Miltefosine for new world cutaneous leishmaniasis.

The oral agent miltefosine has demonstrated a >95% cure rate in Indian visceral leishmaniasis. We performed a large, placebo-controlled study of miltefosine therapy (2.5 mg/kg per day orally for 28 days) against cutaneous leishmaniasis in Colombia and Guatemala. In regions in Colombia where Leishmania vianna panamensis is common, the per-protocol cure rates for miltefosine and placebo were 91% (40 of 44 patients) and 38% (9 of 24). These values are similar to historic values for the antimony standard of care and placebo. In regions in Guatemala where L. v. braziliensis and L. mexicana mexicana are common, the per-protocol cure rates were 53% (20 of 38) for miltefosine and 21% (4 of 19) for placebo. The miltefosine rate was lower than historic antimony cure rates of >90%. Miltefosine was well tolerated. Miltefosine is a useful oral agent against cutaneous leishmaniasis due to L. v. panamensis in Colombia but not against leishmaniasis due to L. v. braziliensis in Guatemala.

Humoral immune responses among mucosal and cutaneous leishmaniasis patients caused by Leishmania braziliensis.

Mucosal leishmaniasis is arguably the most morbid sequelae of cutaneous leishmaniasis. The importance of early diagnosis for effective therapy, coupled with the difficulty of diagnosing the disease parasitologically, prompted this investigation of humoral immune markers of mucosal disease. Promastigote soluble antigens of Leishmania braziliensis, isolated from cutaneous and mucosal lesions, were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis; antigens were identified by immunoblotting with parasite-specific IgG antibody-positive sera of patients with mucosal disease (n = 18) and cutaneous disease (n = 23). For antigens of the cutaneous parasite WR 2095, mucosal sera generally reacted intensely to antigens of 75, 66, and 45 kDa and weakly to 48-50-kDa antigens, whereas cutaneous sera generally detected weakly the first 3 antigens and intensely the latter doublet. The data suggest that the transition from the cutaneous antigenic profile to a mucosal antigenic profile could be used to predict mucosal disease in approximately half of mucosal patients. An additional finding was that antibodies present in the sera of patients with mucosal disease labeled a 66-kDa peptide of normal human lip mucosa more intensely than did cutaneous sera. Autoimmune processes stimulated by the reaction of IgG, originally directed against the 66-kDa of L. braziliensis, to the 66-kDa antigen of mucosal tissue may contribute to the clinical presentation of mucosal leishmaniasis.

Efficacy and safety of liposomal amphotericin B (AmBisome) for visceral leishmaniasis in endemic developing countries.

Reported are the results of a study to determine the efficacy and safety of liposomal amphotericin B (AmBisome) for treating visceral leishmaniasis (kala-azar) in several developing countries where the disease is endemic (Brazil, India, and Kenya). At each study site, sequential cohorts of 10 patients each were treated with AmBisome at a dose of 2 mg.kg-1.day-1 (2 MKD). The first cohort received regimen 1:2 MKD on days 1-6 and day 10 (total dose: 14 mg/kg). If the efficacy with this regimen was satisfactory, a second cohort received regimen 2:2 MKD on days 1-4 and 10 (total dose: 10 mg/kg); and a third cohort received regimen 3:2 MKD on days 1, 5, and 10 (total dose: 6 mg/kg). In India, regimens 1, 2, and 3 (which were studied concurrently) each cured 100% of 10 patients. In Kenya, regimen 1 cured all 10 patients, regimen 2 cured 90% of 10 patients, but regimen 3 cured only 20% of 5 patients. In Brazil, regimen 1 was only partially curative: 5 of 13 patients (62%). Therefore, 15 patients were administered regimen 4 (2 MKD for 10 consecutive days; total dose, 20 mg/kg) and 13 patients were cured (83%). These results suggest that for the treatment of kala-azar the following doses of AmBisome should be administered: in India and Kenya, 2 mg/kg on days 1-4 and day 10; and in Brazil, 2 mg/kg on days 1-10.

PIP: The efficacy and safety of liposomal amphotericin B (AmBisome) for the treatment of visceral leishmaniasis (kala-azar) were evaluated in a phase II clinical trial conducted in Brazil, India, and Kenya--countries where kala-azar is endemic. At each study site, sequential cohorts of 10 patients each received three different dosage regimens of AmBisome. The first cohort received 2 mg/kg/day (MKD) on days 1-6 and day 10 (total dose, 14 mg/kg). If the efficacy of this regimen was satisfactory, the second cohort received 2 MKD on days 1-4 and day 10 (total dose, 10 mg/kg) and a third cohort was administered 2 MKD on days 1, 5, and 10 (total dose, 6 mg/kg). In India, all three regimens (studied concurrently) cured 100% of the total of 30 patients. In Kenya, the first regimen cured all 10 patients (100%), the second cured 9 of 10 patients (90%), and the third cured only 1 of 5 patients (20%). In Brazil, since the first regimen cured only 5 of 13 patients (62%), the next 15 patients were given 2 MKD for 10 consecutive days (total dose, 20 mg/kg); this intensified regimen cured 13 of the 15 patients (83%). Adverse effects were minor, primarily fever and chills associated with infusion and irregular pulse. These findings suggest that leishmaniasis patients in India and Kenya should receive 2 mg/kg of AmBisome on days 1-4 and day 10, while those in Brazil should be given 2 mg/kg on days 1-10. AmBisome treatment is especially recommended for those for whom standard agents are likely to be ineffective, toxic, or difficult to administer.

Treatment of New World cutaneous and mucosal leishmaniases.

The most extensive investigations of treatment of New World cutaneous leishmaniasis have been performed against L. panamensis disease in Colombia, and the relative value of regimens shown there may be instructive for disease from other areas. In Colombia, a 90-95% cure rate was achieved with three different drug regimens: The standard regimen of pentavalent antimony (20 mg/ kg/day for 20 days parenterally) A short course of pentamidine (3 mg/kg every other day for four injections intramuscularly The marketed combination of topical paromomycin (15%)-MBCl (12%) for 10 days, plus antimony (20 mg/kg/day parenterally) for 7 days. My view is that all these regimens could be chosen as first-line therapy for cutaneous disease in Colombia. The antimony regimen has the advantage of established use; the disadvantages are cost, requirement for injections each day for 20 days, and considerable morbidity in the last two weeks of therapy. The pentamidine regimen has the advantage of a short time course; the disadvantages are lack of experience with this new regimen and frequent, although moderate, morbidity. The combined topical-parenteral regimen has the advantage of requiring few and nontoxic injections; the primary disadvantage is that the regimen is novel and its efficacy has not been confirmed. It would be expected that cases of lesions in other areas caused by L. braziliensis complex would respond in a similar manner to these regimens. To date, however, only the efficacy of the standard antimonial regimen has been confirmed. In certain regions of Central America, other regimens may be effective. Thus, ketoconazole appears to be effective for the more rapidly self-curing forms of disease (cutaneous disease caused by L. mexicana and L. panamensis from Central America), and a short course of antimony may be effective against L. braziliensis in Guatemala.

Efficacy of 28-day and 40-day regimens of sodium stibogluconate (Pentostam) in the treatment of mucosal leishmaniasis.

The efficacy and toxicity of two regimens of antimony, 28 and 40 days of 20 mg of antimony/kg/day, were compared in the treatment of culture-positive mucosal leishmaniasis involving more than one anatomic site. Forty consecutive eligible Peruvians with infiltrative or ulcerative mucosal disease of the lips, nose, palate-uvula-pharynx, or larynx-epiglottis were randomized to receive either 28 days (P28) or 40 days (P40) of sodium stibogluconate (Pentostam). Treatment was prematurely terminated due to thrombocytopenia in three patients and two patients did not complete six months of follow-up. At one month post-treatment, 13% (2 of 16) of the P28 patients and 16% (3 of 19) of the P40 patients no longer had infiltrates or ulcers and were initially considered cured. During a further 11 months of follow-up, infiltrated lesions healed in eight more P28 patients and in 10 more P40 patients. The cure rate after 12 months of follow-up was therefore 63% for both groups (10 of 16 in the P28 group and 12 of 19 in the P40 group). The total of 13 patients who had infiltrates or ulcers at the 9-12-month follow-up were considered failures. All seven patients (three in the P28 group and four in the P40 group) whose lesions were culture-positive for Leishmania at some point in the 12 months after treatment, and who were thereby parasitologic failures, were also clinical failures.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy of a short course (10 days) of high-dose meglumine antimonate with or without interferon-gamma in treating cutaneous leishmaniasis in Guatemala.

Sixty-six Guatemalan men with parasitologically confirmed cutaneous leishmaniasis, due most commonly to Leishmania braziliensis, were randomly assigned to receive one of three treatment regimens: meglumine antimonate (meglumine) for 20 days; meglumine for 10 days; and meglumine for 10 days plus alternate-day injections of interferon-gamma. In each group, meglumine was given intravenously as 20 mg of antimony/(kg of body weight.d). All treatment regimens were associated with similar response rates: the lesions of 19 (90%) of 21 patients who received meglumine for 20 days, 18 (90%) of 20 patients who received meglumine for 10 days, and all 22 patients who received meglumine plus interferon-gamma were completely reepithelialized by 13 weeks. In addition, for patients receiving all treatment regimens, test-of-cure cultures for Leishmania were negative and reactivation of lesions did not occur during 12 months of follow-up. The high efficacy of our 10-day course of meglumine indicates that the currently recommended duration of 20 days may be unnecessary for infections caused by L. braziliensis and suggests that a 10-day course of high-dose antimony should be tested as therapy for cutaneous leishmaniasis in other geographic areas.

Pancreatitis induced by pentavalent antimonial agents during treatment of leishmaniasis.

Pentavalent antimony (Sbv), formulated as sodium stibogluconate or meglumine antimoniate, is the standard treatment for the leishmaniases. In 16 of 17 consecutive, prospectively observed patients in Washington D.C., serum levels of amylase and lipase rose to abnormal values after therapy with sodium stibogluconate was started; 12 of 17 had symptoms of pancreatitis. Sbv therapy was continued to completion in 7 of 17 patients and interrupted in 10 of 17. Pancreatitis improved in every patient after Sbv therapy was stopped. Sbv treatment was resumed after brief interruptions in 6 of 10 patients. All six of these patients had flares of pancreatitis, but each completed therapy. Subsequently, we measured amylase and lipase levels in stored sera from 32 patients treated in Peru with either sodium stibogluconate or meglumine antimoniate for mucosal leishmaniasis. In all 32 Peruvian patients, serum amylase and lipase rose to abnormal levels during Sbv therapy; 11 of 32 had symptoms of pancreatitis. Standard Sbv regimens induce pancreatitis in almost all patients, but continued therapy is often tolerated; pancreatitis subsides when therapy is stopped, and rechallenge may be tolerated after a brief halt in treatment.

Treatment of Brazilian kala-azar with a short course of amphocil (amphotericin B cholesterol dispersion).

Amphotericin B is an effective but toxic antileishmanial agent. Lipid-encapsulated amphotericin B should have a high therapeutic index for visceral leishmaniasis because reticuloendothelial cells, the sole site in which Leishmania is found, will phagocytize and concentrate the complex. Amphotericin B cholesterol dispersion (Amphocil; 2 mg/[kg.d] intravenously) was administered to 10 Brazilians with kala-azar for 10 days (cohort 1) and to 10 Brazilians with kala-azar for 7 days (cohort 2). All patients were successfully treated: 19 of the 20 patients were without visible parasites in the bone marrow; the mean time to afebrility was 4.2 days; spleen size regressed by a mean of 79% 2 months after therapy; and no patient had clinical or laboratory abnormalities by the end of 6-12 months of follow-up. Side effects were fever and chills accompanied by respiratory distress, but not nephrotoxicity, in children < 3 years of age.

Evaluation of pentamidine for the treatment of cutaneous leishmaniasis in Colombia.

Ninety-two patients in Colombia with cutaneous leishmaniasis were randomly assigned to groups to be treated with meglumine antimonate (infected control subjects; 10 mg of antimony/kg intramuscularly, twice a day for 20 days), pentamidine (2 mg/kg every other day intramuscularly, for a total of seven injections), or itraconazole (200 mg orally, twice a day for 28 days) or to receive no treatment (negative control subjects). In the group treated with meglumine antimonate, 21 of 23 patients healed by the first follow-up visit, 1.5 months after the end of therapy, and did not relapse (91% cure rate). In the pentamidine-treated group, 23 of 24 patients healed and did not relapse (96%). Four of the 23 pentamidine-treated patients who ultimately were cured had terminated therapy prematurely (after receiving 4-6 injections) because of hypotension (2 patients), hypoglycemia (1 patient), or headache and myalgias (1 patient). In a subsequent group of 19 patients who were administered 2 mg of pentamidine/kg every other day for a total of only four injections, 14 healed without relapse (74% cure rate). The itraconazole-treated group was similar to the no-treatment control group in terms of the number of patients for whom therapy failed (75% and 64%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Placebo-controlled clinical trial of sodium stibogluconate (Pentostam) versus ketoconazole for treating cutaneous leishmaniasis in Guatemala.

To determine the relative efficacy and toxicity of stibogluconate and ketoconazole for the treatment of cutaneous leishmaniasis, a comparative trial was conducted in which 120 Guatemalan men with parasitologically proven cutaneous leishmaniasis were randomly divided into three treatment groups: sodium stibogluconate (20 mg of antimony per kilogram per day intravenously for 20 days), ketoconazole (600 mg per day orally for 28 days), and placebo. Treatment outcome was influenced by species. Among patients infected with Leishmania braziliensis, 24 (96%) of 25 in the stibogluconate group but only 7 (30%) of 23 in the ketoconazole group responded. Among Leishmania mexicana-infected patients, only 4 (57%) of 7 in the stibogluconate group but 8 (89%) of 9 in the ketoconazole group responded. These differences emphasize the importance of speciation in the treatment of leishmaniasis.

Placebo controlled treatment of Ecuadorian cutaneous leishmaniasis.

Pentavalent antimony has been considered to be the standard treatment for leishmaniasis, but more recently, the orally administrable agent allopurinol ribonucleoside has been the subject of several clinical trials. In this study, these two agents were evaluated in patients with Ecuadorian cutaneous leishmaniasis. Patients were randomly assigned to the two treatment groups. The mean reduction in lesion size for the 28 patients treated with Pentostam (20 mg Sb/kg/day intramuscularly for 20 days) was 61%, 23%, and 11% after one, two, and three weeks, respectively. There was a wide range in the individual values, and some lesions markedly enlarged in the first week of therapy. An initially healed lesion was defined as one that had greater than 80% re-epithelialized by the 1.5-month post-treatment followup. All Pentostam patients demonstrated this degree of lesion resolution (100% initial healing rate), but one patient showed evidence of relapse at the three month followup resulting in a 96% complete healing rate for the 12 month observation period. Patients in the untreated control group demonstrated a strikingly high rate of healing with 9 of 12 patients having re-epithelialized all lesions after 1.5 months observation (75% initial healing rate). The mean reduction in lesion size for the untreated patients was 56%, 29%, and 25% after one, two, and three weeks, respectively. Twenty-one patients received allopurinol ribonucleoside (1,500 mg QID) plus probenecid (500 mg QID) for 28 days. Lesions in nine of these patients were healed at the time of the 1.5 month followup (41% healing rate).(ABSTRACT TRUNCATED AT 250 WORDS)

Efficacy and toxicity of pentostam against Panamanian mucosal leishmaniasis.

We tested the World Health Organization (WHO) recommended treatment for mucosal leishmaniasis in 16 Panamanians with disease due to Leishmania braziliensis panamensis. Disease was mild in this population because it was limited to the nasal mucosa and only one patient had septal perforation. The patients were administered 20 mg antimony (in the form of Pentostam) per kg intravenously each day for 28 days. Ten patients completed therapy and were cured at 12 month follow-up. Three patients completed therapy, healed their lesions, but relapsed at the six or 12 month follow-up. Three patients terminated therapy prematurely because of liver enzyme elevations in conjunction with either EKG abnormalities or musculoskeletal complaints; none of these patients were healed. This study indicates that in patients with mild mucosal leishmaniasis, the WHO regimen is curative in 77% patients who complete treatment and in 63% of all patients.

Efficacy and toxicity of sodium stibogluconate for mucosal leishmaniasis.

OBJECTIVE: To determine the efficacy and toxicity of the World Health Organization's (WHO) recommended treatment for mucosal leishmaniasis: antimony, 20 mg/kg body weight per day for 28 days. DESIGN: Open trial with 12-month follow-up. SETTING: Inpatient unit of a regional referral hospital in a developing country. PATIENTS: Twenty-nine consecutive eligible patients with culture-confirmed infection of the mucosa with Leishmania species who were otherwise healthy. Eight patients (28%) had mild to moderate disease (confined to the nasal mucosa). Twenty-one patients (72%) had severe disease (including the oropharynx as well as the nasal mucosa). INTERVENTION: Antimony, 20 mg/kg body weight intravenously every day for 28 days. Patients received antimony in the form of sodium stibogluconate. MEASUREMENTS AND MAIN RESULTS: Initial results of therapy were as follows: 63 of 72 lesions (88%) healed or markedly improved; all lesions were culture-negative for parasites; and 18 of 29 patients (62%) showed complete clinical and parasitologic cure of all lesions. By the 12-month follow-up examinations, however, 37 lesions had recurred, 8 new lesions had appeared, and only 8 patients (30%) showed clinical cure of all lesions. Of the 8 patients with mild to moderate disease, 6 were cured compared with only 2 of the 21 patients with severe disease. Side effects of this treatment regimen included T-wave inversion on electrocardiogram (4 patients), abnormal liver function tests (10 patients), and musculoskeletal pain (24 patients). No side effects occurred during week 1 of therapy. CONCLUSIONS: The only recommended treatment for mucosal leishmaniasis is ineffective in patients with severe disease. The acceptable toxicity of the regimen suggests that longer courses of therapy with antimony, or that trials with other antileishmanial agents alone or combined with antimony be evaluated as initial therapy for this disease.

Efficacy of ketoconazole against Leishmania braziliensis panamensis cutaneous leishmaniasis.

PURPOSE, PATIENTS, AND METHODS: The classic agent for cutaneous leishmaniasis is pentavalent antimony. However, there are no reports of the efficacy of antimony versus placebo or of the efficacy of any alternative therapy versus either antimony or placebo. In the present report, the oral antifungal agent ketoconazole (600 mg/day for 28 days) was compared to a recommended regimen of intramuscular Pentostam (20 mg antimony/kg, with a maximum of 850 mg antimony/day, for 20 days) in a randomized study of the treatment of Panamanian cutaneous leishmaniasis due to Leishmania braziliensis panamensis. A separate group of patients with this disease was administered placebo. RESULTS: Ketoconazole clinically cured 16 of 21 (76%) patients. The lesions on nine patients healed by 1 month after therapy, and the lesions healed by 3 months after therapy on the other seven patients. Side effects were limited to a 27% incidence of mild, reversible hepatocellular enzyme elevation and an asymptomatic, reversible, approximately 70% decrease in serum testosterone in all patients. Pentostam cured 13 of 19 (68%) patients; the lesions on seven patients healed by the end of therapy, and the lesions on four other patients healed by 1 month after the end of therapy. Side effects were a 47% incidence of mild, reversible hepatocellular enzyme elevation and the morbidity due to 20 intramuscular injections in almost all patients. The placebo group of 11 patients had a 0% cure rate. By 1 month after therapy, all placebo-treated patients demonstrated new lesions or one lesion that was 23% to 875% larger than before therapy. CONCLUSION: Both ketoconazole and Pentostam were more effective than placebo against L. braziliensis panamensis cutaneous leishmaniasis. Oral ketoconazole is comparable in efficacy to this parenteral Pentostam regimen and can be recommended as initial treatment for this disease.

Human cutaneous leishmaniasis in Ecuador: identification of parasites by enzyme electrophoresis.

Twenty-six strains of Leishmania were isolated from cutaneous lesions in humans in 3 different geographical areas of Ecuador. The species were identified by enzyme electrophoresis as Leishmania braziliensis, L. panamensis, L. guyanensis, L. mexicana, and L. amazonensis.

Leishmania mexicana: chemistry and biochemistry of sodium stibogluconate (Pentostam).

The chemical properties of the primary antileishmanial agent sodium stibogluconate (Pentostam), and the interaction of Pentostam with Leishmania mexicana amastigotes, have been investigated with the aid of [125Sb]Pentostam. The molecular weight by P2 chromatography showed [125Sb]Pentostam to be of multiple species of MW = 100-4000 Da, rather than the one species of 746 Da predicted by the commonly hypothesized structural formula. Nonradioactive Pentostam had a lower osmolarity (789 mOsm for a 100 mg Sb/ml solution) than predicted (1644 mOsm), which indicates that the multiple components of Pentostam (Sb and derivatives of gluconic acid) are more closely complexed with each other than previously thought. When incubated with L. mexicana amastigotes, labeled drug was bound to at least six polypeptides of molecular weights ranging from 14,000 to 68,000 Da as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Interaction with the polypeptides is presumed to contribute to the antileishmanial action of Pentostam.

Uptake, distribution, and oxidation of fatty acids by Leishmania mexicana amastigotes.

Fatty acid uptake, distribution, and beta-oxidation were investigated in Leishmania mexicana amastigotes. The uptake of radiolabeled palmitic, stearic, and oleic acids was similar, reaching 3-6 nmol/10(8) cells in 2 min and 8-12 nmol/10(8) cells in 60 min. The percent of radiolabeled fatty acid that was esterified in the form of triglycerides or phospholipids increased from less than 25% at 2 min to 65-86% at 60 min. The dehydrogenase(s) in an amastigote granule fraction were unusual in that the Vmax for long-chain substrates (0.95-1.6 delta Abs units/min-mg protein) approximated the Vmax for short-chain substrates (0.82-2.0 delta Abs units/min-mg protein), and the Km for long-chain substrates was high (approximately 250 microM), in contrast to data for a mammalian liver mitochondrial fraction. The high Vmax and Km for long-chain substrates suggest a biochemical mechanism for the postulated high utilization of fatty acids as an energy source for amastigotes. Although the primary anti-leishmanial agent, Sb in the form of Pentostam, inhibited oxidation of palmitic acid to CO2 by intact organisms, Sb did not significantly inhibit fatty acid uptake or esterification by organisms, or beta-oxidation by the granule fraction, and the mechanism of action of Sb remains unclear.

Sodium stibogluconate (Pentostam) inhibition of glucose catabolism via the glycolytic pathway, and fatty acid beta-oxidation in Leishmania mexicana amastigotes.

The biochemical mechanism of action of antimony (Sb) in pentavalent form complexed to gluconic acid (sodium stibogluconate)--the drug of choice for the leishmaniases--has been only slightly investigated. We recently reported that, in stibogluconate-exposed Leishmania mexicana amastigotes, there is a dose-dependent decrease in the ATP/ADP ratio [Berman et al., Antimicrob. Agents Chemother. 27, 916 (1985)]. To investigate mechanisms by which ADP phosphorylation to ATP might be inhibited, stibogluconate-exposed amastigotes were incubated with [14C]glucose, fatty acid, or acetate, and 14CO2 production was determined. In organisms exposed to 500 micrograms Sb/ml, formation of 14CO2 from [6-14C]glucose and [1-14C]palmitate was inhibited 69 and 67% respectively. In comparison, formation of 14CO2 from [1-14C]glucose and [2-14C]acetate was inhibited less than 15%. These results suggest that glucose catabolism via glycolytic enzymes and fatty acid beta-oxidation, but not glucose metabolism via the hexosemonophosphate shunt or the citric acid cycle, is specifically inhibited in stibogluconate-exposed Leishmania mexicana amastigotes. Inhibition of these pathways suggests a mechanism for the inhibition of ADP phosphorylation previously reported.