-
J Moreno,
J Nieto,
S Masina,
C Cañavate,
I Cruz,
C Chicharro,
E Carrillo,
S Napp,
C Reymond,
P M Kaye,
D F Smith,
N Fasel, J Alvar
[show abstract]
[hide abstract]
ABSTRACT: The protective capabilities of three Leishmania recombinant proteins - histone 1 (H1) and hydrophilic acylated surface protein B1 (HASPB1) immunized singly, or together as a protein cocktail vaccine with Montanide, and the polyprotein MML immunized with MPL-SE adjuvant - were assessed in beagle dogs. Clinical examination of the dogs was carried out periodically under blinded conditions and the condition of the dogs defined as asymptomatic or symptomatic. At the end of the trial, we were able to confirm that following infection with L. infantum promastigotes, five out of eight dogs immunized with H1 Montanide, and four out of eight dogs immunized with either the combination of HASPB1 with Montanide or the combination of H1+HASPB1 with Montanidetrade mark, remained free of clinical signs, compared with two out of seven dogs immunized with the polyprotein MML and adjuvant MPL-SE, and two out of eight dogs in the control group. The results demonstrate that HASPB1 and H1 antigens in combination with Montanide were able to induce partial protection against canine leishmaniasis, even under extreme experimental challenge conditions.
Vaccine 08/2007; 25(29):5290-300. · 3.77 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Although the family Trypanosomatidae includes parasites of plants, insects and vertebrates, only two genera in the family, Leishmania and Trypanosoma, are usually found in humans. Since 1995, however, other monoxenous trypanosomatids have been isolated from several HIV-positive individuals, in whom the parasites cause either visceral or cutaneous lesions. These odd cases are reviewed here. It appears that immunocompromised patients may be vulnerable to infection with trypanosomatids (and other parasites) that either fail to survive or never cause detectable morbidity in the immunocompetent.
Annals of Tropical Medicine and Parasitology 11/2003; 97 Suppl 1:75-8. · 1.43 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In many countries, Leishmania/HIV co-infection is now changing the epidemiology of visceral leishmaniasis. The levels of transmission of the parasites causing such leishmaniasis were previously dependent on the conventional zoonotic cycle, in which sandflies transmitted the parasites from infected canids to other canids or humans. The co-infection, however, has led not only to marked increases in the sandfly transmission of the parasites from immunodepressed individuals directly to other humans but also, probably, to artificial transmission between immunodepressed intravenous-drug users, as the result of needle sharing.
Annals of Tropical Medicine and Parasitology 11/2003; 97 Suppl 1:29-45. · 1.43 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In many areas of the Mediterranean basin, leishmaniasis can now be found in HIV-positive individuals. Such cases of Leishmania/HIV co-infection are relatively common in southern Europe, Spain being the country that has reported the greatest number. Since 1984, 359 Spanish isolates of Leishmania infantum have been characterized at the Instituto de Salud Carlos III in Madrid. Most (94.6%) of the isolates came from HIV-positive patients. The results of iso-enzymatic analysis indicated a high level of variability among the isolates, the visceralization in HIV-positive individuals of variants considered to be dermotropic in the immunocompetent, and the appearance of new zymodemes among the HIV-positive human population.
Annals of Tropical Medicine and Parasitology 11/2003; 97 Suppl 1:57-64. · 1.43 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: As the AIDS pandemic spreads to rural areas and human visceral leishmaniasis (VL) becomes more common in suburban areas, there is an ever greater degree of overlap between the geographical distributions of the two diseases and, in consequence, an increasing incidence of Leishmania/HIV co-infection. Cases of the co-infection have been reported from 35 countries around the world but most have been recorded in south-western Europe. There has been a total of 1911 cases detected in Spain, France, Italy and Portugal. The incidence of Leishmania/HIV co-infection is expected to continue increasing in eastern Africa but to fall in south-western Europe as increasing numbers of HIV-positives in the latter region are given the new, highly active, antiretroviral therapy (HAART). In 1998, a world-wide network of surveillance for the co-infection, which now includes 28 member institutions, was established by the World Health Organization (WHO) and the Joint United Nations Programme on HIV/AIDS (UNAIDS). In south-western Europe, the surveillance system is based on 16 institutions and is already well established. The systematic use of standardized and recently computerized case-report forms, a central international registry at the WHO's headquarters in Geneva, and the use of a geographical information system (GIS) for mapping and monitoring the co-infections have together improved the overall quality of the epidemiological data-gathering. All member institutions of the global network report to the WHO on an annual basis. The data collected are then analysed and periodically disseminated through international publications. The GIS allows the relevant epidemiological and demographic data-sets to be integrated and permits all detected cases of co-infection to be mapped down to locality level. The system also allows the spatial distribution of cases to be visualised and analysed and the geographical spread of the co-infection to be monitored over time. The risk posed by co-infected patients, as a source of Leishmania infection for the sandflies feeding on them, has recently been confirmed. The parasites and HIV may also be transmitted as the result of needle-sharing among intravenous-drug users.
Annals of Tropical Medicine and Parasitology 11/2003; 97 Suppl 1:3-15. · 1.43 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The pharmacokinetics and toxicities of free sodium stibogluconate (SSG) and two vesicular formulations of this drug (a nonionic surfactant vesicular formulation of SSG [SSG-NIV] and SSG-NIV-dextran) were determined after treatment with a single intravenous dose in healthy dogs and were related to their antileishmanial efficacies in mice. Analysis of the curves of the concentrations in plasma after intravenous administration of SSG and SSG-NIV in dogs showed that both formulations produced similar antimony (Sb) pharmacokinetics. In contrast, treatment with SSG-NIV-dextran significantly modified the pharmacokinetics of the drug. The elimination half-life was four times longer (280 min) than that observed after administration of SSG (71 min) (P = 0.01), and the volume of distribution at steady state (V(SS)) was also increased (V(SS) for SSG, 0.21 liters/kg; V(SS) for SSG-NIV-dextran, 0.34 liters/kg [P = 0.02]), thus indicating that drug encapsulation favors the distribution of Sb into organs and increases its residence time in tissues. This would explain the superior antileishmanial efficacy of this formulation compared to those of the free drug in mice. No signs of toxicity were found in dogs after SSG and SSG-NIV administration. However, SSG-NIV-dextran treatment was associated with short-term toxicity, demonstrated by the development of chills and diarrhea, which cleared by 24 h postdosing, and hepatic dysfunction at 24 h postdosing (P < 0.05). The levels of all the biochemical parameters had returned to normal at 1 month postdosing. No signs of toxicity were observed in mice treated with all three formulations.
Antimicrobial Agents and Chemotherapy 09/2003; 47(9):2781-7. · 4.84 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In the Mediterranean basin, Leishmania infantum is the causative agent of both visceral and cutaneous leishmaniasis, and is an important opportunistic parasite in patients infected with human immunodeficiency virus (HIV). The commonest method used to study the variability of Leishmania spp. is isoenzyme analysis. In addition to this, we employed 3 assays based on the polymerase chain reaction (PCR): random amplified polymorphic deoxyribonucleic acid (RAPD), intergenic region typing (IRT), based on the amplification of ribosomal ribonucleic acid internal transcribed spacers and restriction fragment length polymorphism (PCR-RFLP). We used 54 L. infantum stocks isolated from HIV co-infected patients, 38 isolated from dogs, 3 isolated from immunocompetent patients and 3 isolated from 1826 sand files in the island of Majorca (Spain), a closed ecological niche. Zymodemes MON-1 (70%), MON-24 (11%) and MON-34 (18%) were found among the human isolates, and MON-1 (95%) and MON-108 (5%) among those from dogs. RAPD and IRT could not discriminate among the strains as they all gave the same pattern, even when different zymodemes were examined. In contrast, PCR-RFLP was able to distinguish the strains and, furthermore, a dendrogram (unweighted pair group method with arithmetic average [UPGMA]) was constructed from the genetic distances derived from RFLP data. The Leishmania isolates from HIV-infected subjects formed a single cluster, supporting the existence of an artificial anthroponotic cycle previously proposed by our group, in which syringes have been substituted for sand flies, and in which certain clones have been spread among intravenous drug users. This contrasts with the clusters representing a zoonotic cycle, involving dogs, sand flies and both immunocompetent and immunocompromised humans.
Transactions of the Royal Society of Tropical Medicine and Hygiene 05/2002; 96 Suppl 1:S93-9. · 2.16 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We investigated a Leishmania-specific nested polymerase chain reaction (Ln-PCR) for the diagnosis and treatment monitoring of L. infantum infections in patients co-infected with human immunodeficiency virus (HIV). Peripheral blood and bone marrow samples from 89 HIV patients in Spain suspected of having leishmaniasis were examined by different diagnostic techniques (Ln-PCR, microscopy, NNN culture and indirect fluorescent antibody test). The sensitivity of Ln-PCR compared with microscopy and culture of bone marrow was 95.45% using blood and 100% when using bone marrow. 38 of these patients with confirmed leishmaniasis were entered in a chemotherapy trial (reported elsewhere), and samples from them were collected before treatment, one month after treatment ended and during follow-up (1-20 months), and examined similarly. Ln-PCR was shown to be a good method for testing efficacy of treatment and for predicting relapses after treatment (relapses were predicted on average 5 months earlier than when using classical diagnostic techniques). We suggest that Ln-PCR (especially using peripheral blood) should be the technique of choice for diagnosis, monitoring the success of treatment, and predicting relapses in patients with HIV and suspected or confirmed L. infantum infection.
Transactions of the Royal Society of Tropical Medicine and Hygiene 05/2002; 96 Suppl 1:S185-9. · 2.16 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Needle sharing by intravenous drug users (IVDUs) has been proposed as providing an alternative, artificial, and anthroponotic cycle for leishmania transmission. We looked for parasites in syringes discarded by IVDUs using two different PCR techniques. Leishmania spp were detected in 65 (52%) of 125 syringes collected in southern Madrid, Spain, in 1998, and in 52 (34%) of 154 collected in southwestern Madrid in 2000-01. We found shared restriction fragment length polymorphisms in 12 of 65 positive samples tested, suggesting that syringe sharing can indeed promote the spread of leishmania clones among IVDUs.
The Lancet 04/2002; 359(9312):1124-5. · 38.28 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Cytokines play an important role in the regulation of the immune system, but low circulating levels in plasma make routine measurement a difficult task. A new methodology based on single tube RT-PCR has been developed to determine the expression of multiple canine cytokines (TNF-alpha, IL-2, IFN-gamma, IL-18, IL-4, IL-6 and IL-10) using primers and protocols designed allow specific amplification of the mRNAs. The technique is performed in one tube in two consecutive steps, a specific transcription of the mRNA of a given cytokine and amplification of the corresponding gene by PCR. The technique was used to analyse the mRNA cytokine profile of peripheral blood mononuclear cells (PBMCs) from healthy dogs using two approaches: (i) analysis of PBMC isolated ex vivo; (ii) analysis of PBMC after in vitro cultures with or without the mitogen ConA. The samples were separated in agarose gels and the intensity of ethidium bromide signals quantified using standard video imaging equipment. Results were interpreted as the ratio of cytokine to GAPDH expression. The results obtained show that the method is easy to use and reproducible. Therefore, this method of monitoring the mRNA cytokine expression might be an useful tool for understanding the immune response in dogs.
Veterinary Immunology and Immunopathology 01/2002; 83(3-4):191-202. · 2.08 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Genetic analysis of the SAG2 locus was performed to determine the prevalence of the different genotypes of Toxoplasma gondii (strain types I, II, and III) associated with human toxoplasmosis in Spain. This determination was made directly from primary clinical samples, obviating the previous process of isolation in mice or cell culture. A total of 34 isolates of T. gondii, collected from immunocompromised patients and congenital infection cases, were analyzed. Restriction fragment length polymorphism in PCR-amplified SAG2 products was used to group strains into one of the three genotypes of T. gondii. Complete characterization of the SAG2 gene was successful in 76.5% of the cases, demonstrating the feasibility of direct genotype analysis from clinical samples of different origins. Strains of T. gondii type II were the most prevalent in immunocompromised patients, with 52% of cases, while strains of type I were present in 75% of the congenital infection cases. These data differ from previous reports that show type II strains to be mostly associated with all kinds of human toxoplasmosis. These differences might be an effect of selection in the process of culture and isolation of the samples performed by other researchers prior to strain characterization.
Journal of Clinical Microbiology 05/2001; 39(4):1566-70. · 4.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The dog is the main reservoir of Leishmania infantum, which is a parasite spread among canine hosts by the bite of sand flies. Phlebotomus perniciosus is the sand fly acting as a major vector in the Mediterranean basin. As a consequence, the dog will suffer from leishmaniasis. In this work the infective capacity of infected dogs, established by direct xenodiagnosis, has been investigated in relation to their immunological status by determining the lymphocyte percentages present in peripheral blood mononuclear cells. We found a significant association between the percentages of T helper cells (CD4/TcR alpha beta(+)and CD4/CD45RA(+)) and the infection rates detected in the vector, while significant association was not detected in the case of the T cytotoxic cells (CD8/TcR alpha beta(+)and CD8/CD45RA(+)). The relationship discovered was that the lower the CD4(+)T cell count, the higher the rate of the infection in the vector.
Research in Veterinary Science 01/2001; 69(3):249-53. · 1.65 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A prospective descriptive study was designed to determine the impact of highly active antiretroviral therapy (HAART) in the evolution of visceral leishmaniasis (VL) in HIV-1 infected patients. Thirty-two patients were treated with meglumine antimoniate or amphotericin B in lipid formulations. Patients who had undergone previous HAART at study entry (n=17) continued with therapy while receiving treatment for VL. Patients who had never undergone HAART started it after VL treatment finished (n=15). Ten patients were lost to follow-up. All of the remaining patients (n=20) continued to receive HAART and were followed for an average of 441 days. Relapses were observed in 5 of 20 patients. These results indicate that HAART neither prevents the incidence of VL relapse nor modifies the clinical picture described in the pre-HAART era.
European Journal of Clinical Microbiology 11/2000; 19(10):798-801. · 2.86 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The use of a new PCR-based method for the diagnosis of malaria in the Spanish Malaria Reference Laboratory has promoted an increase in confirmed cases of malaria. From August 1997 to July 1998, a total of 192 whole-blood samples and 71 serum samples from 168 patients were received from the hospitals of the Spanish National Health System. Most of the patients came from west-central African countries (85%). This molecular method showed more sensitivity and specificity than microscopy, detecting 12.4% more positive samples than microscopy and 13% of mixed infections undetectable by Giemsa stain. Plasmodium falciparum was the main species detected, with 68% of the total positive malaria cases, followed by Plasmodium malariae (29%), Plasmodium vivax (14%), and Plasmodium ovale (7%), including mixed infections in all cases. This report consists of the first wide, centralized survey of malaria surveillance in Spain. The reference laboratory conducted the analysis of all imported cases in order to detect trends in acquisition. The use of a seminested multiplex PCR permitted confirmation of the origins of the infections and the Plasmodium species involved and confirmation of the effectiveness of drug treatments. This PCR also allowed the detection of the presence in Spain of primaquine-tolerant P. vivax strains from west-central Africa, as well as the detection of a P. falciparum infection induced by transfusion.
Journal of Clinical Microbiology 11/1999; 37(10):3260-4. · 4.15 Impact Factor
-
Revista espanola de quimioterapia: publicacion oficial de la Sociedad Espanola de Quimioterapia 07/1999; 12(2):120-5. · 0.81 Impact Factor
-
F Laguna,
R López-Vélez,
F Pulido,
A Salas,
J Torre-Cisneros,
E Torres,
F J Medrano,
J Sanz,
G Picó,
J Gómez-Rodrigo,
J Pasquau, J Alvar
[show abstract]
[hide abstract]
ABSTRACT: Visceral leishmaniasis is common in patients with HIV infection living in endemic areas, but the most effective and safe treatment remains unknown.
To compare the efficacy and safety of meglumine antimoniate versus amphotericin B in HIV-infected patients with first episodes of visceral leishmaniasis (VL).
An open, multicentre, prospective and randomized trial.
Twelve tertiary hospitals.
Eighty-nine consecutive HIV-infected patients diagnosed with VL. Patients were randomly assigned to treatment with either meglumine antimoniate (20 mg pentavalent antimony per kilogram of body weight per day) or amphotericin B (0.7 mg/kg per day) both for 28 days. Treatment was considered successful if a bone marrow aspirate performed 1 month after the end of therapy did not detect parasites. Relapse was defined as the reappearance of parasites after an initial cure.
An initial cure was attained in 29 of 44 patients (65.9%) randomly assigned to treatment with meglumine antimoniate and 28 of 45 (62.2%) randomly assigned to treatment with amphotericin B. The incidence of moderate to severe adverse events was similar in both groups. The patients treated with meglumine antimoniate had higher incidences of cardiotoxicity (14 versus 0%, P = 0.02) and chemical pancreatitis (30 versus 0%, P < 0.01). However, in the amphotericin B group, nephrotoxicity was more frequent (36 versus 5%, P < 0.01). There was no difference in survival or relapse-free interval according to the allocated group of therapy.
Treatment of VL with meglumine antimoniate or amphotericin B was shown to have similar efficacy and toxicity rates in Spanish HIV-infected patients. The differences in the toxicity patterns could be useful in choosing one of these agents as first-line treatment.
AIDS 07/1999; 13(9):1063-9. · 6.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: A semi-nested, multiplex polymerase chain reaction (PCR) based on the amplification of the sequences of the 18S small subunit ribosomal RNA (ssrRNA) gene was tested in a field trial in Equatorial Guinea (a hyperendemic focus of malaria in west central Africa). The method uses a primary PCR amplification reaction with a universal reverse primer and two forward primers specific for the genus Plasmodium and to mammals (the mammalian-specific primer was included as a positive control to distinguish uninfected cases from inhibition of the PCR). The second amplification is carried out with the same Plasmodium genus-specific forward primer and four specific reverse primers for each human Plasmodium species. The PCR amplified products are differentiated by fragment size after electrophoresis on a 2% agarose gel. Four villages from three regions of the island of Bioko (Equatorial Guinea) and two suspected Plasmodium vivax-P. ovale infections from the hospital of Malabo were tested by microscopy and PCR. The PCR method showed greater sensitivity and specificity than microscopic examination and confirmed the existence of a focus of P. vivax infections in Equatorial Guinea suspected by microscopic examination. It also provided evidence of several mixed infections, mainly P. falciparum and P. malariae, the two predominant species causing malaria in Equatorial Guinea.
The American journal of tropical medicine and hygiene 03/1999; 60(2):183-7. · 2.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To determine the role that Leishmania infantum/human immunodeficiency virus (HIV) coinfected patients could play in the epidemiology of visceral leishmaniasis (VL), we applied direct xenodiagnosis of VL in this study to test the infectivity of six coinfected patients to colonized Phlebotomus perniciosus. All patients proved to be infective for the sand flies. The infectivity of patients who had still not received specific treatment for VL was inversely proportional to their absolute CD4+ T lymphocyte cell count. It has been proven that P. perniciosus can acquire and allow the development of L. infantum by feeding on L. infantum/HIV coinfected patients. Since this sand fly is an important vector of VL in southern Europe, a new natural anthroponotic cycle could be considered in the epidemiology of L. infantum/HIV coinfection. The design of leishmaniasis control programs and the management of coinfected individuals should take these findings into account.
The American journal of tropical medicine and hygiene 02/1999; 60(1):51-3. · 2.59 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Serum cytokine levels and peripheral T cell subpopulations of HIV-1-infected patients before, during and after active visceral leishmaniasis (VL) were analysed and compared with appropriate controls. At VL diagnosis, co-infected patients showed higher serum levels of interferon-gamma (IFN-gamma) than matched HIV-1 controls without VL, and lower serum concentrations of IL-10 than non-immunocompromised VL controls. High levels of tumour necrosis factor-alpha (TNF-alpha) and IFN-gamma were present in the sera of HIV-1-infected patients with active VL. TNF-alpha remained elevated after VL recovery. A steady decline in the CD4+ cell count, an increase of serum HIV viraemia and a progressive seroconversion for the HIV-1 p24 antigen was observed during the course of VL disease. Thus, an aberrant activation of the TNF system with possible negative immunological and virological consequences is present in HIV-1-infected patients with VL. A more extensive prospective validation of these findings in a bigger cohort of patients will nevertheless be necessary. The results support the hypothesis that different opportunistic infection agents may trigger the production of proinflammatory cytokines during immunodeficiency, and in this way accelerate the course of HIV-1 disease.
Clinical & Experimental Immunology 01/1999; 114(3):403-7. · 3.36 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: To define the possible role of serology in the diagnosis and prognosis of visceral leishmaniasis (VL) in patients with human immunodeficiency virus type-1 (HIV-1) infection, the dynamics of humoral immune responses was investigated in 20 coinfected patients. Sequential sera obtained before, during, and after VL diagnosis were analyzed by an indirect immunofluorescent antibody test (IFAT), a recombinant ELISA (using the rK39 protein), and immunoblotting. During the active course of the disease, positive results were found by IFAT or ELISA in 22% of the cases and by immunoblotting in 78% of the cases. A great variability in the response was observed during the follow-up with a trend to more positive results near the time of VL diagnosis. Forty-six percent of the patients were positive by IFAT or ELISA on at least one time point before VL and 37.5% were positive during the period following treatment. These results confirm the limited usefulness of the IFAT and ELISA in the diagnosis of VL in coinfected patients and demonstrate their low ability to predict the development or the outcome of disease. In these patients, immunoblotting could be a useful tool for studying the natural course of leishmaniasis, although it has limited value for diagnosis or treatment control.
The American journal of tropical medicine and hygiene 08/1998; 59(1):155-62. · 2.59 Impact Factor
