Tropical sprue--its aetiology and pathogenesis

An In Vitro Small Intestine Model Incorporating a Food Matrix and Bacterial Mock Community for Intestinal Function Testing

Consumed food travels through the gastrointestinal tract to reach the small intestine, where it interacts with the microbiota, forming a complex relationship with the dietary components. Here we present a complex in vitro cell culture model of the small intestine that includes human cells, digestion, a simulated meal, and a microbiota represented by a bacterial community consisting of E. coli, L. rhamnosus, S. salivarius, B. bifidum, and E. faecalis. This model was used to determine the effects of food-grade titanium dioxide nanoparticles (TiO₂ NPs), a common food additive, on epithelial permeability, intestinal alkaline phosphatase activity, and nutrient transport across the epithelium. Physiologically relevant concentrations of TiO₂ had no effect on intestinal permeability but caused an increase in triglyceride transport as part of the food model, which was reversed in the presence of bacteria. Individual bacterial species had no effect on glucose transport, but the bacterial community increased glucose transport, suggesting a change in bacterial behavior when in a community. Bacterial entrapment within the mucus layer was reduced with TiO₂ exposure, which may be due to decreased mucus layer thickness. The combination of human cells, a synthetic meal, and a bacterial mock community provides an opportunity to understand the implications of nutritional changes on small intestinal function, including the microbiota.

El esprúe tropical, una enfermedad olvidada como diagnóstico diferencial de la enfermedad celiaca

Estimado editor, Por medio de la presente nos gustaría traer a discusión la importancia que tiene la enfermedad celiaca (EC), también conocida como esprúe celiaco o enteropatía sensible al gluten, la cual corresponde a una enfermedad autoinmune desencadenada por la ingesta de gluten en individuos predispuestos genéticamente (1). La EC se caracteriza por una amplia variabilidad de manifestaciones clínicas, pero su forma clásica es la más habitual en el adulto; aquí los síntomas guía son de naturaleza gastrointestinal (diarrea, esteatorrea y dolor abdominal inespecífico). Por otro lado, las formas no clásicas y silentes son cada vez más frecuentes y se caracterizan por un amplio abanico de signos y síntomas como osteoporosis, hipovitaminosis D, anemia ferropénica, dermatitis herpetiforme, ataxia, polineuropatía sensitiva periférica, migrañas y alteración de las pruebas de función hepática (2).

Infectious Gastroenteritis as a Risk Factor for Tropical Sprue and Malabsorption: A Case-Control Study

BACKGROUND

Previous studies have linked an increase in functional and pathological gastrointestinal (GI) disorders following antecedent infectious gastroenteritis (IGE), yet studies of other chronic GI disorders such as tropical sprue (TS) and intestinal malabsorption (IM) are lacking. This study was performed to evaluate the association between documented IGE and the risk of TS and IM using a matched case-control study.

METHODS

The odds of IGE (exposure) among subjects with TS and IM were compared to the odds of exposure in matched controls. Data were obtained from the Defense Medical Surveillance System. Incidence was estimated based on the number of active duty military personnel, and conditional logistic regression models were used to evaluate the relationship between IGE and TS/IM while adjusting for potential confounders.

RESULTS

The overall incidence of TS and IM was 0.24 and 1.98 per 100,000 person-years, respectively. After adjusting for important covariates, prior IGE was associated with an increase in the odds of TS (odds ratio (OR) 36.64) and IM (OR 3.93) (p < 0.001). Other covariates demonstrating an increased risk were being of Caucasian race, having greater than high school education, and service in military branches other than the Army.

CONCLUSION

Overall, this study demonstrates the first significant estimates that a case of antecedent IGE is associated with an increased risk of TS and IM in an active duty military population. Ultimately, acquisition of TS or IM has the potential to decrease operational efficiency, which may have a significant impact on deployed military missions.

Spectrum of microorganisms in infected walled-off pancreatic necrosis - impact on organ failure and mortality

OBJECTIVE

Data on the microbial spectrum in infected pancreatic necrosis are scarce. Only few studies have addressed this issue in a larger, consecutive group of patients treated by a standardized algorithm. Since 2005 endoscopic, transmural drainage and necrosectomy (ETDN) has been the treatment of choice for walled-off necrosis in our centre. The present study evaluated the microbial spectrum of infected pancreatic necrosis and the possible relationship between infected necrosis, organ failure, and mortality. Furthermore, we investigated whether the aetiology of pancreatitis, use of external drainage, and antibiotic treatment influenced the microbial findings.

METHODS

Retrospective review of medical charts on 78 patients who underwent ETDN in our tertiary referral centre between November 2005 and November 2011.

RESULTS

Twenty-four patients (31%) developed one or more organ failures, 23 (29%) needed treatment in the intensive care unit (ICU), and 9 (11%) died during hospital admission. The prevailing microbial findings at the index endoscopy were enterococci (45%), enterobacteriaceae (42%), and fungi (22%). There was a significant association between the development of organ failure (p < 0.001), need of treatment in ICU (p < 0.002), in-hospital mortality (p = 0.039) and infected necrosis at the time of index endoscopy. Enterococci (p < 0.0001) and fungi (p = 0.01) were found more frequently in patients who died during admission as compared to survivors.

CONCLUSION

Different microbes in pancreatic necrosis may influence the prognosis. We believe that a detailed knowledge on the microbial spectrum in necrotizing pancreatitis may be utilized in the treatment to improve the outcome.

Tropical sprue

Tropical sprue (TS) is a clinical entity of unknown etiology characterized by an acquired chronic diarrheal illness and malabsorption that affects indigenous inhabitants and expatriates, either long-term residents or short-term visitors, in the tropical countries. The exact pathogenetic sequence of TS remains incompletely characterized. Bacterial overgrowth, disturbed gut motility, and hormonal and histopathologic abnormalities contribute to the development of TS in a susceptible host. Treatment with tetracycline and folate is effective in some patients, although relapses after treatment are common. Research in the areas of microbial factors, pathogenesis, immunogenetics, and hormonal and immune regulation, using modern diagnostic techniques, may be able to settle some of the unanswered issues and open new venues for diagnosis, prevention, and treatment of tropical sprue.

[Tropical sprue: two cases in the Paris area]

Tropical sprue (TS) is a postinfective tropical malabsorption that occurs in tropical countries. TS is associated with a persisting colonization of the small-intestine lumen by enterotoxinogenic bacteria that cause subsequent enterocyte damage affecting all or part of the small-intestine. We report two cases of TS that occurred in inhabitants of Paris area returned from endemic areas. The first observation concerned a 76-year old woman admitted for anorexia, loss of 20 kg and anemia. The second observation concerned a 53-year old man referred for chronic diarrhea and loss of 40 kg within 4 years. In both cases, duodenal lesions consisted of subtotal and total villous atrophy with prominent infiltration of the damaged surface epithelium with lymphocytes and infiltrate of lymphocytes and plasma cells of the lamina propria. The two patients recovered under antibiotics, confirming the diagnosis of TS.

A perspective on tropical sprue

A diagnosis of tropical sprue, an infrequent affliction of inhabitants and travelers in tropical regions, should be considered in patients with a compatible history, malabsorption, and chronic diarrhea. It can occur in either endemic or epidemic form and can be preceded by acute gastroenteritis. The cause of tropical sprue is still unknown, although most data support an infectious etiology. Therapeutic experience is greatest with folic acid and tetracycline. Most patients can be expected to recover with proper nutritional support, although relapses and slow responses occur.

Tropical sprue after travel to Tanzania

Tropical sprue (TS) is a diagnosis to consider in travelers with prolonged diarrhea and a malabsorption syndrome after return from tropical countries, particularly India and Southeast Asia. TS is an unusual condition in tropical Africa. Textbooks of tropical medicine indicate a low endemicity in Nigeria and a limited number of cases in South Africa and Zimbabwe. A Medline search from 1979 to mid 1998 using "Tanzania and tropical sprue" as key words disclosed no hits. We report herein a case of TS in a European traveler, who lived in Tanzania for 8 months.

Tropical sprue and subclinical enteropathy: a vision for the nineties

Aside from infectious intestinal diseases with known etiology, there is a group of gastrointestinal disorders mainly affecting the small intestine of individuals predominantly living in and less often visiting or returning from the Third World, usually the tropics, and ranging from asymptomatic structural and/or functional abnormalities of the gastrointestinal mucosa (subclinical enteropathy, SE) to a fully symptomatic condition highlighted by malabsorption of nutrients with associated nutritional deficiencies responsive to folate and broad spectrum antibiotic treatment (tropical sprue, TS). Mounting evidence supports an infectious cause in many instances. The exact nature of the infection, whether initiated and/or perpetuated by enterotoxigenic coliform bacteria, virus(es) or a combination of these, is not clear. Further studies, including those using molecular techniques, are needed in order to clarify various aspects of these widely prevalent disorders.