Colorectal polyps in young adults: a retrospective review of colonoscopy data from Toowoomba and the Darling Downs.

BACKGROUND: Polyps are the predominant precursors of colorectal cancer. In the past three decades, the incidence and mortality rates of colorectal cancer have been increasing in adults younger than 50 years. AIMS: The aim of this clinical audit was to evaluate the prevalence, characteristics and clinical associations of polyps in adults aged 18-49 years presenting to an established private gastroenterology clinic in the Toowoomba Darling Downs region. METHODS: The audit included data from 353 patient records held by the Toowoomba Gastroenterology Clinic. Data extracted from patient medical records through the Medical Director program software contained structured endoscopy/colonoscopy and histology reports of excised lesions of patients presenting to the clinic. The extract involved identifying all patients aged 18-49 years in the database from January 2019 to March 2022. Patients were screened based on audit inclusion and exclusion criteria. Patients were risk stratified for recommended surveillance intervals as per Australian Clinical Guidelines. RESULTS: Of the sample population, 33.4% were identified with polyps and 22.4% were identified with neoplastic polyps (NPs). A total of 6.7% of 18- to 29-year-old patients were identified with intermediate risk for colorectal cancer (CRC) screening, and 19.8% and 19.3% of 30- to 39-year-old and 40- to 49-year-old patients identified with intermediate or high risk for CRC screening respectively. Increased age, greater size of polyps and surveillance of previous polyps were associated with increased NP prevalence. CONCLUSIONS: Data from this audit supported the temporal trend of increasing prevalence of polyps in adults younger than 50 years. Patient cohorts aged 30-39 and 40-49 years may benefit from earlier first colonoscopies. Findings could be the impetus for future research in young adults presenting for colonoscopy.

Video capsule endoscopy in patients with iron deficiency anaemia: experience at a regional Australian service.

OBJECTIVE: The objective of this study was to identify the diagnostic performance of video capsule endoscopy (VCE) among patients presenting with iron deficiency anaemia (IDA) and negative bidirectional endoscopy to a gasteroendoscopy practice in regional Australia. The secondary objectives were to identify the distribution of findings and factors predictive of positive findings in a regional setting. RESULTS: In total 123 procedures were included in the study. Mean age of the patients was 67.9 years. Females made up 60.2% (n = 74) of the study population. Mean haemoglobin and ferritin levels were 93.3 g/L and 11.9 ug/L, respectively. Positive findings were present in 67 procedures (54.5%) with the most frequent finding being small bowel angiodysplasia (53.7%, n = 36/67), followed by ulceration/significant erosion (26.8%, n = 18/67), fresh blood (20.8%, n = 14/67) and tumour/polyp (16.4%, n = 11/67). Haemoglobin level was the only variable associated with positive findings (p = 0.005) in the study population. Of the procedures reporting positive findings outside the small bowel, the majority (80%) were within reach of conventional upper endoscopy and may have implications for future practice, particularly when allocating health resources in a rural setting.

Comparison of faecal microbiota in Blastocystis-positive and Blastocystis-negative irritable bowel syndrome patients.

BACKGROUND: We investigated whether the carriage of Blastocystis in IBS patients was associated with differences in the faecal microbiota. Forty patients with diarrhoea-predominant IBS (26 Blastocystis-positive and 14 Blastocystis-negative) and 57 healthy controls (HC) (42 Blastocystis-positive and 15 Blastocystis-negative) submitted faecal samples for metataxonomic analysis of the 16S ribosomal RNA gene. Differences in the relative abundance of bacteria in these IBS and HC groups were evaluated from phylum to genus level. RESULTS: Significant changes were observed in two dominant phyla in IBS patients, regardless of Blastocystis infection status, namely a rise in Firmicutes and a statistically significant reduction in relative abundance of Bacteroidetes (with a threefold increase in the Firmicutes to Bacteoridetes ratio). Significant differences at genus level in IBS subjects compared to HC were also observed for many bacterial species. However, further clinical subgroup analysis of Blastocystis-positive and Blastocystis-negative subjects, regardless of symptoms, showed no significant differences at the phylum or genus level in IBS-P compared to IBS-N. CONCLUSIONS: Significant differences in the faecal microbiota between diarrhoea-predominant IBS patients and healthy controls were confirmed, but the carriage of Blastocystis did not significantly alter the faecal microbiota. If Blastocystis-positive patients represent a separate clinical subtype of IBS, this group is not identified by changes in the microbiota.

Blastocystis specific serum immunoglobulin in patients with irritable bowel syndrome (IBS) versus healthy controls.

BACKGROUND: Blastocystis species are common enteric human parasites and carriage has been linked to Irritable Bowel Syndrome (IBS), particularly diarrhoea-predominant IBS. The spectrum of immune reactivity to Blastocystis proteins has been reported previously in symptomatic patients. We investigated differences in serum immunoglobulin profiles between patients with IBS, both positive and negative for Blastocystis carriage, and healthy controls (HC). METHODS: Forty diarrhoea-predominant IBS patients (26 patients positive for Blastocystis sp., 14 negative patients) and forty HC (24 positive, 16 Blastocystis-negative) were enrolled. Age, gender, ethnicity and serum immunoglobulin A (IgA) levels were recorded and faecal specimens were analysed using smear, culture and polymerase chain reaction amplification of ribosomal DNA. Sera were tested in Western blots and the reactivities compared to known targets using monoclonal antibodies Blastofluor® (Blastocystis specific antibody), MAb1D5 (cytopathicto Blastocystis cells), anti-promatrix metalloprotease-9 (anti-MMP-9) and SDS-PAGE zymograms. RESULTS: Levels of serum IgA were significantly lower in Blastocystis carriers (p < 0.001) but had no relationship to symptoms. Western blots demonstrated serum IgG antibodies specific for Blastocystis proteins of 17,27,37,50,60-65, 75-90, 95-105 and 150 kDa MW. Reactivity to the 27, 50 and 75-95 kDa proteins were found more frequently in the IBS group compared to the HC's (p < 0.001) and correlation was greater for Blastocystis-positive IBS patients (p < 0.001) than for negative IBS patients (p < 0.05). MAb1D5 reacted with proteins of 27 and 100 kDa, and anti-MMP-9 with 27, 50 and 75-100 kDa proteins. Bands were seen in zymograms around 100 kDa. CONCLUSIONS: Low serum IgA levels are associated with Blastocystis carriage. All IBS patients were more likely to demonstrate reactivity with Blastocystis proteins of 27 kDa (likely a cysteine protease), 50 and 75-95 kDa MW compared to HC. The presence of antibodies to these Blastocystis proteins in some Blastocystis-negative subjects suggests either prior exposure to Blastocystis organisms or antibody cross reactivities. The anti-proMMP-9 reaction at 50 and 75-100 kDa and the zymogram result suggest that metalloproteases may be important Blastocystis antigens. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials registry ACTRN: 12611000918921.

Features of Blastocystis spp. in xenic culture revealed by deconvolutional microscopy.

Blastocystis spp. are common human enteric parasites with complex morphology and have been reported to cause irritable bowel syndrome (IBS). Deconvolutional microscopy with time-lapse imaging and fluorescent spectroscopy of xenic cultures of Blastocystis spp. from stool samples of IBS patients and from asymptomatic, healthy pigs allowed observations of living organisms in their natural microbial environment. Blastocystis organisms of the vacuolated, granular, amoebic and cystic forms were observed to autofluorescence in the 557/576 emission spectra. Autofluorescence could be distinguished from fluorescein-conjugated Blastocystis-specific antibody labelling in vacuolated and granular forms. This antibody labelled Blastocystis subtypes 1, 3 and 4 but not 5. Surface pores of 1 µm in diameter were observed cyclically opening and closing over 24 h. Vacuolated forms extruded a viscous material from a single surface point with coincident deflation that may demonstrate osmoregulation. Tear-shaped granules were observed exiting from the surface of an amoebic form, but their origin and identity remain unknown.

Clinical pilot study: efficacy of triple antibiotic therapy in Blastocystis positive irritable bowel syndrome patients.

BACKGROUND: Blastocystis species are common human enteric parasites. Carriage has been linked to Irritable Bowel Syndrome (IBS). Treatment of Blastocystis spp. with antimicrobials is problematic and insensitive diagnostic methods and re-infection complicate assessment of eradication. We investigated whether triple antibiotic therapy comprising diloxanide furoate, trimethoprim/sulfamethoxazole and secnidazole (TAB) given to diarrhoea-predominant IBS (D-IBS) patients positive for Blastocystis would achieve eradication. METHODS: In a longitudinal, prospective case study 10 D-IBS Blastocystis-positive patients took 14 days of diloxanide furoate 500 mg thrice daily, trimethoprim/sulfamethoxazole 160/80 mg twice daily and secnidazole 400 mg thrice daily. Faecal specimens were collected at baseline, day 15 and 4 weeks after completion of TAB. Specimens were analysed using faecal smear, culture and polymerase chain reaction (PCR) of the 16 SSU rRNA. Patients kept a concurrent clinical diary. RESULTS: Six (60%) patients cleared Blastocystis spp. after TAB, including three who had failed previous therapy. Subtypes detected were ST3 (60%), ST4 (40%), ST1 (20%) and ST7, 8 (10%); four patients had mixed ST infections. Serum immunoglobulin A (IgA) levels were low in 40% of patients. Higher rates of Blastocystis clearance were observed in patients symptomatic for less than a year (Mann-Whitney, p = 0.032, 95% confidence) with no associations found with age, previous antibiotic therapy, faecal parasite load, ST, IgA level or clinical improvement. CONCLUSIONS: Clearance of Blastocystis spp. was achieved with TAB in 60% of D-IBS patients, an improvement over conventional monotherapy. Higher clearance rates are needed to facilitate investigation of the relevance of this parasite in clinically heterogenous IBS.

Coeliac patients are undiagnosed at routine upper endoscopy.

BACKGROUND AND AIMS: Two out of three patients with Coeliac Disease (CD) in Australia are undiagnosed. This prospective clinical audit aimed to determine how many CD patients would be undiagnosed if duodenal biopsy had only been performed if the mucosa looked abnormal or the patient presented with typical CD symptoms. METHODS: All eligible patients presenting for upper gastrointestinal endoscopy (OGD) in a regional center from 2004-2009 underwent prospective analysis of presenting symptoms and duodenal biopsy. Clinical presentations were defined as either Major (diarrhea, weight loss, iron deficiency, CD family history or positive celiac antibodies- Ab) or Minor Clinical Indicators (CI) to duodenal biopsy (atypical symptoms). Newly diagnosed CD patients had follow up celiac antibody testing. RESULTS: Thirty-five (1.4%) new cases of CD were identified in the 2,559 patients biopsied at upper endoscopy. Almost a quarter (23%) of cases presented with atypical symptoms. There was an inverse relationship between presentation with Major CI's and increasing age (<16, 16-59 and >60: 100%, 81% and 50% respectively, p = 0.03); 28% of newly diagnosed CD patients were aged over 60 years. Endoscopic appearance was a useful diagnostic tool in only 51% (18/35) of CD patients. Coeliac antibodies were positive in 34/35 CD patients (sensitivity 97%). CONCLUSIONS: Almost one quarter of new cases of CD presented with atypical symptoms and half of the new cases had unremarkable duodenal mucosa. At least 10% of new cases of celiac disease are likely to be undiagnosed at routine upper endoscopy, particularly patients over 60 years who more commonly present atypically. All new CD patients could be identified in this study by performing pre-operative celiac antibody testing on all patients presenting for OGD and proceeding to biopsy only positive antibody patients and those presenting with either Major CI or abnormal duodenal mucosa for an estimated cost of AUS$4,629 and AUS$3,710 respectively.

Eradication of Blastocystis carriage with antimicrobials: reality or delusion?

Metronidazole constitutes a mainstay in the antimicrobial therapy of intestinal protozoa, and is also traditionally considered first-line therapy in cases where there is a requirement to treat Blastocystis, a common protist of disputable clinical significance. Many compounds have been used in attempts to eradicate the parasite, and an accumulating body of data indicates that successful antimicrobial eradication of Blastocystis is far from straightforward. This review focuses on some issues that prevent us from reaching a clear understanding of how to eradicate Blastocystis based on chemotherapeutic intervention, by focusing on conflicting reports on the efficacy of metronidazole and other compounds and study design and data limitations. The review provides a comprehensive overview of antimicrobials used to target Blastocystis, and discusses issues pertaining to drug resistance, treatment failure, and reinfection. Finally, key methodological and molecular diagnostic tools that will assist in the generation of data required to improve current knowledge are identified and discussed.