Treatment of colonic varices and gastrointestinal bleeding by recanalization and stenting of splenic-vein-thrombosis:A case report and literature review

BACKGROUND Splenic vein thrombosis is a known complication of pancreatitis.It can lead to increased blood flow through mesenteric collaterals.This segmental hypertension may result in the development of colonic varices(CV)with a high risk of severe gastrointestinal bleeding.While clear guidelines for treatment are lacking,splenectomy or splenic artery embolization are often used to treat bleeding.Splenic vein stenting has been shown to be a safe option.CASE SUMMARY A 45-year-old female patient was admitted due to recurrent gastrointestinal bleeding.She was anemic with a hemoglobin of 8.0 g/dL.As a source of bleeding,CV were identified.Computed tomography scans revealed thrombotic occlusion of the splenic vein,presumably as a result of a severe acute pancreatitis 8 years prior.In a selective angiography,a dilated mesenterial collateral leading from the spleen to enlarged vessels in the right colonic flexure and draining into the superior mesenteric vein could be confirmed.The hepatic venous pressure gradient was within normal range.In an interdisciplinary board,transhepatic recanalization of the splenic vein via balloon dilatation and consecutive stenting,as well as coiling of the aberrant veins was discussed and successfully performed.Consecutive evaluation revealed complete regression of CV and splenomegaly as well as normalization of the red blood cell count during follow-up.CONCLUSION Recanalization and stenting of splenic vein thrombosis might be considered in patients with gastrointestinal bleeding due to CV.However,a multidisciplinary approach with a thorough workup and discussion of individualized therapeutic strategies is crucial in these difficult to treat patients.

miR-20b, miR-98, miR-125b-1*, and let-7e* as new potential diagnostic biomarkers in ulcerative colitis

AIM:To use microarray-based miRNA profiling of colonic mucosal biopsies from patients with ulcerative colitis (UC), Crohn's disease (CD), and controls in order to identify new potential miRNA biomarkers in inflammatory bowel disease. METHODS:Colonic mucosal pinch biopsies from the descending part were obtained endoscopically from patients with active UC or CD, quiescent UC or CD, as well as healthy controls. Total RNA was isolated and miRNA expression assessed using the miRNA microarray Geniom Biochip miRNA Homo sapiens (Febit GmbH, Heidelberg, Germany). Data analysis was carried out by principal component analysis and projection to latent structure-discriminant analysis using the SIMCA-P+12 software package (Umetrics, Umea, Sweden). The microarray data were subsequently validated by quantitative real-time polymerase chain reaction (qPCR) performed on colonic tissue samples from active UC patients (n = 20), patients with quiescent UC (n = 19), and healthy controls (n = 20). The qPCR results were analyzed with Mann-WhitneyU test.In silico prediction analysis were performed to identify potential miRNA target genes and the predicted miRNA targets were then compared with all UC associated susceptibility genes reported in the literature. RESULTS:The colonic mucosal miRNA transcriptome differs significantly between UC and controls, UC and CD, as well as between UC patients with mucosal inflammation and those without. However, no clear differences in the transcriptome of patients with CD and controls were found. The miRNAs with the strongest differential power were identified (miR-20b, miR-99a, miR-203, miR-26b, and miR-98) and found to be upregulated more than a 10-fold in active UC as compared to quiescent UC, CD, and controls. Two miRNAs, miR-125b-1* and let-7e*, were up-regulated more than 5-fold in quiescent UC compared to active UC, CD, and controls. Four of the seven miRNAs (miR-20b, miR-98, miR-125b-1*, and let-7e*) were validated by qPCR and found to be specifically upregulated in patients with UC. Usingin silico analysis we found several predicted pro-inflammatory target genes involved in various pathways, such as mitogen-activated protein kinase and cytokine signaling, which are both key signaling pathways in UC.CONCLUSION:The present study provides the first evidence that miR-20b, miR-98, miR-125b-1*, and let7e* are deregulated in patients with UC. The level of these miRNAs may serve as new potential biomarkers for this chronic disease.

Cirrhotic cardiomyopathy:A cardiologist's perspective

Cardiac dysfunction is frequently observed in patients with cirrhosis, and has long been linked to the direct toxic effect of alcohol. Cirrhotic cardiomyopathy(CCM) has recently been identified as an entity regardless of the cirrhosis etiology. Increased cardiac output due to hyperdynamic circulation is a pathophysiological hallmark of the disease. The underlying mechanisms involved in pathogenesis of CCM are complex and involve various neurohumoral and cellular pathways, including the impaired β-receptor and calcium signaling, altered cardiomyocyte membrane physiology, elevated sympathetic nervous tone and increased activity of vasodilatory pathways predominantly through the actions of nitric oxide, carbon monoxide and endocannabinoids. The main clinical features of CCM include attenuated systolic contractility in response to physiologic or pharmacologic strain, diastolic dysfunction, electrical conductance abnormalities and chronotropic incompetence. Particularly the diastolic dysfunction with impaired ventricularrelaxation and ventricular filling is a prominent feature of CCM.The underlying mechanism of diastolic dysfunction in cirrhosis is likely due to the increased myocardial wall stiffness caused by myocardial hypertrophy,fibrosis and subendothelial edema,subsequently resulting in high filling pressures of the left ventricle and atrium.Currently,no specific treatment exists for CCM.The liver transplantation is the only established effective therapy for patients with end-stage liver disease and associated cardiac failure.Liver transplantation has been shown to reverse systolic and diastolic dysfunction and the prolonged QT interval after transplantation.Here,we review the pathophysiological basis and clinical features of cirrhotic cardiomyopathy,and discuss currently available limited therapeutic options.

Transforming growth factor-β1 induces intestinal myofibroblast differentiation and modulates their migration

AIM： To investigate the effects of transforming growth factor β1 （TGF-β1） on the differentiation of colonic lamina propria fibroblasts （CLPF） into myofibroblasts in vitro.METHODS： Primary CLPF cultures were incubated with TGF-β1 and analyzed for production of m-smooth muscle actin （α-SMA）, fibronectin （FN） and FN isoforms. Migration assays were performed in a modified 48-well Boyden chamber. Levels of total and phosphorylated focal adhesion kinase （FAK） in CLPF were analyzed after induction of migration.did not change α-SMA levels, while TGF-β1 treatment for 6 d significantly increased α-SIVlA production. Short term incubation （6 h） with TGF-β1 enhanced CLPF migration, while long term treatment （6 d） of CLPF with TGF-β1 reduced migration to 15%-37% compared to untreated cells. FN and FN isoform mRNA expression were increased after short term incubation with TGF-β1 （2 d） in contrast to long term incubation with TGF-β1 for 6 d. After induction of migration, TGF-β1-preincubated CLPF showed higher amounts of FN and its isoforms and lower levels of total and phosphorylated FAK than untreated cells.CONCLUSION： Long term incubation of CLPF with TGF-β1 induced differentiation into myofibroblasts with enhanced α-SMA, reduced migratory potential and FAK phosphorylation, and increased FN production. In contrast, short term contact （6 h） of fibroblasts with TGF-β1 induced a dose-dependent increase of cell migration and FAK phosphorylation without induction of α-SMA production.

Psychosocial issues in evidence-based guidelines on inflammatory bowel diseases: A review

AIM: To study statements and recommendations on psychosocial issues as presented in international evidence-based guidelines on the management of inflammatory bowel diseases (IBD).

Assessment of metastatic liver disease in patients with primary extrahepatic tumors by contrast-enhanced sonography versus CT and MRI

AIM： To evaluate contrast-enhanced ultrasonography （CEUS） using SonoVue in the detection of liver metastases in patients with known extrahepatic primary tumors versus the combined gold standard comprising CT, MRI and clinical/histological data. METHODS： It is an international multicenter study, and there were 12 centres and 125 patients （64 males, 61 females, aged 59 ± 11 years） involved, with 102 patients per protocol. Primary tumors were colorectal in 35%, breast in 27%, pancreatic in 17% and others in 21%. CEUS using SonoVue was employed with a Iow-mechanical-index technique and contrast-specific software using Siemens Elegra, Philips HDI 5000 and Acuson Sequoia; continuous scanning for at least five minutes. RESULTS： CEUS with SonoVue increased significantly the number of focal liver lesions detected versus unenhanced sonography. In 31.4% of the patients, more lesions were found after contrast enhancement. The total numbers of lesions detected were comparable with CEUS （55）, triple-phase spiral CT （61） and HRI with a liverspecific contrast agent （53）. Accuracy of detection of metastatic disease （i.e. at least one metastatic lesion） was significantly higher for CEUS （91.2%） than for unenhanced sonography （81.4%） and was similar to that of triple-phase spiral CT （89.2 %）. In 53 patients whose CEUS examination was negative, a follow-up examination 3-6 months later confirmed the absence of metastatic lesions in 50 patients （94.4%）. CONCLUSION： CEUS is proved to be reliable in the detection of liver metastases in patients with known extrahepatic primary tumors and suspected liver lesions.

Treatment of biliary tract cancer with NVP-AEW541:Mechanisms of action and resistance

AIM:To investigate in vitro treatment with NVPAEW541,a small molecule inhibitor of insulin-like growth factor-1 receptor(IGF-1R),in biliary tract cancer (BTC),since this disease is associated with a poor prognosis due to wide resistance to chemotherapeutic agents and radiotherapy.METHODS:Cell growth inhibition by NVP-AEW541 was studied in vitro in 7 human BTC cell lines by automated cell counting.In addition,the anti-tumoral mechanism of NVP-AEW541 was studied by Western blotting,cell cycle analysis and reverse transcription-polymerase chain reaction(RT-PCR).Anti-tumoral drug effect in combination with gemcitabine,5-fluorouracil(5-FU)and Polo-like kinase 1 inhibitor BI2536 was also studied. RESULTS:In vitro treatment with NVP-AEW541 suppressed growth in all human BTC cell lines,however response was lower in gallbladder cancer.Treatment withNVP-AEW541 was associated with dephosphorylation of IGF-1R and AKT.In contrast,phosphorylation of p42/p44 and Stat3 and expression of Bcl-xL were inconsistently downregulated.In addition,treated cells showed cell cycle arrest at the G1/S-checkpoint and an increase in sub-G1 peak.Moreover,IGF-1R and its ligands IGF-1 and IGF-2 were co-expressed in RT-PCR,suggesting an autocrine loop of tumor cell activation.Combined with gemcitabine,NVP-AEW541 exerted synergistic effects, particularly at low concentrations,while effects of combination with 5-FU or BI 2536 were only additive. CONCLUSION:Our findings suggest that NVP-AEW541 is active against BTC in vitro and potentiates the efficacy of gemcitabine.

Inhibition of histone deacetylase for the treatment of biliary tract cancer:A new effective pharmacological approach

AIM： To investigate in vitro and in vivo therapeutic effects of histone deacetylase inhibitors NVP-LAQ824 and NVP-LBH589 on biliary tract cancer. METHODS： Cell growth inhibition by NVP-LAQ824 and NVP-LBH589 was studied in vitro in 7 human biliary tract cancer cell lines by MTT assay. In addition, the antitumoral effect of NVP-LBH589 was studied in a chimeric mouse model. Anti-tumoral drug mechanism was assessed by immunoblotting for acH4 and p21^WAFl/CIP-1, PARP assay, cell cycle analysis, TUNEL assay, and immunhistochemistry for MIB-1. RESULTS： In vitro treatment with both compounds significantly suppressed the growth of all cancer cell lines [mean IC50 （3 d） 0.11 and 0.05 μmol/L, respectively], and was associated with hyperacetylation of nucleosomal histone H4, increased expression of p21^WAF-1/CIP-1, induction of apoptosis （PARP cleavage）, and cell cycle arrest at G2/M checkpoint. After 28 d, NVP- LBH589 significantly reduced tumor mass by 66% （bile duct cancer） and 87% （gallbladder cancer） in vivo in comparison to placebo, and potentiated the efficacy of gemcitabine. Further analysis of the tumor specimens revealed increased apoptosis by TUNEL assay and reduced cell proliferation （MIB-1）. CONCLUSION： Our findings suggest that NVP-LBH589 and NVP-LAQ824 are active against human biliary tract cancer in vitro. In addition, NVP-LBH589 demonstrated significant in vivo activity and potentiated the efficacy of gemcitabine. Therefore, further clinical evaluation of this new drug for the treatment of biliary tract cancer is recommended.

Calcitriol analog ZK191784 ameliorates acute and chronic dextran sodium sulfate-induced colitis by modulation of intestinal dendritic cell numbers and phenotype

AIM: To investigate the effects of ZK1916784, a low calcemic analog of calcitriol on intestinal inflammation. METHODS: Acute and chronic colitis was induced by dextran sodium sulfate (DSS) according to standard procedures. Mice were treated intraperitoneally with ZK1916784 or placebo and colonic inflammation was evaluated. Cytokine production by mesenterial lymph node (MLN) cells was measured by ELISA. Immunohistochemistry was performed to detect intestinal dendritic cells (DCs) within the colonic tissue, and the effect of the calcitriol analog on DCs was investigated. RESULTS: Treatment with ZK191784 resulted in significant amelioration of disease with a reduced histological score in acute and chronic intestinal inflammation. In animals with acute DSS colitis, down- regulation of colonic inflammation was associated with a dramatic reduction in the secretion of the proinflammatory cytokine interferon (IFN)-γ and a significant increase in intereleukin (IL)-10 by MLN cells. Similarly, in chronic colitis, IL-10 expression in colonic tissue increased 1.4-fold when mice were treated with ZK191784, whereas expression of the Th1-specific transcription factor T-beta decreased by 81.6%. Lower numbers of infiltrating activated CD11c+ DCs were found in the colon in ZK191784-treated mice with acute DSScolitis, and secretion of proinflammatory cytokines by primary mucosal DCs was inhibited in the presence of the calcitriol analog. CONCLUSION: The calcitriol analog ZK191784 demonstrated significant anti-inflammatory properties in experimental colitis that were at least partially mediated by the immunosuppressive effects of the derivate on mucosal DCs.

Bifunctional chimeric SuperCD suicide gene -YCD: YUPRT fusion is highly effective in a rat hepatoma model

AIM： To investigate the effects of catalytically superior gene-directed enzyme prodrug therapy systems on a rat hepatoma model. METHODS： To increase hepatoma cell chemosensitivity for the prodrug 5-fluorocytosine （5-FC）, we generated a chimeric bifunctional SuperCD suicide gene, a fusion of the yeast cytosine deaminase （YCD） and the yeast uracil phosphoribosyltransferase （YUPRT） gene. RESULTS： In vitro stably transduced Morris rat hepatoma cells （MH） expressing the bifunctional SuperCD suicide gene （MH SuperCD） showed a clearly marked enhancement in cell killing when incubated with 5-FC as compared with MH cells stably expressing YCD solely （MH YCD） or the cytosine deaminase gene of bacterial origin （MH BCD）, respectively. In vivo, MH SuperCD tumors implanted both subcutaneously as well as orthotopically into the livers of syngeneic ACI rats demonstrated significant tumor regressions （P〈0.01） under both high dose as well as low dose systemic 5-FC application, whereas MH tumors without transgene expression （MH naive） showed rapid progression. For the first time, an order of in vivo suicide gene effectiveness （SuperCD〉〉 YCD〉〉BCD〉〉〉negative control） was defined as a result of a direct in vivo comparison of all three suicide genes. CONCLUSION： Bifunctional SuperCD suicide gene expression is highly effective in a rat hepatoma model, thereby significantly improving both the therapeutic index and the efficacy of hepatocellular carcinoma killing by fluorocytosine.

Ischemic preconditioning inhibits development of edematous cerulein-induced pancreatitis: Involvement of cyclooxygenases and heat shock protein 70

AIM： To determine whether ischemic preconditioning （IP） affects the development of edematous cerulein-induced pancreatitis and to assess the role of cyclooxygenase-1 （COX-l）, COX-2, and heat shock protein 70 （HSP 70） in this process. METHODS： In male Wistar rats, IP was performed by damping of celiac artery （twice for 5 min at 5-min intervals）. Thirty minutes after IP or sham operation, acute pancreatitis was induced by cerulein. Activity of COX-1 or COX-2 was inhibited by resverabol or rofecoxib, respectively （10 rng/kg）. RESULTS： IP significantly reduced pancreatic damage in cerulein-induced pancreatitis as demonstrated by the improvement of pancreas histology, reduction in serum lipase and poly-C ribonuclease activity, and serum concentration of pro-inflammatory interleukin （IL）-1β. Also, IP attenuated the pancreatitis-evoked fall in pancreatic blood flow and pancreatic DNA synthesis. Serum level of anti-inflammatory IL-10 was not affected by IP. Cerulein-induced pancreatitis and IP increased the content of HSP 70 in the pancreas. Maximal increase in HSP 70 was observed when IP was combined with cerulein-induced pancreatitis. Inhibition of COXs, especially COX-2, reduced the protective effect of IP in edematous pancreatitis. CONCLUSION： Our results indicate that IP reducespancreatic damage in cerulein-induced pancreatitis and this effect, at least in part, depends on the activity of COXs and pancreatic production of HSP 70.

Malignant hepatic vascular tumors in adults: Characteristics,diagnostic difficulties and current management

Malignant vascular tumors of the liver include rare primary hepatic mesenchymal tumors developed in the background of a normal liver parenchyma. Most of them are detected incidentally by the increased use of performing imaging techniques. Their diagnosis is challenging, involving clinical and imaging criteria, with final confirmation by histology and immunohistochemistry. Surgery represents the mainstay of treatment. Liver transplantation(LT) has improved substantially the prognosis of hepatic epithelioid hemangioendothelioma(HEHE), with 5-year patient survival rates of up to 81%, based on the European Liver Intestine Transplantation AssociationEuropean Liver Transplant Registry study. Unfortunately, the results of surgery and LT are dismal in cases of hepatic angiosarcoma(HAS). Due to the disappointing results of very short survival periods of approximately 6-7 mo after LT, because of tumor recurrence and rapid progression of the disease, HAS is considered an absolute contraindication to LT. Recurrences after surgical resection are high in cases of HEHE and invariably present in cases of HAS. The discovery of reliable prognostic markers and the elaboration of prognostic scores following LT are needed to provide the best therapeutic choice for each patient.Studies on a few patients have demonstrated the stabilization of the disease in a proportion of patients with hepatic vascular tumors using novel targeted antiangiogenic agents, cytokines or immunotherapy. These new approaches,alone or in combination with other therapeutic modalities, such as surgery and classical chemotherapy, need further investigation to assess their role in prolonging patient survival. Personalized therapeutic algorithms according to the histopathological features, behavior, molecular biology and genetics of the tumors should be elaborated in the near future for the management of patients diagnosed with primary malignant vascular tumors of the liver.

Pregnancy is not a risk factor for gallstone disease: Results of a randomly selected population sample

AIM： To investigate the prevalence, risk factors, and selection of the study population for cholecystolithiasis in an urban population in Germany, in relation to our own findings and to the results in the international literature. METHODS： A total of 2 147 persons （1 111 females, age 42.8 ＋ 12.7 years; 1 036 males, age 42.3 ＋ 13.1 years） participating in an investigation on the prevalence of Echinococcus rnultilocularis were studied for risk factors and prevalence of gallbladder stone disease. Risk factors were assessed by means of a standardized interview and calculation of body mass index （BMI）. A diagnostic ultrasound examination of the gallbladder was performed. Data were analyzed by multiple logistic regression, using the SAS statistical software package. RESULTS： Gallbladder stones were detected in 171 study participants （8.0%, n = 2 147）. Risk factors for the development of gallbladder stone disease included age, sex, BMI, and positive family history. In a separate analysis of female study participants, pregnancy （yes/no） and number of pregnancies did not exert any influence. CONCLUSION： Findings of the present study confirm that age, female sex, BMI, and positive family history are risk factors for the development of gallbladder stone disease. Pregnancy and the number of pregnancies, however, could not be shown to be risk factors. There seem to be no differences in the respective prevalence for gallbladder stone disease in urban and rural populations.

A common variant in the precursor miR-146a sequence does not predispose to cholangiocarcinoma in a large European cohort

BACKGROUND:Micro-RNAs(miRNAs) are small,non-coding RNA species considered to fine-tune basic cellular functions by modulating target gene translation and/or mRNA stability.A common G/C polymorphism(rs2910164) in the precursor(pre-) miR-146a gene engaged in NF-κB signaling and apoptosis pathways has been reported to modulate the genetic risk of hepatocellular carcinoma by increased G-allelic production of mature miR-146a.We investigated rs2910164 in a large Europeanbased cholangiocarcinoma(CCA) cohort.METHODS:We recruited 182 CCA patients and 350 controls in three academic medical centers.Genotyping for rs2910164 was performed by PCR-based assays with 5’-nuclease and fluorescence detection.Genotype frequencies were tested for consistency with the Hardy-Weinberg equilibrium using an exact test;allelic and genotypic differences between the patients and controls were assessed by the Chi-square test and Armitage’s trend test.Exploratory subgroup analyses included gender,tumor localization(extra-versus intrahepatic CCA) and early-onset CCA.RESULTS:Genotype distributions were consistent with the Hardy-Weinberg equilibrium.No significant differences in either allele or genotype distributions were detected between the CCA and control groups or the respective subgroups investigated.However,there was a trend for a protective effect of the heterozygous single-nucleotide polymorphism state GC,as indicated by an underrepresentation in the CCA group in general(29% vs 35%;P=0.18) and,in particular,for extrahepatic tumor sites(26% vs 35%;OR=0.67;95% CI,0.43-1.02;P=0.065).CONCLUSIONS:Our data do not support a prominent contribution of the pre-miR-146a sequence variant in the genetic predisposition to CCA.However,current studies functionally characterizing rs2910164 have proposed that distinct repertoires of target genes are addressed by genotype-specific mature miR146a species.Given the detected trend towards a potentially protective role of GC heterozygosity,a subtle modulation of genetic CCA risk by the pre-miR-146a GC genotype may exist and should be evaluated further.

Sirolimus-induced drug fever and ciclosporin-induced leukencephalopathia with seizures in one liver transplant recipient

We describe the first case of sirolimus-induced drug fever in a female liver transplant recipient, with a history of hepatitis C-induced end-stage liver cirrhosis in 1999. In 2005, six years after transplantation, she developed calcineurin inhibitor-induced renal function impairment. Immunosuppression was switched from tacrolimus to sirolimus. Two days after the intake of sirolimus, she developed daily fever spikes, but no infectious focus was found. Antibiotic therapy had no influence on the fever. After fourteen days, sirolimus was switched back to tacrolimus and the fever disappeared. In history, the patient developed ciclosporin-induced generalized seizures eleven days after liver transplantation, followed by the development of a motoric speech disorder. Magnetic resonance imaging (MRI) findings were consistent with leucoencephalopathy, therefore immunosuppressive therapy was changed from ciclosporin to tacrolimus and the neurologic symptoms improved significantly. Our case is the first reported case of sirolimus-induced drug fever. In addition, the patient showed the rare occurrence of ciclosporin-induced leukencephalopathy with seizures.

Prevalence of celiac disease in Germany:A prospective follow-up study

AIM:To determine the prevalence of celiac disease in a randomly selected population sample. METHODS:A total of 2157 subjects (1036 males; 1121 females) participating in a population-based cross-sectional study underwent laboratory testing for tissue transglutaminase and antibodies to immunoglobulin A, endomysium and antigliadin. In a second step, all subjects who had been examined serologically were surveyed using a questionnaire that included questions specific to celiac disease. Subjects with positive antibody titers and those with histories positive for celiac disease then underwent biopsy. At the first follow up, antibody titers were again determined in these subjects and subjects were questioned regarding symptoms specific for celiac disease and disorders associated with celiac disease. The second follow up consisted of a telephone interview with subjects positive for celiac disease.RESULTS:Antibody tests consistent with celiac disease were reported in eight subjects, corresponding to an overall prevalence of 1:270 (8/2157). The prevalence among women was 1:224 and 1:518 in men. Classical symptoms were observed in 62.5% of subjects. Atypical celiac disease was present in 25.0%, and transient celiac disease in 12.5%. False-negative test results were returned in three subjects. This yields a sensitivity and specificity of 62.5% and 50.0%, respectively, for tissue transglutaminase immunoglobulin-A antibody; of 62.5% and 71.4% respectively, for endomysium antibody; and of 62.5% and 71.4%, respectively, for antigliadin antibody.CONCLUSION:The prevalence rate in our collective lies within the middle tertile of comparable studies in Europe. The use of a single antibody test for screening purposes must be called into question.

Pancreatic cancer risk variant ABO rs505922 in patients with cholangiocarcinoma

The aim of this study was to investigate an association between the development of cholangiocarcinoma(CCA)and the ABO variant rs505922(known to increase pan-creatic cancer risk)in a large cohort of European individuals with CCA.In total,180 individuals with CCA and 350 CCA-free controls were included.The ABO variant rs505922 was genotyped using a polymerase chain reaction-based assay.Association between this single nucleotide polymorphism(SNP)and CCA was tested in contingency tables.Neither allele distributions nor association tests and regression analysis provided evidence for an increased risk of CCA among carriers of the ABO variant(all P > 0.05).Nevertheless,we documented a deviation from Hardy-Weinberg equilibrium in the entire CCA cohort(P = 0.028)and for patients with intrahe-patic(P = 0.037)but not extrahepatic tumor localization(P > 0.05).The association tests did not provide evidence for a prominent role of the investigated SNP in the genetic risk of CCA.However,Hardy-Weinberg disequilibrium in the entire cohort and the intrahepatic CCA subgroup warrants future studies investigating a potential CCA risk modulation by individual blood groups.