 97.6% (41/42) and a specificity of 94.4% (17/18) and score values above 10 with severe GI GvHD with a sensitivity of 91.7% (11/12) and specificity of 79.2% (38/48). The additional use of inflammatory parameters did not improve the predictive power. CEUS is a promising, non-invasive tool for the diagnosis of acute GI GvHD. Together with further descriptive parameters for inflammatory processes, it gains significant diagnostic accuracy in identifying patients with severe stages of acute intestinal GvHD.

Introduction: Patients (pts) with acute myeloid leukemia (AML) who are refractory to intensive frontline treatment have a dismal outcome. In case of ineligibility for allogeneic stem cell transplantation (HSCT), the median survival of chemo-refractory AML is about 2 months and less than 5% of these pts are alive after 1-year (retrospective analysis from the AMLSG database). To date, there is no universally accepted standard approach for the treatment of chemo-refractory AML in older pts. Several retrospective studies have assessed the role of hypomethylating agents in this patient group, but complete remission (CR) rates were disappointingly low (≤10%) when compared to first line treatment. The presented study represents a novel approach focusing on hematopoietic tissue reprogramming (i.e. anakoinosis) (ClinicalTrials.gov Identifier: NCT02942758). Methods: The initial dose-finding phase I of the study evaluated the combination of azacitidine (AZA) 75 mg/d s.c. for 7 days, repeated every 28-days, pioglitazone 45 mg/d p.o. continuously from day 1 and all-trans retinoic acid (ATRA). A modified 3+3 design has been used to establish the maximum-tolerated dose of ATRA. Patients have been enrolled at an ATRA dose of 45 mg/m²/d from day 1 to day 28 and 15 mg/m²/d continuously thereafter if no dose limiting toxicity (DLT) occurred until start of next cycle on day 29. The safety DLTs were defined as toxicities attributable to ATRA, expected or unexpected, except if these are likely associated with another cause. Eligible patients had confirmed diagnosis of AML refractory to induction therapy and were not eligible for further intensive induction therapy or were not immediate candidates for allogeneic HSCT. The severity of adverse events was graded using the Common Terminology Criteria for Adverse Events (CTCAE) V. 4.03. The response to treatment was evaluated using standard criteria defined by the expert panel on behalf of the European LeukemiaNet and international working group (IWG) response. Results: Ten pts were enrolled in the safety-run-in phase I (one pt withdrew informed consent on day 9 of cycle 1). Among all treated pts, the median age was 67 years (range, 62-76 years), and the majority of pts (70%) had an ECOG PS of 1 (see table 1). Two pts had secondary AML; another two pts had therapy-related AML (t-AML). Eight pts had a complex karyotype. Concerning safety, hematological adverse events (AEs) were the most common toxicities observed. Because pts with baseline cytopenia were included (leukopenia n=8; 80%; thrombocytopenia n=9; 90%), occurrences of many hematological AEs began before study drug initiation and were attributed to underlying hematologic disease. Common 3°/4° AEs included neutropenia (50%), anemia (50%), thrombocytopenia (30%), and infections (40%). 50% of pts experienced a serious AE; one 5° AE (gastric hemorrhage) occurred. No DLTs were observed. Five pts discontinued the study, with progressive disease (PD) or relapse being the most common reason for discontinuation. Concerning efficacy, 3 pts (30%) achieved a CR and one pt a long-lasting stable disease (14 months). Morphologic review showed signs of differentiation of blasts in responding pts, which has already been shown in in-vitro analysis. In line with this observation, one pt demonstrated resolution of fungal pneumonia during the study. Conclusions: In summary, the low-intensity, biomodulatory regimen of low-dose AZA, pioglitazone, and ATRA demonstrated a tolerable safety profile and encouraging signals for efficacy in pts with AML refractory to standard induction chemotherapy warranting further investigation. S.T. and A.R. contributed equally to this abstract as senior co-authors. Disclosures Paschka: Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Speakers Bureau; Astellas: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Other: Travel expenses, Speakers Bureau; Abbvie: Other: Travel expenses; Amgen: Other: Travel expenses; Otsuka: Membership on an entity's Board of Directors or advisory committees; BMS: Other: Travel expenses, Speakers Bureau; Astex: Membership on an entity's Board of Directors or advisory committees, Travel expenses; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Jazz: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Janssen: Other: Travel expenses; Takeda: Other: Travel expenses; Sunesis: Membership on an entity's Board of Directors or advisory committees. Döhner:Celgene, Novartis, Sunesis: Honoraria, Research Funding; AROG, Bristol Myers Squibb, Pfizer: Research Funding; AbbVie, Agios, Amgen, Astellas, Astex, Celator, Janssen, Jazz, Seattle Genetics: Consultancy, Honoraria. Thomas:Celgene: Consultancy, Other: Travel support, Research Funding, Speakers Bureau; Gilead: Membership on an entity's Board of Directors or advisory committees, Other: Travel support; Medigene AG: Consultancy, Other: Travel support; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Travel support, Speakers Bureau; Pfizer: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Medac: Other: Travel support; Janssen: Other: Travel support.

In allogeneic stem cell transplantation (ASCT), systemic broad-spectrum antibiotics are frequently used for treatment of infectious complications, but their effect on microbiota composition is still poorly understood. This retrospective analysis of 621 patients who underwent ASCT at the University Medical Center of Regensburg and Memorial Sloan Kettering Cancer Center in New York assessed the impact of timing of peritransplant antibiotic treatment on intestinal microbiota composition as well as transplant-related mortality (TRM) and overall survival. Early exposure to antibiotics was associated with lower urinary 3-indoxyl sulfate levels (P .001) and a decrease in fecal abundance of commensal Clostridiales (P = .03) compared with late antibiotic treatment, which was particularly significant (P = .005) for Clostridium cluster XIVa in the Regensburg group. Earlier antibiotic treatment before ASCT was further associated with a higher TRM (34%, 79/236) compared with post-ASCT (21%, 62/297, P = .001) or no antibiotics (7%, 6/88, P .001). Timing of antibiotic treatment was the dominant independent risk factor for TRM (HR, 2.0; P ≤ .001) in multivariate analysis besides increase age (HR, 2.15; P = .004), reduced Karnofsky performance status (HR, 1.47; P = .03), and female donor-male recipient sex combination (HR, 1.56; P = .02) A competing risk analysis revealed the independent effect of early initiation of antibiotics on graft-versus-host disease-related TRM (P = .004) in contrast to infection-related TRM and relapse (not significant). The poor outcome associated with early administration of antibiotic therapy that is active against commensal organisms, and specifically the possibly protective Clostridiales, calls for the use of Clostridiales-sparing antibiotics and rapid restoration of microbiota diversity after cessation of antibiotic treatment.

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.

Bronchiolitis obliterans (BO) is a serious complication after allogeneic stem cell transplantation. We hypothesized that single nucleotide polymorphisms (SNPs) of the NOD2/CARD15 gene (= NOD2/CARD15 variants) contribute to changes in host defense and subsequent alloreaction, leading to BO. We analyzed 427 donor–recipient pairs for the association of NOD2/CARD15 variants (SNP8 [Arg702Trp], SNP12 [Gly908Arg], and SNP13 [Leu1007fsinsC]) with BO occurrence. Overall, 11 patients (2.6%) developed BO. The cumulative incidence of BO rose from 1.3% in donor–recipient pairs without mutation to 18.7% in pairs with donor or recipient NOD2/CARD15 variants (P < .001). Recipient NOD2/CARD15 variants alone led to BO in 22.3% (P < .001), whereas donor variants alone associated with BO in 13.2% (P = .04). Multivariate analysis proved recipient but not donor NOD2/CARD15 variants to be a novel independent risk factor for BO development, and NOD2/CARD15 typing may help identify patients at increased risk for BO.

Intestinal dysbiosis has been associated with acute gastrointestinal GvHD and poor outcome following allogeneic stem cell transplantation (ASCT). To assess the effect of a switch in 2012 from ciprofloxacin/metronidazole to rifaximin for gut decontamination on intestinal microbiota composition and ASCT outcome, we retrospectively analyzed 394 patients receiving ASCT from September 2008 through June 2015. In 131 and 90 patients, respectively, urinary 3-indoxyl sulfate levels and intestinal enterococcal load were measured before conditioning and weekly within the first 28 days after ASCT. The use of rifaximin correlated with lower enterococcal positivity (6.9 vs 21.9%, P=0.05) and higher urinary 3-indoxyl sulfate concentrations (10.5 vs 4.6 μmoL/mmoL crea, P

Urinary 3-IS levels predict outcome after ASCT and are associated with antibiotics and NOD2/CARD15 variants.Publisher’s Note: There is an Inside Blood Commentary on this article in this issue.Indole, which is produced from l-tryptophan by commensal bacteria expressing tryptophanase, not only is an important intercellular signal in microbial communities, but also modulates mucosal barrier function and expression of pro- and anti-inflammatory genes by intestinal epithelial cells. Here, we hypothesized that decreased urinary excretion of 3-indoxyl sulfate (3-IS), the major conjugate of indole found in humans, may be a marker of gut microbiota disruption and increased risk of developing gastrointestinal (GI) graft-versus-host-disease. Using liquid chromatography/tandem mass spectrometry, 3-IS was determined in urine specimens collected weekly within the first 28 days after allogeneic stem cell transplantation (ASCT) in 131 patients. Low 3-IS levels within the first 10 days after ASCT were associated with significantly higher transplant-related mortality (P = .017) and worse overall survival (P = .05) 1 year after ASCT. Least absolute shrinkage and selection operator regression models trained on log-normalized counts of 763 operational taxonomic units derived from next-generation sequencing of the hypervariable V3 region of the 16S ribosomal RNA gene showed members of the families of Lachnospiraceae and Ruminococcaceae of the class of Clostridia to be associated with high urinary 3-IS levels, whereas members of the class of Bacilli were associated with low 3-IS levels. Risk factors of early suppression of 3-IS levels were the type of GI decontamination (P = .01), early onset of antibiotic treatment (P = .001), and recipient NOD2/CARD15 genotype (P = .04). In conclusion, our findings underscore the relevance of microbiota-derived indole and metabolites thereof in mucosal integrity and protection from inflammation.

Treosulphan has recently demonstrated antileukaemic activity and potent haematopoietic stem cell toxicity. Dose-escalated treosulphan (3 x 12 or 3 x 14 g/m2) combined with cyclophosphamide (Cy) was chosen for a new preparative regimen before allogeneic haematopoietic stem cell transplantation in 18 patients (median age 44, range 19-64 years) with haematological malignancies, considered ineligible for other myeloablative preparative regimens. Pharmacokinetic studies demonstrated rapid treosulphan plasma clearance and a dose-dependent increase of its maximum plasma concentrations and area under the concentration-time curves. Rapid and sustained white blood cell and platelet recovery and full donor chimerism was attained in all evaluable patients. Nonhaematological regimen-related CTC grades 3-4 adverse events were transient and predominantly consisted of cardiac (28%), gastrointestinal (39%), and hepatic (39%) toxicities. The 1-year nonrelapse mortality was 22%. Principal causes of transplant-related lethal events were infections in three of four affected patients. Only one patient died from regimen-related cardiac toxicity. The 1-year relapse estimate is 22%, overall and progression-free survival estimates are 67 and 56%, respectively. In conclusion, this new treosulphan and Cy combination is an effective, comparatively well-tolerated myeloablative preparative regimen even in patients with an increased risk for regimen-related toxic complications.

Single nucleotide polymorphisms (SNPs) of the NOD2/CARD15 gene resulting in a diminished nuclear factor-κB (NF-κB) response to bacterial cell wall products have been associated with an increased incidence of Crohn disease. To assess a possible contribution of NOD2/CARD15 mutations to graft-versus-host disease (GvHD) and complications following allogeneic stem cell transplantation, we retrospectively typed DNA from donor/recipient pairs in 169 consecutive patients receiving transplants from related or unrelated donors. Mutated alleles were observed in 21% of patients and in 14% of donors. Cumulative incidence of 1-year, transplant-related mortality rose from 20% in donor/recipient pairs without mutated SNPs to 49% in pairs with recipient mutations (P = .03) and 59% in pairs with donor mutations (P < .005), and was highest in 12 pairs with mutated alleles in both donor and recipients (83%; P < .001). Similar associations were observed for severe overall and severe gastrointestinal GvHD. The impact of NOD2/CARD15 mutations was more prominent for HLA-identical sibling transplantations but was also observed in unrelated donor transplantation. Mutations proved to be independent risk factors for transplant-related mortality. Our findings indicate a major role of monocyte/macrophage dysfunction in the pathophysiology of GvHD and strongly suggest a future risk assessment or even donor selection through NOD2/CARD15 typing.

Background: Pulmonary invasive fungal infections (IFI) are well-recognized complications with high morbiditiy and mortality in patients with hematologic malignancies. Patients and Methods: Aerosolized liposomal amphotericin B (lipAmB) was evaluated as an antifungal prophylaxis in patients with an expected neutropenia of more than 10 days due to intensive chemotherapy or stem cell transplantation, in a prospective phase II trial. Results: 98 treatment episodes were included in the study and compared to 105 historical control patients. Inhalation was performed between 0 and 103 days. No severe side effects of therapy occurred. 40 patients considered inhalations as unpleasant, 2 as very unpleasant, mostly due to bad taste or cough. Few cases of definite or probable IFI were recorded, whereas a large number of patients were treated with systemic antifungal therapy for pneumonia or fever of unknown origin without a significant difference between study patients and controls. In a predefined subgroup analysis of 48 patients with newly diagnosed acute myeloid leukemia (AML), significantly more patients survived for 1 year in the AmB prophylaxis than in the control group (80% vs. 54%, p < 0.01). Conclusions: Inhalations of lipAmB are feasible and safe. Results in the subgroup of patients with AML together with data from other trials suggest further evaluation of effectiveness., OA-Komponente aus Allianzlizenz

In this retrospective analysis, 30 patients with acute GVHD (aGVHD) and 32 patients with chronic GVHD (cGVHD) treated with extracorporeal photopheresis (ECP) performed by the COBE Spectra System were evaluated. After 3 months of ECP treatment, a CR and PR were observed in 9 (30%) and 6 (20%) patients with aGVHD and in 2 (6%) and 12 (38%) patients with cGVHD. In 16 (53%) patients with aGVHD and 9 (28%) with cGVHD ECP treatment was already stopped after 3 months. One (3%) patient with aGVHD and 7 (22%) patients with cGVHD received new additional immunosuppressive therapy started during the first 3 months of ECP treatment and were classified as 'nonresponder' with regard to ECP. Of these patients a PR was achieved in one patient with aGVHD and in three patients with cGVHD. Steroids could be tapered by 50 in 83% of patients with aGVHD and in 29% of patients with cGVHD after 3 months of ECP treatment. Patients with aGVHD achieving a CR or PR showed a significant improved OS after allo-SCT (P=0.019). ECP is associated with significant response rates and successful reduction of steroids in patients with GVHD.

Depletion of host Langerhans cells (LCs) prevents cutaneous graft-versus-host disease (GvHD) in mice. We analyzed whether UVB irradiation is tolerated during the course of human allogeneic hematopoietic cell transplantation and whether depletion of LCs by broadband UVB could improve GvHD outcome. A total of 17 patients received six whole-body UVB irradiations with 75% of the individually determined minimal erythemal dose after conditioning with a reduced intensity protocol. LCs, dermal dendritic cells (DCs), and macrophages were analyzed before and after UVB irradiation by immunohistochemical analysis. Circulating blood cells and serum factors were analyzed in parallel. In striking contrast to previous data, our irradiation protocol was well tolerated in all patients. UVB treatment decreased the number of LCs and also affected dermal DCs. UVB-treated patients also had significantly higher 25-hydroxyvitamin D3 serum levels and higher numbers of circulating CD4+ FoxP3+ regulatory T cells. Strikingly, nine out of nine patients with complete LC depletion (

In AML, a complex aberrant karyotype is associated with poor response to chemotherapy and dismal prognosis. We prospectively studied the concept of allogeneic haematopoietic SCT (HSCT), performed early and regardless of response to induction treatment in patients with complex karyotype AML (CK-AML). The preparative regimen consisted of fludarabine, Ara-C and amsacrine (FLAMSA) chemotherapy, followed by reduced intensity conditioning (RIC) 3 days later. In vivo T-cell depletion by anti-thymocyte globulin was used to protect from early GvHD, and prophylactic donor lymphocyte transfusion was given from day+120 to augment the GvL effect, once tolerance was established. Eighteen consecutive patients with CK-AML (median age: 53 years) received HSCT from related (n=7) or unrelated (n=11) donors. Before FLAMSA–RIC, nine patients each had received one and two induction courses. Stage at start of FLAMSA–RIC was CR/CRi (n=8) or persistent disease (n=10). Following HSCT, 16 patients achieved CR. After a follow-up of 51 months, 11 patients are alive in CR, whereas seven have died in remission (n=3), or from leukaemia (n=4). Cumulative incidence of relapse, non-relapse mortality, acute GvHD⩾II and chronic GvHD were 0.222±0.098, 0.235±0.104, 0.367±0.120 and 0.481±0.123, respectively. Four-year survival from HSCT is 61%. Early HSCT following FLAMSA–RIC may improve the outcome of this unfavourable AML subgroup.

Immunomodulation by IFN-γ in patients with resistant infections and accompanying bronchiolitis obliterans following allo-SCT

Allogeneic stem cell transplantation (ASCT) after reduced-intensity conditioning has become a reasonable treatment option for patients with advanced myelofibrosis. The role of characteristic molecular genetic abnormalities, such as JAK2V617F on outcome of ASCT, is not yet elucidated. In 139 of 162 myelofibrosis patients with known JAK2V617F mutation status who received ASCT after reduced-intensity conditioning, the impact of JAK2 genotype, JAK2V617F allele burden, and clearance of mutation after ASCT was evaluated. Overall survival was significantly reduced in multivariate analysis in patients harboring JAK2 wild-type (hazard ratio = 2.14, P = .01) compared with JAK2 mutated patients. No significant influence on outcome was noted for the mutated allele burden analyzed either as continuous variable or after dividing into quartiles. Achievement of JAK2V617F negativity after ASCT was significantly associated with a decreased incidence of relapse (hazard ratio = 0.22, P = .04). In a landmark analysis, patients who cleared JAK2 mutation level in peripheral blood 6 months after ASCT had a significant lower risk of relapse (5% vs 35%, P = .03). We conclude that JAK2V617F-mutated status, but not allele frequency, resulted in an improved survival and rapid clearance after allografting reduces the risk of relapse.

Summary 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.

Mesenchymal stem cells (MSCs) represent an attractive cell population for the regeneration of mesenchymal tissues. Their special immunological characteristics suggest that MSCs could be used in nonautologous applications. In this study, the regenerative capacity of human and ovine MSCs was assessed in an ovine critical size defect model. Human and ovine MSCs from bone marrow were cultured on mineralized collagen and implanted into a 3.0-cm-long sheep tibia bone defect (n = 7). Unloaded mineralized collagen served as control. Bone healing was assessed until euthanasia 26 weeks after surgery by radiology and histologically after euthanasia. The presence of human cells after xenogenic transplantation was analyzed using human-specific in situ hybridization. Both radiology and histology demonstrated significantly better bone formation after transplantation of autologous ovine MSCs on mineralized collagen compared with unloaded matrices and with the xenogenic treatment group. Nevertheless, no local or systemic rejection reactions could be observed after transplantation of human MSCs, although the presence of human MSCs could be demonstrated. It can be concluded that despite successful demonstration of the presence of human MSCs after xenogenic transplantation, the xenogenic transplantation of human MSCs leads to poorer bone regeneration than autologous transplantation of ovine MSCs.

Summary Previous studies from our group indicated a role of SNPs within the innate immunity receptor NOD2/CARD15 as a risk factor for GvHD and treatment-related mortality allogeneic stem cell transplantation from HLA-identical siblings. We now extended these studies to assess the role of NOD2/CARD15 SNPs in 342 unrelated donor transplants. Overall, presence of any SNPs in patients or donor resulted in an increased risk of severe GvHD (25% in wildtype versus 38% in recipients and donors with variants, P= 0.01), which did not translate in increased mortality. When the analysis was broken down to individual SNPs, the presence of a SNP13 in the donor turned out to be the only highly significant risk factor (GvHD III/IV 22% wt, 42% SNP13 donor, P < 0.004; TRM 33% wt versus 59% SNP13 donor, P= 0.01; overall survival 49% wt versus 26% SNP13 donor, P= 0.007). This association was confirmed in multivariate analysis. Analysis of clinical risk factors suggested that this effect was most prominent in patients receiving any form of T cell depletion. Thus our observation indicates that the presence of a defect in innate immunity signalling in donor monocytes and possibly antigen presenting cells is most prominent in patients having additional T cell deficiency.

Toxicity-reduced conditioning is being used for allogeneic stem cell transplantation in older and/or comorbid patients. We report on the treatment of 133 patients (median age: 55.6 years [23-73 years]) with acute myeloid leukemia (AML)/myelodysplastic syndrome (MDS; n = 81), myeloproliferative syndromes (MPS; n = 20), and lymphoid malignancies (n = 32) using conditioning with FBM: fludarabine (5 × 30 mg/m2), 1,3-bis(2-chloroethyl)-1-nitrosourea (or carmustine, BCNU; 2 × 200 mg/m2), and melphalan (140 mg/m2). Patients 55 years or older received fludarabine with reduced BCNU (2 ×150 mg/m2) and melphalan (110 mg/m2). After engraftment, chimerism analyses revealed complete donor hematopoiesis in 95.7% of patients. With a median follow-up of 58.5 months, 3- and 5-year overall survival (OS) was 53.0% and 46.1%, event-free survival (EFS) was 46.4% and 41.9%. No significant differences in OS and EFS were evident considering disease status (early vs advanced), patient age (

The JAK2-V617F mutation occurs in about 50% of patients with myelofibrosis and might be a reliable marker to monitor residual disease after allogeneic stem cell transplantation. We describe a new, highly sensitive (≥ 0.01%) real-time polymerase chain reaction (PCR) to monitor and quantify V617F-JAK2–positive cells after dose-reduced allogeneic stem cell transplantation. After 22 allogeneic stem cell transplantation procedures in 21 JAK2-positive patients with myelofibrosis, 78% became PCR negative. In 15 of 17 patients (88%), JAK2 remained negative after a median follow-up of 20 months. JAK2 negativity was achieved after a median of 89 days after allograft (range, 19-750 days). A significant inverse correlation was seen for JAK2 positivity and donor-cell chimerism (r: −0.91, P < .001). Four of 5 patients who never achieved JAK2 negativity fulfilled during the entire follow-up all criteria for complete remission recently proposed by the International Working Group, suggesting a major role for JAK2 measurement to determine depths of remission. In one case, residual JAK2-positive cells were successfully eliminated by donor lymphocyte infusion. In conclusion, allogeneic stem cell transplantation after dose-reduced conditioning induces high rates of molecular remission in JAK2-positive patients with myelofibrosis, and quantification of V617F-JAK2 mutation by real-time PCR allows the detection of minimal residual disease to guide adoptive immunotherapy.

Transplantation-associated microangiopathy (TAM) or renal insufficiency (RI) after allogeneic hematopoietic stem cell transplantation is associated with a high mortality. As calcineurin inhibitors (CI) may contribute to TAM or RI, we evaluated the efficacy of replacing CI by daclizumab in patients with graft-versus-host disease (GVHD). Thirteen patients with GVHD-associated TAM and five patients with RI were treated with daclizumab 1 mg/kg intravenous (i.v.)/week, discontinuation of the CI and continuation of the remaining GVHD treatment. All patients had acute GVHD (steroid-sensitive (n=4), steroid-refractory (n=10)) or chronic GVHD (n=4) and were treated with CI before the start of daclizumab. Nine of 13 patients with TAM treated with daclizumab and discontinuation of CI achieved complete remission of TAM, two had stable disease, and one patient did not respond. Patients receiving daclizumab for RI without TAM showed stabilization (2/5) or improvement (3/5) of renal function. Four of 14 patients with acute GVHD achieved CR, two partial remission, eight patients did not respond and 11/14 died at a median of 39 days after start of the daclizumab. Our data demonstrate that replacement of CI by daclizumab can improve TAM and RI. However, mortality remains high in patients with acute GVHD.

To assess the role of NOD2/CARD15 variants on the long-term outcome of allogeneic stem cell transplantation in a genetically homogeneous group, we extended our previous study (cohort I, n = 78) and typed DNA for NOD2/CARD15 single nucleotide polymorphisms (SNPs) from an additional 225 recipients and their HLA-identical sibling donors (cohort II) treated at four other European centers. Results of genotyping were compared with clinical outcome. The strong association of NOD2/CARD15 variants with transplantation-related mortality (TRM) was confirmed in univariate and multivariate analysis; TRM increased from 20% in cohort I/22% in cohort II in recipient/donor pairs without any NOD2/CARD15 variants to 47% in cohort I/32% in cohort II in the presence of one variant in either donor or recipient and further to 57% in cohort I/74% in cohort II in the presence of 2 or more variants (P < .002 in both cohorts). NOD2/CARD15 SNPs were not associated with relapse rate but had a strong impact on overall survival. In an analysis of center effects, the type of gastrointestinal decontamination was the only factor interfering with the prognostic significance of NOD2/CARD15 SNPs. Our data further support an interaction between gastrointestinal defense mechanisms, activation of the innate immune system, and specific transplant-related complications.

Monitoring of Epstein-Barr virus (EBV) infection and reactivation in immunocompromized patients (e.g., after organ or bone-marrow transplantation) is based mainly on serological assays and detection of viral DNA. For further characterization of virus reactivation and monitoring of viral transcription we established real-time RT-PCR assays using TaqMan technology to sensitively quantify viral transcripts expressed at different times of the lytic cycle: for BZLF1, an immediate early transactivator initiating the transition from latency to lytic replication, for the DNA-polymerase BALF5 and for the major viral glycoprotein gp350/220 (BLLF1). RNA-isolation was optimized to eliminate contaminating DNA. Preparations were shown to be virtually DNA-free for up to 10(6) copies of RNA. With our PCR systems, it is possible to detect 10 copies of DNA or 100 copies of RNA per reaction as shown with serial dilutions of DNA-plasmids or in vitro transcribed RNA, respectively. This corresponds to a detection limit of 8 x 10(2) copies/10(6) peripheral blood mononuclear cells (PBMCs). Evaluation of this system showed that even in healthy carriers borderline levels of BLLF1 mRNA were sometimes detectable. In patients with acute infectious mononucleosis (IM) viral transcripts were regularly found in varying concentrations. Extremely high levels of all three mRNA species could be seen in a patient after bone-marrow transplantation monitored during an episode of lymphoproliferation which regressed during treatment with acyclovir and transfusion of donor T-cells. This sensitive and reproducible method to detect and quantify different transcripts of EBV can be used to closely monitor reactivation of EBV, e.g., in immunocompromized patients.

Background: Parvovirus B19 infection is associated with a variety of symptoms like erythema infectiosum, anaemia and arthritis. In immunocompetent persons, viraemia is usually cleared a few weeks after infection. Objective: An immunocompromised adult female patient was persistently infected with B19 after allogenic bone marrow transplantation (BMT) and developed chronic anaemia. Study design: B19-specific antibodies were determined by ELISA and viral load was assessed using a quantitative real time B19 PCR. The patient was evaluated clinically. Results: Two years after successful BMT, the patient received intensified immunosuppressive treatment, erythropoetin and erythrocyte concentrates due to chronic graft-versus-host disease with renal failure. Despite of this treatment, the aplastic anaemia worsened. PCR revealed B19 viraemia with 1012 geq/ml serum. After 7 months of repeated applications of immunoglobulins and reduction of immunosuppressive treatment, reticulocyte counts and haemoglobin levels normalized and the viral load finally dropped to 103 geq/ml serum. One of the back-up samples of the erythrocyte concentrates tested positive, the respective transfusion had been applied 2 months after the beginning of viraemia. Conclusions: The source of the primary infection remained unclear, but at least re-infection by blood transfusion is likely. Treatment did not result in virus elimination from peripheral blood but in resolvement of symptoms.

Hepatitis B virus (HBV) reactivation after allogeneic haematopoietic stem cell transplantation (allo-HSCT) is well known in HBsAg-positive carriers but has only occasionally been reported in patients with resolved HBV infection. We investigated six allo-HSCT recipients with pretransplant anti-HBs and anti-HBc antibodies for serologic markers of HBV infection and for the presence of HBV-DNA in serum. Reverse seroconversion, that is, reappearance of HBsAg after a gradual loss of anti-HBs, but no severe liver damage was observed in three patients at 14, 22 and 12 months after HSCT, respectively. There was an increase in HBV-DNA concentration prior to reverse seroconversion. One patient was repeatedly HBV-DNA positive (10(2)-10(3) copies/ml) without reverse seroconversion. Sequencing of the HBsAg and precore region derived from the four HBV-DNA-positive patients showed no relevant mutations. In conclusion, this study demonstrated a high risk (50%) of reverse seroconversion in allo-HSCT recipients with resolved HBV infection. A highly sensitive HBV-DNA assay (TaqMan-PCR) allowed early identification of the individual patients at risk.

Outcome of high risk leukemias as defined by unfavorable cytogenetics at the time of diagnosis is poor in almost all large trials on induction therapy of AML. Complete remission rates are in the range of 50–60%, and longterm survival after chemotherapy alone is reported to be lower than 10–15%. These data strongly suggest that transplantation strategies in 1st CR or PR are needed in this particular subgroup of patients. As recent studies adressed longterm outcome following autologous and allogeneic stem cell transplantation in pts with unfavorable cytogenetics, we will summarize these conflicting and still disappointing results and discuss potential problems as well as actual approaches to overcome major obstacles.

Pneumatosis cystoides intestinalis (PCI) is still a poorly understood phenomenon, currently considered to result from primary mucosal insult from varying causes. We report a case of severe PCI in a patient with chronic GVHD after bone marrow transplantation (BMT) performed to treat secondary AML. Post BMT, the patient suffered acute intestinal and cutaneous GVHD, eventually developing intestinal and biopsy-proven cutaneous chronic GVHD, which necessitated continuous steroid therapy. Chronic pancreatitis associated with GVHD was diagnosed by explorative surgery in February 2000 on the basis of increasing epigastric discomfort, tumour marker (CA 125) increase and the CT finding of a suspicious mass in the pancreas. Readmission occurred in April 2000 for rapid onset of inferior abdominal pain with distinct peritoneal signs. Relaparotomy, deemed necessary on the grounds of both clinical and radiological findings, revealed marked PCI of the ascending and transverse colon and attached mesentery in an otherwise intact gastrointestinal tract. Post-operative reconvalescence was uneventful, with no clinical or radiological recurrence of PCI in the following 10 months. In the context of a review of the relevant literature, this case report illustrates the complex underlying pathophysiology, and difficulty in making a differential diagnosis and treating PCI.

between august 1998 and july 1999, 21 patients received a novel protocol of reduced conditioning with fludarabine, carmustine and melphalan (fbm) followed by matched-related allogeneic peripheral blood stem cell transplantation (pbsct) in a prospective multicenter phase i/ii study. cyclosporin a and ‘mini-methotrexate’ were used for gvhd prophylaxis. patients were included because of age, advanced disease, previous transplantation or co-morbidity. hematopoietic engraftment after allogeneic transplantation was rapid with a median white blood count (wbc) >1 × 109/l on day +11 (range 10–17) and a median platelet count >20 × 109/l on day +13 (range 9–36). Donor chimerism was complete in 16/21 (76%) patients at all time points during follow-up and mixed at least on one occasion in 5/21 (24%) patients. The conditioning regimen was well tolerated with low toxicity even in previously transplanted patients. Thirteen patients (62%) developed acute GVHD grades II–IV. Nineteen out of 21 patients achieved complete (CR, n = 15) or partial remission (PR, n = 4) with a median patient follow-up of 354+ days (range 258–577) for patients alive. The reduced intensity protocol FBM is feasible with rapid engraftment, early achievement of complete donor chimerism, low toxicity, especially in heavily pretreated patients, and good response rates in advanced disease patients. Bone Marrow Transplantation (2000) 26, 243–250.

Abstract 4958 Introduction Therapeutic options for patients with refractory and multifold pretreated multiple myeloma (MM) are limited, as patients have already received the novel targeted therapy approaches at this stage. Continuous production and release of pro-inflammatory cytokines may account for its resistance towards cytotoxic agents. Therefore, a multi-targeted approach consisting of anti-angiogenic, anti-inflammatory and anti-tumor components was implemented for response induction prior to and after allogeneic transplantation. Methods Within a compassionate-use program eight patients suffering from refractory or relapsed osteolytic multiple myeloma (MM) or plasma cell leukemia (PCL) and proven progression of serum paraprotein levels were treated in third-line continuously with daily lenalidomide 10 mg, pioglitazone 60 mg, treosulfan 250 mg once daily, and dexamethasone 1 mg. Results Here we report results of eight patients (48 to 63 years old) treated for refractory (n= 7) or relapsed (n= 1) multiple myeloma (n= 7) or PCL (n= 1). Prior therapy consisted of double autologous transplantation with high-dose treosulfan/melphalan conditioning, lenalidomide and/or bortezomib. One patient suffered from progressive disease following allogeneic stem cell transplantation (allo-SCT). No side effects > WHO 2 occurred on treatment. In one patient, bortezomib-induced motoric polyneuropathia partially resolved on study medication. Biomodulatory therapy induced clinically meaningful and very rapid responses, stable disease, n= 2, partial remission (PR), n= 3, and very good PR (VPR, n= 3). Therapy-induced PR and VPR facilitated allo-SCT in 2 refractory patients. A third patient with refractory disease after allo-SCT received donor lymphocytes. Two patients with allo-SCT survived in VPR for 10+ and 3+ months, respectively. One patient remained in ongoing VPR since 9 months after donor lymphocyte infusion. Patients not proceeding to allo-SCT had SD for 3 (PLC) and 4 months, VPR and PR for 3+, 4+ and 5+ months. Conclusions Together, biomodulatory therapy has remarkable clinical activity in pretreated and refractory patients with MM. The eight cases show comparatively high efficacy at low toxicity rates of a biomodulatory acting therapy approach: Although the substances have limited or no efficacy at the respective dose levels, and were already administered previously at higher dose-levels (i.e. treosulfan and/or lenalidomide), the combined treatment setting is promising since it targets the myeloma cells itself as well as the surrounding stroma. Therefore, this treatment schedule deserves further investigation and discharges now in a novel multi-center phase II trial for third-line therapy in multiple myeloma. Disclosures No relevant conflicts of interest to declare.

Conditioning with reduced intensity regimens have been proven problematic for the control of advanced hematologic diseases. Therefore we applied a new protocol (FBM) in a prospective, two-center, phase II trial in 133 patients (median age: 55.6 years, 23–73) undergoing allogeneic cell transplantation (HCT). FBM contains fludarabine (5×30mg/m2), BCNU (2×200mg/m2) and melphalan (140mg/m2). Patients >=55 years received dose reduction in BCNU (2×150mg/m2) and melphalan (110mg/m2). Diagnoses and patients included AML (58), MDS (23), CML (11), MPS (9), ALL (3), myeloma (9), lymphoma (13) and CLL (7). Most patients (n=106) had advanced disease (AD) defined as ≥ CR2/CP2, refractory, relapsed or untreated. Only 27 patients presented with early disease (ED): CR1, CP1 or MDS RA/RARS. The stem cell graft was BM in 15 and PBSCT in 116 patients. Related (SIB) donors were used in 68, unrelated (MUD) donors in 65 cases. GvHD prophylaxis was CsA+MTX (23pts) and CsA+MMF (110pts) with additional ATG in MUD HCT. Median time to leukocyte engraftment (WBC >1×10e9/L) was 12.7 (1–41) days. One primary graft failure occurred. Platelet count >= 20×10e9/L was reached median day 17.4 (5–113). Complete donor chimerism at day 30 was reported in 95.7% of patients. Grade 3 organ toxicity according to Bearman et al. was observed in 21 cases, three patients died due to toxic complications. After a median follow up of 58.5 months, non-relapse mortality (NRM) was 15.8% (95%CI 10.7–23.4) and 27.8% (95%CI 21.2–36.6) at day 100 and 2 years. The relapse rate was 14.3% (95%CI 9.4–21.7) at 2 years. Acute GvHD III-IV developed in 23.3%, extensive chronic GvHD in 32.3% of all evaluable patients. Overall survival (OS) after 3 years was 53.0% (95%CI 44.5–61.6) and 46.1% (95%CI 36.9–55.2) after 5 years. Cases with ED had an OS of 63.0% (95%CI 44.7–81.2) and patients with AD experienced a 50.4% (95%CI 40.8–60.1) OS after 3 years. Event free survival (EFS) after 3 years was 46.4% (95%CI 37.9–54.9) and 41.9% (95%CI 33.1–50.7) after 5 years. EFS for ED patients was 55.6% (95%CI 36.8–74.3), for patients with AD 44.0% (CI 34.5–53.5) after 3 years. Interestingly, patients allografted from female donors showed a significant reduction in EFS with increased incidence of chronic GvHD in uni- and multivariate analyses. No significant differences were observed between patients >= 55 years and < 55 years or MUD/SIB donors. The subgroup of AML/MDS patients (n=81) showed a 5-year OS/EFS of 52.9% (95%CI 29.2–76.7)/47.1% (95%CI 23.3–70.8) for ED and 42.4% (95%CI 29.9–54.9)/38.6% (95%CI 26.5–50.7) for AD patients. There were no relapses in ED patients after HCT. NRM after 100 days was 17.3% (95%CI 10.7–27.8). Patients age and donor choice did not show statistically significance for OS and EFS in AML/MDS cases. Among cases with advanced disease, patients (n=33) with circulating blasts (median 21,1%) at the time of HCT, showed an OS of 44.4% after 5 years. We conclude that FBM conditioning prior to allogeneic HCT is especially effective in cases of advanced myeloid disease and can be safely administered to older or comorbid patients.

The NIH staging and response criteria offer for the first time the chance for uniform documentation and evaluation of physical functioning and quality of life aspects of chronic graft-versus-host disease (cGVHD) as well as its response to immunosuppressive treatment. Here we present the interim analysis of a prospective Germany multicenter study on the NIH staging criteria in cGVHD. Methods: Seventy-six patients (median age 46 years, range 19–64) after allogeneic hematopoetic stem cell transplantation (HSCT) for hematologic malignancies were evaluated according to the NIH criteria based cGVHD activity assessment, the Lee Chronic GVHD Symptom-Scale, FACT-BMT, human activity profile (HAP), SF 36, Berliner Social Support Scale (BSSS), 24 item Adjective Measure (24 - AM), Hospital Anxiety and Depression Scale (HADS) and the NCCN-Distress-Thermometer. Enrolment occurred between day 100 and 1 year after HSCT or in the presence of active cGVHD also at later time points. Follow-up surveys were conducted at 1, 2, 3, 5, 8, 12 and 18 months after baseline survey. At all time points disease status, comorbidities and medication were documented. Additionally the NIH-Symptom-Scale was applied for clinician rating of cGVHD symptoms. Results: Fifty-one patients had cGVHD (mild n=15, moderate n=32, severe n=4) while 25 patients did not have cGVHD. The cGVHD NIH consensus grading as well as the 10 point scale correlated with impairment of physical functioning (p

The V617F-JAK2-mutation occurs in about 50 % of patients with myelofibrosis and is a reliable marker to monitor residual disease after allogeneic stem cell transplantation. The establishment of valid complete remission criteria for myelofibrosis especially after allogeneic stem cell transplantation remains a major issue. We developed a new, highly sensitive real-time PCR to monitor and quantify V617F-JAK2-positive cells after dose-reduced allogeneic stem cell transplantation. The mutated differs from the wild-type JAK2 allele by just one nucleotide exchange (G à T) leading to the valine to phenylalanine (V à F) transition. Using PrimerExpress® we designed a TaqMan® PCR where the reverse primer (RP) terminates at the (3′) nucleotide corresponding to this point mutation. Thus, this reverse primer should bind with higher affinity to the mutated than to the wild-type allele. To increase the specificity while conserving optimal sensitivity of the MRD-specific PCR we generated a set of primers shortened each time by one nucleotide at their 5’ end. In parallel, all those shortened primers were designed to contain an additional mutation at the third to last 3’ position. This allowed us to identify the reverse primer combining high specificity with so far not reported sensitivity(0.01 %). After 22 allogeneic stem cell transplantation procedures in 21 JAK2-positive patients with myelofibrosis, 78 % became PCR-negative. In 15 out of 17 patients (88 %), JAK2 remained negative after a median follow-up of 20 months. JAK2-negativity was achieved after a median of 89 days post allograft (range, 19 – 750 days). A significant inverse correlation was seen for JAK2 positivity and donor cell chimerism (r: −0.91, p

Long-term engraftment after stem cell transplantation is dependent on pluripotent hematopoietic stem cells capable to multi-lineage reconstitution. The engraftment and prolonged repopulation of B lymphoid progenitor cells is dependent on pluripotent hematopoietic stem cells. We have recently shown that a high number of B-cell progenitors is detectable in the bone marrow from patients both after allogeneic PBSCT and after allogeneic BMT. The percentage of CD19/CD10+ pro-B/pre-B cells showed a high variability and ranged from 0 to 98% of all B-lymphocytes. Interestingly, no difference in numbers of precursor B-lymphocytes between BM recipients and PBSC recipients was found. In micro-satellite analysis, both in PBSC and in BM recipients the B cell precursors were derived exclusively from the donor. To identify predictors of B lymphopoiesis in the bone marrow after stem cells transplantation, a stepwise, multiple regression analysis was performed. The stem cell source, BM or PBSC, the occurrence of GVHD, the conditioning with or without TBI and whether ATG was given, were entered as categorical variables. Time point of BM sampling after transplantation, age of the donor and the recipient, the quantity of stem cell transplanted and the T cell content of the BM sample served as continuous variables. Time elapsed after transplantation (p=0.002) and severe GVHD (aGVHD grade III/IV or extensive cGVHD) (p=0.036) could be identified as parameters with an independent influence on the percentage of B cell precursors. The highest percentage of precursor B cells was found during the first year after transplantation, unless severe GvHD was present, leading to neglible precursor B-cells. This hyperactive B lymphopoiesis in the first year after transplantation contrasts to low circulating B cell counts. Finally, it could be formally demonstrated, that G-CSF mobilized PBSC contain hematopoietic stem cells capable of long-term reconstitution of the B cell compartment.

Recently, our group reported a strong association of the most frequent single nucleotide polymorphisms (SNPs) in the antibacterial defense gene NOD2/CARD15 with GvHD and outcome following allogeneic stem cell transplantation (SCT). We now extended our analysis in HLA-identical sibling transplants by adding a second cohort of 133 donor /recipient pairs collected in 3 centers to our previously analyzed group of 78 consecutive transplants. PCR analysis for major SNPs 8,12, and 13 of the NOD2/CARD15 gene was performed in DNA samples from recipients and their donors after receiving informed consent, and occurrence or absence of mutations was correlated with major outcome variables. Heterozygous NOD2/CARD15 mutations were observed in 54/211 (25,6%), whereas only 1 patient and 2 donors revealed homozygous mutations. Analysis of the second cohort confirmed the significant association of occurrence of any NOD2/CARD15 mutation with treatment related mortality (TRM) and graft-versus-host disease (GvHD): Incidence of severe GvHD rose from 13% (cohort1 + 2) to 48% (cohort1, p The strong association of recipient mutations points to a major role of NOD2/CARD15 mutations in intestinal inflammation, and otherwise asymptomatic heterozygous mutations might become symptomatic in the context of additional epithelial damage induced in the course of SCT.