J Nattermann

Toll-like receptor (TLR) 2 promoter and intron 2 polymorphisms are associated with increased risk for spontaneous bacterial peritonitis in liver cirrhosis

BACKGROUND & AIMSnToll-like receptor (TLR) 2 and nucleotide-binding oligomerisation domain (NOD) 2 recognize distinct pathogen-associated molecular patterns (PAMS) on the cell surface and in the cytoplasm, respectively. Since they may contribute to susceptibility to spontaneous bacterial peritonitis (SBP), we studied the effects of TLR2 gene variants on susceptibility for SBP in relation to the previously reported NOD2 alleles.nnnMETHODSnOverall, 150 patients with liver cirrhosis and ascites were genotyped for TLR2 gene variants -16934 (rs4696480), Arg753Gln (rs5743708), Pro631His (rs5743704) and the TLR2 GT microsatellite polymorphism in intron 2. Patients were monitored for SBP over two years. TLR2 SNPs were identified by hybridization probe assays on a LightCycler system. Numbers of GT repeats were determined with an ABI310 sequencer and Genescan Analysis 2.1 software.nnnRESULTSnFifty two patients (35%) had SBP. Unlike the TLR2 Arg753Gln and Pro631His mutations, SBP was significantly more frequent in patients with the TLR2 -16934 TT genotype (38.5% vs. 15.3%; p = 0.002) and in carriers with two long tandem GT repeat alleles (>20) (53.8% vs. 25.5%; p = 0.001). A multivariate analysis confirmed TLR2 GT microsatellite polymorphism (OR = 3.8, p = 0.002) and NOD2 variants (OR = 3.3, p = 0.011) as independent predictors of SBP, and the simultaneous presence of both risk factors indicated a particularly high risk for SBP (OR = 11.3, p = 0.00002).nnnCONCLUSIONSnAnalogous to NOD2 risk variants, TLR2 polymorphisms indicate increased susceptibility toward SBP in cirrhotic patients with ascites, and the combination of the TLR2 GT microsatellite polymorphism with at least one NOD2 risk variant enables improved identification of patients with a high risk for SBP.

Lower copy numbers of the chemokine CCL3L1 gene in patients with chronic hepatitis C.

BACKGROUND & AIMSnRecently, variation of gene copy numbers was recognized as a novel type of common genetic diversity, but its impact on viral hepatitis is unknown. Here, we determine the influence of copy number variation on the susceptibility and disease severity in hepatitis C virus (HCV) infection, investigating copy number variants (CNVs) of the chemokine CCL3L1 gene, which encodes a potent CCR5 ligand.nnnMETHODSnCNVs were determined in 254 patients with chronic hepatitis C, 144 HCV/HIV co-infected patients, and 210 HCV negative controls, using quality-controlled real-time fluorescent dye-labeled quantitative PCR. Liver biopsies were obtained from HCV infected patients.nnnRESULTSnCopy numbers of the CCL3L1 gene range from 0 to 12 (mean 2.7+/-1.4 copies). Patients with two or less copies are over-represented in the HCV infected cohort compared to HCV negative controls (odds ratio [OR] 1.54; p=0.02). CCL3L1 copies are shifted to lower numbers in HCV infected patients (means 2.6 vs. 2.9 in controls; p=0.011). HCV/HIV co-infected patients carry even lower CCL3L1 copy numbers compared to controls (means 2.2 vs. 2.9; p<0.001), with a higher proportion of patients possessing two or less copies (OR=3.42; p<0.001). No association was detected between CCL3L1 copy numbers and histological grades of inflammation or stages of fibrosis.nnnCONCLUSIONSnLower CCL3L1 gene copy number compared to the population median is associated with chronic hepatitis C. Copy number variation of host genes represents a novel class of genetic diversity associated with viral hepatitis.

Viral hepatitis: human genes that limit infection.

Treatment response and susceptibility to chronic viral hepatitis C and B may be modified by host genetic factors. The majority of genetic variants that confer a significant risk have been localized in genes involved in immune response. However, many findings could not be replicated and almost none of the identified risk factors had a noticeable impact on clinical decisions. In contrast, recent findings in independent large genome wide association studies confirmed genetic variants in the interferon gamma gene locus as strong predictors of outcome with outstanding clinical relevance. This review gives an overview on significant genetic susceptibility factors for susceptibility and treatment outcome in chronic viral hepatitis C and B that have been identified by the classical candidate gene approach and genome wide studies and also highlights some recent findings on genetic factors for common adverse drug reactions.

Genomic and transcriptomic heterogeneity of colorectal tumors arising in Lynch Syndrome

Colorectal cancer (CRC) arising in Lynch syndrome (LS) comprises tumours with constitutional mutations in DNA mismatch repair genes. There is still a lack of whole‐genome and transcriptome studies of LS‐CRC to address questions about similarities and differences in mutation and gene expression characteristics between LS‐CRC and sporadic CRC, about the molecular heterogeneity of LS‐CRC, and about specific mechanisms of LS‐CRC genesis linked to dysfunctional mismatch repair in LS colonic mucosa and the possible role of immune editing. Here, we provide a first molecular characterization of LS tumours and of matched tumour‐distant reference colonic mucosa based on whole‐genome DNA‐sequencing and RNA‐sequencing analyses. Our data support two subgroups of LS‐CRCs, G1 and G2, whereby G1 tumours show a higher number of somatic mutations, a higher amount of microsatellite slippage, and a different mutation spectrum. The gene expression phenotypes support this difference. Reference mucosa of G1 shows a strong immune response associated with the expression of HLA and immune checkpoint genes and the invasion of CD4+ T cells. Such an immune response is not observed in LS tumours, G2 reference and normal (non‐Lynch) mucosa, and sporadic CRC. We hypothesize that G1 tumours are edited for escape from a highly immunogenic microenvironment via loss of HLA presentation and T‐cell exhaustion. In contrast, G2 tumours seem to develop in a less immunogenic microenvironment where tumour‐promoting inflammation parallels tumourigenesis. Larger studies on non‐neoplastic mucosa tissue of mutation carriers are required to better understand the early phases of emerging tumours. Copyright

Prophylactic total gastrectomy in the management of hereditary tumor syndromes

PurposeGermline mutations in several genes confer a relevant lifetime risk of gastric cancer. In this context, an increasing involvement of a surgeon can be seen, mainly with the question of performing a prophylactic operation.MethodsPatients with hereditary tumor syndromes predisposing for gastric cancer who received care leading to prophylactic total gastrectomy in our Center for Hereditary Tumor Syndromes were analyzed. For each patient, the multidisciplinary decision-making process, the perioperative course, and the histopathologic findings were assessed. Short-term morbidity was evaluated based on the medical reports.ResultsThe analysis includes nine patients (six female, three male) with a median age of 41.6 (range 23–60)xa0years. Indication for prophylactic total gastrectomy was based on family history and genetic analysis (eight patients with a germline mutation of the CDH1 gene and one patient with a SMAD4 mutation). Removal of the entire gastric mucosa was documented intraoperatively by fresh frozen section examination. Extended (DII) lymphadenectomy was performed in four patients. Histopathologic examination of gastrectomy specimens revealed six patients (6/9, 67xa0%) with multifocal signet ring cell carcinomas. In our series, prophylactic total gastrectomy was a safe procedure without mortality and low morbidity.ConclusionsPatients with hereditary syndromes predisposing for gastric cancer should be evaluated for this curative procedure in a specialized center. Further research is necessary, and the implementation of nationwide registers including patients with prophylactic gastrointestinal operations due to hereditary tumor syndrome is advisable.

Chromoendoscopy in combination with random biopsies does not improve detection of gastric cancer foci in CDH1 mutation positive patients

Background and study aims: Hereditary diffuse gastric cancer (HGGC), an autosomal dominant tumor-syndrome, accounts for 1u200a% to 3u200a% of gastric cancers worldwide. Presumably 30u200a% to 40u200a% of all patients fulfilling the clinical guidelines for HDGC are carriers of a pathogenic mutation in the CDH1 gene. Patients often show multiple foci of signet ring cell carcinoma at early age and are advised to undergo prophylactic total gastrectomy (PTG). Our aim was to improve the endoscopic detection of HDGC by using an enhanced endoscopic protocol. Patient and methods: Patients with a proven CDH1 germline mutation identified in our institute were prospectively included. Patients were advised to undergo PTG and offered a baseline endoscopic examination prior surgery. Examination was performed by using high-resolution white-light endoscopy and pan-gastric chromoendoscopy with indigo carmine as dye combined with targeted and multiple random biopsies assessed by an expert histopathologist. Postoperative histopathology was compared with results from endoscopic biopsies. Results: Between September 2012 and November 2014 8 patients with a proven CDH1 germline mutation were included. We conducted 44 targeted (6.3/patient) and 225 random (32.1/patient) biopsies in 7 patients. We detected 1 gastric cancer by random biopsy (14u200a%). All other examinations showed no signs of cancer. Histopathology of gastrectomy specimen revealed multiple foci of gastric carcinoma in 6 patients (86u200a%) with a total number of 27 cancer foci. Conclusions: Examination with targeted and random biopsies combined with chromoendoscopy is not able to detect small foci of gastric cancer in CDH1 mutation carriers. Therefore PTG is advocated in these patients.

Dysregulierte Interaktion zwischen CD4+ T Zellen und NK Zellen in der HIV/HCV Koinfektion

Hintergrund: Die HCV/HIV Koinfektion ist im Vergleich zur HCV Monoinfektion mit einer schnelleren Progression einer Lebererkrankung assoziiert. Naturliche Killer (NK) Zellen haben auf die Viruseliminierung bei Hepatitis C einen enormen Einfluss. Bei der Aktivierung von NK Zellen sind nach bisheriger Erkenntnis CD4+ T Zellen involviert. Allerdings ist eine HIV Infektion insbesondere durch dysfunktionelle CD4+ T Zellen gekennzeichnet. Aus diesem Grunde vermuten wir bei der Immunpathogense der HIV/HCV Koinfektion eine gestorte Interaktion zwischen CD4+ T Zellen und NK Zellen. Material undMethoden: In diese Studie wurden 40 HIV Patienten, davon 21 HIV RNA(-) Patienten mit HAART und 19 HIV RNA(+) Patienten ohne Therapie, und 20 gesunde HIV(-)/HCV(-)Probanden eingeschlossen. Die IL2-Produktion CD4+ T Zellen wurde nach CD3/CD28 Stimulation mittels Durchflusszytometrie getestet. Die anti-HCV Aktivitat von PBMC wurde mit Hilfe des HCV-Replikon-Systems untersucht. Die AnaIyse der IFN-γ Produktion isolierter NK Zellen und der anti-HCV Aktivitat erfolgte nach Koinkubation mit HCV-Replikonzellen in Kokultur mit bzw. ohne aktivierten CD4+ T Zellen. Ergebnisse: Die Hemmung der HCV Replikation war bei PBMC von HIV Infizierten signifikant niedriger als bei gesunden Probanden (p < 0.001). Passend dazu war bei HIV Infizierten die IFN-γ Produktion der NK Zellen signifikant gehemmt (p < 0.001). Interessanterweise korrelierte bei Therapie-naiven HIV RNA(+) Patienten die CD4+ T Zellzahl positiv mit der anti-HCV Aktivitat und IFN-γ Produktion von NK Zellen, allerdings nicht bei HIV RNA(-) Patienten unter HAART (p < 0.5). Zudem war die viramische HIV Infektion im Vergleich zu gesunden Kontrollen und HIV RNA(-) Patienten mit einer verminderten IL2 Sezernierung von CD4+ T Zellen assoziiert. In Ubereinstimmung mit bisher von uns veroffentlichten Arbeiten induzieren aktivierte CD4+ T Zellen effektiv die IFN-γ Produktion von gesunden NK Zellen. Allerdings gab es zwischen CD4+ T Zellen von HIV Patienten und Gesunden keine Unterschiede in der Stimulierbarkeit der NK Zellen gesunder Probanden. Uberraschenderweise liesen sich NK Zellen von viramischen HIV Patienten weder durch autologe CD4+ T Zellen noch von gesunden Kontrollen stimulieren. Das lasst einen intrinsischen Defekt der NK Zellen vermuten. Diese dysregulierte Funktion wurde auch bei NK Zellen von therapierten HIV RNA(-) Patienten beobachtet. Diskussion: Unsere Daten deuten auf eine gestorte Interaktion zwischen CD4+ T Zellen und NK Zellen bei der HIV Infektion hin. Dies hat einen negativen Einfluss auf die anti-HCV Aktivitat von NK Zellen und fuhrt moglicherweise zur schnelleren Progression einer HCV assoziierten Lebererkrankung in der HIV Koinfektion. Korrespondierender Autor: Kramer, Benjamin E-Mail:m.benjamin.kraemer@gmail.com

P485 THE RATIO OF ASCITES CALPROTECTIN TO TOTAL PROTEIN IS A DIAGNOSTIC AND PROGNOSTIC MARKER FOR SPONTANEOUS BACTERIAL PERITONITIS IN LIVER CIRRHOSIS

inclusion. The median follow up time was 283 days (range 1– 1382 days). M30 levels differed between Child Pugh stages and correlated with the MELD score (model of end stage liver disease). When patients were grouped according to M30 levels in individuals with low ( 3000U/l) M30 levels, M30 could differentiate overall survival of patients according to the log-rank test (P < 0.001). Furthermore, M30 level was an independent risk factor for mortality in addition to age, gender, Child Pugh stage and the MELD score in a multivariate Cox regression model. Conclusions: The M30 serum level correlates with the stage of cirrhosis and is predictive for survival in patients with liver cirrhosis.