[Unusual presentation of visceral leishmaniasis in an immunocompetent patient]

Infection by Leishmania (Leishmania) infantum chagasi causes intestinal changes B-1 cells dependent

Evaluating the histopathological and morphometric changes caused by Leishmania (Leishmania) infantum chagasi infection either in the presence or absence of B-1 cells. Wild-type Balb/c and XID mice were used. Half of XID mice received B-1 cells adoptive transfer (XID + B1). Five animals from each group were infected (Balb/c I, XID I and XID + B1 I), totalizing six groups (n = 5). After 45 days of infection, the ileum was collected for histological processing and analysis. After infection, the XID animals showed an increase in the thickness of the intestinal layers, in the depth and width of the crypt and in the villi width. However, the Balb/c I group showed a reduction in almost all these parameters, whereas the villi width was increased. The villi height decreased in the infected XID animals; however, it was increased in the XID + B1 I group. Leishmania (L) infantum chagasiinfection caused a decrease in the number of Paneth cells; however, their area was increased. Finally, goblet cells and enterocytes presented different change profiles among groups. This study showed that the parasite infection causes structural and histopathological alterations in the intestine. These changes might be influenced by the absence of B-1 cells.

Dyarrheal Syndrome in a Patient Co-Infected with Leishmania infantum and Schistosoma mansoni

This case report describes an atypical clinical presentation of visceral leishmaniasis affecting the digestive tract and causing malabsorption syndrome in a patient without recognized immunosuppressive condition. After appropriate treatment for the classical visceral form of the disease, diarrhea persisted as the main symptom and massive infection by Leishmania was detected by histopathology analysis of the duodenal mucosa. Schistosoma mansoni coinfection was also confirmed and treated without impact on diarrhea. New course of amphotericin B finally led to complete improvement of diarrhea. Atypical visceral leishmaniasis involving the gastrointestinal tract is well recognized in HIV coinfection but very rare in immunocompetent patients. The factors determining the control or evolution of the Leishmania infection have not been completely identified. This case stresses the importance of atypical symptoms and the unusual location of visceral leishmaniasis, not only in immunodepressed patients, and raises the possible influence of chronic infection by S. mansoni reducing the immune response to Leishmania.

Macrophage-related diseases of the gut: a pathologist's perspective

The resident macrophages of the gastrointestinal tract represent the largest population of macrophages in the human body and are usually located in the subepithelial lamina propria. This strategic location guarantees a first-line defense to the huge numbers of potentially harmful bacteria and antigenic stimuli that are present in the intestinal lumen. In non-inflamed mucosa, macrophages phagocytose and kill microbes in the absence of an inflammatory response. However, in the event of an epithelial breach and/or microbial invasion, new circulating monocytes and lymphocytes will be recruited to the damaged area of the gut, which will result in the secretion of proinflammatory mediators and engage a protective inflammatory response. Although macrophages are usually not conspicuous in normal mucosal samples of the gut, they can easily be detected when they accumulate exogenous particulate material or endogenous substances or when they become very numerous. These events will mostly occur in pathologic conditions, and this review presents an overview of the diseases which are either mediated by or affecting the resident macrophages of the gut.

[Visceral leishmaniasis in immunocompetent adults. About six cases]

OBJECTIVE

Studying the epidemiological variations of visceral leishmaniasis in Tunisia and proving the importance of parasitological investigations to raise the diagnosis.

PATIENTS AND METHODS

Six patients hospitalised during the period between January 1998 and January 2009 at Fattouma Bourguiba Teaching Hospital in Monastir, five men and an only one woman, aged from 26 to 70 years old, originating from the central and eastern regions of the country. Epidemiological, clinical, biological and therapeutic data were obtained from the patient's medical files.

RESULTS

The major clinical symptoms were fever, weakness and spleen enlargement. Biological data revealed the presence of anaemia in every case and leucopoenia associated or not associated with thrombopenia in four cases. The diagnosis of visceral leishmaniasis was confirmed by the identification of the parasite in the blood or in the bone marrow. All patients were treated with two courses of antimoniate of meglumine separated by a 6-week interval. The outcome was positive and the patients were cured.

CONCLUSION

Visceral leishmaniasis is increasing among adults in Tunisia. Moreover, it is spreading outside its epidemiological area in the north to reach the central and southern regions. It should be raised when fever and spleen enlargement occur. Biological data are hardly specific. Diagnosis is based on finding the parasite in human fluids, mainly by molecular techniques. The rapid establishment of a specific treatment is vital.

Visceral Leishmaniasis presenting with intestinal failure: a case report and literature review

We describe an unusual case of visceral Leishmaniasis affecting the gastrointestinal tract in a young immunocompetent patient whose only recent foreign travel was a trip to Mexico 9 months previously. She presented insidiously with diarrhoea, weight loss and developed subacute intestinal failure. Interestingly, she lacked most of the typical features of acute infection, including visceromegaly, fevers and hypergammaglobulinaemia. Atypical visceral involvement involving the gastrointestinal tract is well recognized in HIV coinfection, but very rare in immunocompetent patients. Repeated microscopy and culture of endoscopic biopsies failed to identify Leishmania parasites. Serological tests - direct agglutination test and anti-K39 antibody tests - were negative. This case highlights a very rare presentation of the condition with the absence of other visceral involvement and diagnosis being eventually made solely on polymerase chain reaction of rectal tissue, with a subsequent excellent response to therapy with intravenous liposomal amphotericin.