Correction: Endomicroscopic and Transcriptomic Analysis of Impaired Barrier Function and Malabsorption in Environmental Enteropathy.

[This corrects the article DOI: 10.1371/journal.pntd.0004600.].

Tryptophan, glutamine, leucine, and micronutrient supplementation improves environmental enteropathy in Zambian adults: a randomized controlled trial.

BACKGROUND: Environmental enteropathy (EE) refers to villus blunting, reduced absorption, and microbial translocation in children and adults in tropical or deprived residential areas. In previous work we observed an effect of micronutrients on villus height (VH). OBJECTIVE: We aimed to determine, in a randomized controlled trial, if amino acid (AA) or multiple micronutrient (MM) supplementation can improve intestinal structure or barrier dysfunction in Zambian adults with EE. METHODS: AA (tryptophan, leucine, and glutamine) and/or MM supplements were given for 16 wk in a 2 × 2 factorial comparison against placebo. Primary outcomes were changes in VH, in vivo small intestinal barrier dysfunction assessed by confocal laser endomicroscopy (CLE), and mechanistic (or mammalian) target of rapamycin complex 1 (MTORC1) nutrient responsiveness in lamina propria CD4+ lymphocytes. RESULTS: Over 16 wk AA, but not MM, supplementation increased VH by 16% (34.5 µm) compared with placebo (P = 0.04). Fluorescein leak, measured by CLE, improved only in those allocated to both AA and MM supplementation. No effect was seen on MTORC1 activation, but posttreatment MTORC1 and VH were correlated (ρ = 0.51; P = 0.001), and change in MTORC1 was correlated with change in VH in the placebo group (ρ = 0.63; P = 0.03). In secondary analyses no effect was observed on biomarkers of microbial translocation. Metabolomic analyses suggest alterations in a number of microbial- and host-derived metabolites including the leucine metabolite ß-hydroxy-ß-methylbutyrate, which was increased by AA supplementation and correlated with VH. CONCLUSIONS: In this phase 2 trial, AA supplementation protected against a decline in VH over the supplementation period, and improved barrier function when combined with micronutrients. Leucine and MTORC1 metabolism may be involved in the mechanism of effect. This trial was registered at www.pactr.org as PACTR201505001104412.

Endomicroscopic and Transcriptomic Analysis of Impaired Barrier Function and Malabsorption in Environmental Enteropathy.

INTRODUCTION: Environmental enteropathy (EE) is associated with growth failure, micronutrient malabsorption and impaired responses to oral vaccines. We set out to define cellular mechanisms of impaired barrier function in EE and explore protective mechanisms. METHODS: We studied 49 adults with environmental enteropathy in Lusaka, Zambia using confocal laser endomicroscopy (CLE); histology, immunohistochemistry and mRNA sequencing of small intestinal biopsies; and correlated these with plasma lipopolysaccharide (LPS) and a zinc uptake test. RESULTS: CLE images (median 134 for each study) showed virtually ubiquitous small intestinal damage. Epithelial defects, imaged by histology and claudin 4 immunostaining, were predominantly seen at the tips of villi and corresponded with leakage imaged in vivo by CLE. In multivariate analysis, circulating log-transformed LPS was correlated with cell shedding events (ß = 0.83; P = 0.035) and with serum glucagon-like peptide-2 (ß = -0.13; P = 0.007). Zinc uptake from a test dose of 25mg was attenuated in 30/47 (64%) individuals and in multivariate analysis was reduced by HIV, but positively correlated with GLP-2 (ß = 2.72; P = 0.03). There was a U-shaped relationship between circulating LPS and villus surface area. Transcriptomic analysis identified 23 differentially expressed genes in severe enteropathy, including protective peptides and proteins. CONCLUSIONS: Confocal endomicroscopy, claudin 4 immunostaining and histology identify epithelial defects which are probably sites of bacterial translocation, in the presence of which increased epithelial surface area increases the burden of translocation. GLP 2 and other protective peptides may play an important role in mucosal protection in EE.

Esophageal squamous cell cancer in a highly endemic region.

AIM: To identify risk factors associated with esophageal cancer in Zambia and association between dietary intake and urinary 8-iso prostaglandin F2α (8-isoPGF2α). METHODS: We conducted a prospective, case control study at the University Teaching Hospital. Subjects included both individuals admitted to the hospital and those presenting for an outpatient upper endoscopy. Esophageal cancer cases were compared to age and sex-matched controls. Cases were defined as patients with biopsy proven esophageal cancer; controls were defined as subjects without endoscopic evidence of esophageal cancer. Clinical and dietary data were collected using a standard questionnaire, developed a priori. Blood was collected for human immunodeficiency virus (HIV) serology. Urine was collected, and 8-isoPGF2α was measured primarily by enzyme-linked immunosorbent assay and expressed as a ratio to creatinine. RESULTS: Forty five controls (mean age 54.2 ± 15.3, 31 male) and 27 cases (mean age 54.6 ± 16.4, 17 males) were studied. Body mass index was lower in cases (median 16.8) than controls (median 23.2), P = 0.01. Histopathologically, 25/27 (93%) were squamous cell carcinoma and 2/27 (7%) adenocarcinoma. More cases smoked cigarettes (OR = 11.24, 95%CI: 1.37-92.4, P = 0.02) but alcohol consumption and HIV seropositivity did not differ significantly (P = 0.14 for both). Fruit, vegetables and fish consumption did not differ significantly between groups (P = 0.11, 0.12, and 0.10, respectively). Mean isoprostane level was significantly higher in cases (0.03 ng/mg creatinine) than controls (0.01 ng/mg creatinine) (OR = 2.35, 95%CI: 1.19-4.65, P = 0.014). CONCLUSION: Smoking and isoprostane levels were significantly associated with esophageal cancer in Zambians, but diet, HIV status, and alcohol consumption were not.

Trends in upper gastrointestinal diagnosis over four decades in Lusaka, Zambia: a retrospective analysis of endoscopic findings.

BACKGROUND AND AIMS: There a shortage of robust information about profiles of gastrointestinal disease in sub-Saharan Africa. The endoscopy unit of the University Teaching Hospital in Lusaka has been running without interruption since 1977 and this 38-year record is largely intact. We report an analysis of endoscopic findings over this period. METHODS: Written endoscopy records from 29th September 1977 to 16th December 2014 were recovered, computerised, coded by two experienced endoscopists and analysed. Temporal trends were analysed using tables, graphs, and unconditional logistic regression, with age, sex of patient, decade, and endoscopist as independent variables to adjust for inter-observer variation. RESULTS: Sixteen thousand nine hundred fifty-three records were identified and analysed. Diagnosis of gastric ulcer rose by 22 %, and that of duodenal ulcer fell by 14 % per decade. Endoscopically diagnosed oesophageal cancer increased by 32 % per decade, but gastric cancer rose only in patients under 60 years of age (21 % per decade). Oesophageal varices were the commonest finding in patients presenting with haematemesis, increasing by 14 % per decade in that patient group. Two HIV-related diagnoses, oesophageal candidiasis and Kaposi's sarcoma, rose from almost zero to very high levels in the 1990s but fell substantially after 2005 when anti-retroviral therapy became widely available. CONCLUSIONS: This useful dataset suggests that there are important trends in some endoscopic findings over four decades. These trends are not explained by inter-observer variation. Reasons for the divergent trends in incidence of peptic ulceration and apparent trends in diagnosis of upper gastrointestinal cancers merit further exploration.

HIV infection and domestic smoke exposure, but not human papillomavirus, are risk factors for esophageal squamous cell carcinoma in Zambia: a case-control study.

There is emerging evidence that esophageal cancer occurs in younger adults in sub-Saharan Africa than in Europe or North America. The burden of human immunodeficiency virus (HIV) is also high in this region. We postulated that HIV and human papillomavirus (HPV) infections might contribute to esophageal squamous cell carcinoma (OSCC) risk. This was a case-control study based at the University Teaching Hospital in Lusaka, Zambia. Cases were patients with confirmed OSCC and controls had completely normal upper endoscopic evaluations. A total of 222 patients were included to analyze the influence of HIV infection; of these, 100 patients were used to analyze the influence of HPV infection, alcohol, smoking, and exposure to wood smoke. The presence of HIV infection was determined using antibody kits, and HPV infection was detected by polymerase chain reaction. HIV infection on its own conferred increased risk of developing OSCC (odds ratio [OR] 2.3; 95% confidence interval [CI] 1.0-5.1; P = 0.03). The OR was stronger when only people under 60 years were included (OR 4.3; 95% CI 1.5-13.2; P = 0.003). Cooking with charcoal or firewood, and cigarette smoking, both increased the odds of developing OSCC ([OR 3.5; 95% CI 1.4-9.3; P = 0.004] and [OR 9.1; 95% CI 3.0-30.4; P < 0.001], respectively). There was no significant difference in HPV detection or alcohol intake between cases and controls. We conclude that HIV infection and exposure to domestic and cigarette smoke are risk factors for OSCC, and HPV immunization unlikely to reduce OSCC incidence in Zambia.