Human enterovirus species B in ileocecal Crohn's disease.

OBJECTIVES: Advanced ileocecal Crohn's disease (ICD) is characterized by strictures, inflammation in the enteric nervous system (myenteric plexitis), and a high frequency of NOD2 mutations. Recent findings implicate a role of NOD2 and another CD susceptibility gene, ATG16L1, in the host response against single-stranded RNA (ssRNA) viruses. However, the role of viruses in CD is unknown. We hypothesized that human enterovirus species B (HEV-B), which are ssRNA viruses with dual tropism both for the intestinal epithelium and the nervous system, could play a role in ICD. METHODS: We used immunohistochemistry and in situ hybridization to study the general presence of HEV-B and the presence of the two HEV-B subspecies, Coxsackie B virus (CBV) and Echovirus, in ileocecal resections from 9 children with advanced, stricturing ICD and 6 patients with volvulus, and in intestinal biopsies from 15 CD patients at the time of diagnosis. RESULTS: All patients with ICD had disease-associated polymorphisms in NOD2 or ATG16L1. Positive staining for HEV-B was detected both in the mucosa and in myenteric nerve ganglia in all ICD patients, but in none of the volvulus patients. Expression of the cellular receptor for CBV, CAR, was detected in nerve cell ganglia. CONCLUSIONS: The common presence of HEV-B in the mucosa and enteric nervous system of ICD patients in this small cohort is a novel finding that warrants further investigation to analyze whether HEV-B has a role in disease onset or progress. The presence of CAR in myenteric nerve cell ganglia provides a possible route of entry for CBV into the enteric nervous system.

Genome-wide association study of susceptibility loci for cervical cancer.

BACKGROUND: Cervical carcinoma has a heritable genetic component, but the genetic basis of cervical cancer is still not well understood. METHODS: We performed a genome-wide association study of 731 422 single nucleotide polymorphisms (SNPs) in 1075 cervical cancer case subjects and 4014 control subjects and replicated it in 1140 case subjects and 1058 control subjects. The association between top SNPs and cervical cancer was estimated by odds ratios (ORs) and 95% confidence intervals (CIs) with unconditional logistic regression. All statistical tests were two-sided. RESULTS: Three independent loci in the major histocompatibility complex (MHC) region at 6p21.3 were associated with cervical cancer: the first is adjacent to the MHC class I polypeptide-related sequence A gene (MICA) (rs2516448; OR = 1.42, 95% CI = 1.31 to 1.54; P = 1.6×10(-18)); the second is between HLA-DRB1 and HLA-DQA1 (rs9272143; OR = 0.67, 95% CI = 0.62 to 0.72; P = 9.3×10(-24)); and the third is at HLA-DPB2 (rs3117027; OR=1.25, 95% CI = 1.15 to 1.35; P = 4.9×10(-8)). We also confirmed previously reported associations of B*0702 and DRB1*1501-DQB1*0602 with susceptibility to and DRB1*1301-DQA1*0103-DQB1*0603 with protection against cervical cancer. The three new loci are statistically independent of these specific human leukocyte antigen alleles/haplotypes. MICA encodes a membrane-bound protein that acts as a ligand for NKG2D to activate antitumor effects. The risk allele of rs2516448 is in perfect linkage disequilibrium with a frameshift mutation (A5.1) of MICA, which results in a truncated protein. Functional analysis shows that women carrying this mutation have lower levels of membrane-bound MICA. CONCLUSIONS: Three novel loci in the MHC may affect susceptibility to cervical cancer in situ, including the MICA-A5.1 allele that may cause impaired immune activation and increased risk of tumor development.

Contribution of TMC6 and TMC8 (EVER1 and EVER2) variants to cervical cancer susceptibility.

Cervical cancer (CxCa) is caused by persistent human papillomavirus (HPV) infection; genetic predisposition is also suspected to play a role. Our study is a targeted candidate gene follow-up based on: (i) strong clinical evidence demonstrating that mutations in the TMC6 and TMC8 (EVER1 and EVER2) genes associate with the HPV-associated disease epidermodysplasia verruciformis (EV) and (ii) recent epidemiological data suggesting a genetic susceptibility conferred by polymorphisms in such genes for skin and CxCa. Clarifying the association of the TMC6/8 genes with risk of CxCa will help in understanding why some HPV-infected women develop persistent infection, cervical lesions and eventually cancer while others do not. Twenty-two single nucleotide polymorphisms (SNPs) harboring the TMC6/8 genes were genotyped in 2,989 cases with cervical intraepithelial neoplasia grade III or invasive CxCa and 2,281 controls from the Swedish population. Association was evaluated in logistic regression models. Two SNPs displayed association with cervical disease: rs2290907 [odds ratio (OR)(GGvsAA) = 0.6, 95% confidence interval (95% CI): 0.3-0.9, p = 0.02)] and rs16970849 (OR(AGvsGG) = 0.8, 95% CI: 0.66-0.98, p = 0.03). The present data support the involvement of the TMC6/8 region in CxCa susceptibility but further analyses are needed to replicate our findings, fully characterize the region and understand the function of the genetic variants involved.

Evaluation of Fanconi anaemia genes FANCA, FANCC and FANCL in cervical cancer susceptibility.

OBJECTIVE: Disrupting the function of any of the 13 Fanconi anaemia (FA) genes causes a DNA repair deficiency disorder, with patients being susceptible to a number of cancer types. Variation in the family of FA genes has been suggested to affect risk of cervical cancer. The current study evaluates the influence of three genes in the FA pathway on cervical cancer risk in Swedish women. METHODS: TagSNPs in FANCA, FANCC and FANCL were selected using the Tagger algorithm in Haploview. A total of 81 tagSNPs were genotyped in 782 cases (CIN3 or ICC) and 775 controls using the Illumina GoldenGate Assay and statistically analyzed for association with cervical cancer. RESULTS: 72 SNPs were successfully genotyped in >98% of the samples. Nominal associations were detected for FANCA rs11649196 (p=0.05) and rs4128763 in FANCC (p=0.02). The associations did not withstand correction for multiple testing. CONCLUSIONS: The current study does not support that genetic variation in FANCA, FANCC or FANCL genes affects susceptibility to cervical cancer in the Swedish population.

Interaction of immunological genes on chromosome 2q33 and IFNG in susceptibility to cervical cancer.

OBJECTIVE: Cervical cancer is caused by persistent infection with human papillomavirus and genetic susceptibility factors may augment disease risk. The immune response consists of complex interactions and it was recently proposed that the association of combinations of genotypes at several genes should be examined. In support of this the combination CD28+17(TT)/IFNG+874(AA) was shown to increase cervical cancer risk in a Brazilian population (VB Guzman et al. New approach reveals CD28 and IFNG gene interaction in the susceptibility to cervical cancer. Hum Mol Genet 2008;17:1838-44) and our aim was to replicate this finding. METHODS: We re-examined the proposed associations by analysis of polymorphisms at CD28, IFNG, TNF, PDCD1, ICOS and CTLA4 in 1306 Swedish cases and 811 controls. RESULTS: Logistic regression analysis detected association at single SNP level for CD28+17 (p=0.01), IFNG+874 (p=0.02), and PDCD1+7785 (p=0.04). The two locus combination CD28+17(TT)/IFNG+874(AA) (OR=0.76 (0.60-0.96, empirical p=0.03) and the three-locus combination CD28+17(TT)/IFNG+874(AA)/ICOS+1564(TT) (OR=0.65(0.49-0.87), empirical p=0.006) were associated with decreased risk. The strongest association was detected for the combination CTLA4-319 (CC)/IFNG (AA) (OR=0.67(0.53-0.84), empirical p=0.0007). CONCLUSION: The observation that these combinations of loci are associated in different populations supports their importance in cervical cancer development although the opposite directions of the effect call for clarification. The polymorphisms studied might not be the functional variants per se, but linked to those exerting a functional effect. The opposite associations in the two populations could then be explained by differences in linkage disequilibrium and population structure.

Comparison between the Hybrid Capture 2 and the hpVIR real-time PCR for detection of human papillomavirus in women with ASCUS or low grade dysplasia.

BACKGROUND: Human papillomavirus (HPV) testing is an important part of cervical carcinoma screening, and the most widely used assay for detection of HPV is Hybrid Capture 2 (HC2). OBJECTIVES: We compare the HC2 with the real-time PCR hpVIR assay for detection of HPV in follow-up smears of 398 women diagnosed with atypical squamous cells of unknown significance (ASCUS) or low grade cervical intraepithelial neoplasia (CIN 1) in their initial smear. STUDY DESIGN: The two assays target the same set of high-risk (HR) HPVs with exception of HPV68. hpVIR identify individual or groups of HPV types as well as their viral load, while HC2 identify HR HPVs without specification of type. RESULTS: 34% (131/391) of the women were positive with HC2 and 45% (175/391) with hpVIR. 16% (63/391) were positive only with hpVIR and among those with cytology available 6% (3/52) had a CIN 2. The 3% (13/391) of women positive only with HC2 either contained low-risk HPVs or copy numbers below the cut-off for the hpVIR assay. CONCLUSION: The hpVIR assay has a similar sensitivity and specificity as HC2, but hpVIR detect a higher frequency of high-risk HPV infections.