Jejunal function and pathology in visceral Leishmaniasis

Lower levels of leptin are associated with severity parameters in visceral leishmaniasis patients

Visceral leishmaniasis (VL) is the most severe clinical form of leishmaniasis, and if untreated may be fatal. It affects important organs of the immune system and is characterized by a specific immunosuppression, along with intense cellular activation and cytokine storm. Moreover, VL is now recognized as a systemic inflammatory response syndrome (SIRS), in which multiple cytokines and other pro-inflammatory molecules are released. The action of these inflammatory mediators may be considered risk factors for poor prognosis and death. Leptin, a hormone derived from adipose tissue, has been described with several immunoregulatory functions in vitro and in vivo Leishmania infection models, particularly for enhancing the macrophage microbicidal mechanisms. Considering that evaluation of immunologic parameters that may be associated with this clinical scenario may help to decrease VL lethality, we evaluated whether leptin is associated with VL pathogenesis. Thirty-one patients were recruited in the active phase of VL, of which 22 were followed up until one month after therapy (1mpt). Except for creatinine levels, all clinical parameters were altered in active VL patients, especially leucocyte counts and albumin and hemoglobin levels. Also, elevated levels of lipopolysaccharide (LPS), immunoglobulins (Ig)G1 and G3 anti-Leishmania and interleukins (IL)-6 and -10 were higher than in healthy individuals. In contrast, active VL patients presented diminished serum leptin levels and positive correlation with leukocytes counts and hemoglobin and albumin levels. After 1mpt, VL patients showed a significant increase in leptin levels, reaching values similar to healthy volunteers. As expected, only LPS levels remained elevated after 1mpt. These findings suggest that leptin levels are affected in Leishmania infection and the correlation with important parameters associated with the prognosis of VL points to the involvement of this molecule in VL immunopathogenesis. Additional studies are needed to evaluate the possibility of leptin as a prognostic marker of VL.

Hyponatremia and risk factors for death in human visceral leishmaniasis: new insights from a cross-sectional study in Brazil

Background

Visceral leishmaniasis (VL) is an important and potentially fatal neglected tropical disease. The aim of this study was to investigate hyponatremia and risk factors for death among VL patients.

Methods

This is a cross-sectional study with VL patients admitted to a tertiary hospital in Northeast Brazil, from 2002 to 2009. Patients were divided into two groups: non-survivors and survivors. Hyponatremia was defined as serum sodium < 135 mEq/L. A logistic regression model was done to investigate risk factors for death.

Results

A total of 285 VL patients were included, with mean age 37 ± 15 years, and 74% were males. Thirty-four patients died (11.9%). Non-survivors had a significantly higher prevalence of dyspnea (38.2 vs. 16.7%, p = 0.003), pulmonary crackles (11.8 vs. 4.0%, p = 0.049), dehydration (23.5 vs. 10.8%, p = 0.033), oliguria (8.8 vs. 0.8%, p = 0.001) and jaundice (47.1 vs. 14.3%, p < 0.001). They also presented higher prevalence of hyponatremia (41.9 vs. 24.1%, p = 0.035), thrombocytopenia (91.2 vs. 65.3%, p = 0.002) and severe hypoalbuminemia (78.3 vs. 35.3%, p < 0.001). In multivariate analysis, moderate/severe hyponatremia (OR = 2.278, 95% CI = 1.046–4.962), thrombocytopenia (OR = 5.482, 95% CI = 1.629–18.443), jaundice (OR = 5.133, 95% CI = 1.793–14.696) and severe hypoalbuminemia (OR = 6.479, 95% CI = 2.124–19.766) were predictors of death.

Conclusion

Higher prevalence of dehydration, oliguria, pulmonary symptoms and liver involvement was found in non-survivors VL patients. Hypoalbuminemia and hyponatremia were frequent and significantly associated with mortality.

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.

Evaluation of parasitological and immunological parameters of Leishmania chagasi infection in BALB/c mice using different doses and routes of inoculation of parasites

Experimental vaccines to protect against visceral leishmaniasis (VL) have been developed by using BALB/c mice infected with a large (10⁷ to 10⁸) inoculum of parasites. Remarkably, prior literature has reported that the poor protection observed is mainly due to the high susceptibility of this strain. To determine factors inherent to mice that might abrogate vaccine-induced efficacy, the present research sought to investigate the impact of the administration of different infective inoculums of Leishmania chagasi (syn. L. infantum) in BALB/c mice, evaluating subcutaneous and intravenous routes of administration as well as parasitological and immunological parameters over different periods of time. This study shows that the injection of a highly infective inoculum in mice, through both subcutaneous and intravenous routes, results in a sustained infection. The mice developed a high parasite load in the liver; however, these values diminished over time. This result did not corroborate with the parasite load in the bone marrow and brain and proved to be expressively different in the spleen and draining lymph nodes, where the values increased over time. Mice infected with a low dose of parasites (10³) showed a certain resistance against infection, based mainly on the IFN-γ and oxide nitric production. Considering all the elements, it could be concluded that the models employing high doses (10⁷) of L. chagasi in BALB/c mice can bring about an imbalance in the animals' immune response, thus allowing for the development of the disease at the expense of efficacy within the vaccine candidates.

Evidence that lipopolisaccharide may contribute to the cytokine storm and cellular activation in patients with visceral leishmaniasis

Background

Visceral leishmaniasis (VL) is characterized by parasite-specific immunosuppression besides an intense pro-inflammatory response. Lipopolisaccharide (LPS) has been implicated in the immune activation of T-cell deficient diseases such as HIV/AIDS and idiopathic lymphocytopenia. The source of LPS is gram-negative bacteria that enter the circulation because of immunological mucosal barrier breakdown. As gut parasitization also occurs in VL, it was hypothesized that LPS may be elevated in leishmaniasis, contributing to cell activation.

Methodology/Principal Findings

Flow cytometry analysis and immunoassays (ELISA and luminex micro-beads system) were used to quantify T-cells and soluble factors. Higher LPS and soluble CD14 levels were observed in active VL in comparison to healthy subjects, indicating that LPS was bioactive; there was a positive correlation between these molecules (r = 0.61;p<0.05). Interestingly, LPS was negatively correlated with CD4⁺ (r = −0.71;p<0.01) and CD8⁺ T-cells (r = −0.65;p<0.05). Moreover, higher levels of activation-associated molecules (HLA-DR, CD38, CD25) were seen on T lymphocytes, which were positively associated with LPS levels. Pro-inflammatory cytokines and macrophage migration inhibitory factor (MIF) were also augmented in VL patients. Consistent with the higher immune activation status, LPS levels were positively correlated with the inflammatory cytokines IL-6 (r = 0.63;p<0.05), IL-8 (r = 0.89;p<0.05), and MIF (r = 0.64;p<0.05). Also, higher plasma intestinal fatty acid binding protein (IFABP) levels were observed in VL patients, which correlated with LPS levels (r = 0.57;p<0.05).

Conclusions/Significance

Elevated levels of LPS in VL, in correlation with T-cell activation and elevated pro-inflammatory cytokines and MIF indicate that this bacterial product may contribute to the impairment in immune effector function. The cytokine storm and chronic immune hyperactivation status may contribute to the observed T-cell depletion. LPS probably originates from microbial translocation as suggested by IFABP levels and, along with Leishmania antigen-mediated immune suppression, may play a role in the immunopathogenesis of VL. These findings point to possible benefits of antimicrobial prophylaxis in conjunction with anti-Leishmania therapy.

Visceral leishmaniasis (VL) affects organs rich in lymphocytes, being characterized by intense Leishmania-induced T-cell depletion and reduction in other hematopoietic cells. In other infectious and non-infectious diseases in which the immune system is affected, such as HIV-AIDS and inflammatory bowel disease, damage to gut-associated lymphocyte tissues occurs, enabling luminal bacteria to enter into the circulation. Lipopolisaccharide (LPS) is a bacterial product that stimulates macrophages, leading to the production of pro-inflammatory cytokines and other soluble factors such as MIF, which in turn activate lymphocytes. Continuous and exaggerated stimulation causes exhaustion of the T-cell compartment, contributing to immunosuppression.

Herein, we show that an increment in LPS plasma levels also occurs in VL; the higher the LPS levels, the lower the TCD4⁺ and TCD8⁺ cell count in the blood. This T-cell depletion may affect the mucosal immune system, which, along with intestinal parasitization by amastigotes, may contribute to gut barrier damage and consequent microbial translocation. LPS levels were correlated with T-cell activation, pro-inflammatory cytokine plasma levels, MIF, and IFABP, showing that a bacterial molecule, probably from luminal origin, not associated with Leishmania infection can negatively affect the immune system. These findings points to possible benefits of antimicrobial prophylaxis in conjunction with anti-Leishmania therapy.

Cytokine expression in the duodenal mucosa of patients with visceral leishmaniasis

INTRODUCTION

Visceral leishmaniasis (VL) is a neglected tropical disease with a complex immune response in different organs. This pattern of organ-specific immune response has never been evaluated in the gastrointestinal tract. The aim of this study was to determine the in situ immune response in duodenal biopsies on patients with VL.

METHODS

A case-control study was conducted on 13 patients with VL in comparison with nine controls. The immune response was evaluated using immunohistochemistry, for CD4, CD8, CD68, IL-4, IFN-gamma, TNF-alpha and IL-10. Histological findings from the villi, crypts and inflammatory process were analyzed.

RESULTS

All the cases of VL presented Leishmania antigens. No antigen was detected in the control group. The villus size was greater in the VL patients (p < 0.05). CD68 (macrophages) and CD4 levels were higher in the VL patients (p < 0.05). No differences in the expression of CD8, TNF-alpha, IL-10 or IL-4 were demonstrated. The number of cells expressing IFN-gamma was lower in the VL patients (p < 0.05).

CONCLUSIONS

Low levels of cytokines were found in the gastrointestinal tract of patients with VL. This pattern was not found in other organs affected by the disease. Immunotolerance of this tissue against Leishmania could explain these findings, as occurs with intestinal bacteria.

Neto A, Fuc G, Verde EML. Hyponatremia in visceral leishmaniasis

There are few reports linking hyponatremia and visceral leishmaniasis (kala-azar). This is a study of 55 consecutive kala-azar patients and 20 normal individuals as a control group. Hyponatremia and serum hypo-osmolality were detected in 100% of kala-azar patients. High first morning urine osmolality (750.0 ± 52.0 vs. 894.5 ± 30.0mOsm/kg H2O, p < 0.05), and high 24-hour urine osmolality (426.0 ± 167.0 vs. 514.6 ± 132.0 mOsm/kg H2O, p < 0.05) demonstrated persistent antidiuretic hormone secretion. Urinary sodium was high (82.3 ± 44.2 vs.110.3 ± 34.7 mEq/L, p < 0.05). Low seric uric acid occurred in 61.8% of patients and increased fractional urinary uric acid excretion was detected in 74.5% of them. Increased glomerular filtration rate was present in 25.4% of patients. There was no evidence of extracellular volume depletion. Normal plasma ADH levels were observed in kala-azar patients. No endocrine or renal dysfunction was detected. It is possible that most hyponatremic kala-azar patients present the syndrome of inappropriate antidiuretic hormone secretion.

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.

Tropical malabsorption

Malabsorption is an important clinical problem both in visitors to the tropics and in native residents of tropical countries. Infections of the small intestine are the most important cause of tropical malabsorption. Protozoal infections cause malabsorption in immunocompetent hosts, but do so more commonly in the setting of immune deficiency. Helminth infections occasionally cause malabsorption or protein-losing enteropathy. Intestinal tuberculosis, chronic pancreatitis and small-bowel bacterial overgrowth are important causes of tropical malabsorption. In recent years, inflammatory bowel disease and coeliac disease have become major causes of malabsorption in the tropics. Sporadic tropical sprue is still an important cause of malabsorption in adults and in children in South Asia. Investigations to exclude specific infective, immunological or inflammatory causes are important before considering tropical sprue as a diagnosis. This article briefly reviews the management of tropical sprue and presents an algorithm for its investigation and management.

[Unusual presentation of visceral leishmaniasis in an immunocompetent patient]

Visceral leishmaniasis due to Leishmania infantum is endemic in Tunisia. The incidence in adult patients has increased in recent years; but most of these patients are not HIV positive as in other Mediterranean countries where all the cases are associated with HIV. We present the case of a woman with symptoms suggestive of leishmaniasis but whose bone marrow was sterile and whose serological tests for Leishmania spp. were negative. For this patient, the parasite was only detected in a routine duodenal biopsy. There are few reports of visceral leishmaniasis cases diagnosed by duodenal biopsy and almost all patients were HIV positive in that case. Thus it seems interesting to perform a duodenal biopsy in case of a difficult diagnostic even in the absence of gastrointestinal symptoms and/or HIV infection.

Leishmaniasis and AIDS co-infection: the Spanish example

There are an estimated 300 instances of Leishmania/HIV co-infection, of which 200 have occurred in Spain. Jorge Alvar here asks: is there an epidemiological or immunological basis for this high proportion?

An alternative immunohistochemical method for detecting Leishmania amastigotes in paraffin-embedded canine tissues

Canine visceral leishmaniasis (CVL) is a zoonosis and a chronic systemic disease of the dog caused by a protozoan by the species Leishmania infantum in the Old World and Leishmania chagasi in the New World. Several methods are currently employed for the diagnosis of CVL including microscopic detection of the parasite in bone marrow and lymph node aspirates, demonstration of specific antibodies anti-Leishmania in sera from infected animals, and isolation of the parasite by in vitro culture or by inoculation of laboratory animals. However, a definitive diagnosis is based on the actual detection of the parasite, which is conventionally achieved by examining Giemsa-stained smears or histopathological sections stained with hematoxylin and eosin. These methods have a low sensitivity, and therefore, they are often inconclusive. This is particularly true in canine organs that have a low level of parasitism such as kidneys, lungs, central nervous system, and testis, or, in some cases, the skin. The technique for immunohistochemical detection of leishmanial amastigotes in canine tissues has been reported previously and has proved to be undoubtedly efficient for the diagnosis. In this paper, we describe a straightforward and inexpensive immunohistochemical approach for Leishmania detection in formalin-fixed paraffin-embedded canine tissues. Amastigote forms of Leishmania were easily observed within macrophages in several organs from naturally infected dogs using the streptavidin-biotin immunohistochemical method with canine hyperimmune serum as the primary antibody. In addition, the secondary antibody used was not specific to canine immunoglobulin, characterizing a cross-immune reaction. Our results indicate that this technique could be a useful tool for epidemiological, clinical, and histopathological studies.

Anti-leishmania antibodies in cerebrospinal fluid from dogs with visceral leishmaniasis

Visceral leishmaniasis in Brazil is caused by Leishmania (Leishmania) chagasi and the dog is its most important reservoir. The clinical features in dogs include loss of weight, lymphadenopathy, renal failure, skin lesions, fever, hypergammaglobulinemia, hepatosplenomegaly, anemia, and, rarely, neurological symptoms. Most infected animals develop active disease, characterized by high anti-leishmania antibody titers and depressed lymphoproliferative ability. Antibody production is not primarily important for protection but might be involved in the pathogenesis of tissue lesions. An ELISA test was used to determine if there is an association between neurological symptoms and the presence of anti-L. chagasi antibodies in cerebrospinal fluid (CSF). Thirty serum and CSF samples from symptomatic mixed breed dogs (three with neurological symptoms) from a region of high incidence of visceral leishmaniasis in Brazil were examined for antibody using total parasite antigen and anti-dog IgG peroxidase conjugate. A high level of L. chagasi antibodies was observed in sera (mean absorbance SD, 1.939 0.405; negative control, N = 20, 0.154 0.074) and CSF (1.571 0.532; negative control, N = 10, 0.0195 0.040) from all animals studied. This observation suggests that L. chagasi can cause breakdown of filtration barriers and the transfer of antibodies and antigens from the blood to the CSF compartment. No correlation was observed between antibody titer in CSF and neurological symptoms.

Meningeal leishmaniosis induced by Leishmania infantum in naturally infected dogs

We report two cases of meningitis caused by Leishmania infantum in naturally infected dogs. In both of these dogs the typical phenotypic features of granulomatous meningitis were observed with important lympho-plasma-cellular infiltrates and the presence of large numbers of parasites inside and outside macrophages. The immunological study of the cerebrospinal fluid of both animals showed that a large number of protein bands were recognized by those fluids and that they were similar to the ones recognized by the sera from the same animals. To our knowledge, this is the first description of meningitis associated to leishmaniosis.

[Vitamin A serum level in children with visceral leishmaniasis]

Vitamin A is considered an anti-infectious disease vitamin, and its deficiency is associated with severe infections such as in measles. In developing countries the low concentrations of vitamin A are a public health problem. The aim of this study is to describe serum vitamin A concentrations among children with visceral leishmaniasis (VL). Blood sample was collected from 22 children with VL, and stored in a freezer, 9 siblings, with no clinical signs of the VL patients had their blood collected for a control group. Samples were assayed by high performance liquid chromatography. The median vitamin A concentration in the LV group was 21.38 microg/100ml and in the control group it was 31.39 microg/100. The mean in the LV was statistically lower than in the control group, using Student's t test, p<0.01.

Leishmaniasis in Sudan. Visceral leishmaniasis

From the early 1900s, visceral leishmaniasis (VL; kala-azar) has been among the most important health problems in Sudan, particularly in the main endemic area in the eastern and central regions. Several major epidemics have occurred, the most recent--in Western Upper Nile province in southern Sudan, detected in 1988--claiming over 100,000 lives. The disease spread to other areas that were previously not known to be endemic for VL. A major upsurge in the number of cases was noted in the endemic area. These events triggered renewed interest in the disease. Epidemiological and entomological studies confirmed Phlebotomus orientalis as the vector in several parts of the country, typically associated with Acacia seyal and Balanites aegyptiaca vegetation. Infection rates with Leishmania were high, but subject to seasonal variation, as were the numbers of sand flies. Parasites isolated from humans and sand flies belonged to three zymodemes (MON-18, MON-30 and MON-82), which all belong to the L. donovani sensu lato cluster. Transmission dynamics have not been elucidated fully; heavy transmission in relatively scarcely populated areas such as Dinder national park suggested zoonotic transmission whereas the large numbers of patients with post kala-azar dermal leishmaniasis (PKDL) in heavily affected villages may indicate a human reservoir and anthroponotic transmission. Clinical presentation in adults and in children did not differ significantly, except that children were more anaemic. Fever, weight loss, hepato-splenomegaly and lymphadenopathy were the most common findings. PKDL was much more common than expected (56% of patients with VL developed PKDL), but other post-VL manifestations were also found affecting the eyes (uveitis, conjunctivitis, blepharitis), nasal and/or oral mucosa. Evaluation of diagnostic methods showed that parasitological diagnosis should still be the mainstay in diagnosis, with sensitivities for lymph node, bone marrow and spleen aspirates of 58%, 70% and 96%, respectively. Simple, cheap serological tests are needed. The direct agglutination test (DAT) had a sensitivity of 72%, specificity of 94%, positive predictive value of 78% and negative predictive value of 92%. As with other serological tests, the DAT cannot distinguish between active disease, subclinical infection or past infection. The introduction of freeze-dried antigen and control sera greatly improved the practicality and accuracy of the DAT in the field. An enzyme-linked immunosorbent assay using recombinant K39 antigen had higher sensitivity than DAT (93%). The polymerase chain reaction using peripheral blood gave a sensitivity of 70-93% and was more sensitive than microscopy of lymph node or bone marrow aspirates in patients with suspected VL. The leishmanin skin test (LST) was typically negative during active VL and converted to positive in c. 80% of patients 6 months after treatment. Immunological studies showed that both Th1 and Th2 cell responses could be demonstrated in lymph nodes from VL patients as evidenced by the presence of messenger ribonucleic acid for interleukin (IL)-10, interferon gamma and IL-2. Treatment of peripheral blood mononuclear cells from VL patients with IL-12 was found to drive the immune response toward a Th1 type response with the production of interferon gamma, indicating a potential therapeutic role for IL-12. VL responded well to treatment with sodium stibogluconate, which is still the first line drug at a dose of 20 mg/kg intravenously or intramuscularly per day for 15-30 d. Side effects and resistance were rare. Liposomal amphotericin B was effective, with few side effects. Control measures have not been implemented. Based on observations that VL does not occur in individuals who have a positive LST, probably because of previous cutaneous leishmaniasis, a vaccine containing heat-killed L. major promastigotes is currently undergoing a phase III trial.

Visceral leishmaniasis in human immunodeficiency virus (HIV)-infected and non-HIV-infected patients. A comparative study

Visceral leishmaniasis is an endemic infection in Mediterranean countries, where it has become a frequent complication of acquired immunodeficiency syndrome (AIDS). The incidence of visceral leishmaniasis is increasing in Spain due to human immunodeficiency virus (HIV)-related cases, but some aspects of its epidemiology, clinical features, and management remain unknown. In addition, no comparative clinical studies about the disease in HIV-infected and non-HIV-infected patients have been reported. During a 24-year period, 120 cases of visceral leishmaniasis were diagnosed at our institution and 80 (66%) were associated with HIV infection. The mean age at diagnosis was higher in HIV-infected that in non-HIV-infected patients (33.2 versus 23.2 yr; p = 0.002), but the male/female ratio was similar in both groups. The main risk factor for HIV infection was intravenous drug abuse (78.7%). The clinical presentation of leishmaniasis was similar in both groups, but HIV-infected patients had a lower frequency of splenomegaly than HIV-negative individuals (80.8% versus 97.4%; p = 0.02). HIV-infected patients had a greater frequency and degree of leukopenia, lymphocytopenia, and thrombocytopenia. Most of them were profoundly immunosuppressed (mean CD4+ lymphocyte count, 90 cells/mm3) at the time of diagnosis of leishmaniasis, and 53.7% had AIDS. The sensitivity of serologic studies for Leishmania was significantly lower in HIV-infected than in non-HIV-infected patients (50% versus 80%; p < 0.001), but the diagnostic yield of bone marrow aspirate (67.1% versus 79.4%) and bone marrow culture (62.9% versus 66.6%) was similar in both groups. After initial treatment, the response rate was significantly lower in HIV-infected than in non-HIV-infected individuals (54.8% versus 89.7%; p = 0.001). The relapse rate was 46.2% and 7.5%, respectively (p < 0.001). Secondary prophylaxis with antimonial compounds or amphotericin B seems to be useful in preventing relapses in HIV-infected patients. The mortality rate was higher (53.7% versus 7.5%; p < 0.001) and the median survival time shorter (25 versus > 160 mo; p < 0.001) in AIDS patients than in HIV-negative individuals. Although leishmaniasis could contribute to death in a significant number of HIV-infected patients, it was the main cause of death in only a few of them. The CD4+ lymphocyte count and the use of highly active antiretroviral therapy and secondary prophylaxis for leishmaniasis were the most significant prognostic factors for survival in AIDS patients. Visceral leishmaniasis behaves as an opportunistic infection in HIV-infected individuals and should be considered as an AIDS-defining disease.

The histological spectrum of visceral leishmaniasis caused by Leishmania infantum MON-1 in acquired immune deficiency syndrome

Visceral leishmaniasis (VL) due to Leishmania infantum is endemic in Southern France and can be considered as an opportunistic infection in patients with acquired immunodeficiency syndrome (AIDS). Co-infection with Leishmania sp. and human immunodeficiency virus (HIV) is emerging, but pathological findings of leishmaniasis in AIDS have been poorly documented, and scattered case reports have include morphological descriptions. The clinicopathologic analysis of 16 patients with HIV and VL were evaluated. The clinical presentation was characteristic of VL, with fever, hepatosplenomegaly, and pancytopenia in 6 patients, and the diagnosis was confirmed by finding amastigotes of Leishmania sp. in bone marrow smears and biopsy specimens. In 4 patients, the initial diagnosis of VL was made fortuitously in gastrointestinal biopsies performed systematically (3 patients) or in case of diarrhea (1 patient). In one duodenal biopsy, Leishmania sp. and Mycobacteria sp. were associated. Liver biopsy allowed the diagnosis of VL in 3 cases. Autopsy was performed in 9 patients, showing a disseminated leishmaniasis with very unusual localizations (adrenal and heart) in 2 cases. Cutaneous leishmaniasis involvement was noted before (4 patients), at the same time (2 patient), or after (1 patient) the diagnosis of VL. Inflammatory infiltrates noted with Leishmania sp. infection were made by CD68 macrophages with (8 patients) or without (8 patients) associated CD8 positive lymphocytes. Immunoperoxidase study using polyclonal anti-Leishmania sp. antibodies contributed to the diagnosis in all cases. Electron microscopy of 2 digestive biopsy specimens showed the ultrastructural characteristics of Leishmania sp. amastigotes. The zymodeme MON-1 of L infantum was identified by isoenzyme electrophoresis in all patients. The mean of CD4 counts was 37/mm3 at the time of diagnosis, and the mean duration before the death was 8 months. As shown in this study, VL in AIDS can be diagnosed in gastrointestinal or liver biopsies. Diagnosis of VL was made when the CD4 count was very low and was correlated with a poor prognosis.

[Visceral leishmaniasis and malnutrition: a case report]

BACKGROUND

Visceral leishmaniasis occurring in malnourished subjects can have an uncommon course, which explains difficulties in its diagnosis.

CASE REPORT

A 22-month-old infant was admitted because of malnutrition and prolonged fever. The bacteriological investigation was negative. When his nutritional status improved, he developed a splenomegaly. The medullogram confirmed the diagnosis of visceral leishmaniasis. The course was then favorable with treatment by pentavalent antimonial.

CONCLUSION

Malnutrition constitutes a risk factor of opportunist parasitic disease such as leishmaniasis. Its diagnosis can be very difficult.

Leishmania and human immunodeficiency virus coinfection: the first 10 years

Over 850 Leishmania-human immunodeficiency virus (HIV) coinfection cases have been recorded, the majority in Europe, where 7 to 17% of HIV-positive individuals with fever have amastigotes, suggesting that Leishmania-infected individuals without symptoms will express symptoms of leishmaniasis if they become immunosuppressed. However, there are indirect reasons and statistical data demonstrating that intravenous drug addiction plays a specific role in Leishmania infantum transmission: an anthroponotic cycle complementary to the zoonotic one has been suggested. Due to anergy in patients with coinfection, L. infantum dermotropic zymodemes are isolated from patient viscera and a higher L. infantum phenotypic variability is seen. Moreover, insect trypanosomatids that are currently considered nonpathogenic have been isolated from coinfected patients. HIV infection and Leishmania infection each induce important analogous immunological changes whose effects are multiplied if they occur concomitantly, such as a Th1-to-Th2 response switch; however, the consequences of the viral infection predominate. In fact, a large proportion of coinfected patients have no detectable anti-Leishmania antibodies. The microorganisms share target cells, and it has been demonstrated in vitro how L. infantum induces the expression of latent HIV-1. Bone marrow culture is the most useful diagnostic technique, but it is invasive. Blood smears and culture are good alternatives. PCR, xenodiagnosis, and circulating-antigen detection are available only in specialized laboratories. The relationship with low levels of CD4+ cells conditions the clinical presentation and evolution of disease. Most patients have visceral leishmaniasis, but asymptomatic, cutaneous, mucocutaneous, diffuse cutaneous, and post-kala-azar dermal leishmaniasis can be produced by L. infantum. The digestive and respiratory tracts are frequently parasitized. The course of coinfection is marked by a high relapse rate. There is a lack of randomized prospective treatment trials; therefore, coinfected patients are treated by conventional regimens. Prophylactic therapy is suggested to be helpful in preventing relapses.