Human Immunodeficiency Virus-Infected Immunological Nonresponders Have Colon-Restricted Gut Mucosal Immune Dysfunction.

BACKGROUND: Human immunodeficiency virus (HIV)-infected immunological nonresponders (INRs) fail to reconstitute their CD4+ T-cell pool after initiation of antiretroviral therapy, and their prognosis is inferior to that of immunological responders (IRs). A prevailing hypothesis is that the INR phenotype is caused by a persistently disrupted mucosal barrier, but assessments of gut mucosal immunology in different anatomical compartments are scarce. METHODS: We investigated circulating markers of mucosal dysfunction, immune activation, mucosal Th17 and Th22 cells, and mucosa-adherent microbiota signatures in gut mucosal specimens from sigmoid colon and terminal ileum of 19 INRs and 20 IRs in addition to 20 HIV-negative individuals. RESULTS: INRs had higher blood levels of the enterocyte damage marker intestinal fatty acid-binding protein than IRs. In gut mucosal biopsies, INRs had lower fractions of CD4+ T cells, higher fractions of interleukin 22, and a tendency to higher fractions of interleukin 17-producing CD4+ T cells. These findings were all restricted to the colon and correlated to circulating markers of enterocyte damage. There were no observed differences in gut microbial composition between INRs and IRs. CONCLUSIONS: Restricted to the colon, enterocyte damage and mucosal immune dysfunction play a role for insufficient immune reconstitution in HIV infection independent of the gut microbiota.

Impact of Human Immunodeficiency Virus-Related Gut Microbiota Alterations on Metabolic Comorbid Conditions.

BACKGROUND: We aimed to identify a human immunodeficiency virus (HIV)-related microbiota signature, independent of sexual preferences and demographic confounders, in order to assess a possible impact of the microbiome on metabolic comorbid conditions. METHODS: Bacterial 16S ribosomal RNA analyses were performed on stool samples from 405 HIV-infected and 111 uninfected participants of the Copenhagen Comorbidity in HIV Infection (COCOMO) study. Individuals were stratified according to sexual behavior (men who have sex with men [MSM] vs non-MSM). RESULTS: After excluding MSM-associated microbiota traits and adjusting for confounders, we identified an HIV-related microbiota signature, consisting of lower biodiversity, increased relative abundance of the bacterial clades Gammaproteobacteria and Desulfovibrionaceae and decrease in several Clostridia. This microbiota profile was associated with a 2-fold excess risk of metabolic syndrome, driven by increase in Desulfovibrionaceae and decrease in Clostridia (Butyrivibrio, Coprococcus 2, Lachnospiraceae UCG-001 and CAG-56). This association was accentuated (5-fold excess risk) in individuals with previous severe immunodeficiency, which also modified the association between HIV-related microbiota signature and visceral adipose tissue (VAT) area (P for interaction = .01). Accordingly, HIV-related microbiota was associated with 30-cm2 larger VAT in individuals with history of severe immunodeficiency, but not in those without. CONCLUSION: The HIV-related microbiota was associated with increased risk of metabolic syndrome and VAT accumulation, particularly in individuals with previous severe immunodeficiency, driven by increased Desulfovibrionaceae and lower abundance of several Clostridia. Our findings suggest a potential interplay between HIV-related microbiota, immune dysfunction and metabolic comorbid conditions. Interventions targeting the gut microbiome may be warranted to reduce cardiovascular risk, particularly in individuals with previous immunodeficiency.

Assessment of Bowel Inflammation and Strictures by Magnetic Resonance Enterography in Long-term Crohn's Disease.

BACKGROUND: Crohns disease [CD] is a chronic inflammation in the gut that often progresses to fibrosis. Magnetic resonance enterography [MRE] is an important diagnostic tool in evaluating CD. We aimed to assess the prevalence of inflammation and stricturing disease in patients with long-term CD, and to investigate associations with clinical factors. METHODS: We performed a follow-up analysis of a population-based cohort of 237 CD patients in south-eastern Norway 20 years after diagnosis; 95 patients were examined with MRE, and the magnetic enterographic global score [MEGS] was calculated. We assessed inflammation and strictures during the follow-up. Association of the MEGS and bowel strictures with clinical variables was examined by univariate regression analysis. RESULTS: Of the 237 patients, 62 [65.3%] had active inflammation mostly affecting the terminal ileum; 35 [36.8%] had substantial inflammation according to MEGS, which associated with inflammatory biomarkers during the follow-up; and 25 [26.3%] had stricturing disease that associated with age (odds ratio [OR] = 0.92), initial use of systemic steroids [OR = 3.36], and inflammatory biomarkers. Most patients with strictures were treated with surgery without recurrence [n = 24, 42.1%] and seven [21.2%] strictures in the terminal ileum healed without surgery. CONCLUSIONS: Twenty years after the diagnosis, the majority of patients had active inflammation, often complicated by stricturing disease. Most patients with strictures were treated with surgery without recurrence, and some strictures resolved over time. Inflammatory biomarkers, extensive and complicated disease type, and use of systemic medication associated with both inflammation and stricturing disease.

Bowel Damage in Patients With Long-term Crohn's Disease, Assessed by Magnetic Resonance Enterography and the Lémann Index.

BACKGROUND & AIMS: Magnetic resonance enterography (MRE) is used to evaluate the extent and complications of Crohn's disease (CD). MRE results are used in calculation of the Lémann index (LI) score, which quantifies bowel damage. The long-term outcomes of CD are uncertain; we aimed to assess bowel disease and damage in patients with CD for 20 years using MRE and the LI. METHODS: We performed a follow-up analysis of a population-based cohort of 237 patients in southeastern Norway diagnosed with CD from 1990 to 1993. Twenty years after diagnosis, 156 attended the evaluation in which they were offered routine clinical blood tests and colonoscopies. Ninety-six patients were examined by MRE and LI scores were calculated. The independent association of the LI score with clinical variables was examined by univariate analysis. RESULTS: Sixty-five patients (67.7%) had CD manifestations based on findings from MRE (36.9%), colonoscopy (29.2%), or both (33.9%). MRE findings changed disease classification for 8 patients (8.3%). The median LI score was 4.6 (interquartile range, 17.5) and associated with younger age (P = .02), complicated ileocolonic phenotype (P < .001), and use of biologic (P < .001), or immunosuppressant therapies (P = .045). Factors independently associated with LI score during the follow-up period were age, complicated disease, use of medication, and markers of inflammation. CONCLUSIONS: In a population-based study of 237 patients with CD in Norway, we found that almost 68% had imaging features of CD, half of which were only detectable by MRE. LI score associated with ongoing active disease. Young age, complicated disease, and persistent inflammation were associated with bowel damage.

Anti-GP2 IgA autoantibodies are associated with poor survival and cholangiocarcinoma in primary sclerosing cholangitis.

OBJECTIVE: Pancreatic autoantibodies (PABs), comprising antibodies against glycoprotein 2 (anti-GP2), are typically associated with complicated phenotypes in Crohn's disease, but have also been observed with variable frequencies in patients with UC. In a previous study, we observed a high frequency of primary sclerosing cholangitis (PSC) in patients with anti-GP2-positive UC. We therefore aimed to characterise the role of anti-GP2 in PSC. DESIGN: In an evaluation phase, sera from 138 well-characterised Norwegian patients with PSC were compared with healthy controls (n=52), and patients with UC without PSC (n=62) for the presence of PABs by indirect immunofluorescence. Further, 180 German patients with PSC served as a validation cohort together with 56 cases of cholangiocarcinoma without PSC, 20 of secondary sclerosing cholangitis (SSC) and 18 of autoimmune hepatitis. RESULTS: Anti-GP2 IgA specifically occurred at considerable rates in large bile duct diseases (cholangiocarcinoma=36%, PSC and SSC about 50%). In PSC, anti-GP2 IgA consistently identified patients with poor survival during follow-up (Norwegian/German cohort: p Log Rank=0.016/0.018). Anti-GP2 IgA was associated with the development of cholangiocarcinoma in both PSC cohorts, yielding an overall OR of cholangiocarcinoma in patients with anti-GP2 IgA-positive PSC of 5.0 (p=0.001). Importantly, this association remained independent of disease duration, bilirubin level and age. CONCLUSIONS: Anti-GP2 IgA can be hypothesised as a novel marker in large bile duct diseases. In particular, in PSC, anti-GP2 IgA identified a subgroup of patients with severe phenotype and poor survival due to cholangiocarcinoma. Anti-GP2 IgA may therefore be a clinically valuable tool for risk stratification in PSC.

Prevalence of Sclerosing Cholangitis Detected by Magnetic Resonance Cholangiography in Patients With Long-term Inflammatory Bowel Disease.

BACKGROUND & AIMS: The prevalence of primary sclerosing cholangitis (PSC) among patients with inflammatory bowel disease (IBD) is unclear. Patients with IBD might be screened for PSC using magnetic resonance cholangiography (MRC). We aimed to estimate the frequency and distribution of MRC-detected lesions that indicate PSC in patients with IBD 20 years after their initial diagnosis and to identify clinical characteristics associated with these findings. METHODS: We performed a follow-up analysis of a population-based cohort of 756 patients in South-Eastern Norway diagnosed with IBD from January 1, 1990 through December 31, 1993. Of these subjects, 470 attended a follow-up evaluation 20 years later in which they were offered routine clinical blood testing and ileocolonoscopy; 322 were screened by MRC (222 with ulcerative colitis and 100 with Crohn's disease). Two radiologists independently evaluated results from the MRC examinations. RESULTS: In the MRC examination, 24 patients (7.5%) were found to have PSC-like lesions; only 7 of these patients (2.2%) were known to have PSC. One patient was initially missed and 1 had small-duct PSC, so the final prevalence of PSC was 8.1%. Extensive colitis, a high prevalence of colectomy, and chronic and continuous symptoms of IBD occurred in significantly more patients with suspected PSC than without PSC (P = .029, P = .002, and P = .012, respectively). Among patients with subclinical features of PSC, the MRC progression score for PSC increased when they were re-examined after a median 3.2 years (P = .046). CONCLUSIONS: Using MRC analysis of patients with long-term IBD, we found the prevalence of PSC to be around 3-fold higher than that detected based on symptoms. Sixty-five percent of patients had subclinical PSC associated with progressive IBD, with no biochemical abnormalities and mild disease, based on radiology findings. PSC appears to progress in patients with subclinical disease, but long-term outcomes are not known.

PNPLA3 in end-stage liver disease: alcohol consumption, hepatocellular carcinoma development, and transplantation-free survival.

BACKGROUND AND AIMS: The rs738409 variant (I148M) of the patatin-like phospholipase domain-containing protein 3 (PNPLA3) gene is associated with several liver malfunctions. Its impact on end-stage liver disease has not been addressed yet. METHODS: The I148M polymorphism was genotyped in a well-characterized cohort of 421 Caucasian patients and retrospectively analyzed from the time of enrollment at Eurotransplant. RESULTS: The G allele of the I148M variant was significantly overrepresented in patients with alcoholic liver disease (ALD, P < 0.001) and associated with hepatocellular carcinoma (HCC) development (odds ratio [OR] = 2.399; 95% confidence interval [CI]: 1.292-4.455; P = 0.008) while not affecting the other liver disease entities. Time until hydropic decompensation (P = 0.04) and hepatic encephalopathy (P = 0.043) was significantly impaired for ALD patients carrying either one or two mutated G alleles. Actuarial survival free of liver transplantation was further reduced for ALD carriers of the I148M variant (CC = 30.7 months ± 7.9, 95% CI: 15.1-46.2 vs CG/GG: 17.1 months ± 3.3, 95% CI: 3.3-10.6; P = 0.012) compared with wild-type patients. Cox multivariate analysis identified the PNPLA3 I148M genotype as an independent predictor actuarial survival free of liver transplantation (OR = 1.77; 95% CI: 1.27-2.47; P = 0.001). CONCLUSIONS: In end-stage liver disease patients, we identified ALD to be predominantly affected by the PNPLA3 I148M variant resulting in an increased risk of HCC and reduced transplantation free survival. Genetic testing of the I148M genotype in ALD patients awaiting liver transplantation might be beneficial for these patients.

Effects of coffee consumption, smoking, and hormones on risk for primary sclerosing cholangitis.

BACKGROUND & AIMS: Little is known about nongenetic risk factors for primary sclerosing cholangitis (PSC), except a possible protective effect of smoking. We investigated the relationship between environmental risk factors and susceptibility to PSC. METHODS: A questionnaire was distributed to patients with PSC, recruited from Oslo University Hospital Rikshospitalet in Norway through 2011, and randomly chosen individuals from the Norwegian Bone Marrow Donor Registry (control subjects). Data were analyzed from 240 patients with PSC and 245 control subjects, matched for gender and age. RESULTS: A lower proportion of patients with PSC were daily coffee drinkers than control subjects, both currently (76% vs 86%; odds ratio [OR], 0.52; 95% confidence interval [CI], 0.32-0.82; P = .006) and at the age of 18 years (35% vs 49%; OR, 0.58; 95% CI, 0.40-0.83; P = .003). The associations were mainly attributed to differences observed in men. Twenty percent of the patients were ever (current or former) daily smokers compared with 43% of control subjects (OR, 0.33; 95% CI, 0.22-0.50; P < .001). Ever daily smoking before PSC diagnosis was associated with older age at diagnosis (42 years vs 32 years; P < .001). Ever daily smoking (P < .001) and being a coffee drinker at the age of 18 years (P = .048) were independently and negatively associated with PSC. Fewer female patients with PSC than control subjects reported ever use of hormonal contraception (51% vs 85%; P < .001). Among female patients, there was a strong correlation between increasing number of children before the diagnosis of PSC and increasing age at diagnosis (r = 0.63; P < .001). CONCLUSIONS: Coffee consumption and smoking might protect against development of PSC. In women, the disease might be influenced by hormonal factors.

FUT2 and FUT3 genotype determines CA19-9 cut-off values for detection of cholangiocarcinoma in patients with primary sclerosing cholangitis.

BACKGROUND & AIMS: Allelic variants of fucosyltransferases 2 and 3 (FUT2/3) influence serum levels of CA19-9, a screening parameter commonly used for detection of biliary malignancy in PSC. We aimed at improving diagnostic accuracy of CA19-9 by determining the impact of FUT2/3 genotypes. METHODS: CA19-9 levels were measured in 433 PSC patients, 41 of whom had biliary malignancy. Genotypes for FUT3 and FUT2 were used to assign patients to one of three groups: A, no FUT3 activity regardless of FUT2 activity; B, both FUT2 and FUT3 activity and C, no FUT2 activity without loss of FUT3 activity. Group-specific cut-off values were determined by Youden's index. RESULTS: The median CA19-9 values of cancer-free patients were significantly different (p<0.001) in Groups A (2.0U/ml), B (17.0U/ml), and C (37.0U/ml). Biliary malignancy patients in Groups B and C had significantly higher CA19-9 values than cancer-free patients (p<0.001). The optimal cut-off, as determined by ROC analysis, for all patients was 88.5U/ml. Optimal cut-off values in Groups A, B, and C were 4.0U/ml, 74.5U/ml, and 106.8U/ml, respectively. Use of these values improved sensitivity of CA19-9 in Groups B and C. Further, use of group-dependent cut-off values with 90% sensitivity resulted in a 42.9% reduction of false positive results. CONCLUSIONS: Use of FUT2/3 genotype-dependent cut-off values for CA19-9 improved sensitivity and reduced the number of false positive results.

Extended analysis of a genome-wide association study in primary sclerosing cholangitis detects multiple novel risk loci.

BACKGROUND & AIMS: A limited number of genetic risk factors have been reported in primary sclerosing cholangitis (PSC). To discover further genetic susceptibility factors for PSC, we followed up on a second tier of single nucleotide polymorphisms (SNPs) from a genome-wide association study (GWAS). METHODS: We analyzed 45 SNPs in 1221 PSC cases and 3508 controls. The association results from the replication analysis and the original GWAS (715 PSC cases and 2962 controls) were combined in a meta-analysis comprising 1936 PSC cases and 6470 controls. We performed an analysis of bile microbial community composition in 39 PSC patients by 16S rRNA sequencing. RESULTS: Seventeen SNPs representing 12 distinct genetic loci achieved nominal significance (p(replication) <0.05) in the replication. The most robust novel association was detected at chromosome 1p36 (rs3748816; p(combined)=2.1 × 10(-8)) where the MMEL1 and TNFRSF14 genes represent potential disease genes. Eight additional novel loci showed suggestive evidence of association (p(repl) <0.05). FUT2 at chromosome 19q13 (rs602662; p(comb)=1.9 × 10(-6), rs281377; p(comb)=2.1 × 10(-6) and rs601338; p(comb)=2.7 × 10(-6)) is notable due to its implication in altered susceptibility to infectious agents. We found that FUT2 secretor status and genotype defined by rs601338 significantly influence biliary microbial community composition in PSC patients. CONCLUSIONS: We identify multiple new PSC risk loci by extended analysis of a PSC GWAS. FUT2 genotype needs to be taken into account when assessing the influence of microbiota on biliary pathology in PSC.

Genome-wide association analysis in primary sclerosing cholangitis identifies two non-HLA susceptibility loci.

Primary sclerosing cholangitis (PSC) is a chronic bile duct disease affecting 2.4-7.5% of individuals with inflammatory bowel disease. We performed a genome-wide association analysis of 2,466,182 SNPs in 715 individuals with PSC and 2,962 controls, followed by replication in 1,025 PSC cases and 2,174 controls. We detected non-HLA associations at rs3197999 in MST1 and rs6720394 near BCL2L11 (combined P = 1.1 × 10⁻¹6 and P = 4.1 × 10⁻8, respectively).

Autoantibodies in primary sclerosing cholangitis.

The aetiology of primary sclerosing cholangitis (PSC) is not known and controversy exists as to whether PSC should be denominated an autoimmune disease. A large number of autoantibodies have been detected in PSC patients, but the specificity of these antibodies is generally low, and the frequencies vary largely between different studies. The presence of autoantibodies in PSC may be the result of a nonspecific dysregulation of the immune system, but the literature in PSC points to the possible presence of specific antibody targets in the biliary epithelium and in neutrophil granulocytes. The present review aims to give an overview of the studies of autoantibodies in PSC, with a particular emphasis on the prevalence, clinical relevance and possible pathogenetic importance of each individual marker.