There are no plasma biomarkers specific for GVHD of the gastrointestinal (GI) tract, the GVHD target organ most associated with nonrelapse mortality (NRM) following hematopoietic cell transplantation ...(HCT). Using an unbiased, large-scale, quantitative proteomic discovery approach to identify candidate biomarkers that were increased in plasma from HCT patients with GI GVHD, 74 proteins were increased at least 2-fold; 5 were of GI origin. We validated the lead candidate, REG3α, by ELISA in samples from 1014 HCT patients from 3 transplantation centers. Plasma REG3α concentrations were 3-fold higher in patients at GI GVHD onset than in all other patients and correlated most closely with lower GI GVHD. REG3α concentrations at GVHD onset predicted response to therapy at 4 weeks, 1-year NRM, and 1-year survival (P ≤ .001). In a multivariate analysis, advanced clinical stage, severe histologic damage, and high REG3α concentrations at GVHD diagnosis independently predicted 1-year NRM, which progressively increased with higher numbers of onset risk factors present: 25% for patients with 0 risk factors to 86% with 3 risk factors present (P < .001). REG3α is a plasma biomarker of GI GVHD that can be combined with clinical stage and histologic grade to improve risk stratification of patients.
The lower gastrointestinal tract (LGI) and liver are the GVHD target organs most associated with treatment failure and nonrelapse mortality. We recently identified regenerating islet-derived 3-α ...(REG3α) as a plasma biomarker of LGI GVHD. We compared REG3α with 2 previously reported GI and liver GVHD diagnostic biomarkers, hepatocyte growth factor (HGF) and cytokeratin fragment 18, in 954 hematopoietic cell transplantation patients. All 3 biomarkers were significantly elevated in LGI GVHD compared with non-GVHD diarrhea; REG3α discerned LGI GVHD from non-GVHD diarrhea better than HGF and cytokeratin fragment 18. Although all 3 biomarkers predicted nonresponse to therapy at day 28 in LGI GVHD patients, only REG3α and HGF concentrations predicted 1-year nonrelapse mortality (P = .01 and P = .02, respectively). Liver GVHD without GI involvement at GVHD onset and non-GVHD liver complications were uncommon; all 3 biomarkers were elevated in liver GVHD, but did not distinguish GVHD from other causes of hyperbilirubinemia.
Peripancreatic necrosis determines clinical severity in acute pancreatitis. Early markers predicting peripancreatic necrosis and clinical severity are lacking. Because adipocytes of peripancreatic ...adipose tissue secret highly active adipocytokines, the aim of the study was to investigate whether adipocytokines are able to serve as early markers predicting peripancreatic necrosis and clinical severity.
A total of 50 patients (20 women, 30 men) with acute pancreatitis were included in this noninterventional, prospective, and monocentric cohort study on diagnostic accuracy. Clinical severity was classified by the Ranson score and the APACHE (Acute Physiology And Chronic Health Evaluation) II score. Pancreatic and peripancreatic necrosis were quantified by using the computed tomography-based Balthazar score, the Schroeder score, and the pancreatic necrosis score. Adiponectin, leptin, and resistin were measured at admission and daily for at least 10 days by enzyme-linked immunosorbent assay.
In contrast to admission C-reactive protein values, admission resistin values were significantly correlated with clinical severity and even with clinical end points such as death and need for interventions. Admission resistin levels were significantly elevated in patients with higher pancreatic and extrapancreatic necrosis scores. It was shown by receiver-operator characteristics that admission resistin concentration provides a positive predictive value of 89% in predicting the extent of peripancreatic necrosis (area under the curve, 0.8; P=0.002; sensitivity, 80%; specificity, 70%) by using a cutoff value of 11.9 ng/ml.
Admission resistin concentration serves as an early predictive marker of peripancreatic necrosis and clinical severity in acute pancreatitis. Resistin may have potential for clinical use as a new and diagnostic serum marker.
Induction of indoleamine 2,3-dioxygenase (IDO), the rate-limiting enzyme in tryptophan degradation along the kynurenine pathway, acts as a potent immunoregulatory loop. To address its role in human ...allogeneic stem cell transplantation, we measured major tryptophan metabolites, such as quinolinic acid and kynurenine, in serial urine specimens from 51 patients by liquid chromatography-tandem mass spectrometry. Samples were collected between admission and day 90 after transplantation, and metabolite levels were correlated with early clinical events and outcome. In selected patients, IDO gene expression was assessed by quantitative RT-PCR in intestinal biopsies. Surviving patients had significantly lower metabolite levels on days 28, 42, and 90, respectively, compared with patients dying of GVHD and associated complications (n = 10). Kynurenine levels were directly correlated with severity and clinical course of GVHD: Mean urinary quinolinic acid levels were 4.5 ± 0.3 μmol/mmol creatinine in the absence of acute GVHD, 8.0 ± 1.1 μmol/mmol creatinine for GVHD grade 1 or 2, and 13.5 ± 2.7 μmol/mmol creatinine for GVHD grade 3 or 4 (P < .001), respectively. GVHD-dependent induction of IDO was further suggested by increased expression of IDO mRNA in intestinal biopsies from patients with severe GVHD. Our data indicate reactive release of kynurenines in GVHD-associated inflammation.
Adipocytes of peripancreatic and intrapancreatic adipose tissue secret adipocytokines such as leptin, adiponectin, and resistin. For resistin, a role as an early predictor of peripancreatic necrosis ...and clinical severity in acute pancreatitis has been reported. It was the aim of this study to investigate whether the adipocytokine visfatin is able to serve as an early marker predicting peripancreatic necrosis and clinical severity.
A total of 50 patients (20 females and 30 males) with acute pancreatitis were included in this noninterventional, prospective, and monocentric cohort study on diagnostic accuracy. Clinical severity was classified by the Ranson score and APACHE-II (Acute Physiology and Chronic Health Evaluation II) score. Pancreatic and peripancreatic necrosis were quantified by the computed tomography-based Balthazar score, the Schroeder score, and the pancreatic necrosis score. Visfatin was measured at admission and daily for 10 days by enzyme-linked immunosorbent assay (ELISA).
Visfatin values were significantly and positively correlated with clinical severity (APACHE-II score and Ranson score) and with clinical end points such as death and need for interventions. Admission visfatin levels were significantly elevated in patients with higher pancreatic and extrapancreatic necrosis scores. It was shown by receiver operator characteristics that admission visfatin concentration provides a positive predictive value of 93.3% in predicting the extent of peripancreatic necrosis (area under the curve (AUC): 0.89, P<0.001, sensitivity: 93.3%, specificity: 81.8%, likelihood ratio: 5.1, post-test probability: 93%) by using a cutoff value of 1.8 ng/ml.
Admission visfatin concentration serves as an early predictive marker of peripancreatic necrosis and clinical severity in acute pancreatitis. Visfatin may have potential for clinical use as a new and diagnostic serum marker.
Both indirect and direct effects contribute to changes in the clinical presentation of graft-versus-host disease (GvHD) after reduced-intensity conditioning (RIC) compared with standard intensity ...regimens. A delay in acute GvHD after RIC may be explained by reduced conditioning-related inflammation and by altered allostimulatory capacities of recipient antigen-presenting cells (APC). A higher frequency of chronic GvHD results from the almost exclusive use of peripheral blood stem cells, the absence of tolerance induction by current regimens for prophylactic immunosuppression and modified kinetics in the replacement of recipient APC. Established acute and chronic GvHD requires standard treatment irrespective of the type of conditioning. To improve long-term outcome in GvHD, pre-emptive strategies or more selective approaches aimed at immunomodulation rather than immunosuppression are needed.
Background and Aim: Severe acute pancreatitis is characterized by lipase‐induced peripancreatic fat cell necrosis. Because adipocytes secret several highly active molecules, the aim of the present ...study was to investigate the hypothesis that adipocytokines could serve as potential markers predicting peripancreatic necrosis and severity in acute pancreatitis.
Methods: A total of 23 patients (11 females, 12 males) with acute pancreatitis were included and a computed tomography (CT) examination was available in 20 patients. Balthazar score, Schröder score, pancreatic necrosis score, Ranson score and APACHE II score were calculated, correlated with biochemical parameters and analyzed using receiver‐operator characteristics (ROC) analysis. Adipocytokine serum levels were measured daily by enzyme‐linked immunosorbent assay (ELISA) over 10 days after admission.
Results: Resistin and leptin were significantly elevated in patients with severe pancreatitis and were correlated with a radiological scoring system for extrapancreatic necrosis. Whereas resistin correlated positively with clinical scoring systems, time until discharge and the need for interventions, leptin was correlated positively with C‐reactive protein (CRP) levels. Resistin levels measured on the day of admittance had a positive predictive value of 93.3% (cut‐off: >6.95 ng/mL) in predicting a Schröder score >3.
Conclusion: Resistin, and to a lesser extent leptin, but not adiponectin levels are novel potential markers for extrapancreatic necrosis and severity of acute pancreatitis and should therefore be tested in larger cohorts of patients.
Abstract SCI-50
A dysregulated interaction of the intestinal microbiome with the patient’s innate and adaptive immune response seems to contribute to both inflammatory bowel disease (IBD) and ...intestinal graft-versus-host disease (GVHD). In IBD, polymorphisms within genes involved in antibacterial defense have been identified as genetic risk factors, such as in NOD2, a gene coding for an intracytoplasmatic receptor for muramyldipeptide, a bacterial cell wall compound, or in ATG16L1, a gene involved in autophagy of bacteria. Disruption of these genes results in dysfunction of Paneth cells, which are the major producers of antimicrobial peptides such as defensins. They thereby protect epithelial stem cells from invasion and destruction by intestinal bacteria and contribute to homeostasis of the intestinal microbiota. Based on van Bekkum’s finding of the absence of intestinal GVHD in germ-free mice and the central role of TNF-α release in intestinal GVHD, our group focused on the microbiome/host interactions in GVHD. In prospective studies on genetic risk factors of GVHD, single-nucleotide polymorphisms (SNPs) of NOD2 and also ATG16L1 turned out to be predictive for severe intestinal GVHD and IBD. In addition, however, pulmonary complications revealed an altered production of antibacterial peptides in the presence of NOD2 SNPs. We therefore speculated that human intestinal GVHD similar to IBD might be associated with disruption of the bacterial diversity. We applied metabolomic analyses of metabolites processed in the presence of intestinal bacteria as well as 16s rRNA sequencing to serial urine and stool samples from patients receiving allogeneic stem cell transplantation. Urinary indoxylsulfate (IS) levels dropped during the period of decontamination and use of antibiotics during the neutropenic period but recovered to pretransplant levels in patients with uneventful courses. In contrast, patients developing intestinal GVHD had significantly lower IS levels, suggesting suppression of bacterial diversity in intestinal GVHD. Analysis of 16s rRNA confirmed a major shift from an almost normal distribution pretransplant toward a loss of Firmicutes and an increase in enterococci in the neutropenic period. Although this shift may be partially explained by antibiotic decontamination or treatment during this period that was given to all patients, those patients with subsequent development of intestinal GVHD showed a significantly stronger shift toward enterococci in this period (p=0.002). Whereas patients without intestinal GVHD returned to pretransplant diversity thereafter, predominance of enteroccal flora persisted in patients with intestinal GVHD. These data indicate early microbiome changes in patients with intestinal GVHD. We are currently addressing potential Paneth cell damage and loss of antimicrobial peptides as an underlying mechanism. In summary, our data confirm the relevance of the close interaction of microbiome and host defense in GVHD patients, similar to what has been described in IBD, and raise new options for immune system modulation by restoration of intestinal tolerance.
No relevant conflicts of interest to declare.
Abstract 1155
Poster Board I-177
A genome wide association scan of DNA polymorphisms identified association of a threonine-to-alanine substitution (T300A) in the autophagy-related 16-like gene ATG16 ...L1 as a new genetic risk factor of Crohn's disease. As our group had previously reported SNPs of another innate immunity receptor important in Crohn's disease, NOD2/CARD15, as a risk factor of severe graft-versus-host disease (GvHD) and treatment related mortality (TRM) following allogeneic stem cell transplantation (SCT), we now assessed the role of ATG16L in complications following SCT.
A total of 127 HLAidentical sibling donor/recipient pairs were included. DNA from donors and recipients were analyzed for the ATG16L1 polymorphism and presence or absence of NOD2/CARD15 variants as previously published. Results of ATG16L1 and NOD2/CARD15 were correlated with clinical characteristics and outcome data, which were documented in a SPSS 17 database. The role of polymorphisms in GvHD III/IV was assessed by cross tabs, treatment related mortality (TRM) and overall survival were assessed by Kaplan Meier analysis. All patients and donors gave informed consent to analysis of genetic risk factors of GvHD.
In 15 (12%) both recipient and donor were wildtype ATG16L1, in 25 (19%) either donor or recipient had the variant; and in 87 (69%) both donor and recipient had the variant. In 34 pairs, additional NOD2/CARD15 SNPs were observed.
Severe GvHD occured in 6%, if both donor and recipient were ATG16L1 wildtype but increased to 22% if donor or recipient had the variant. Treatment related mortality increased in the presence of a donor variant (16% versus 46%, p 0.03) or if both; recipient and donor had variants (21% vs 48%, p 0.03). There seemed to be a gene dose effect for TRM, which was 13% if both were wildtype, 27% in the presence of either a donor or recipeint varaint and 48% if both had the variant (p≤ 0.05). Overall survival was not significantly different between these groups. In multivariate analysis, presence of ATG16L1 variant in both, donor and recipient was an independent risk factor for treatment related mortality when compared with age and stage of underlying disease (Hazard ratio 2.5, 95% confidence interval 1.1 – 6.1). Additional presence of NOD2/CARD15 variants seemed to be additive: TRM rose from 36% in recipients with ATG16L1 variant to 59% in the presence of additional recipient NOD2/CARD15 variants and from 34% in donors with ATG16L1 variants to 64%, if donors had additional NOD2/CARD15 SNPs.
As reported ATG16L1 polymorphism is a genetic risk factor for inflammatory bowel disease. In our work ATG16L1 polymorphism seems also to contribute to increased TRM in patients receiving allogeneic SCT. An accurate analysis of the causes of death is still accomplished. Altogether the data underline the role of the innate immunity and the disturbed antibacterial defense in the pathophysiology of transplant-associated complications.
No relevant conflicts of interest to declare.
The progression of acute pancreatitis to necrotizing pancreatitis which often results in high morbidity and mortality is difficult to predict. Here we report that serum concentrations of sCD137 are ...increased in patients with acute pancreatitis. Admission levels and 10-day median sCD137 levels positively correlate with markers of biliary pancreatitis and the 10-day sCD137 median is significantly higher in metabolic than in alcoholic pancreatitis. Serum concentrations of sCD137 at time of admission and the 10-day median of sCD137 correlate with the Ranson and APACHE II disease scores but not with the radiological Balthazar and Schroeder scores that reflect pancreatic and peripancreatic necrosis. Further, sCD137 levels correlate with the probability of complications and lethality. The association of sCD137, a product of activated T cells, with the severity of acute pancreatitis suggests that T cells contribute to the pathogenesis of acute pancreatitis.
► Soluble CD137 (sCD137) is secreted by activated T cells. ► Levels of sCD137 are elevated in patients with acute pancreatitis. ► sCD137 levels correlate with the Ranson and APACHE II disease scores. ► sCD137 levels correlate with the probability of complications and lethality. ► These data imply that T cells contribute to pathogenesis of acute pancreatitis.
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