Gunnar Järnerot

Ulcerative colitis and Crohn's disease in an unselected population of monozygotic and dizygotic twins. A study of heritability and the influence of smoking.

By running the Swedish twin registry containing about 25,000 pairs of twins of the same sex together with the central national diagnosis register of hospital inpatients, 80 twin pairs suffering from inflammatory bowel disease were found. In the ulcerative colitis group one of 16 monozygotic pairs was concordant for the disease, but all the other 20 pairs (dizygotic or unknown zygosity) were discordant. In the Crohns disease group eight of 18 monozygotic pairs and one of 26 dizygotic pairs were concordant. The proband concordance rate among monozygotic twins was 6.3% for ulcerative colitis and 58.3% for Crohns disease. The calculated heritability of liability based on monozygotic pairs was 0.53 and 1.0 respectively. Thus heredity as an aetiological factor is stronger in Crohns disease than in ulcerative colitis. Monozygotic twins with Crohns disease were more likely to be smokers than monozygotic twins with ulcerative colitis. Smoking did not explain the discordance of twin pairs with either ulcerative colitis, or Crohns disease. The combination of identical heredity and similar smoking habit is not sufficient to cause disease.

A Pyrosequencing Study in Twins Shows That Gastrointestinal Microbial Profiles Vary With Inflammatory Bowel Disease Phenotypes

BACKGROUND & AIMS The composition of the gastrointestinal microbiota is thought to have an important role in the etiology of inflammatory bowel diseases (IBDs) such as Crohns disease (CD) and ulcerative colitis (UC). Interindividual variation and an inability to detect less abundant bacteria have made it difficult to correlate specific bacteria with disease. METHODS We used 454 pyrotag sequencing to determine the compositions of microbial communities in feces samples collected from a cohort of 40 twin pairs who were concordant or discordant for CD or UC, and in mucosal samples from a subset of the cohort. The cohort primarily comprised patients who were in remission, but also some with active disease. RESULTS The profiles of the microbial community differed with disease phenotypes; relative amounts of bacterial populations correlated with IBD phenotypes. The microbial compositions of individuals with CD differed from those of healthy individuals, but were similar between healthy individuals and individuals with UC. Profiles from individuals with CD that predominantly involved the ileum differed from those with CD that predominantly involved the colon; several bacterial populations increased or decreased with disease type. Changes specific to patients with ileal CD included the disappearance of core bacteria, such as Faecalibacterium and Roseburia, and increased amounts of Enterobacteriaceae and Ruminococcus gnavus. CONCLUSIONS Bacterial populations differ in abundance among individuals with different phenotypes of CD. Specific species of bacteria are associated with ileal CD; further studies should investigate their role in pathogenesis.

Subcutaneous golimumab induces clinical response and remission in patients with moderate-to-severe ulcerative colitis

BACKGROUND & AIMS Little is known about the efficacy of golimumab, a fully human monoclonal antibody to tumor necrosis factor (TNF) -α, for treatment of ulcerative colitis (UC). We evaluated subcutaneous golimumab induction therapy in TNF-α antagonist-naïve patients with moderate-to-severe UC despite conventional treatment. METHODS We integrated double-blind phase 2 dose-finding and phase 3 dose-confirmation trials in a study of 1064 adults with UC (Mayo score: 6-12; endoscopic subscore ≥ 2; 774 patients in phase 3). Patients were randomly assigned to groups given golimumab doses of 100 mg and then 50 mg (phase 2 only), 200 mg and then 100 mg, or 400 mg and then 200 mg, 2 weeks apart. The phase 3 primary end point was week-6 clinical response. Secondary end points included week-6 clinical remission, mucosal healing, and Inflammatory Bowel Disease Questionnaire (IBDQ) score change. RESULTS In phase 2, median changes from baseline in the Mayo score were -1.0, -3.0, -2.0, and -3.0, in the groups given placebo, 100 mg/50 mg, 200/100 mg, and 400/200 mg golimumab, respectively. In phase 3, rates of clinical response at week 6 were 51.0% and 54.9% among patients given 200 mg/100 mg and 400 mg/200 mg golimumab, respectively, vs 30.3% among those given placebo (both, P ≤ .0001). Rates of clinical remission and mucosal healing and mean changes in IBDQ scores were significantly greater in both golimumab groups vs the placebo group (P ≤ .0014, all comparisons). Rates of serious adverse events were 6.1% and 3.0%, and rates of serious infection were 1.8% and 0.5%, in the placebo and golimumab groups, respectively. One patient in the 400 mg/200 mg group died as a result of surgical complications of an ischiorectal abscess. CONCLUSIONS Treatment with subcutaneous golimumab induces clinical response, remission, and mucosal healing, and increases quality of life in larger percentages of patients with active UC than placebo. ClinicalTrials.gov Number: NCT00487539.

Subcutaneous Golimumab Maintains Clinical Response in Patients With Moderate-to-Severe Ulcerative Colitis

BACKGROUND & AIMS Subcutaneous golimumab, a fully human monoclonal antibody to tumor necrosis factor-α (TNFα), was evaluated as maintenance therapy in TNFα antagonist-naive adults with moderate-to-severe active ulcerative colitis, despite conventional therapy, who responded to golimumab induction therapy. METHODS We performed a phase 3, double-blind trial of patients who completed golimumab induction trials (Program of Ulcerative Colitis Research Studies Utilizing an Investigational Treatment, eg, PURSUIT). Patients who responded to induction therapy with golimumab (n = 464) were assigned randomly to groups given placebo or injections of 50 or 100 mg golimumab every 4 weeks through week 52. Patients who responded to placebo in the induction study continued to receive placebo. Nonresponders in the induction study received 100 mg golimumab. The primary end point was clinical response maintained through week 54; secondary end points included clinical remission and mucosal healing at both weeks 30 and 54. RESULTS Clinical response was maintained through week 54 in 47.0% of patients receiving 50 mg golimumab, 49.7% of patients receiving 100 mg golimumab, and 31.2% of patients receiving placebo (P = .010 and P < .001, respectively). At weeks 30 and 54, a higher percentage of patients who received 100 mg golimumab were in clinical remission and had mucosal healing (27.8% and 42.4%) than patients given placebo (15.6% and 26.6%; P = .004 and P = .002, respectively) or 50 mg golimumab (23.2% and 41.7%, respectively). Percentages of serious adverse events were 7.7%, 8.4%, and 14.3% among patients given placebo, 50 mg, or 100 mg golimumab, respectively; percentages of serious infections were 1.9%, 3.2%, and 3.2%, respectively. Among all patients given golimumab in the study, 3 died (from sepsis, tuberculosis, and cardiac failure, all in patients who received 100 mg golimumab) and 4 developed active tuberculosis. CONCLUSIONS Golimumab (50 mg or 100 mg) maintained clinical response through week 54 in patients who responded to induction therapy with golimumab and had moderate-to-severe active ulcerative colitis; patients who received 100 mg golimumab had clinical remission and mucosal healing at weeks 30 and 54. Safety was consistent with that reported for other TNFα antagonists and golimumab in other approved indications. ClinicalTrials.gov number: NCT00488631.

Twin studies reveal specific imbalances in the mucosa-associated microbiota of patients with ileal Crohn's disease

Background: Large interindividual variation in the composition of the intestinal microbiota between unrelated individuals has made it challenging to identify specific aspects of dysbiosis that lead to Crohns disease (CD). Methods: To reduce variations in exposure during establishment of the gut flora and the influence of genotype, we studied the mucosa‐associated microbiota of monozygotic twin pairs that were discordant (n = 6) or concordant (n = 4) for CD. DNA was extracted from biopsies collected from 5 locations between the ileum and rectum. Bacterial 16S ribosomal RNA genes were amplified and community composition assessed by terminal‐restriction fragment length polymorphism, cloning and sequencing, and quantitative real‐time polymerase chain reaction (PCR). Results: The microbial compositions at all biopsy locations for each individual were similar, regardless of disease state, but there were differences between individuals. In particular, individuals with predominantly ileal CD had a dramatically lower abundance (P < 0.001) of Faecalibacterium prausnitzii and increased abundance (P < 0.03) of Escherichia coli compared to healthy co‐twins and those with CD localized in the colon. This dysbiosis was significantly correlated to the disease phenotype rather than genotype. Conclusions: The reduced abundance of F. prausnitzii and increased abundance of E. coli are indicative of an ileal CD phenotype, distinct from colonic CD, and the relative abundances of these specific bacterial populations are promising biomarker candidates for differential diagnosis of CD and eventually customized treatment.

Inflammatory Bowel Disease in a Swedish Twin Cohort: A Long- Term Follow-up of Concordance and Clinical Characteristics

BACKGROUND & AIMS In 1988, we reported the first twin study in inflammatory bowel disease. The aim of the current study was to follow up these twins regarding new cases of inflammatory bowel disease and Crohns disease characteristics using the Vienna classification. METHODS The official Swedish population register and the cause of death register were used to search for the twins. All living patients were interviewed. RESULTS Three monozygotic twins earlier classified as healthy had been diagnosed with inflammatory bowel disease (ulcerative colitis, n = 2; Crohns disease, n = 1). Retrospectively, all 3 were symptomatic at the original survey. This changed the pair concordance in monozygotic twins from 6.3% to 18.8% in ulcerative colitis and from 44.4% to 50.0% in Crohns disease. A high degree of concordance regarding age at diagnosis, disease location at diagnosis and during the course, and disease behavior was found in concordant monozygotic twin pairs with Crohns disease. Seven of 9 pairs were identical in 3 or more of these disease characteristics compared with an expected number of 1.5 (P = 0.000076). CONCLUSIONS This study confirms that the genetic influence is stronger in Crohns disease than in ulcerative colitis. A remarkable phenotype similarity within concordant pairs with Crohns disease was found using the Vienna classification.

Molecular analysis of the gut microbiota of identical twins with Crohn's disease

Increasing evidence suggests that a combination of host genetics and the composition of the gut microbiota are important for development of Crohns disease (CD). Our aim was to study identical twins with CD to determine microbial factors independent of host genetics. Fecal samples were studied from 10 monozygotic twin pairs with CD (discordant n=6 and concordant n=4) and 8 healthy twin pairs. DNA was extracted, 16S rRNA genes were PCR amplified and T-RFLP fingerprints generated using general bacterial and Bacteroides group-specific primers. The microbial communities were also profiled based on their percentage G+C contents. Bacteroides 16S rRNA genes were cloned and sequenced from a subset of the samples. The bacterial diversity in each sample and similarity indices between samples were estimated based on the T-RFLP data using a combination of statistical approaches. Healthy individuals had a significantly higher bacterial diversity compared to individuals with CD. The fecal microbial communities were more similar between healthy twins than between twins with CD, especially when these were discordant for the disease. The microbial community profiles of individuals with ileal CD were significantly different from healthy individuals and those with colonic CD. Also, CD individuals had a lower relative abundance of B. uniformis and higher relative abundances of B. ovatus and B. vulgatus. Our results suggest that genetics and/or environmental exposure during childhood, in part, determine the gut microbial composition. However, CD is associated with dramatic changes in the gut microbiota and this was particularly evident for individuals with ileal CD.

Collagenous colitis: a retrospective study of clinical presentation and treatment in 163 patients.

BACKGROUND: Data on collagenous colitis have been based on a limited number of patients. AIMS: To obtain more information on this disease from a register set up at Orebro Medical Center Hospital. PATIENTS AND METHODS: Twenty five Swedish hospitals have contributed to this patient register, which comprises 163 histopathologically verified cases. Clinical data were retrospectively analysed. RESULTS: Collagenous colitis followed a chronic intermittent course in most cases (85%) with a sudden onset in 42%. Symptoms were chronic watery diarrhoea, often nocturnal (27%), abdominal pain (41%), and weight loss (42%). Sixty six patients (40%) had one or more associated diseases. Routine laboratory data were mostly normal. The median age at diagnosis was 55 (range 16-86) years, but 25% of the patients were younger than 45 years. Seven patients died of unrelated diseases. The response rate for sulphasalazine was 59%, and 50% and 40% for mesalazine and olsalazine. Prednisolone was most effective with a response rate of 82%, but the required dose was often high and the effect was not sustained after withdrawal. Antibiotics were efficient in 63%. Cholestyramine and loperamide had response rates of 59% and 71% respectively. CONCLUSIONS: Collagenous colitis follows a chronic continuous course. Symptoms can be socially disabling, but the disease does not seem to have a malignant potential. A plan for the treatment of a newly diagnosed patient with collagenous colitis is proposed.

Intensive intravenous treatment of ulcerative colitis

Two hundred four courses of intensive intravenous treatment were given to 158 patients with ulcerative colitis. The remission rates in the severe, moderate, or mild attacks were 55.7%, 86.9%, and 91.8%. Total colitis had a great impact on the results, especially in severe attacks. Of these patients, 52.8% were operated on within 3 wk. The relapse rate was exponential, and during the first year 48.1% of the patients in remission relapsed. The extent of the colitis, severity of the attack, or duration of intensive intravenous treatment had no influence on the time of relapse. Twelve patients with chronic continuous disease were given intensive intravenous treatment. No long-term benefit was seen in patients with total ulcerative colitis, but half of those with less extensive colitis showed a good to excellent response to treatment.

A comparative study of metronidazole and sulfasalazine for active Crohn's disease: the cooperative Crohn's disease study in Sweden. II. Result.

Seventy-eight patients with active Crohns disease participated in a randomized, double-blind, cross-over trial. The study comprised two 4-mo period. The purpose was to test the efficacy of metronidazole in comparison with that of sulfasalazine. As the main evaluation criteria the Crohns Disease Activity Index and plasma levels of orosomucoid were chosen. In the first period no difference in efficacy as measured by Crohns Disease Activity Index was found between the treatment groups. The reduction of the plasma orosomucoid level was significantly more pronounced in the metronidazole group. The hemoglobin concentration increased more in this group than in the sulfasalazine group, possibly due to a toxic effect of sulfasalazine. The erythrocyte sedimentation rate decreased similarly with both drugs. In 15 patients who had active disease throughout the first period, Crohns Disease Activity Index decreased significantly in the second period for those who switched to metronidazole, but not for those who switched to sulfasalazine. After crossover, no apparent further change in Crohns Disease Activity Index occurred in either of the treatment groups among patients who had responded favorably in the first period. The plasma concentration of orosomucoid increased significantly among the patients in the sulfasalazine group but not in the metronidazole group. It is therefore concluded that metronidazole is slightly more effective than sulfasalazine in the treatment of crohns disease. It is worthwhile switching the drug regimen from sulfasalazine, when it fails, to metronidazole, but not from metronidazole to sulfasalazine.