Mother-to-child transmission of hepatitis B: Examining viral cut-offs, maternal HBsAg serology and infant testing.

BACKGROUND & AIMS: Antipartum antiviral therapy in the setting of high viral load is recommended to prevent mother-to-child transmission of hepatitis B although recommended viral load cut-offs vary. Quantitative HBsAg has been proposed as an alternative screening strategy to identify high viral load in this setting. Guidelines suggest testing all infants for vaccine response and infection. We set out to re-examine viral load cut-offs; the predictive value of quantitative HBsAg and the need for follow-up infant testing in our cohort. METHODS: A retrospective cohort study of 469 HBsAg positive mother-baby pairs from 2 tertiary hospitals in Sydney was performed. Antiviral therapy (lamivudine or tenofovir disoproxil fumarate) was offered to women with viral load ≥6 log10  IU/mL (high) from 32 weeks gestation. Transmission and vaccine response was analysed according to viral load. The utility of quantitative HBsAg in identifying high viral load was examined. RESULTS: Mother-to-child transmission only occurred in setting of high viral load, in 0.85% (1/117) of those who received antiviral therapy and in 8.66% (2/23) of those who chose not to. Quantitative HBsAg did not accurately identify high-risk mothers HBV DNA ≥6 log10  IU/mL. Successful infant vaccine response was 98.7% overall, and 99.4% when viral load was <6 log10  IU/mL. CONCLUSION: Antiviral therapy initiated at 32 weeks when maternal viral load is ≥6 log10  IU/mL almost completely abrogates transmission. Quantitative HBsAg does not reliably predict high viral load. When maternal viral load is <6 log10  IU/mL, high vaccine efficacy and zero transmission suggests testing infants is of little value.

Prospective single-blinded single-center randomized controlled trial of Prep Kit-C and Moviprep: Does underlying inflammatory bowel disease impact tolerability and efficacy?

BACKGROUND: Colonoscopy remains the gold standard for detection of colonic disease. An optimal evaluation depends on adequate bowel cleansing. Patients with inflammatory bowel disease (IBD), require frequent endoscopic assessment for both activity and dysplasia assessment. Two commonly used bowel preparations in Australia are Prep Kit-C (Pc) and Moviprep (Mp). Little is known about tolerability, efficacy and safety of split protocols of Mp and Pc in both IBD and non-IBD patients. AIM: To primary aim was to compare the tolerability, efficacy and safety of split protocols of Mp and Pc in patients having a colonoscopy. The secondary aim was to compare the efficacy, tolerability and safety of either preparation in patients with or without IBD. METHODS: Patients were randomized to Pc or Mp bowel preparation. Patients completed a questionnaire to assess tolerability. Efficacy was assessed using the Ottawa Bowel Preparation Score. Serum electrolytes and renal function were collected one week prior to colonoscopy and on the day of colonoscopy. RESULTS: Of 338 patients met the inclusion criteria. Of 168 patients randomized to Mp and 170 to Pc. The efficacy of bowel preparation (mean Ottawa Bowel Preparation Score) was similar between Mp (5.4 ± 2.4) and Pc (5.1 ± 2.1) (P = 0.3). Mean tolerability scores were similar in Mp (11.84 ± 5.4) and Pc (10.99 ± 5.2; P = 0.17). 125 patients had IBD (73 had Crohn's Disease and 52 had Ulcerative colitis). Sixty-four IBD patients were allocated to Mp and 61 to Pc. In non-IBD patients, 104 were allocated to Mp and 109 to Pc. The mean tolerability score in the IBD group was lower than the non-IBD group (mean tolerability scores: IBD: 10.3 ± 5.1 and non-IBD: 12.0 ± 5.3; P = 0.01). IBD patients described more abdominal pain with Mp when compared with Pc; (Mp: 5.7 ± 4.4 vs Pc: 3.6 ± 2.6, P = 0.046). Serum magnesium level increased with Pc compared with Mp in all patients (mean increase in mmol/L: Mp: 0.03 ± 0.117 and Pc: 0.11 ± 0.106; P < 0.0001). CONCLUSION: In this study, the efficacy, tolerability and safety of Mp and Pc were similar in all patients. However, patients with IBD reported lower tolerability with both preparations. Specifically, IBD patients had more abdominal pain with Mp. These results should be considered when recommending bowel preparation especially to IBD patients.

Australia IBD Microbiome (AIM) Study: protocol for a multicentre longitudinal prospective cohort study.

INTRODUCTION: Crohn's disease and ulcerative colitis are common chronic idiopathic inflammatory bowel diseases (IBD), which cause considerable morbidity. Although the precise mechanisms of disease remain unclear, evidence implicates a strong multidirectional interplay between diet, environmental factors, genetic determinants/immune perturbations and the gut microbiota. IBD can be brought into remission using a number of medications, which act by suppressing the immune response. However, none of the available medications address any of the underlying potential mechanisms. As we understand more about how the microbiota drives inflammation, much interest has focused on identifying microbial signals/triggers in the search for effective therapeutic targets. We describe the establishment of the Australian IBD Microbiota (AIM) Study, Australia's first longitudinal IBD bioresource, which will identify and correlate longitudinal microbial and metagenomics signals to disease activity as evaluated by validated clinical instruments, patient-reported surveys, as well as biomarkers. The AIM Study will also gather extensive demographic, clinical, lifestyle and dietary data known to influence microbial composition in order to generate a more complete understanding of the interplay between patients with IBD and their microbiota. METHODS: The AIM Study is an Australian multicentre longitudinal prospective cohort study, which will enrol 1000 participants; 500 patients with IBD and 500 healthy controls over a 5-year period. Assessment occurs at 3 monthly intervals over a 24-month period. At each assessment oral and faecal samples are self-collected along with patient-reported outcome measures, with clinical data also collected at baseline, 12 and 24 months. Intestinal tissue will be sampled whenever a colonoscopy is performed. Dietary intake, general health and psychological state will be assessed using validated self-report questionnaires. Samples will undergo metagenomic, transcriptomic, proteomic, metabolomic and culturomic analyses. Omics data will be integrated with clinical data to identify predictive biomarkers of response to therapy, disease behaviour and environmental factors in patients with IBD. ETHICS AND DISSEMINATION: Ethical approval for this study has been obtained from the South Eastern Sydney Local Health District Research Ethics Committee (HREC 2019/ETH11443). Findings will be reported at national and international gastroenterology meetings and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ACTRN12619000911190.

The Role of Diet in the Pathogenesis and Management of Inflammatory Bowel Disease: A Review.

Inflammatory bowel diseases, which include ulcerative colitis and Crohn's disease, are chronic relapsing and remitting inflammatory diseases of the gastrointestinal tract that are increasing in prevalence and incidence globally. They are associated with significant morbidity, reduced quality of life to individual sufferers and are an increasing burden on society through direct and indirect costs. Current treatment strategies rely on immunosuppression, which, while effective, is associated with adverse events. Epidemiological evidence suggests that diet impacts the risk of developing IBD and modulates disease activity. Using diet as a therapeutic option is attractive to patients and clinicians alike due to its availability, low cost and few side effects. Diet may influence IBD risk and disease behaviour through several mechanisms. Firstly, some components of the diet influence microbiota structure and function with downstream effects on immune activity. Secondly, dietary components act to alter the structure and permeability of the mucosal barrier, and lastly dietary elements may have direct interactions with components of the immune response. This review will summarise the mechanisms of diet-microbial-immune system interaction, outline key studies examining associations between diet and IBD and evidence demonstrating the impact of diet on disease control. Finally, this review will outline current prescribed dietary therapies for active CD.