A Genome-wide Association Study Identifying RAP1A as a Novel Susceptibility Gene for Crohn's Disease in Japanese Individuals

BACKGROUND AND AIMS

Genome-wide association studies [GWASs] of European populations have identified numerous susceptibility loci for Crohn's disease [CD]. Susceptibility genes differ by ethnicity, however, so GWASs specific for Asian populations are required. This study aimed to clarify the Japanese-specific genetic background for CD by a GWAS using the Japonica array [JPA] and subsequent imputation with the 1KJPN reference panel.

METHODS

Two independent Japanese case/control sets (Tohoku region [379 CD patients, 1621 controls] and Kyushu region [334 CD patients, 462 controls]) were included. GWASs were performed separately for each population, followed by a meta-analysis. Two additional replication sets [254 + 516 CD patients and 287 + 565 controls] were analysed for top hit single nucleotide polymorphisms [SNPs] from novel genomic regions.

RESULTS

Genotype data of 4 335 144 SNPs from 713 Japanese CD patients and 2083 controls were analysed. SNPs located in TNFSF15 (rs78898421, Pmeta = 2.59 × 10-26, odds ratio [OR] = 2.10), HLA-DQB1 [rs184950714, pmeta = 3.56 × 10-19, OR = 2.05], ZNF365, and 4p14 loci were significantly associated with CD in Japanese individuals. Replication analyses were performed for four novel candidate loci [p <1 × 10-6], and rs488200 located upstream of RAP1A was significantly associated with CD [pcombined = 4.36 × 10-8, OR = 1.31]. Transcriptome analysis of CD4+ effector memory T cells from lamina propria mononuclear cells of CD patients revealed a significant association of rs488200 with RAP1A expression.

CONCLUSIONS

RAP1A is a novel susceptibility locus for CD in the Japanese population.

Tacrolimus Dose Optimization Strategy for Refractory Ulcerative Colitis Based on the Cytochrome P450 3A5 Polymorphism Prediction Using Trough Concentration after 24 Hours

BACKGROUND

In the tacrolimus treatment for refractory ulcerative colitis (UC), dose adjustment is necessary because the required doses to keep appropriate drug concentrations are significantly different among individuals. Cytochrome P450 (CYP) 3A5 polymorphism affects tacrolimus blood concentrations. However, it is difficult to obtain genetic information in real clinical practice. In the present study, we investigated possible factors that may predict CYP3A5 polymorphism and proposed a dose optimization strategy based on the obtained predicting factors.

SUMMARY

We retrospectively analyzed 41 patients who underwent remission induction therapy with tacrolimus for UC in our hospital. First, we performed a correlation analysis of CYP3A5 polymorphism and pharmacokinetics. In the CYP3A5 non-expressers, the dose of tacrolimus (mg/kg) was lower and dose-adjusted trough levels (ng/mL per mg/kg) were higher compared with those in expressers. Next, we investigated factors that could predict CYP3A5 polymorphism. Trough concentration 24 h following tacrolimus administration was extracted as a significant factor. When the trough cutoff value at 24 h was set to 2.6 ng/mL, sensitivity and specificity for estimation of CYP3A5 polymorphism were 63 and 96% respectively. Therefore, when the trough concentration 24 h after administration is ≤2.6 ng/mL, the patient can be estimated as a CYP3A5 expresser and an increase in dose should be proposed. Key Message: The trough concentration 24 h after the first tacrolimus administration appears to be a useful predictor of -CYP3A5 polymorphism. Performing dose optimization strategy based on the prediction of CYP3A5 polymorphism can lead to earlier and safer remission induction.

Allele-specific DNA methylation of disease susceptibility genes in Japanese patients with inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) has an unknown etiology; however, accumulating evidence suggests that IBD is a multifactorial disease influenced by a combination of genetic and environmental factors. The influence of genetic variants on DNA methylation in cis and cis effects on expression have been demonstrated. We hypothesized that IBD susceptibility single-nucleotide polymorphisms (SNPs) regulate susceptibility gene expressions in cis by regulating DNA methylation around SNPs. For this, we determined cis-regulated allele-specific DNA methylation (ASM) around IBD susceptibility genes in CD4+ effector/memory T cells (Tem) in lamina propria mononuclear cells (LPMCs) in patients with IBD and examined the association between the ASM SNP genotype and neighboring susceptibility gene expressions.

METHODS

CD4+ effector/memory T cells (Tem) were isolated from LPMCs in 15 Japanese IBD patients (ten Crohn's disease [CD] and five ulcerative colitis [UC] patients). ASM analysis was performed by methylation-sensitive SNP array analysis. We defined ASM as a changing average relative allele score ([Formula: see text]) >0.1 after digestion by methylation-sensitive restriction enzymes. Among SNPs showing [Formula: see text] >0.1, we extracted the probes located on tag-SNPs of 200 IBD susceptibility loci and around IBD susceptibility genes as candidate ASM SNPs. To validate ASM, bisulfite-pyrosequencing was performed. Transcriptome analysis was examined in 11 IBD patients (seven CD and four UC patients). The relation between rs36221701 genotype and neighboring gene expressions were analyzed.

RESULTS

We extracted six candidate ASM SNPs around IBD susceptibility genes. The top of [Formula: see text] (0.23) was rs1130368 located on HLA-DQB1. ASM around rs36221701 ([Formula: see text] = 0.14) located near SMAD3 was validated using bisulfite pyrosequencing. The SMAD3 expression was significantly associated with the rs36221701 genotype (p = 0.016).

CONCLUSIONS

We confirmed the existence of cis-regulated ASM around IBD susceptibility genes and the association between ASM SNP (rs36221701) genotype and SMAD3 expression, a susceptibility gene for IBD. These results give us supporting evidence that DNA methylation mediates genetic effects on disease susceptibility.

Increased expression of IL12B mRNA transcribed from the risk haplotype for Crohn's disease is a risk factor for disease relapse in Japanese patients

BACKGROUND

IL12B is a promising candidate for a susceptibility gene in Crohn's disease (CD). The aim of this study was to perform a candidate gene analysis of IL12B in Japanese CD patients, investigate whether the genotype is associated with disease phenotypes, and determine how the risk allele affects susceptibility to CD.

METHODS

Three hundred seventy-five patients with CD, 265 patients with ulcerative colitis, and 463 healthy controls were examined. Ten single-nucleotide polymorphisms (SNPs) around IL12B were genotyped. Case-control and subphenotype (including disease course) analyses were performed. The allelic expression ratio of IL12B messenger RNA (mRNA) was examined by a SNaPshot analysis in lipopolysaccharide-stimulated monocytes.

RESULTS

Four SNPs located upstream of the IL12B gene were significantly associated with CD. A conditional analysis revealed that these associations included two independent signals tagged by IL12B_1 and IL12B_3 (P = 9.42 × 10^-6 and  1.49 × 10^-4 respectively). IL12B_3 was also associated with earlier relapse in CD (P = 0.0144). The allelic expression ratios of IL12B mRNA transcribed from the risk haplotype to the protective haplotype tagged by IL12B_3 in lipopolysaccharide-stimulated monocytes from ten healthy controls heterozygous for IL12B_3 were significantly higher than that of the respective genomic DNA (P = 0.00923). No SNP was associated with ulcerative colitis.

CONCLUSIONS

We confirmed the association of SNPs located upstream of IL12B with CD in Japanese patients. The demonstrated allelic expression imbalance supports the idea that the IL12B risk haplotype confers susceptibility not only to CD onset but to also relapse through increased IL12B mRNA expression.

ATP-binding cassette subfamily B member 1 1236C/T polymorphism significantly affects the therapeutic outcome of tacrolimus in patients with refractory ulcerative colitis

BACKGROUND AND AIM

Tacrolimus is now considered to be one of the main therapeutic options for refractory ulcerative colitis. Both cytochrome P-450 3A5 (CYP3A5) and ATP-binding cassette subfamily B member 1 (ABCB1) associated with tacrolimus metabolism are known to have several genetic polymorphisms. However, it remains controversial whether these polymorphisms affect the therapeutic efficacy for ulcerative colitis. We aimed to investigate the influence of both CYP3A5 and ABCB1 polymorphisms on the efficacy of tacrolimus in ulcerative colitis treatment under the tight dose-adjusting strategy.

METHODS

Sixty-one Japanese patients with ulcerative colitis treated with tacrolimus were enrolled retrospectively. Tacrolimus treatment was performed using the tight dose-adjusting strategy. Genotyping for CYP3A5*3, ABCB1 1236C>T, 2677G>A,T, and 3435C>T were performed, and the clinical outcomes at 12 weeks after the initiation of tacrolimus were compared among the genotypes.

RESULTS

There was no association between the CYP3A5 genotypes and therapeutic efficacy. In contrast, a significant association was observed with the ABCB1 1236C > T polymorphism and therapeutic efficacy. The ABCB1 1236CC+CT groups (n = 41) had a significantly higher response rate (73% vs 35%; P = 0.004) and remission rate (61% vs 20%; P = 0.002) than the TT group (n = 20). The multivariate logistic regression analysis also revealed that ABCB1 1236C>T was identified as an independent factor associated with remission.

CONCLUSIONS

ABCB1 1236C>T polymorphism significantly affects the therapeutic efficacy of tarcolimus at 12 weeks under the tight dose-adjusting treatment for ulcerative colitis.

Polymorphism at Codon 72 of the p53 Gene Is Not associated With Endometriosis in a Japanese Population

OBJECTIVE

Endometriosis is inherited as a complex trait, which means that multiple susceptibility genes interact with each other and the environment to produce the phenotype. Previous studies have implicated p53, a tumor suppressor gene, as a factor in the development of the disease. In a Japanese population, we investigated the frequency of the p53 polymorphism in women affected with endometriosis.

METHODS

We compared the distribution of the p53 codon 72 polymorphism in endometriosis cases (n = 111) and population controls consisting of female neonates (n = 180) by using polymerase chain reaction restriction fragment-length polymorphism analysis in a Japanese population.

RESULTS

The frequencies of the three p53 genotypes, Arginine (Arg)/Arg, Arg/Proline (Pro), and Pro/Pro in controls were 39.4%, 41.7%, and 18.9 %, respectively. The crude genotype frequencies in the endometriosis cases were similar to those of the controls (35.2%, 48.6%, and 16.2%, respectively). Using the Arg/Arg genotype as the reference, the odds ratios of the Arg/Pro and Pro/Pro genotypes were 1.30 (95% confidence interval [CI] 0.72-1.86, P =.33) and 0.96 (95% CI 0.47-1.94, P =.91), respectively. Thus, there were no significant differences in the frequency of the p53 codon 72 polymorphism between endometriosis cases and controls in this population. The endometriosis cases with severe disease only were also evaluated, but no significant difference was observed in the frequency of the polymorphism between this subgroup and the controls.

CONCLUSION

Our findings suggest that the p53 codon 72 polymorphism is unlikely to be associated with endometriosis in Japanese women.

Increased expression of NKX2.3 mRNA transcribed from the risk haplotype for ulcerative colitis in the involved colonic mucosa

NKX2.3 is a promising candidate for susceptibility genes to inflammatory bowel disease (IBD). The aim of this study was to perform a candidate gene analysis of NKX2.3 in Japanese IBD and to examine how the risk allele (haplotype) affects susceptibility to IBD using allelic expression ratios of NKX2.3 mRNA in the involved colonic mucosa. A total of 344 patients with Crohn's disease (CD), 253 patients with ulcerative colitis (UC), and 243 healthy controls (HCs) were genotyped for 3 tag-single nucleotide polymorphisms (SNPs; rs10883365, rs888208, and rs11596008) around NKX2.3. The allelic expression ratio of NKX2.3-mRNA was examined by TaqMan assay using rs888208 as an allelic (haplotypic) marker. Two SNPs (rs10883365 and rs888208) were significantly associated with UC (p = 7.79 × 10(-4), odds ratio [OR] = 1.54 [95% confidence interval (95% CI) 1.20-1.99], p = 7.70 × 10(-3), OR = 1.41 [95% CI 1.10-1.81], respectively) and 1 SNP (rs10883365) was associated with CD (p = 0.0366, OR = 1.29 [95% CI 1.02-1.63]). Haplotype B formed by the 3 SNPs demonstrated a significant association with UC (p = 6.11 × 10(-4), OR = 1.56 [95% CI 1.21-2.00]). Subgroup analyses indicated that rs10883365 was significantly associated mainly with colonic CD (p = 1.99 × 10(-3), OR = 1.91 [95% CI 1.27-2.88], vs HCs). The allelic expression ratios of NKX2.3 mRNA transcribed from haplotype B (risk haplotype) to haplotype A (the nonrisk haplotype) in the involved mucosa from 10 IBD patients were significantly higher than the allelic ratio of respective genomic DNA (p = 0.00195). We confirmed the association of SNP rs10883365 located in the 5' flanking region of NKX2-3 with Japanese UC and colonic CD and determined the risk haplotype (haplotype B) for UC. The demonstrated allelic expression imbalance supports the idea that the risk haplotype of NKX2.3 confers susceptibility to UC through increasing expression of NKX2.3 mRNA in the colonic mucosa.

What determines the later clinical course of patients who do not undergo colectomy at the first attack? A Japanese cohort study on ulcerative colitis

BACKGROUND/AIMS

Several earlier studies on factors predicting the long-term outcome of ulcerative colitis only encompassed treatment failure for one severe episode, or suffered from a lack of multivariate analyses. We aimed to identify factors assessable at diagnosis or after the first induction therapy which predicted relapse or later colectomy in patients with mild to severe ulcerative colitis.

METHODS

Clinical parameters (age, sex, disease extent, and disease activity at diagnosis) and laboratory data (hemoglobin, albumin, C-reactive protein, and erythrocyte sedimentation rate at diagnosis and 4 weeks after the first induction therapy) were evaluated in 296 patients (median follow-up 87 months). Factors predicting relapse and later colectomy were sought using the Cox proportional hazard model.

RESULTS

The presence of moderate or severe disease at diagnosis were significant predictors of relapse [adjusted hazard ratio (95% CI) 2.07 (1.48-2.89) and 1.70 (1.06-2.72), respectively] and later colectomy [3.40 (1.09-10.54) and 6.77 (1.92-23.86)]. After the first induction therapy, hemoglobin and albumin were associated with relapse [0.87 (0.76-0.99) and 0.58 (0.41-0.83)] and later colectomy [0.60 (0.47-0.77) and 0.11 (0.06-0.22)].

CONCLUSION

Relapse and later colectomy were associated with (1) disease activity at diagnosis and (2) lower levels of hemoglobin and albumin after the first induction therapy.

TNFSF15 transcripts from risk haplotype for Crohn's disease are overexpressed in stimulated T cells

TNFSF15 is a susceptibility gene for Crohn's disease (CD). It remains to be elucidated how the associated single nucleotide polymorphisms (SNPs) in TNFSF15 affect the susceptibility to CD. Because there are no non-synonymous SNPs in TNFSF15, we speculated that one or more of the SNPs associated with CD may act as cis-regulatory SNPs. To reveal the effects of the SNPs on the transcriptional activity of TNFSF15, we first examined the allelic expression imbalance of TNFSF15 in peripheral blood mononuclear cells (PBMCs). When PBMCs stimulated by phytohemagglutinin (PHA) were examined, the allelic ratio of mRNA transcribed from the risk haplotype to the non-risk haplotype increased, compared with the ratio without stimulation. When peripheral blood T cells and Jurkat cells stimulated by phorbol 12-myristate 13-acetate + ionomycin were examined, an allelic expression imbalance similar to that observed in PBMCs stimulated by PHA was confirmed. The promoter assay in stimulated Jurkat cells showed that the luciferase activity of the promoter region (-979 to +35) of the risk haplotype was significantly higher than that of the non-risk haplotype, and deletion and mutagenesis analysis demonstrated that this difference resulted from the -358T/C SNP. The promoter activity of -358C (risk allele) was higher than that of -358T (non-risk allele) in stimulated T cells. This effect of -358T/C on the transcriptional activity in stimulated T cells may confer susceptibility to CD.

HLA-DRB1 alleles influence clinical phenotypes in Japanese patients with ulcerative colitis

The human leukocyte antigen (HLA) region has been implicated in the disease susceptibility of inflammatory bowel disease by several linkage and association studies. In Caucasians, HLA-DRB1 has been reported to determine the clinical phenotypes of ulcerative colitis (UC). Others and we previously reported that HLA-DRB1*1502 was strongly associated with UC in the Japanese population. However, the contribution of HLA-DRB1 to the clinical phenotypes in Japanese UC has not been elucidated yet. The aim of this study was to determine whether HLA-DRB1 alleles were associated with the clinical phenotypes in Japanese patients with UC. A total of 353 patients with UC were recruited. Patients were classified into subgroups by sex, age at diagnosis, disease extent, need for steroid therapy or need for surgical treatment. The allele frequency of HLA-DRB1*08 was significantly higher in patients whose disease extended beyond the rectum (left-sided and extensive UC) than in those with proctitis [odds ratio (OR)=2.20, Pc=0.043). The allele frequency of HLA-DRB1*09 was significantly higher in patients with UC diagnosed at the age of 40 years or older than in those with UC diagnosed before the age of 40 years (OR=2.31, Pc=0.022). Besides these positive associations, no significant differences were found in the allele frequencies between the other subgroups. We conclude that HLA-DRB1*09 is associated with the age at diagnosis and HLA-DRB1*08 is associated with the disease extent of UC in Japanese. These results indicate that HLA-DRB1 is not only associated with the overall UC susceptibility but also associated with the clinical phenotypes in Japanese.

Effect of osmolarity on glycosaminoglycan production and cell metabolism of articular chondrocyte under three-dimensional culture system

OBJECTIVES

This study examined how physiological levels of extracellular osmolarity influence proteoglycan accumulation in articular chondrocytes in a three-dimensional culture system.

METHODS

Cells were obtained from metacarpal phalangeal joints of 18-24 month bovine. They were cultured for 6 days in alginate beads at 4 million cells/ml in DMEM containing 6% FBS under 21% O2. Medium osmolarity was altered by NaCl addition over the range 270-570 mOsm and monitored using a freezing point osmometer. Profiles across intact beads were determined by manual counting using fluorescent probes and transmission electron microscope. Lactate production was measured enzymatically and glycosaminoglycan (GAG) accumulation was measured using a modified dimethylmethylene blue assay. Rate of sulfate GAG synthesis was measured using a standard 35S-sulfate radioactive method.

RESULTS

The cell viability was similar for the high and low osmolarity cultures. However, confocal microscopy showed that the cells were the largest under 270 mOsm and became smaller with increasing osmotic pressure. GAG production was largest in the 370mOsm, and the capacity for GAG production and cell metabolism (lactate production) was low under hypo-osmolarity and hyper-osmolarity, and cell deaths were often observed on electron microscopy.

CONCLUSIONS

In our model the prevailing osmolarity was a powerful regulator of GAG accumulation by cultured chondrocytes. These results thus indicate GAG synthesis rates are regulated by GAG concentration, with implications both for the aetiology of osteoarthritis and for tissue engineering.

Butyrophilin-like 2 gene is associated with ulcerative colitis in the Japanese under strong linkage disequilibrium with HLA-DRB1*1502

The human leukocyte antigen (HLA) region has been implicated in the pathogenesis of inflammatory bowel disease (IBD), which is classified into Crohn's disease (CD) and ulcerative colitis (UC). Recently, an association between sarcoidosis and the butyrophilin-like 2 (BTNL2) gene was reported. BTNL2 is located in the HLA region and its messenger RNA is expressed most abundantly in the intestine. In this study, we performed a case-control association study of BTNL2 in the Japanese patients with IBD and performed linkage disequilibrium (LD) analysis between BTNL2 and HLA-DRB1. We analyzed eight polymorphisms selected after direct sequencing and found that none of the polymorphisms were associated with the Japanese CD cohort. In contrast, five polymorphisms were significantly associated with UC, especially three single nucleotide polymorphisms (BTNL2_19, BTNL2_22 and BTNL2_23) were associated as a haplotype. The most frequent haplotype (GGC haplotype) was a low-risk haplotype (P= 0.000052), whereas the other TCT haplotype was a high-risk haplotype (P= 0.0000085). Among the eight polymorphisms, the strongest association with UC was found in BTNL2_19 (OR = 1.92, P= 0.0000035). As expected, the BTNL2_19-T allele showed strong LD with DRB1*1502 (D'= 0.92). When BTNL2_19 was tested as conditional on the DRB1*1502 carrier status, the significant association disappeared, suggesting that the association was because of its strong LD with DRB1*1502. We conclude that BTNL2 does not contribute to the susceptibility to Japanese CD but is associated with Japanese UC because of the strong LD with HLA-DRB1*1502. The strong LD between BTNL2 and HLA-DRB1 raises another issue about the potential role of BTNL2 in other diseases associated with HLA-DRB1.

Mapping of a disease susceptibility locus in the HLA region for Primary Biliary Cirrhosis in Japan

AIMS

Primary biliary cirrhosis (PBC) is a chronic progressive cholestatic disease of unknown pathogenesis. However, several reports have demonstrated the involvement of genetic backgrounds in this syndrome. The aim of this study is to examine the genetic disequilibrium in the HLA region in Japanese patients using six microsatellite markers.

METHODS

Genomic DNAs were obtained from 73 patients with PBC (patient cohort) and 186 healthy volunteers (control cohort). Genetic polymorphisms at six microsatellite markers (D6S1568, DQ.CAR, D6S273, TNF-d, C1-2-A, C3-2-11) were determined using fluorescence-labeled polymerase chain reaction (PCR) genetic analyzer. Allele frequencies were estimated by direct counting and the genotypic differentiation test was performed by the Markov chain method using Genepop software.

RESULTS

Among these six microsatellite markers, four markers in the patients significantly (P < 0.05) deviated from the Hardy-Weinberg equilibrium: DQ.CAR (P = 0.0278), D6S273 (P = 0.0168), TNF-d (P = 0.0089) and C1-2-A (P = 0.0005). Genotypic differentiation test between the patients and controls demonstrated that DQ.CAR (P = 0.0111), TNF-d (P = 0.0051) and C1-2-A (P = 0.0371) were significant. Finally, allelic association test revealed before correction for multiple testing demonstrated allele125 of TNF-d (P = 0.00065, Pc = 0.0052) and allele246 of C1-2-A (P = 0.0026 Pc = 0.033) had significant association after Bonferroni's correction.

CONCLUSION

Disequilibrium mapping using microsatellite markers was a useful method to narrow a disease susceptibility locus. The possible susceptibility gene in the HLA region is thought to be localized around or in the TNF gene. Further studies seem feasible using more closely distributed microsatellite markers or single nucleotide polymorphisms (SNPs) to narrow the susceptibility locus in PBC in Japanese populations.

TUCAN (CARD8) genetic variants and inflammatory bowel disease

BACKGROUND & AIMS

The identification of the association between Crohn's disease (CD) and NOD2 (CARD15) confirmed both the heritability of CD and highlighted the role of the nuclear factor kappaB (NFkappaB) pathway in disease pathogenesis. Other susceptibility loci exist. TUCAN (CARD8) is located beneath a CD peak of linkage on chromosome 19q. TUCAN is expressed in the gut and is a negative regulator of NFkappaB, making it an excellent candidate gene for gastrointestinal inflammation.

METHODS

Ten single nucleotide polymorphisms (SNP) across TUCAN were genotyped in 365 controls, 372 patients with CD, and 373 patients with ulcerative colitis. A diagnostic panel for CD was constructed using smoking status and TUCAN, NOD2, IBD5, NOD1, and TNFSF15 data.

RESULTS

We demonstrate significant association between a TUCAN SNP and CD (OR 1.35, P = .0083). The association was more pronounced with disease affecting sites other than the colon (odds ratio, 1.52) and NOD2-negative CD (odds ratio, 1.50). Combination of these data with smoking and NOD2, IBD5, NOD1, and TNFSF15 status demonstrated very strong associations with CD and high sensitivities (96.3%), specificities (99.4%), and likelihood ratios (12.8) for CD, although further work will be needed before this model can be translated into direct clinical utility.

CONCLUSIONS

We have shown an association between a likely functional polymorphism in TUCAN and CD. The combination of these data in a genetic panel suggests that clinicians may soon be able to translate genetic advances into direct benefits for patients.

Efficacy and safety of endoscopic balloon dilation for Crohn's strictures

PURPOSE

This study was designed to investigate retrospectively the efficacy and safety of endoscopic balloon dilation for intestinal strictures in Crohn's disease.

METHODS

Sixteen patients with 20 strictures were treated. The stricture sites were as follows: at the ileocolonic (n = 6) or ileoileal (n = 1) anastomosis, in the colon (n = 10), ileum (n = 2), and at the ileocecal valve (n = 1). The dilations were performed with through-the-scope balloons, with diameters of 15 to 20 mm on inflation and lengths of 30 to 80 mm.

RESULTS

In 15 of 16 patients, the strictures were successfully dilated and the symptoms caused by the strictures disappeared after the first session. The patients were followed for a median of 38.5 months. Repeat symptomatic stricture formation occurred after a mean of 19.7 months in seven patients. Four patients needed second-round dilation and three patients were treated surgically. Complications occurred in four patients who had primary strictures: bleeding in one, high fever in one, and colorectal perforation in two. One of the patients complicated with colorectal perforation was treated surgically, and the other was treated conservatively. The cumulative nonsurgical rates for the dilation strictures were 93 percent at 12 months and 65 percent at 36 months, respectively. Three patients were treated surgically because of strictures or fistulas that were not related to the procedure of dilation. As a whole, the cumulative nonsurgical rates were 81 percent at 12 months and 46 percent at 36 months. Nine patients (56.3 percent) were able to avoid surgery.

CONCLUSIONS

Using endoscopic balloon dilation, it may be possible to avoid or postpone surgery. Primary strictures seem to have increased risk of perforation.

IL-10 deficiency leads to somatic mutations in a model of IBD

Individuals with inflammatory bowel disease (IBD) are at increased risk of developing gastrointestinal cancer. Here, we have tested the possibility that chronic inflammation could trigger mutations. For this, we have used IL-10-deficient (IL-10-/-) mice, which spontaneously develop intestinal inflammation, in combination with a transgenic gpt gene and red/gam gene (gpt+IL-10-/-), which is a well-characterized mutation reporter locus. The total mutation frequency in the colon of gpt+IL-10-/- mice was about five times higher than that in normal gpt+IL-10+/+ mice. In the particular case of G:C to A:T transitions, the frequency of mutations in gpt+IL-10-/- mice was 4.1 times higher than that in control mice. Interestingly, the frequency of small deletions and insertions was also strikingly increased (approximately 10 times). The majority of the deletion or insertion mutations were observed in the monotonous base runs or adjacent repeats of short tandem sequences. In contrast, the frequency of large deletions, detected by loss of the Spi marker present in the red/gam transgene, was similar among the mouse strains. Finally, as a control, the mutation frequency in non-inflamed tissues, such as the liver, were similar between gpt+IL-10-/- mice and gpt+IL-10+/+ mice. Our data demonstrate that the chronic inflammatory environment in the colon promotes the generation of mutations.

Lack of association between IBD5 and Crohn's disease in Japanese patients demonstrates population-specific differences in inflammatory bowel disease

OBJECTIVE

Population-specific differences in the genetic susceptibility to inflammatory bowel disease (IBD) are indicated by the fact that Crohn's disease (CD) in Japanese patients does not have any of the common CARD15 variants that are associated with CD in Caucasians. Recently, the disease-causing mutation in the IBD5 haplotype was identified. The TC haplotype, composed of L503F in SLC22A4 and -207G/C in SLC22A5 promoters, was reported to alter the function of the organic cation transporter and to be associated with CD in Caucasians. To determine whether the TC haplotype is also associated with IBD in a Japanese population, we genotyped L503F and -207G/C variants in Japanese subjects. Furthermore, we also performed a case-control association study with all representative single nucleotide polymorphisms (SNPs) in IBD5 using previous information of linkage disequilibrium extension reported in Japanese patients to determine whether there were variants in IBD5 specifically associated with IBD in Japanese patients.

MATERIAL AND METHODS

A total of 758 Japanese individuals, 241 patients with CD, 247 patients with ulcerative colitis (UC) and 270 healthy controls, were analyzed in this study. Genotyping for SNPs was determined by polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

We found L503F and -207G/C to be very rare (<1% frequency) in CD, UC and HC in the Japanese population. Furthermore, we also found that none of the representative SNPs in IBD5 was associated with CD or UC in the Japanese subjects.

CONCLUSIONS

In contrast to Caucasians, IBD5 is not a major component of the susceptibility to IBD in the Japanese population.

Muramyl dipeptide and toll-like receptor sensitivity in NOD2-associated Crohn's disease

Both NOD2 (CARD15) alleles are mutated in roughly 15% of patients with Crohn's disease, but functional effects are unclear. We analysed the cytokine response of peripheral blood mononuclear cells to muramyl dipeptide (MDP), the ligand for NOD2. MDP induced little TNFalpha or interleukin 1beta, but strong interleukin-8 secretion. MDP also substantially upregulated secretion of TNFalpha and interleukin 1beta induced by toll-like receptor ligands. These effects were abolished by the most common Crohn's NOD2 double mutant genotypes at low nanomolar MDP concentrations, and provide the basis to develop a test of NOD2 functional deficiency. In Crohn's disease, there are defects in neutrophil recruitment driven by NOD2 and interleukin 8 and in cross talk between the NOD2 and toll-like receptor pathways, which suggests that the immune system fails to receive an early priming signal.

Significance of colonoscopy in patients with intestinal graft-versus-host disease after hematopoietic stem cell transplantation

BACKGROUND AND STUDY AIMS

Patients with intestinal graft-versus-host disease (GVHD) are generally in poor clinical condition. In this study we aimed to establish the clinical significance of endoscopic diagnosis of this condition, observing only the distal section of the large intestine.

PATIENTS AND METHODS

Endoscopic and pathological findings at colonoscopy were evaluated retrospectively in 12 patients who were diagnosed with intestinal GVHD after undergoing hematopoietic stem cell transplantation.

RESULTS

The main mucosal changes observed at endoscopy were granular change, edema, "spotty redness", and sloughing. These were clearly displayed after enhancement with Indigo carmine staining, and with insertion of the colonoscope only as far as the distal section of the large intestine. A histological diagnosis of intestinal GVHD was made in 50 % of the patients, whose intestinal epithelium specimens showed numerous apoptotic bodies. It was possible to perform total colonoscopy in two patients who were in relatively good condition clinically, but there were no remarkable differences in the endoscopic findings throughout the large intestine, from the terminal ileum to the rectum. In terms of clinical outcomes of the 12 patients, their prognosis was poor in that they all either went on to suffer from chronic GVHD or died.

CONCLUSIONS

Endoscopic and histological findings on distal colonoscopy are clinically significant in the diagnosis of intestinal GVHD, and limiting this examination to the distal section of the large intestine avoids causing further clinical deterioration in patients who are already in very poor general condition and the possibility of causing endoscopy-related complications.

Genotype and phenotype relation in inflammatory bowel disease

Genotype-phenotype analysis helps us to discriminate among various subgroups of IBD and consequently helps us to understand the etiology and pathogenesis as well as develop effective treatments for each subgroup of IBD.

Mapping of a disease susceptibility locus in chromosome 6p in Japanese patients with ulcerative colitis

Ulcerative colitis (UC) is a multifactorial disorder with both genetic and environmental factors. HLA-B*52 and DRB1*1502 are reported to be strongly associated with UC in Japan. However, the actual susceptible gene has not been identified yet. In this study, to map precisely the susceptible locus for UC, we performed association mapping in the chromosome 6p using 24 microsatellite markers distributed over 16 Mb. A total of 183 patients with UC and 186 healthy controls (HC) were included in this study. In all, 15 markers around the human leukocyte antigen (HLA) region showed statistical significance in the genotypic differentiation test concerned with the allelic distribution between the UC and HC. Especially, the markers between the centromeric region of HLA class I and the telomeric region of class III showed remarkably low P-values and the allele239 of C2-4-4 in class I marker showed the strongest association (Pc=2.9 x 10(-9): OR=3.74, 95% CI=2.50-5.60). Furthermore, we found strong linkage disequilibrium (LD) between the allele239 of C2-4-4 and HLA-B*52 in haplotype analysis. These results provide evidence that, in Japanese, important determinants of disease susceptibility to UC may exist in HLA, especially between the centromeric region of class I and the telomeric region of class III, under the strong LD with HLA-B*52.

Promoter polymorphism of SLC11A1 (formerly NRAMP1) confers susceptibility to autoimmune type 1 diabetes mellitus in Japanese

Defective function of antigen-presenting cells has been postulated to be one of the non-HLA-linked susceptibility factors for type 1 diabetes mellitus, though the underlying genetic factors remain unclear. SLC11A1 (formerly NRAMP1), a divalent cation transporter, plays a crucial role in macrophage activation. We performed a case-control study in 224 healthy and 95 type 1 diabetic Japanese subjects, examining the length polymorphisms in the promoter region (-377 to -222) of SLC11A1, which may influence transcriptional activity. Alleles designated 2, 3, and 7 have been identified in Japanese subjects. The frequency of allele 7 was significantly higher in subjects with type 1 diabetes (9.47%) than in the healthy controls (4.46%). The difference is more marked in the subpopulation of Japanese subjects with type 1 diabetes; diabetic subjects with at least one protective HLA class II allele and those without any susceptibility HLA class II haplotypes, DR4-DQ4 or DR9-DQ9, had a much higher allele 7 frequency than controls. These findings suggest that the novel promoter polymorphism of SLC11A1 influences the susceptibility to type 1 diabetes in Japanese subjects.

The tumor necrosis factor-alpha promoter -1031C polymorphism is associated with decreased risk of endometriosis in a Japanese population

BACKGROUND

Tumor necrosis factor-alpha (TNF-alpha) is a multifunctional proinflammatory cytokine, associated with various inflammatory and autoimmune diseases. Elevated TNF-alpha levels in peritoneal fluid have been reported in women with endometriosis, suggesting that TNF-alpha may be involved in the development of endometriosis. In this study, we investigated the possible association between endometriosis and the TNF-alpha gene promoter polymorphisms -238G/A, -308G/A, -857C/T, -863C/A and -1031T/C in a Japanese population.

METHODS

We compared the distribution of the -238G/A, -308G/A, -857C/T, -863C/A and -1031T/C polymorphisms in the promoter region of TNF-alpha in 130 endometriosis cases and 185 controls using PCR-RFLP analysis.

RESULTS

The allele frequencies of -238A, -308A, -857T, -863A and -1031C in controls were 2.0%, 1.3%, 19.4%, 17.0% and 18.6%, and in the cases 1.1%, 0.3%, 19.6%, 18.6% and 13.6%, respectively. No significant differences in frequencies were found between the crude endometriosis cases and controls. However, when the endometriosis group was divided into a subgroup of women with stage IV disease only, the frequency of the -1031C allele was significantly lower in this subgroup than controls.

CONCLUSIONS

The variability of the -1031T/C polymorphism of the TNF-alpha gene may be associated with susceptibility to (AUTHOR: as meant?) endometriosis.

Polymorphisms in the estrogen receptor beta gene but not estrogen receptor alpha gene affect the risk of developing endometriosis in a Japanese population

OBJECTIVE

To determine whether polymorphisms in the estrogen receptor (ER) alpha and beta genes are associated with endometriosis in a Japanese population.

DESIGN

Association study.

SETTING

University hospital.

PATIENT(S)

Japanese women diagnosed with endometriosis by laparotomy or laparoscopy.

INTERVENTION(S)

Determination of polymorphisms in the ERalpha and ERbeta genes was performed by polymerase chain reaction restriction fragment-length polymorphism analysis in 132 affected women and 182 controls.

MAIN OUTCOME MEASURE(S)

Frequency and distribution of AluI and RsaI polymorphisms in ERbeta gene and of PvuII and XbaI polymorphisms in ERalpha gene.

RESULT(S)

No significant differences in the frequency of either AluI and RsaI polymorphisms in the ERbeta gene or of XbaI and PvuII polymorphisms in the ERalpha gene were found between endometriosis patients and controls. However, a positive association was noted between the AluI polymorphism in the ERbeta gene and stage IV endometriosis patients in the population studied.

CONCLUSION(S)

The AluI polymorphism in the ERbeta gene is associated with an increased risk of stage IV endometriosis in a Japanese population.

Multiparameter analysis for discreet differential diagnosis of mucosa-associated lymphoid tissue lymphoma in the intestine

BACKGROUND

The diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma in the intestine is occasionally difficult from histological examination on small biopsy specimens obtained by endoscopy. This study focused on unusual cases of reactive lymphoproliferative disorders in the intestine in order to make a differential diagnosis of MALT lymphoma.

MATERIALS AND METHODS

Five patients were examined with regards to clinical symptoms, endoscopic findings and multiparameter analysis (the morphological examination using routine hematoxylin and eosin staining by light microscopy, immunophenotyping by flow cytometry (FCM), immunohistochemistry and genotyping of extracted DNA).

RESULTS

All cases showed an aggregation of lymphocytes and one case showed similar features to lymphoepithelial lesions. Analyses of FCM and genetic rearrangements denied the monoclonality in all cases. Consequently, we considered that all cases should be diagnosed as reactive lymphoid hyperplasia and inflammatory change.

CONCLUSION

Multiparameter analysis is useful in making an exact diagnosis of MALT lymphoma and therefore contributes to prevent unnecessary overtreatment.

Clinical course and longterm prognosis of Japanese patients with Crohn's disease: predictive factors, rates of operation, and mortality

BACKGROUND

The purpose of this study was to clarify the long-term course of Crohn's disease (CD) and predictors of its prognosis in Japan.

METHODS

This was a historical cohort study of 276 patients with CD who had been diagnosed between 1965 and 1998. The clinical course was evaluated by the course of the CD score (CCDS) according to the required treatments. The predictive factors were examined by stepwise regression test. The cumulative rates of operation and survival were calculated by the Kaplan-Meier method.

RESULTS

Patients with colitis-type CD had significantly lower annual and cumulative operation rates than those with other types, and showed significantly better progress, estimated by the CCDS, than patients with ileocolitis type. Reliable predictors for the 2- to 5-year clinical course after starting treatment were the CCDS, the presence of laparotomy during the initial year, and onset at age 30 years or more. The predictors for the 6- to 10-year clinical course were the duration of symptoms at diagnosis and onset at age 16 years or less. The predictors for the 11- to 15-year clinical course were the CCDS, the maximum International Organization of the Study of Inflammatory Bowel Disease (IOIBD) assessment score during the first year after starting treatment, and the effectiveness of the initial treatment. Relative survival rates at 5, 10, 15, and 20 years after the onset were 98.9%, 98.1%, 97.7%, and 94.9%, respectively.

CONCLUSIONS

CD patients with colitis type showed a better clinical course and had significantly different clinical features compared with the patients with ileitis and ileocolitis type. Prediction of the longterm course of CD is possible by using clinical factors during the first year after starting treatment. The relative survival rates in Japanese patients with CD are not different from those seen in Western countries. The purpose of this study was to clarify the long-term course of Crohn's disease (CD) and predictors of its prognosis in Japan.

Microsatellite instability and loss of heterozygosity in the nondysplastic colonic epithelium of ulcerative colitis

Background. A major longterm risk for patients with ulcerative colitis (UC) is the development of colorectal dysplasia and cancer. Microsatellite instability (MI) has now been reported not only in colitic cancers but also in dysplasias, and even in nondysplastic inflamed mucosa. With the conventional microdissection technique, however, contamination by nonepithelial cells cannot be prevented and this could produce less reliable results than other methods. Therefore, we examined the condition of MI and loss of heterozygosity (LOH) of UC epithelium using a crypt isolation technique. Methods. One hundred and twenty-nine biopsy samples from 21 patients with UC were investigated for histology and microsatellite status, using nine microsatellite markers. A total of 1031 polymenase chain reaction (PCR) products were evaluated. Results. We found that no microsatellite markers displayed instability, but LOH at the 3p locus was detected in the nondysplastic epithelium of one patient with longstanding UC. Conclusions. Our study strongly suggests that MI does not contribute to the progression of the colitis-dysplasia sequence.

The IBD6 Crohn's disease locus demonstrates complex interactions with CARD15 and IBD5 disease-associated variants

Genetic studies in inflammatory bowel disease have identified multiple susceptibility loci, whose relevance depends critically on verification in independent cohorts. Genetic variants associated with Crohn's disease have now been identified on chromosomes 5 (IBD5/5q31 risk haplotype) and 16 (IBD1 locus, CARD15/NOD2 mutations). Stratification of genome-wide linkage analyses by disease associated variants is now possible, offering both increased power for identification of other loci and improved understanding of genetic mechanisms. We performed a genome-wide scan of 137 Crohn's disease affected relative pairs from 112 families. Multipoint non-parametric linkage analyses were performed, with further stratification of affection status by common CARD15 mutations and the IBD5 haplotype. We verified linkage of Crohn's disease to regions on chromosome 3 (P=0.0009) and X (P=0.001) in our cohort. Linkage to chromosome 16 (IBD1) was observed in Crohn's disease pairs not possessing common CARD15 mutations (P=0.0007), approximately 25 cM q telomeric of CARD15. Evidence for linkage to chromosome 19 (IBD6) was observed in Crohn's disease pairs not possessing CARD15 mutations (P=0.0001), and in pairs possessing one or two copies of the IBD5 risk haplotype (P=0.0005), with significant evidence for genetic heterogeneity and epistasis, respectively. These analyses demonstrate the complex genetic basis to Crohn's disease, and show that the discovery of disease-causing variants may be used to aid identification of further susceptibility loci in complex disease.

Hla-B genotype in Japanese patients with Crohn's disease

PURPOSE

The HLA-B gene is one of the susceptibility genes for inflammatory bowel disease. Previous association studies of HLA-B showed several associated alleles and haplotypes of HLA-B in patients with ulcerative colitis, and among the associated alleles HLA-B*52 is well known to be strongly associated with ulcerative colitis in Japanese patients. However, there are no convincing reports about HLA-B including the B*52 allele in patients with Crohn's disease. The purpose of this study was to determine if HLA-B, especially the B*52 allele, confers susceptibility to Crohn's disease or determines the disease phenotype of Crohn's disease.

METHODS

A total of 195 patients with Crohn's disease (49 ileitis, 106 ileocolitis, 34 colitis, 6 uncertain) and 185 healthy controls were studied in this case-controlled study. All patients and healthy controls were Japanese. Genotyping of the HLA-B gene was performed by a polymerase chain reaction, sequence-specific primer that can classify the gene into 23 allele groups. Allele frequencies were compared between patients with Crohn's disease and healthy controls with chi-squared test using a 2 x 2 contingency table. P value was corrected by the number of allele groups (n = 23) observed in the Japanese population or the number of clinical subgroups. Corrected P values of <0.05 were considered to be statistically significant.

RESULTS

Before the correction for multiple testing, B*4001 and B*44 were associated with patients with Crohn's disease, positively and negatively, respectively. However, after the correction there were no significant differences in any HLA-B alleles between patients with Crohn's disease and healthy controls. In the subgroup analysis according to clinical phenotypes (disease location, anal lesion, age at diagnosis, need for surgery), none of the HLA-B alleles except B*52 showed any disease phenotype-genotype associations. The allele frequency of B*52 in the colitis type (16.2 percent; corrected P = 0.011) was significantly higher than that in the combined group of the ileitis (7.1 percent) and ileocolitis (5.2 percent) types.

CONCLUSIONS

These results demonstrated that HLA-B did not confer overall susceptibility to Crohn's disease in Japan, but the B*52 allele may affect the location of the disease.

Analysis of the IBD5 locus and potential gene-gene interactions in Crohn's disease

BACKGROUND AND AIMS

Genetic variation in the chromosome 5q31 cytokine cluster (IBD5 risk haplotype) has been associated with Crohn's disease (CD) in a Canadian population. We studied the IBD5 risk haplotype in both British and Japanese cohorts. Disease associations have also been reported for CARD15/NOD2 and TNF variants. Complex interactions between susceptibility loci have been shown in animal models, and we tested for potential gene-gene interactions between the three CD associated loci.

METHODS

Family based association analyses were performed in 457 British families (252 ulcerative colitis, 282 CD trios) genotyped for the IBD5 haplotype, common CARD15, and TNF-857 variants. To test for possible epistatic interactions between variants, transmission disequilibrium test analyses were further stratified by genotype at other loci, and novel log linear analyses were performed using the haplotype relative risk model. Case control association analyses were performed in 178 Japanese CD patients and 156 healthy controls genotyped for the IBD5 haplotype.

RESULTS

The IBD5 haplotype was associated with CD (p=0.007), but not with UC, in the British Caucasian population. The CARD15 variants and IBD5 haplotype showed additive main effects, and in particular no evidence for epistatic interactions was found. Variants from the IBD5 haplotype were extremely rare in the Japanese.

CONCLUSIONS

The IBD5 risk haplotype is associated with British CD. Genetic variants predisposing to CD show heterogeneity and population specific differences.

Correlative polymorphism of NAD(P)H: quinone oxidoreductase (NQO1) with telomere shortening in colorectal cancer

AIM

The aim of this study was to examine whether and relationships could be found among polymorphism of the NQO1 gene, telomere length and telomerase activity in colorectal cancers.

MATERIALS AND METHODS

Fifty-one invasive colorectal cancers were studied. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was undergone to detect mutation of the NQO1 gene. Telomere length was examined by Southern blot analysis. Telomerase activity was assayed by telomeric repeat amplification protocol with minor modifications.

RESULTS

Of the 51 tumors, 20 (39.2%) and 9 (17.6%) were heterozygous and homozygous for the mutation, respectively. Most of the cases homozygous for the mutation (88.9%) showed short telomeres and its frequency was significantly higher than in those heterozygous (p = 0.0432). However no relationship was found between the telomerase activity and mutation in the NQO1 gene.

CONCLUSION

Our data suggest that oxidative stress by the lack of NQO1 activity could result in telomere shortening through colorectal cancinogenesis.

Ulcerative colitis is associated with a promoter polymorphism of lipopolysaccharide receptor gene, CD14

BACKGROUND

Inflammatory bowel disease (IBD) is a multifactorial disease with a significant genetic background. Evidence is accumulating that molecules such as CD14, which interact with luminal bacterial constituents, are involved in the pathogenesis. It has recently been shown that the T allele of the 5'-flanking region of the CD14 gene at position -159 is related to high expression of CD14. In further exploring the genetic background of IBD, we investigated this novel polymorphism of CD14 gene in patients with ulcerative colitis or Crohn disease.

METHODS

DNA was obtained from 101 patients with ulcerative colitis, 82 with Crohn disease and 123 healthy controls. All were typed for the promoter polymorphism of the CD14 gene at position -159 by restriction fragment length polymorphism analysis. Serum samples were obtained from 105 healthy controls and serum sCD14 levels were measured.

RESULTS

T allele frequencies were 57.4%, 48.2% and 44.7% in ulcerative colitis, Crohn disease and healthy controls, respectively. The T allele and T/T genotype frequencies were significantly higher in ulcerative colitis patients than in healthy controls (P = 0.0074, OR = 1.67, 95% CI = 1.15-2.42, P = 0.022, OR= 1.96 95% CI: 1.10-3.48, respectively). The sCD14 level was significantly higher in TT genotype populations than CC (P = 0.0205).

CONCLUSIONS

The promoter polymorphism of the CD14 gene at -159T plays a significant role in regulating the CD14 expression and is positively associated with ulcerative colitis, and this polymorphism may confer a genetic predisposition to ulcerative colitis. The results also support the concept that bacterial constituents may be involved in the pathogenesis of ulcerative colitis.

Inflammatory bowel disease is associated with a novel promoter polymorphism of natural resistance-associated macrophage protein 1 (NRAMP1) gene

Inflammatory bowel diseases (IBD) representing both Crohn's disease and ulcerative colitis are characterized by chronic activation of macrophages. Natural resistance-associated macrophage protein 1 (NRAMP1) gene regulates macrophage activation of antimicrobial activity and has many pleiotropic effects on macrophage functions. To explore the role of the NRAMP1 gene in IBD susceptibility, we examined the promoter sequence of the NRAMP1 gene whose polymorphisms have been reported to influence the transcriptional activity of the NRAMP1 gene. One novel allele (allele 7) and two previously reported alleles (alleles 2 and 3) have been determined in a Japanese population. We investigated the association of IBD with these three alleles. The allele frequency of allele 7 was significantly higher in patients with Crohn's disease (11.1%) and ulcerative colitis (11.2%) than those in the healthy control group (4.5%) (Pc=0.015, Pc=0.018, respectively). Therefore, our findings suggest that the novel promoter polymorphism of the NRAMP1 gene may influence susceptibility to IBD in the Japanese population.

[A case presenting with Raeder's syndrome-like symptoms due to vertebral artery aneurysm]

A 50-year-old man complained of headache around his left orbit, left frontal pain and paresthesia associated with left incomplete Horner syndrome. MRI demonstrated a mass at the level of medulla oblongata. Left vertebral angiogram revealed an aneurysm of left vertebral artery. Following the removal of the aneurysm, these Raeder's syndrome-like symptoms improved. Therefore, they were probably caused by a compression of the spinal tract of the trigeminal nerve and the central sympathetic tract by the aneurysm. This is the first report of Reader's syndrome-like symptoms caused by vertebral artery aneurysm, thus indicating that MRI and cerebral angiogram are necessary for differential diagnosis of this syndrome.

Findings in a patient with herpes simplex viral meningitis associated with acute retinal necrosis syndrome

We report the case of a 41-year-old man with clinical findings of viral meningitis associated with acute retinal necrosis syndrome in his right eye. MR images showed right optic nerve enlargement and high-intensity signal abnormalities in the region of the left lateral geniculate body and the left occipital lobe.

Analysis of the PTEN gene mutation in polyposis syndromes and sporadic gastrointestinal tumors in Japanese patients

PURPOSE

PTEN is a candidate tumor suppressor gene for mutations which are responsible for Cowden disease. Recently, it has been shown that PTEN is mutated in several human neoplasms. To investigate the role of PTEN in tumorigenesis, we screened its mutation in Japanese patients with gastrointestinal polyposis and various sporadic tumors.

METHODS

The entire coding region of PTEN was screened by single strand conformational polymorphism or direct sequencing for somatic mutations in 16 gingival papillomas, 4 juvenile polyps, 10 esophageal papillomas, and 20 colorectal cancers and for germline mutations in three patients with Cowden disease (including one with Lhermitte-Duclos disease) and one patient each with juvenile polyposis syndrome, Turcot's syndrome, and Cronkhite-Canada syndrome.

RESULTS

Germline mutations were found in all cases of Cowden disease. One mutation was a nonsense mutation at codon 130 (CGA-->TGA), and the other two were splice site mutations at the 5' site of intron 4 and the 3' site of intron 8. We could not detect germline mutations in other patients with gastrointestinal polyposis or somatic mutations in sporadic tumors.

CONCLUSIONS

We confirmed previous reports that germline mutations in PTEN are responsible for Cowden disease. However, somatic mutations of PTEN may not play a major role in tumorigenesis, at least in colorectal cancers, esophageal papillomas and gingival papillomas.

Relationship between microsatellite instability and telomere shortening in colorectal cancer

PURPOSE

Two pathways have been proposed for the development of colorectal cancers: loss of heterozygosity and replication error. Colorectal cancers arising through the replication error pathway, like most hereditary nonpolyposis colorectal cancers, show microsatellite instability. It has been also reported that telomere shortening frequently occurs in colorectal cancers and that telomerase is often activated strongly in them. The aim of this study was to examine whether any relationships can be found among microsatellite instability, telomere length, and telomerase activity in colorectal cancers.

METHODS

Genomic DNA was extracted from 55 invasive cancers and corresponding normal mucosas. Five microsatellite loci were analyzed by polymerase chain reaction. Telomere length was examined by Southern blot analysis. Telomerase activity was assayed by telomeric repeat amplification protocol with minor modifications.

RESULTS

Microsatellite instability was found in 8 (14.5 percent) of 55 tumors, and all of them showed short telomeres. Furthermore, four high-frequency microsatellite instability tumors that showed microsatellite instability at more than two loci exhibited remarkably short telomeres. The microsatellite instability correlated significantly with frequency of telomere shortening (P = 0.0183; Fisher's exact probability test), but not with strength of telomerase activity.

CONCLUSION

The relationship identified by this study between microsatellite instability and telomere shortening might suggest some association between the DNA mismatch repair system and the telomere maintenance mechanism in colorectal cancers.

Benign hot bath-related headache

We describe three cases of women with hot bath-related headache who reported that their severe paroxysmal headache could be provoked by pouring hot water over themselves or by soaking in a hot bath. In one patient, the headache was also brought on by exposure to cold wind. Another patient had headaches after she dived into a pool and started swimming. Neurological examination, routine laboratory tests, electroencephalography, and brain imaging showed no abnormality in any of the patients. Hot bath-related headache is a benign headache unassociated with a structural lesion.

Telomere shortening and the clinicopathologic characteristics of human colorectal carcinomas

BACKGROUND

It has been reported that shortening of telomeres and strong activation of telomerase occur frequently in colorectal carcinomas. In the current study, the authors examined the correlations between the telomere length of colorectal carcinomas and their clinicopathologic characteristics as well as the activity of telomerase to clarify whether telomere length might represent the biologic behavior of tumors and the mode of tumor development.

METHODS

Telomere length was examined by Southern blot analysis in 61 invasive colorectal carcinomas and corresponding normal mucosas. Telomerase activity was assayed by the telomeric repeat amplification protocol with minor modifications.

RESULTS

Shortening of the telomere was detected in 38 (62.3%) and elongation in 3 (4. 9%) of the 61 carcinomas. The telomere shortening occurred more frequently in nonulcerating polypoid carcinomas than in ulcerating carcinomas (P = 0.0373) and also occurred more frequently in ascending colon carcinomas than in sigmoid colon or rectal carcinomas (P = 0.0259 and P = 0.0407, respectively). However, no significant correlation was found between the activity of telomerase and the length of telomere.

CONCLUSIONS

The results of this study indicate that telomere length may represent the biologic behavior of individual tumors and possibly the mode of development of colorectal carcinomas.

Crohn's disease is associated with novel polymorphisms in the 5'-flanking region of the tumor necrosis factor gene

BACKGROUND & AIMS

Tumor necrosis factor (TNF) is considered to play an important role in the pathogenesis of Crohn's disease (CD). Recently, 3 polymorphisms in the 5'-flanking region of the TNF gene at positions -1031, -863, and -857, which are related to high transcriptional promoter activity, have been identified in the Japanese population. In an effort to understand potential genetic association with CD, we evaluated patients diagnosed with CD and ulcerative colitis (UC) in the presence of other novel polymorphisms.

METHODS

Blood samples were obtained from 103 patients with CD and 76 patients with UC. Polymorphisms in the TNF gene at their respective positions were analyzed by direct sequencing, and the allele frequencies were compared with those determined previously in a healthy Japanese population.

RESULTS

Allele frequencies of -1031C, -863A, and -857T in normal controls were 16.0%, 14.0%, and 17.7%, respectively. Polymorphic allele frequencies at positions -1031, -863, and -857 were 24.3%, 21.8%, and 27.2% in CD and 11.8%, 11.2%, and 11.8% in UC, respectively. The frequencies at all 3 positions were significantly higher in CD patients than in UC patients or healthy controls. Among the subgroups of CD, small bowel disease showed the highest frequencies.

CONCLUSIONS

Although the findings need to be confirmed in other populations with larger numbers of patients, TNF gene polymorphisms -1031C, -863A, and -857T are positively associated with CD; they may influence not only the susceptibility to CD but also the disease location.

High-signal basal ganglia on T1-weighted images in a patient with Sydenham's chorea

We report a 16-year-old girl with Sydenham's chorea. Choreiform movements involved both sides of her body. MRI 2 months after the onset revealed abnormal increased signal on T2-weighted images and enlargement of the caudate and putamen bilaterally. MRI 5 months later showed resolution of the swelling, but with increased signal on T1-weighted images in the putamen, globus pallidus and the head of the caudate nucleus bilaterally, with slightly increased signal intensity on T2-weighted images.