Visceral leishmaniasis: rapid response to AmBisome treatment

Visceral Leishmaniasis as a Possible Reason for Pancytopenia

Leishmaniasis is caused by different species of the protozoa, Leishmania, and frequently found in South-Western Asia, Eastern Africa, Brazil, and Mediterranean countries. Leishmania are transmitted to humans by the bite of sandflies. After weeks to months, unspecific symptoms may occur, accompanied by more specific findings like pancytopenia and organomegaly. We report two children with pancytopenia and hepato-/splenomegaly: a 1-year-old boy was first diagnosed with an Adenovirus-infection, accompanied by fever, pancytopenia, and hepatosplenomegaly who had spent his summer vacation in Spain and a 3-year-old boy of Macedonian origin who was first diagnosed with a Parvovirus B19-infection again accompanied by splenomegaly and pancytopenia. In both children, leukemia was excluded by an initial bone marrow puncture. As fever was still persistent weeks after the children's first hospital stay, both children received antibiotics empirically without sustainable effect. While different autoantibodies were present in both children, an immunosuppressive therapy was initiated in the younger boy without therapeutic success. A second bone marrow puncture was performed and Leishmania were finally detected morphologically and proven serologically. After weight-adjusted treatment with liposomal Amphotericin B for 10 days, both children recovered completely without relapse. Aim of this report is to broaden the spectrum of differential diagnoses in children with pancytopenia, splenomegaly, and fever to visceral leishmaniasis particularly when travel history is positive for the Mediterranean area. The infection may mimic more common diseases, such as leukemia, viral infections, or autoimmune diseases, because polyclonal B cell activation and other mechanisms may lead to multiple positive serologic tests. Both cases illustrate typical pitfalls and shall encourage taking Leishmaniasis into diagnostic consideration.

[Visceral leishmaniasis: new drugs]

The standard treatment of visceral leishmaniasis is pentavalent antimony (meglumine antimoniate or sodium stibogluconate), but toxicity is frequent with this drug. Moreover, antimony unresponsiveness is increasing, both in immunocompetent and in immunosuppressed patients. Amphotericin B is a polyene macrolide antibiotic that binds to sterols in cell membranes. It is the most active antileishmanial agent in use. Its infusion-related and renal toxicity may be reduced by lipid-based delivery. Liposomal amphotericin B (Ambisome) seems to be less toxic than other amphotericin B lipid formulations (Amphocil, Amphotec). Optimal drug regimens of Ambisome vary from one geographical area to another. In the Mediterranean Basin, a total dose of 18 to 24 mg/kg is safe and effective. Shortening the duration of treatment without decreasing the total dose (i.e., 10 mg/kg/day for 2 days) seems promising to reduce the global cost of the therapy.

[Short course treatment for visceral leishmaniasis with liposomal amphotericin B in immunocompetent patients]

INTRODUCTION

Visceral leishmaniasis is endemic in southern Europe. Traditional treatment consists of pentavalent antimonial compounds. However, treatment failures, the treatment's long duration, and toxicity have led to the introduction of new therapies, such as liposomal amphotericin B (LAB). In this study we evaluate the safety and efficacy of LAB at a maximum dose of 4 mg/kg/day on days 1, 2, 3, 4, 5, and 10.

PATIENTS AND METHODS

A prospective, observational, open study was conducted in 13 Spanish centers. The diagnosis of visceral leishmaniasis was based on visualization of Leishmanias sp. in bone marrow aspirate or culture or positive serology together with compatible clinical symptoms.

RESULTS

Thirty-two immunocompetent children aged from 7 months to 7 years were treated. All the children had rapid clinical response and bone marrow aspirate performed on day 21 was normal in the 24 patients (100 %) who underwent this procedure. In the remaining eight children efficacy was assessed by clinical response. Two relapses were observed. Cure was achieved in 18 patients (90.0 %) and in 87.5 % of the patients with microbiological confirmation of the disease. No adverse events were detected.

CONCLUSIONS

A total dosage of 24 mg/kg of liposomal amphotericin B administered in 6 doses within 10 days is safe and effective for the treatment of visceral leishmaniasis and reduces the length of hospital stay.

Visceral leishmaniasis misdiagnosed as probable acute lymphoblastic leukaemia

A4-year old girl was transferred from a local district general hospital with a presumptive diagnosis of acute lymphoblastic leukaemia. She had been referred with coryzal symptoms and recurrent epistaxes for 6 months. Her parents had noticed pallor, lethargy and anorexia.

Liposomal amphotericin B in the treatment of visceral leishmaniasis in immunocompetent patients

The leishmaniases are protozoan diseases caused by Leishmania parasites. The first-line treatment of its visceral forms is pentavalent antimony (meglumine antimoniate or sodium stibogluconate), but toxicity is frequent with this drug. Moreover antimony unresponsiveness is increasing in Leishmania infantum and L. donovani foci, both in immunocompetent and in immunosuppressed patients. Amphotericin B is a polyene macrolide antibiotic that binds to sterols in cell membranes. It is the most active antileishmanial agent in use. Its infusion-related and renal toxicity may be reduced by lipid-based delivery. Liposomal amphotericin B (AmBisome); Gilead Science, Paris, France) seems to be less toxic than other amphotericin B lipid formulations (Amphocil); Liposome Technology Inc., Menlo Park, CA, USA, Amphotec); Ben Venue Laboratories Inc., Bedford, OH, USA). Optimal drug regimens of AmBisome) vary from one geographical area to another. In the Mediterranean Basin, a total dose of 18 mg/kg (3 mg/kg on days 1-5 and 3 mg/kg on day 10) could be used as first-line treatment of visceral leishmaniasis in immunocompetent patients. In immunocompromised patients, especially those co-infected with HIV, relapses are frequent with AmBisome), as with other drugs.

Visceral leishmaniasis in a German child who had never entered a known endemic area: case report and review of the literature

We describe a case of visceral leishmaniasis in a 15-month-old German child. Diagnosis was significantly delayed because the patient had no history of travel to known endemic areas. Congenital or blood transfusion-associated leishmaniasis was ruled out. Possible modes of transmission (including a potential new autochthonous focus of the disease in central Europe) are discussed.

Improvement of in vitro and in vivo antileishmanial activities of 2', 6'-dihydroxy-4'-methoxychalcone by entrapment in poly(D,L-lactide) nanoparticles

The inhibition of intracellular Leishmania amazonensis growth by 2', 6'-dihydroxy-4'-methoxychalcone (DMC) isolated from Piper aduncum was further enhanced after encapsulation of DMC in polymeric nanoparticles. Encapsulated DMC also showed increased antileishmanial activity in infected BALB/c mice, as evidenced by significantly smaller lesions and fewer parasites in the lesions.

[Treatment of infantile visceral leishmaniasis]

Visceral leishmaniasis is an endemic disease in the Mediterranean Basin. Children are one of the targets of the infection. Treatment usually requires parenteral injections of pentavalent antimony (Glucantime or Pentostam), but the high frequency of adverse events and the occurrence of primary or secondary resistance cases limit the use of these medications. Diamidines (Pentacarinat) or amphotericin B derivatives are alternatives to antimony. Unfortunately, pharmacokinetics and optimal dosage of diamidines are not well-known, and numerous adverse events are described. Liposomal preparations of amphotericin B enhance its efficiency and tolerance, and the duration of treatment may be reduced to 5 days. Moreover, primary resistance to amphotericin B is not described in immunocompetent children. Allopurinol associated with antimony seems no more efficient than antimony alone. Aminosidine is not evaluated.

Treatment of visceral leishmaniasis in children with liposomal amphotericin B

We used liposomal amphotericin B as first-choice treatment of visceral leishmaniasis in 106 immunocompetent children who acquired the infection in a temperate region of southern Europe (Italy) where Leishmania infantum visceral leishmaniasis is endemic. The aim of the study was to identify the minimum total dose of liposomal amphotericin B needed to cure the infection in children and reduce the period of hospitalization. We conclude that the optimal regimen in immunocompetent children with L. infantum visceral leishmaniasis to be a total dose of 18 mg/kg of liposomal amphotericin B (3 mg/kg per day for 5 days, followed by 3 mg/kg administered as an outpatient regimen on day 10).