Mucosal leishmaniasis ("espundia" Escomel, 1911)

One of the more serious clinical forms of leishmaniasis occurs in espundia when the mucosae of the upper respiratory passages are inflamed. This complication is a metastasis from a skin lesion caused by Leishmania braziliensis braziliensis (Lbb) although cases have been described associated with other leishmanial species. Epidemiological data suggest that a detectable mucosal metastasis occurs in fewer than 5% of patients infected with Lbb in our study area. The determinants of this complication are still largely obscure. The granuloma usually commences on the nasal septum. In about two-thirds of our patients the lesion remained restricted to the nose. In the rest the pharynx, palate, larynx and lips were involved, in this order. It is often difficult to isolate the parasite and for routine diagnosis the leishmanin skin reaction and serological tests are helpful. Although a serious condition, with possible mutilation and even death as subsequent complications, treatment is still mainly with pentavalent antimonials, introduced 40 years ago. These are most unsatisfactory for field use, being given parenterally and relatively toxic. In mucosal leishmaniasis, if sufficient antimony can be administered in a regular daily dose, the relapse rate is small (3 of 42 patients followed for a mean of 5 years). Also, antimony treatment of the initial skin ulcer due to Lbb followed for a mean of 4 years of 83 patients resulted in subsequent mucosal metastasis in only 2. Since espundia is relatively rare, specific treatment targeted to this specific problem is the efficient short term solution. At present there is no satisfactory alternative drug to those in current use.

Influence ofLeishmania (Viannia)Species on the Response to Antimonial Treatment in Patients with American Tegumentary Leishmaniasis

BACKGROUND

Pentavalent antimonials (SbV) are the first-line chemotherapy for American tegumentary leishmaniasis (ATL). There are, however, reports of the occurrence of treatment failure with these drugs. Few studies in Latin America have compared the response to SbV treatment in ATL caused by different Leishmania species.

METHODS

Clinical parameters and response to SbV chemotherapy were studied in 103 patients with cutaneous leishmaniasis (CL) in Peru. Leishmania isolates were collected before treatment and typed by multilocus polymerase-chain-reaction restriction fragment-length polymorphism analysis.

RESULTS

The 103 isolates were identified as L. (Viannia) peruviana (47.6%), L. (V.) guyanensis (23.3%), L. (V.) braziliensis (22.3%), L. (V.) lainsoni (4.9%), L. (Leishmania) mexicana (1%), and a putative hybrid, L. (V.) braziliensis/L. (V.) peruviana (1%). L. (V.) guyanensis was most abundant in central Peru. Of patients infected with the 3 former species, 21 (21.9%) did not respond to SbV chemotherapy. The proportions of treatment failure (after 12 months of follow-up) were 30.4%, 24.5%, and 8.3% in patients infected with L. (V.) braziliensis, L. (V.) peruviana, and L. (V.) guyanensis, respectively. Infection with L. (V.) guyanensis was associated with significantly less treatment failure than L. (V.) braziliensis, as determined by multiple logistic regression analysis (odds ratio, 0.07 [95% confidence interval, 0.007-0.8]; P=.03).

CONCLUSIONS

Leishmania species can influence SbV treatment outcome in patients with CL. Therefore, parasite identification is of utmost clinical importance, because it should lead to a species-oriented treatment.

Comparison of cutaneous leishmaniasis due to Leishmania (Viannia) braziliensis and L. (V.) guyanensis in Brazil: therapeutic response to meglumine antimoniate

We conducted a quasi-experimental study to compare the response to meglumine antimoniate in patients with localized cutaneous leishmaniasis from two endemic areas of Brazil that were infected by two Leishmania species. Sixty-one were infected by Leishmania (Viannia) braziliensis (group B) and 57 by L. (V.) guyanensis (group G). All had a parasitologically proven diagnosis and were treated with 20 mg of pentavalent antimonial (SbV)/kg/day given intravenously or intramuscularly for 20 days. Main outcomes were diagnosed using clinical criteria three months after treatment and patients were followed for six months. Intention-to-treat analysis showed a higher failure rate in group G (relative risk [RR] = 1.5, 95% confidence interval [CI] = 1.1-2.0, chi2 = 7.44, P = 0.006). The analysis using an explanatory approach including 52 patients from group B and 49 from group G, who were regularly treated and followed for six months, showed a low cure rate (50.8% in group B and 26.3% in group G) with a greater risk of failure in the latter group (RR = 1.7, 95% CI = 1.2-2.5, chi2 = 8.56, P = 0.003). The effect of the etiologic agent remained significant after adjusting for age, disease duration, and site and number of lesions that were identified as predictors of failure in a logistic regression model. We concluded that Leishmania species constitute an important factor in predicting the outcome of cutaneous leishmaniasis treated with a pentavalent antimonial.

Studies on canine leishmaniasis control. 1. Evolution of infection of different clinical forms of canine leishmaniasis following antimonial treatment

81 dogs naturally infected with Leishmania infantum in the Isle of Elba, Italy, were treated with meglumine antimoniate (Glucantime). 36 of them (45.5%) were asymptomatic cases. 4-24 months after treatment the dogs were clinically and serologically examined; the recovery rates were 47.2% for asymptomatic cases, 33.3% for oligosymptomatic cases, and 11.1% for symptomatic cases. Furthermore, treatment had prevented the development of patent disease in 90% of non-recovered asymptomatic cases, whereas it had produced only slight improvement of clinical condition in patent dogs which were still infected after drug administration. Treatment with antimonial drugs is therefore recommended in canine leishmaniasis control if non-patent or sub-clinical forms of the disease are detected by seroepidemiological surveys.

Canine leishmaniasis: clinical, parasitological and entomological follow-up after chemotherapy

Six naturally infected dogs [two with no signs of leishmaniasis ('asymptomatic'), two with a few signs ('oligosymptomatic') and two with many signs ('polysymptomatic')] were studied before and after chemotherapy. Another two, non-infected dogs were kept as controls. The dogs were studied clinically, haematologically and parasitologically five times over 11 months and their infectivity to sandflies was evaluated before and after the treatment. The 'asymptomatic' dogs were as infective to sandflies as the 'symptomatic' before treatment but all dogs were un-infective for at least a few months following chemotherapy. Treatment led to a temporary improvement in the clinical and biochemical condition of most of the dogs, the symptomatic dogs becoming asymptomatic, but parasitological cure was uncommon after 10 months' follow-up. There was often no correlation between clinical condition, parasitological condition and infectivity to sandflies. Some dogs from both the 'asymptomatic' and 'symptomatic' groups became infective to sandflies several months post-treatment.

Resistance to Antimony and Treatment Failure in HumanLeishmania (Viannia)Infection

BACKGROUND

Failure of antimonial therapy has been increasingly reported in anthroponotic visceral leishmaniasis and in cutaneous disease. The role of drug resistance in treatment failure has been difficult to ascertain because therapeutic response is multifactorial, and the efficacy of antimonial drugs depends on an effective immune response. In this study, we sought to determine whether standard treatment selects for resistant organisms and whether drug resistance contributes to treatment failure.

METHODS

We evaluated the susceptibility to antimony of 19 strains isolated before treatment with meglumine antimoniate and 21 strains isolated at treatment failure from 20 patients. The 50% effective dose (ED50) of antimony in the form of additive-free meglumine antimoniate was determined for intracellular amastigotes in human promonocytic U-937 cells.

RESULTS

Before treatment, 16% of strains (3/19) showed primary resistance (ED50 of >128 microg Sb/mL), whereas 84% (16/19) were susceptible (ED50 of <20 microg Sb/mL). However, 88% of susceptible strains (14/16) had ED90 values of >128 microg Sb/mL. At treatment failure, 40% of strains (8/20) were resistant. Secondary resistance was documented in 4 patients.

CONCLUSIONS

Primary and secondary resistance to antimony can contribute to treatment failure in American cutaneous leishmaniasis. Selection for resistance to antimony occurs during standard treatment with antimonial drugs, and primary resistance to antimony supports the plausibility of anthroponotic transmission.

In vitro and in vivo resistance of Leishmania infantum to meglumine antimoniate: a study of 37 strains collected from patients with visceral leishmaniasis

Primary and secondary unresponsiveness to meglumine has long been described in human visceral leishmaniasis. However, no studies have been performed to elucidate if these therapeutic failures were due to strain variability in meglumine sensitivity or were related to host factors. We have studied the in vitro sensitivity of 37 strains of Leishmania infantum isolated from 23 patients (11 human immunodeficiency virus-infected and 12 immunocompetent patients) with visceral leishmaniasis. Sensitivity tests were performed by infecting murine macrophages with Leishmania parasites and culturing them in medium containing different concentrations of meglumine. For each test we calculated a 50% effective dose (ED50) corresponding to the meglumine concentration at which 50% of the Leishmania parasites survived. In vitro results were strongly correlated to immediate clinical outcome. All strains requiring an ED50 of >70 microg/ml were related to therapeutic failures, whereas all strains requiring an ED50 of <40 microg/ml corresponded to an initial efficiency of meglumine. Among those patients who were initially improved, relapses occurred in all immunocompromised patients and in most immunocompetent patients who had a short duration of treatment (15 days). Finally, we found that in vitro sensitivity of strains decreased progressively in relapsing patients treated with meglumine. Consequently, the physician may be encouraged to alternate meglumine with other treatments such as amphotericin B or pentamidine, especially in the case of relapsing patients.

Successful treatment of drug-resistant cutaneous leishmaniasis in humans by use of imiquimod, an immunomodulator

Treatment failures for leishmaniasis with pentavalent antimonials, including meglumine antimonate, are increasingly common in many endemic areas. Imiquimod (Aldara; 3M Pharmaceuticals) is a novel immune response-activating compound, approved by the United States Food and Drug Administration, that is currently used to treat cervical warts and has been shown to activate macrophage killing of Leishmania species. Therefore, an open-label, prospective study was conducted of combined imiquimod plus meglumine antimonate therapy in 12 patients with cutaneous leishmaniasis who had previously not responded to meglumine antimonate therapy. All of the patients responded well to this combination therapy, and 90% were found to be cured at the 6-month follow-up period.

Up-regulation of cholecystokinin in primary sensory neurons is associated with morphine insensitivity in experimental neuropathic pain in the rat

We examined the distribution of mRNA for the peptide cholecystokinin (CCK) with in situ hybridization in adult rat lumbar dorsal root ganglia following unilateral section of the sciatic nerve, as well as the effect of systemic CI 988, a selective antagonist of the CCK type B receptor, applied alone or in combination with intrathecal (i.t.) morphine, on the self-mutilating behavior of rats (autotomy) after axotomy, a sign of neuropathic pain and/or dysesthesia. There was a dramatic increase in the number of neurons in dorsal root ganglia synthesizing the peptide cholecystokinin (CCK) after sciatic nerve section. Furthermore, the autotomy behavior of rats was significantly inhibited by chronic i.t. administration of morphine in conjunction with subcutaneous (s.c.) injection of CI 988. Neither i.t. morphine nor s.c. CI 988 alone produced a comparable effect on autotomy. Our results suggested that up-regulation of the mRNA for CCK in primary afferents after nerve injury may be related to the clinical phenomenon of opioid insensitivity. Thus, coadministration of CCK antagonists in combination with opioids may offer a new approach in treating neuropathic pain.

Balance of IL-10 and interferon-gamma plasma levels in human visceral leishmaniasis: implications in the pathogenesis

BACKGROUND

Leishmaniasis remains a serious public health problem in several parts of the developing world. Effective prophylactic measurements are hampered by imprecise comprehension of different aspects of the disease, including its immunoregulation. A better comprehension of immunoregulation in human VL may be useful both for designing and evaluating immunoprophylaxis.

METHODS

To explore immunoregulatory mechanisms, 20 visceral leishmaniasis (VL) patients were evaluated during active disease and at different periods up to one year after treatment determining their plasma cytokine levels, clinical parameters (palpable spleen and liver) and antibody levels.

RESULTS

Elevated plasma levels of IFN-gamma and of IL-12 p40 were observed during active disease, significantly decreasing after treatment whereas in vitro Leishmania antigen-stimulated IFN-gamma production by PBMC exhibited an inverse pattern being low during disease and increasing steadily thereafter. Absence of IFN-gamma activity is a hallmark of VL. The main candidate for blunting IFN-gamma activity is IL-10, a cytokine highly elevated in plasma with sharp decrease after treatment. Activity of IL-10 is inferred by high levels of anti-Leishmania specific IgG1 and IgG3. TGF-beta had elevated total, but not of active, levels lessening the likelihood of being the IFN-gamma counterpart. Spleen or liver size presented a steady decrease but return to normal values at only 120 days after treatment. Anti-Leishmania IgG (total and subclasses) levels and DTH or Leishmania-stimulated lymphocyte proliferation conversion to positive also present a slow decrease after treatment. IL-6 plasma levels were elevated in only a few patients.

CONCLUSION

Taken together our results suggest that IFN-gamma and IL-10 are the molecules most likely involved in determining fate of disease. After treatment, there is a long delay before the immune profile returns to normal what precludes using plasma cytokine levels as criteria of cure as simpler clinical evaluations, as a palpable spleen or liver, can be used.

Treatment of canine Old World visceral leishmaniasis: a systematic review

Canine visceral leishmaniasis is a systemic disease caused by Leishmania infantum. The aim of this systematic review was to identify and evaluate the evidence of efficacy of interventions for treatment or prevention of canine visceral leishmaniasis, and to propose recommendations for or against their use. Forty-seven articles describing clinical trials published between 1980 and 2004 fulfilled selection criteria. The evaluation of clinical trials provided good evidence for recommending the use of meglumine antimoniate at a minimum dosage of 100 mg kg(-1) daily for at least 3-4 weeks, combined with allopurinol in order to obtain a good clinical efficacy and a reduced relapse rate. The evaluation of the articles also provided fair evidence for recommending the use of pentamidine (4 mg kg(-1) twice weekly) and aminosidine (5 mg kg(-1) twice daily) for 3-4 weeks. There was insufficient evidence for recommending the use of allopurinol alone, amphotericin B, buparvaquone, ketoconazole, enrofloxacin, and the combinations of metronidazole with spiramicyn or metronidazole with enrofloxacin. Fair evidence against the use of aminosidine at high dosages (20-80 mg kg(-1) per day) was proposed due to its side effects. Evaluation of articles on repellent measures against sand fly vectors of leishmaniasis provided good evidence for recommending deltamethrin collars and fair evidence for recommending spot-on permethrin.

Specific IgG1 and IgG2 antibody responses of dogs to Leishmania infantum and other parasites

Sera from dogs naturally infected with Leishmania infantum were analysed for the IgG subclass specificity of their antibody response by ELISA. Dogs infected with L. infantum produced both IgG1 and IgG2 antibodies with IgG2 being associated with asymptomatic infections and IgG1 being associated with disease (symptomatic dogs, non- or low-responsive to chemotherapy). The differential responses of IgG1 and IgG2 serum antibodies in asymptomatic and symptomatic dogs may indicate a dichotomous immune response to infection with L. infantum. To confirm this, on a broader scale, sera from dogs naturally exposed to an asymptomatic protozoan infection, Toxoplasma gondii, were also analysed as were sera from dogs exposed to the helminths, Dirofilaria immitis and Toxocara canis. Antibodies specific for T. gondii antigen detected in sera from 17 dogs were of the IgG2 subclass only. Both IgG1 and IgG2 antibodies to D. immitis and T. canis were present in the sera of naturally infected dogs but IgG1 appeared to be the predominant subclass. Furthermore, in dogs experimentally infected with T. canis, selective regulation of IgG2 and IgG1 responses was apparent since production of the two subclasses occurred at different times following infection, with IgG2 levels declining as IgG1 levels rose. Thus, the analysis of IgG subsets in parasitized dogs provides evidence of a dichotomous response to infection: IgG2 is associated with asymptomatic protozoan infections and IgG1 is associated with helminth infections and disease caused by protozoan infection.

Immunotherapy versus chemotherapy in localised cutaneous leishmaniasis

In a randomised trial a combination vaccine consisting of live BCG together with killed leishmania promastigotes was compared with a standard antimonial regimen in 94 patients with localised cutaneous leishmaniasis. Three vaccinations over 32 weeks gave a similar cure rate (94%) to three 20-day courses of meglumine antimonate. In the immunotherapy group side-effects were few (5.8%) and slight whereas in the chemotherapy group they were frequent (52.4%) and often serious. Immunotherapy is a low-cost, low-risk alternative to chemotherapy in localised cutaneous leishmaniasis, applicable by primary health services in rural areas.

Serological and parasitological follow-up in dogs experimentally infected with Leishmania infantum and treated with meglumine antimoniate

Six healthy beagle dogs were infected with Leishmania infantum (MCAN/ES/92/BCN-83/MON-1) by intravenous inoculation of 5 x 10(7) promastigotes and two others were used as controls. When animals showed clinical signs of disease at 29, 37, 41 and 45 weeks post-infection (p.i.), they were treated with meglumine antimoniate (20.4 mg Sb/kg/12 h) subcutaneously for two periods of 10 days each. Sera were tested periodically for Leishmania antibodies by Dot-ELISA, ELISA and Western blot (WB). Aspirates of popliteal lymph node (PLN), peripheral blood sample (PB) and healthy skin were cultured in NNN and Schneider's medium. PLNs were positive between 8 and 20 weeks p.i. and in one animal PB was positive 6 weeks p.i. Samples of healthy skin, obtained before treatment, were also positive. Dot-ELISA and ELISA detected specific antibodies at an early stage between 4 and 12 weeks p.i and surpassed the cut-off between 16-24 weeks p.i., while the WB was positive between 10-19 weeks p.i. The pattern of bands revealed during the first stages of infection was variable and only in two cases did the positivity start with bands of low molecular weight (12-14 kD); the number of bands increased until 15-24 weeks p.i., after which sera revealed a complete pattern of bands, from 12 to 85 kD, in the antigen of Leishmania. After treatment the clinical improvement of the animals was accompanied by a decrease in antibody titers (Dot-ELISA and ELISA) although the parasites remained in the PLN. This was reflected in the WB by a decrease in the intensity of bands, especially those in the region of 12-30 kD. A new increase in the antibody levels between 3 and 5 months after terminating the therapy was detected in the WB by a restoration of the initial complete pattern of bands.

2-substituted quinoline alkaloids as potential antileishmanial drugs

Ten 2-substituted quinoline alkaloids isolated from a plant used for treatment of New World cutaneous leishmaniasis have antileishmanial in vitro activities against the extracellular forms of Leishmania spp. BALB/c mice infected with Leishmania amazonensis PH8 or H-142 or Leishmania venezuelensis were treated 1 day after the parasitic infection with a quinoline alkaloid (100 mg/kg of body weight per day) or with reference drug N-methylglucamine antimonate (Glucantime) (56 mg of pentavalent antimony [Sbv] per kg per day) for 14 days. Lesion development was the criterium used to assess disease severity. Two three-carbon chain quinolines [2-n-propylquinoline and 2-(1',2'-trans-epoxypropyl)quinoline (chimanine D)] were more potent than N-methylglucamine antimonate against L. amazonensis PH8, and five quinoline alkaloids [2-(3,4-methylenedioxyphenylethyl)quinoline, cusparine, 2-(3,4-dimethoxyphenylethyl)quinoline, 2-(E)-prop-1'-enylquinoline (chimanine B), and skimmianine] were as effective as the reference drug. Single treatment near the site of infection, 14 days after infection with L. amazonensis, with 2-n-propylquinoline or chimanine B reduced the severity of lesions but less notably than N-methylglucamine antimonate. 2-n-Propylquinoline exhibited significant activity against the virulent strain L. venezuelensis. The active products did not show any apparent toxicities during the experiment. This study is, to our knowledge, the first to show the activity of 2-substituted quinoline alkaloids for experimental treatment of New World cutaneous leishmaniasis. Further investigations of these compounds might yet prove helpful for the development of new antileishmanial drugs.

Allopurinol in the treatment of American cutaneous leishmaniasis

BACKGROUND

Pentavalent antimony, the generally accepted treatment for leishmaniasis, is given parenterally, and it is expensive and not readily available in developing countries. An inexpensive, orally administered compound would be a substantial advance in treatment. Previous studies in vitro have shown synergism between allopurinol and pentavalent antimony in tissue-culture systems. We designed this clinical study to determine whether synergism could be demonstrated in patients.

METHODS

We performed a randomized, controlled study of the efficacy of allopurinol plus meglumine antimoniate (Glucantime), as compared with meglumine antimoniate alone, in patients with cutaneous leishmaniasis, who were recruited from a village in southeastern Colombia. In addition, those who declined injections were treated with allopurinol alone, and those who declined any treatment were considered controls. All the patients were followed for one year after the completion of treatment. Lesions that healed completely at three months and remained healed during follow-up were considered to be cured.

RESULTS

The cure rate for patients treated with meglumine antimoniate was 36 percent; the addition of allopurinol increased the rate to 74 percent (P less than 0.001). Treatment with allopurinol alone yielded a cure rate of 80 percent (P less than 0.001). There were no cures among the untreated patients. There was no significant difference between the cure rate with allopurinol plus meglumine antimoniate and that with allopurinol alone. No major toxic effects were observed.

CONCLUSIONS

For the treatment of American cutaneous leishmaniasis, the combination of allopurinol and meglumine antimoniate is significantly more effective than meglumine antimoniate alone, probably because of the efficacy of allopurinol alone, which appears to be as good as the combination.

Leishmania infantum-specific IgG, IgG1 and IgG2 antibody responses in healthy and ill dogs from endemic areas. Evolution in the course of infection and after treatment

The expression of IgG, IgG1 and IgG2 specific antibodies for Leishmania infantum was studied in five groups of dogs in Catalonia (Spain): I, 99 asymptomatic dogs (infected and uninfected) from a highly endemic area for leishmaniosis; II, 139 untreated dogs with clinically patent leishmaniosis; III, 11 naturally infected asymptomatic dogs monitored for up to 5 years since they were found seropositive to Leishmania antigen and without treatment; IV, 25 naturally infected dogs with clinically patent leishmaniosis and treated with either meglumine antimoniate and allopurinol or allopurinol alone and V, six experimentally infected dogs, treated with meglumine antimoniate and controlled for 5 years. The levels (ELISA units) of IgG, IgG1 and IgG2 in asymptomatic dogs (group I) were very variable (24+/-33, 32+/-31 and 26+/-31, respectively), and, as expected, lower than in ill dogs (group II) (168+/-34, 84+/-71 and 172+/-31, respectively). In both groups, the correlation between IgG and IgG2 levels (r=0.95, P<0.001 in group I and r=0.63, P<0.001 in group II) was higher than between IgG and IgG1 levels (r=0.01, P>0.05 in group I and r=0.31, P<0.001 in group II). In group III, IgG and IgG2 expression increased during infection, while IgG1 expression remained the same. In dogs of group IV, IgG levels after 1 year of treatment decreased more in responsive (mean values, 163+/-42 before treatment (b.t.) and 100+/-36 after treatment (a.t.)) than in unresponsive dogs (158+/-29 b.t. and 124+/-51 a.t.), especially for IgG1 (94+/-89 b.t. and 20+/-21 a.t. in responsive dogs and 35+/-25 b.t. and 22+/-13 a.t. in unresponsive dogs) rather than for IgG2 (156+/-16 b.t. and 114+/-45 a.t. in responsive and 151+/-11 b.t. and 125+/-36 a.t. in unresponsive dogs). Similar results were observed in the evolution of experimentally infected animals after consecutive and specific treatments. Overall results show the great variation in Leishmania-specific IgG1 expression in asymptomatic and symptomatic dogs, their lack of correlation with that of IgG2 and chemotherapy is more effective in dogs with initially high expression of IgG1.

Canine visceral leishmaniasis: Diagnosis and management of the reservoir living among us

This article reviews essential topics of canine visceral leishmaniasis (CVL) due to Leishmania infantum infection. It focuses on the current serological and molecular diagnostic methods used in epidemiological research and veterinary clinics to diagnose CVL and includes new point-of-care (POC) tests under development. The efficacy of different treatment regimens on the clinical improvement and infectiousness of dogs is also addressed. In the last section, the review provides a critical appraisal of the effectiveness of different control measures that have been implemented to curb disease transmission.

Dogs are the principal reservoir hosts of L. infantum and consequently play a critical role in the transmission cycle of urban VL, which also affects humans. This review provides updated information on important topics such as diagnostic tests and dog treatments that improve dog health and decrease their transmission efficacy to insect vectors. A critical review of control measures is also provided.

Visceral leishmaniasis in patients infected with human immunodeficiency virus (HIV)

In an 8-month period nine patients with human immunodeficiency virus (HIV) infection were diagnosed as having visceral leishmaniasis; all diagnoses were based on cultures (eight from bone marrow and one from the skin). Visceral leishmaniasis developed before full-blown acquired immunodeficiency syndrome (AIDS) in seven patients and at the same time as or after AIDS in the other two patients. Three patients had a history of leishmaniasis. Clinical manifestations and laboratory findings were atypical. Leishmania species were cultured from samples taken from all patients; however, six patients had an insignificant antileishmanial antibody titer and Leishmania amastigotes were not seen in their bone marrow smears. Four isolates were identified by isoenzyme analysis as Leishmania donovani infantum. Five patients died, including two patients who had completed at least one 3-week course of therapy with N-methylglucamine antimoniate. Screening should be done for visceral leishmaniasis in patients with HIV infection who live or travel in areas where the disease is endemic. The diagnosis of visceral leishmaniasis may frequently be missed if cultures are not done.

In vivo efficacy of oral and intralesional administration of 2-substituted quinolines in experimental treatment of new world cutaneous leishmaniasis caused by Leishmania amazonensis

The antileishmanial efficacies of 2-n-propylquinoline, chimanines B and D, 2-n-pentylquinoline, 2-phenylquinoline, 2-(3,4-methylenedioxyphenylethyl) quinoline, and two total alkaloidal extracts of Galipea longiflora were evaluated in BALB/c mice infected with Leishmania amazonensis or Leishmania venezuelensis. Animals were treated for 4 to 6 weeks postinfection with a quinoline by the oral route at 50 mg/kg of body weight twice daily for 15 days or by five intralesional injections at intervals of 4 days with a quinoline at 50 mg/kg of body weight. The reference drug, N-methylglucamine antimonate (Glucantime), was administered by subcutaneous or intralesional injection (regimens of 14, 28, or 56 mg of pentavalent antimony [Sbv] per kg of body weight daily). Twice-daily oral treatment with chimanine B at 50 mg/kg resulted in a decrease in lesion weight by 70% (P < 0.001) and a decrease in the parasite loads by 95% (P < 0.001). Five injections of chimanine B at intervals of 4 days reduced the lesion weight by 74% and the parasite loads in the lesion by 90% compared with the values for the group of untreated mice. Subcutaneous administration of N-methylglucamine antimonate at 28 mg of Sbv kg per day for 15 days reduced the parasite burden by 95% (P < 0.001), and five intralesional injections at the same concentration reduced the parasite burden by 96% (P < 0.001). Other 2-substituted quinolines, 2-n-propylquinoline administered by the oral and intralesional routes, 2-phenylquinoline administered by the oral route, 2-n-pentylquinoline administered by intralesional injection, and two total alkaloidal extracts of G. longiflora administered by the oral route, had intermediate effects. These findings suggest that chimanine B may be chosen as a lead molecule in the development of oral therapy against leishmaniasis.

Comparative study of the efficacy of combined cryotherapy and intralesional meglumine antimoniate (GlucantimeR) vs. cryotherapy and intralesional meglumine antimoniate (GlucantimeR) alone for the treatment of cutaneous leishmaniasis

BACKGROUND

Cutaneous leishmaniasis (CL) is a parasitic disease caused by Leishmania species. There is a need for more effective and less time-consuming therapeutic methods for this condition.

AIM

To evaluate the efficacy of combined cryotherapy and intralesional meglumine antimoniate (MA) (Glucantime, Specia, Paris, France) for the treatment of CL.

METHODS

Patients were divided into three groups: Group 1, 100 patients with 149 lesions were treated with cryotherapy plus intralesional MA; Group 2, 200 patients with 230 lesions were treated with cryotherapy; Group 3, 100 patients with 160 lesions were treated with intralesional MA. These groups were followed for 6 months after the end of treatment.

RESULTS

The results showed complete cure in 90.9% of cases in Group 1, 57.15% of cases in Group 2, and 55.63% of cases in Group 3. The difference between Group 1 and the other groups was statistically significant (P < 0.05).

CONCLUSIONS

Combined cryotherapy and intralesional MA is more effective than either cryotherapy or intralesional MA alone for the treatment of CL.

Treatment of visceral leishmaniasis in HIV-infected patients: a randomized trial comparing meglumine antimoniate with amphotericin B. Spanish HIV-Leishmania Study Group

BACKGROUND

Visceral leishmaniasis is common in patients with HIV infection living in endemic areas, but the most effective and safe treatment remains unknown.

OBJECTIVE

To compare the efficacy and safety of meglumine antimoniate versus amphotericin B in HIV-infected patients with first episodes of visceral leishmaniasis (VL).

DESIGN

An open, multicentre, prospective and randomized trial.

SETTING

Twelve tertiary hospitals.

PATIENTS

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.

RESULTS

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.

CONCLUSION

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.

Comparison of miltefosine and meglumine antimoniate for the treatment of zoonotic cutaneous leishmaniasis (ZCL) by a randomized clinical trial in Iran

This study was a randomized, open label comparison that was designed to determine efficacy and safety of miltefosine as the first oral drug for the treatment of zoonotic cutaneous leishmaniasis caused by Leishmania major in comparison with meglumine antimoniate. Complete clinical response was defined as 100% re-epithelialization of the lesion. Definitions of lesion cure and failure were based on both clinical and parasitological criteria two weeks after the end of treatment and clinical recovery three months after this period. Of 32 patients enrolled for miltefosine treatment 28 patients completed treatment, of which 26 were cured at three months, corresponding to a cure rate of 92.9% on a per protocol analysis, and 81.3% according to intention to treat analysis. There was one failure (3.1%), one relapse (3.1%) and four dropouts due to lack of tolerability (12.5%) during the first week of treatment. Of 31 patients who received intramuscular meglumine antimoniate (20mgSb(5)/kg body weight daily for 14 days) 25 were cured (83.3% on a per protocol basis, 80.6% on intention to treat basis), five failed (16.1%) and one was lost (3.2%) at 3-month follow-up. At 6-month follow-up after the end of treatment, no relapse was observed. Both regimens were tolerated but averages of nausea (32.2%) and vomiting (21.5%) were observed in patients during two weeks after initiation of miltefosine treatment. Other gastrointestinal, musculoskeletal, and total adverse events were not statistically different in the two groups during one to four weeks after therapy initiation. No relevant changes were observed in levels of liver enzymes, creatinine and hematological tests before and after end of treatment in both groups. In conclusion, miltefosine is apparently at least as good as meglumine antimoniate for the treatment of cutaneous leishmaniasis caused by L. major in Iran, based on parasitological as well as clinical criteria two weeks, three months, and six months after end of treatment.

Randomized, Double-Blind Clinical Trial of Topical Imiquimod 5% with Parenteral Meglumine Antimoniate in the Treatment of Cutaneous Leishmaniasis in Peru

BACKGROUND

Current treatments for cutaneous leishmaniasis are limited by their toxicity, high cost, and discomfort and the emergence of drug resistance. New approaches, including combination therapies, are urgently needed. We performed a double-blind, randomized trial of therapy with parenteral antimony plus topical imiquimod, an innate immune-response modulator, versus therapy with antimony alone, in subjects with cutaneous leishmaniasis for whom an initial course of antimony therapy had failed.

METHODS

Forty subjects with clinical resistance to antimony were recruited in Lima, Peru, between February 2001 and December 2002. All subjects received meglumine antimoniate (20 mg/kg/day im or iv) and were randomized to receive either topical imiquimod 5% cream (Aldara; 3M Pharmaceuticals) or vehicle control every other day for 20 days. Lesions and adverse events were evaluated during treatment and at 1, 2, 3, 6, and 12 months after the treatment period.

RESULTS

The mean number of lesions was 1.2 per person; 71% of the lesions were facial and 76% were ulcerative. There were no major differences between the groups, and all but 2 subjects completed therapy. Mild adverse events were reported by 73% of the subjects, but only erythema occurred more commonly in the imiquimod group (P < or = .02). Lesions resolved more rapidly in the imiquimod group: 50% of the imiquimod group achieved cure at 1 month after the treatment period versus 15% of the vehicle cream group (P < or = .02); 61% of the imiquimod group at 2 months versus 25% of the vehicle cream group (P < or = .03); and 72% of the imiquimod group at 3 months versus 35% of the vehicle cream group (P < or = .02). Residual scarring in the imiquimod group was less prominent than in the vehicle cream group.

CONCLUSIONS

Combined antimony plus imiquimod treatment was well tolerated, accelerated healing of lesions, and improved scar quality. This therapy may have particular advantages for subjects with facial lesions.

Decreased sensitivity to meglumine antimoniate (Glucantime) of Leishmania infantum isolated from dogs after several courses of drug treatment

Although unresponsiveness to antimonial drugs in human leishmaniasis appears to be increasing, resistance to antimony in Leishmania is not well documented. Treatment of leishmaniasis in dogs, the domestic reservoir of L. infantum, with meglumine antimoniate (Glucantime) is a common practice in many Mediterranean countries. The dogs, however, remain highly infective to the phlebotomine vectors, even after several courses of treatment. A study was therefore carried out to test the comparative susceptibility to meglumine antimoniate of L. infantum stocks isolated from four naturally-infected dogs, before (BT) and after treatment (AT) with three to six courses of the drug, and used to infect Balb/c mice. Significant differences in suppression between the BT and AT stocks were observed in the infected mice when they were given the drug at a rate of 0.01-10 mg kg-1 day-1 for five days. Each AT stock was between eight and 41 times more resistant to meglumine antimoniate than the BT stock from the same dog, in terms of the ratios of the AT ED50 values to the corresponding BT values, which were calculated as indices of resistance. This result underlines the futility and danger of repeated antimonial treatments of dogs with signs of leishmaniasis, as these may produce a permanent reservoir of parasites unsusceptible to the drugs in human clinical use.