Variants in ACTG2 underlie a substantial number of Australasian patients with primary chronic intestinal pseudo-obstruction

BACKGROUND

Primary chronic intestinal pseudo-obstruction (CIPO) is a rare, potentially life-threatening disorder characterized by severely impaired gastrointestinal motility. The objective of this study was to examine the contribution of ACTG2, LMOD1, MYH11, and MYLK mutations in an Australasian cohort of patients with a diagnosis of primary CIPO associated with visceral myopathy.

METHODS

Pediatric and adult patients with primary CIPO and suspected visceral myopathy were recruited from across Australia and New Zealand. Sanger sequencing of the genes encoding enteric gamma-actin (ACTG2) and smooth muscle leiomodin (LMOD1) was performed on DNA from patients, and their relatives, where available. MYH11 and MYLK were screened by next-generation sequencing.

KEY RESULTS

We identified heterozygous missense variants in ACTG2 in 7 of 17 families (~41%) diagnosed with CIPO and its associated conditions. We also identified a previously unpublished missense mutation (c.443C>T, p.Arg148Leu) in one family. One case presented with megacystis-microcolon-intestinal hypoperistalsis syndrome in utero with subsequent termination of pregnancy at 28 weeks' gestation. All of the substitutions identified occurred at arginine residues. No likely pathogenic variants in LMOD1, MYH11, or MYLK were identified within our cohort.

CONCLUSIONS AND INFERENCES

ACTG2 mutations represent a significant underlying cause of primary CIPO with visceral myopathy and associated phenotypes in Australasian patients. Thus, ACTG2 sequencing should be considered in cases presenting with hypoperistalsis phenotypes with suspected visceral myopathy. It is likely that variants in other genes encoding enteric smooth muscle contractile proteins will contribute further to the genetic heterogeneity of hypoperistalsis phenotypes.

Review article: consensus statements on therapeutic drug monitoring of anti-tumour necrosis factor therapy in inflammatory bowel diseases

BACKGROUND

Therapeutic drug monitoring (TDM) in inflammatory bowel disease (IBD) patients receiving anti-tumour necrosis factor (TNF) agents can help optimise outcomes. Consensus statements based on current evidence will help the development of treatment guidelines.

AIM

To develop evidence-based consensus statements for TDM-guided anti-TNF therapy in IBD.

METHODS

A committee of 25 Australian and international experts was assembled. The initial draft statements were produced following a systematic literature search. A modified Delphi technique was used with 3 iterations. Statements were modified according to anonymous voting and feedback at each iteration. Statements with 80% agreement without or with minor reservation were accepted.

RESULTS

22/24 statements met criteria for consensus. For anti-TNF agents, TDM should be performed upon treatment failure, following successful induction, when contemplating a drug holiday and periodically in clinical remission only when results would change management. To achieve clinical remission in luminal IBD, infliximab and adalimumab trough concentrations in the range of 3-8 and 5-12 μg/mL, respectively, were deemed appropriate. The range may differ for different disease phenotypes or treatment endpoints-such as fistulising disease or to achieve mucosal healing. In treatment failure, TDM may identify mechanisms to guide subsequent decision-making. In stable clinical response, TDM-guided dosing may avoid future relapse. Data indicate drug-tolerant anti-drug antibody assays do not offer an advantage over drug-sensitive assays. Further data are required prior to recommending TDM for non-anti-TNF biological agents.

CONCLUSION

Consensus statements support the role of TDM in optimising anti-TNF agents to treat IBD, especially in situations of treatment failure.

Review article: acute severe ulcerative colitis - evidence-based consensus statements

BACKGROUND

Acute severe ulcerative colitis (ASUC) is a potentially life-threatening complication of ulcerative colitis.

AIM

To develop consensus statements based on a systematic review of the literature of the management of ASUC to improve patient outcome.

METHODS

Following a literature review, the Delphi method was used to develop the consensus statements. A steering committee, based in Australia, generated the statements of interest. Three rounds of anonymous voting were carried out to achieve the final results. Acceptance of statements was pre-determined by ≥80% votes in 'complete agreement' or 'agreement with minor reservation'.

RESULTS

Key recommendations include that patients with ASUC should be: hospitalised, undergo unprepared flexible sigmoidoscopy to assess severity and to exclude cytomegalovirus colitis, and be provided with venous thromboembolism prophylaxis and intravenous hydrocortisone 100 mg three or four times daily with close monitoring by a multidisciplinary team. Rescue therapy such as infliximab or ciclosporin should be started if insufficient response by day 3, and colectomy considered if no response to 7 days of rescue therapy or earlier if deterioration. With such an approach, it is expected that colectomy rate during admission will be below 30% and mortality less than 1% in specialist centres.

CONCLUSION

These evidenced-based consensus statements on acute severe ulcerative colitis, developed by a multidisciplinary group, provide up-to-date best practice recommendations that improve and harmonise management as well as provide auditable quality assessments.

Perspectives of paediatric and adult gastroenterologists on transfer and transition care of adolescents with inflammatory bowel disease

BACKGROUND

Programmes specific to inflammatory bowel disease (IBD) that facilitate transition from paediatric to adult care are currently lacking.

AIM

We aimed to explore the perceived needs of adolescents with IBD among paediatric and adult gastroenterologists and to identify barriers to effective transition.

METHODS

A web-based survey of paediatric and adult gastroenterologists in Australia and New Zealand employed both ranked items (Likert scale; from 1 not important to 5 very important) and forced choice items regarding the importance of various factors in facilitating effective transition of adolescents from paediatric to adult care.

RESULTS

Response rate among 178 clinicians was 41%. Only 23% of respondents felt that adolescents with IBD were adequately prepared for transition to adult care. Psychological maturity (Mean = 4.3, standard deviation (SD) = 0.70) and readiness as assessed by adult caregiver (Mean = 4, SD = 0.72) were prioritised as the most important factors in determining timing of transfer. Self-efficacy and readiness as assessed by adult caregiver were considered the two most important factors to determine timing of transition by both groups of gastroenterologists. Poor medical and surgical handover (Mean = 4.10, SD = 0.8) and patients' lack of responsibility for their own care (Mean= 4.10, SD = 0.82) were perceived as major barriers to successful transition by both paediatric and adult gastroenterologists.

CONCLUSIONS

Deficiencies exist in current transition care of adolescents with IBD in Australia and New Zealand. Standardising transition care practices with strategies aimed at optimising communication, patient education, self-efficacy and adherence may improve outcomes.

Managing inflammatory bowel disease in adolescent patients

Increasing numbers of adolescents are being diagnosed with Crohn's disease or ulcerative colitis, the two main subtypes of inflammatory bowel disease. These young people face many short- and long-term challenges; one or more medical therapies may be required indefinitely; their disease may have great impact, in terms of their schooling and social activities. However, the management of adolescents with one of these incurable conditions needs to encompass more than just medical therapies. Growth, pubertal development, schooling, transition, adherence, and psychological well-being are all important aspects. A multidisciplinary team setting, catering to these components of care, is required to ensure optimal outcomes in adolescents with inflammatory bowel disease.

Eosinophilic esophagitis in children with esophageal atresia

Eosinophilic esophagitis (EoE) has only rarely been reported in esophageal atresia (EA) patients. A retrospective case analysis of all EA patients born at our center between January 1999 and April 2012 was performed. A total of 113 of patients were identified; 10 patients were excluded as a result of inadequate data. Eighteen patients (17%) were diagnosed with EoE. The average number of eosinophilis was 30/high-power field (HPF) (19/HPF-80/HPF). The median age for diagnosis of EoE was 1 year and 6 months (8 months-8 years and 7 months). Children with EoE had a significantly greater incidence of reflux symptoms, dysphagia, tracheomalacia, and 'hypoxic spells' (P < 0.05). EoE patients also underwent significantly more surgery including fundoplication and aortopexy when compared with those without EoE (P < 0.0001). Although the incidence of gastrostomy was greater in the EoE group (33% vs. 13%), this was not statistically significant. Half of the EoE patients had a coexisting atopic condition at time of diagnosis. The commonest condition was asthma 7/18 (38%) followed by specific food allergy 6/18 (33%). EoE was treated in 11 patients with either swallowed fluticasone or budesonide slurry. All improved clinically. Histologically, five had complete resolution and six had partial improvement. Six children with EoE were treated with acid suppression alone. All improved clinically, and 5/6 had subsequent histological resolution. One child who received acid suppression and an exclusion diet also improved. Seven patients (38%) had an esophageal stricture at time of EoE diagnosis. Five were dilated at time of the initial endoscopy, prior to the diagnosis of EoE being available. Two patients had resolution of their strictures on medical treatment of their EoE alone and did not require further dilatation. EoE was seen in 17% of children with EA in this study. EoE should be considered in EA patients with persistent symptoms on standard reflux treatment, increasing dysphagia, and recurrent strictures.

Fecal M2-PK in children with Crohn's disease: a preliminary report

BACKGROUND AND AIMS

Although active inflammatory changes in chronic Crohn's disease (CD) can be detected with serum inflammatory markers, these have low specificity and sensitivity. Stool markers of inflammation, such as M2-pyruvate kinase (M2-PK), permit more direct assessment of mucosal inflammation. The aim of this study was to assess levels of M2-PK in children with active CD and to compare to levels in healthy control children.

METHODS

Fecal levels of M2-PK were measured by immunoassay using stored stool samples from children with untreated (active) CD and healthy control children. Correlations between M2-PK levels and disease activity scores and serum inflammatory markers were performed. Comparison was also made between M2PK and a second fecal inflammatory marker, S100A12.

RESULTS

Mean fecal M2-PK levels were higher in the 17 patients with active CD than in the 21 healthy controls (p = 0.0007). M2-PK levels did not correlate with disease activity scores or serum inflammatory markers. There was a trend for children with ileocolonic disease to have higher levels of M2-PK in their stool compared to those with colonic disease or isolated ileal disease. Fecal M2PK did not correlate with fecal S100A12 in children with active CD.

CONCLUSION

Fecal M2-PK is increased in children with active CD, indicating that this marker may be a useful non-invasive marker for gut inflammation. Further studies of M2PK are required in additional settings with larger cohorts of children with CD and with comparison to other stool markers.

Nutritional status of children with coeliac disease

AIMS

The main aim of this study was to assess the nutritional status of children with newly diagnosed Coeliac disease (CD)with comparison to matched controls. A further aim was to assess relationships between presentation patterns and nutrition in childhood CD.

METHODS

The nutritional status of newly diagnosed CD was assessed by anthropometry, Bioelectrical Impedance and serum leptin levels, and contrasted to age and gender matched controls.

RESULTS

Twenty-five children with CD (mean age of 8.2 +/- 4.5 years) and 25 control children (mean age 8.1 +/- 4.4.) were enrolled. Thirteen (52%) children with CD had gastrointestinal symptoms with 14 having a family history of CD. At presentation 8.7% were wasted, 4.2% were stunted and 20.8% overweight, although none were obese. Mean height and weight for age, other nutritional parameters and serum leptin did not differ between the groups. Serum leptin correlated with BMI in both groups.

CONCLUSIONS

Children with CD more commonly present with atypical symptoms than with classical features. Variations in nutrition (under to overnutrition) may be seen at diagnosis, without relationship to the presence of symptoms. Leptin levels were not altered specifically in the setting of CD. Nutritional assessment remains important in the assessment and management of CD in children.

Systematic review: nutritional therapy in paediatric Crohn's disease

BACKGROUND

At least 25% of individuals diagnosed with Crohn's disease (CD) have onset of disease in childhood. Almost all children with CD have nutritional impairments, such as weight loss or stunting, at diagnosis or subsequently. Nutritional therapy (exclusive enteral nutrition) is established as a valid and effective treatment in paediatric CD. The advantages of this approach are induction of remission and control of inflammatory changes, mucosal healing, positive benefits to growth and overall nutritional status, and avoidance of other medical therapies.

AIM

To provide a comprehensive up-to-date review of the roles of nutritional therapy in CD and of the data supporting this therapy.

METHODS

A search of PubMed was performed with search terms 'enteral nutrition', 'nutritional therapy', 'Crohn disease' and 'children'. Relevant articles were selected from this search. In addition, the reference lists of available articles were reviewed for further relevant articles.

RESULTS

Nutritional therapy offers numerous benefits in the management of CD. Recent work has begun to elucidate the likely mechanisms of this therapy. These include direct mucosal anti-inflammatory effects and alteration of intestinal microflora.

CONCLUSION

Further studies are required to define longer-term effects of nutritional therapy in patients with CD.

Surgical intervention in children with Crohn's disease

INTRODUCTION

Crohn's disease (CD) causes chronic inflammation of the gastrointestinal tract leading to extensive medical treatments and surgery with two thirds of patients having surgery over their lifetime. In this study, we reviewed the pediatric population at the British Columbia Children's Hospital diagnosed with CD and examined their demographics and treatments, in particular assessing those who ultimately underwent surgery.

MATERIALS AND METHODS

Two hundred and eighty children (median age 11.9 years [CI 11.5-12.28]) diagnosed with CD from January 1994 to December 2003 were included. Demographic data were documented including age, ethnicity, duration of symptoms before diagnosis, treatment to date and surgical parameters. Comparison was made between operative and non-operative patients including involvement of disease, medical treatment, complications and recurrence of disease leading to repeat operations.

RESULTS

Fifty-five (19.6%) children had surgical procedures. There was a significant increase in surgery in those patients who had not received immunomodulator therapy before surgery (odds ratio 1.95 [CI 1.02-3.73]). We also observed that those CD patients with extensive small intestinal involvement had lower likelihood of having surgery (odds ratio 0.386 [CI 0.145-1.033]). No significant difference was found between the two groups with regard to age of diagnosis (p = 0.41), duration of symptoms (p = 0.22), gender (p = 0.50) or ethnicity (p = 0.451).

CONCLUSION

There was an increased incidence of surgery in those patients who were not treated with immunomodulator therapy. In addition, children with extensive as opposed to isolated small intestinal disease were less likely to have surgery in childhood.