Sonia del Pilar Agudelo

Inefficacy of Allopurinol as Monotherapy for Colombian Cutaneous Leishmaniasis: A Randomized, Controlled Trial

New World cutaneous leishmaniasis classically presents as an ulcerating papule or nodule. The ulcer then reepithelializes during a period of a few to many months. Infection frequently spreads to draining lymph nodes; less frequently, it spreads to the mucous membranes of the nose and mouth. The disease is treated to relieve the discomfort of a weeping ulcer and to prevent mucosal disease. Treatment currently requires large daily doses of pentavalent antimony (20 mg/kg of body weight per day) by injection for 20 days [1]. This regimen creates considerable morbidity: Severe arthralgias or myalgias occur in at least 50% of patients, gastrointestinal discomfort develops in 30% of patients, hepatocellular enzyme levels are elevated in 30% of patients, diminution of T-wave height as seen on electrocardiography occurs in at least 10% of patients, and-rarely-thrombocytopenia and neutropenia occur [1]. Antimony treatment also causes chemical pancreatitis in almost all patients; gastrointestinal discomfort may be a symptom of clinical pancreatitis [2]. The treatment of cutaneous leishmaniasis, therefore, leads to morbidity similar to that of the disease itself. Such considerations have led to a 20-year search for an oral, well-tolerated therapeutic agent. The hypoxanthine analogue allopurinol, an inhibitor of uric acid formation in mammalian cells, was shown by LaFon and colleagues [3] to inhibit purine anabolism in Leishmania. In a randomized study done in Colombia, Martinez and Marr [4] found that a daily regimen of allopurinol (20 mg/kg per day) and antimony (20 mg/kg per day) for 15 days was much more effective than therapy with antimony alone (20 of 25 patients receiving allopurinol plus antimony [80%] recovered completely compared with 12 of 33 patients [36%] receiving antimony alone). However, the rate of cure for antimony alone in this study was surprisingly low [5]. Because of the controversy about the Colombian study and the lack of a well-controlled study on the efficacy of allopurinol in treating clinical leishmaniasis, we planned a randomized, blinded, controlled, large-scale clinical trial of the efficacy of allopurinol. To improve our ability to evaluate the efficacy of therapy, we chose the same endemic area (Colombia) and parasite (Leishmania panamensis) on which the major 1992 report focused. Methods Study Design In this randomized, controlled, partially double-blinded phase III study, we compared allopurinol with placebo and Glucantime (Rhone Poulenc, Paris, France). One hundred eighty-seven patients with cutaneous leishmaniasis were randomly assigned to one of three treatment groups. Patients in the first group received allopurinol, 300 mg (three 100-mg tablets) four times daily for 28 days, so that the dosage given was approximately 5 mg/kg four times daily or 20 mg/kg daily for 28 days. Patients in the second group received placebo, three tablets four times daily for 28 days. Patients in the third group received Glucantime, 20 mg of antimony/kg daily (no maximum daily dose) intramuscularly for 20 days. Patients in the allopurinol and placebo groups were assigned to treatment in a double-blinded manner. Study Sample, Inclusion Criteria, and Exclusion Criteria The study sample was composed of patients who were clinically suspected of having cutaneous leishmaniasis and who were from the following regions of Colombia: Arma, Dabeiba, Herveo, La Mesa, Marquetalia, Medellin, San Carlos, San Luis, Taraza, Valdivia, and Victoria. Patients were eligible for the study if they were 6 to 60 years of age, had cutaneous leishmaniasis as confirmed by the presence of parasites, had not received treatment for leishmaniasis with recognized agents during the previous 6 months, did not have lesions close to the eyes or on the mucosa, had body weight that was appropriate for height, and were amenable to prolonged follow-up. Exclusion criteria were the presence of concomitant diseases that required medical intervention, abnormalities in the complete blood count, abnormal glutamate oxaloacetate aminotransferase levels, abnormal creatinine levels, abnormal uric acid levels, and pregnancy. The ethical review committee of the Antioquia University School of Medicine and Hospital San Vicente de Paul, Medellin, Colombia, approved the study, and all patients gave written, informed consent. Parasitologic Diagnosis Leishmaniasis was diagnosed by visualizing amastigotes in lesion material or culturing promastigotes from lesion material. Two scrapings from one lesion on each patient (one scraping taken from the border of the lesion and one taken from the center) were examined with Giemsa stain for amastigotes; needle aspirates of the same lesion were added to culture medium to permit promastigotes to grow. Cultures were maintained at 26 C for 4 weeks before they were reported as negative. In each isolate that was cultured, species were identified by the use of monoclonal antibodies [6]. Conduct of Clinical Trial The first patient was entered into the study in April 1992; the last follow-up examination was completed in November 1995. Before the start of therapy, a complete history, a physical examination, and laboratory testing were done for each patient as described above. A photograph of each patients lesions was also taken. Patients were monitored every 10 days during the treatment phase of the study. Oral therapy was self-administered, and compliance was self-recorded. At each monitoring session, a 10-day supply of pills was dispensed and the patients compliance record was checked and verified by counting the number of pills. Glucantime was administered by medical support personnel. In addition, the occurrence and severity of anticipated adverse effects were recorded at each monitoring session. Lesions were examined before the start of therapy; at the end of therapy; and 1.5, 3, 6, 9, and 12 months after the end of therapy. Attendance at monitoring sessions and follow-up appointments was aided by telephone calls and home visits by study staff. At each evaluation, the induration (measured by using the ballpoint-pen technique) and the area of ulceration were both measured in two directions, which we designated R1 and R2. The areas of the indurated and ulcerated regions were calculated using the formula R1 x R2. Definition of Responses Response of lesions to therapy was determined clinically. Lesions treated with standard Glucantime regimens may increase in size or may not completely heal by the end of therapy; however, they generally heal by 1.5 months after therapy. We therefore used the response pattern of lesions treated with Glucantime as our standard in developing our definitions. For each lesion, we used the following definitions and dispositions: Complete clinical response: Complete reepithelialization of the ulcer and disappearance of all induration. Lesions that showed a complete clinical response were followed for as long as 12 months to verify lack of relapse. Clinical improvement: Fifty percent to 99% reepithelialization of the ulcer area and diminution of induration relative to the previous examination. Lesions that showed clinical improvement at the end of therapy or 1.5 months after the end of therapy were followed until either a complete clinical response or no clinical response was seen at subsequent follow-up sessions. No clinical response: Less than 50% enlargement or diminution of the ulcer area and of induration. If no clinical response was seen at the end of therapy, the lesion was monitored further. If no clinical response was seen at a later follow-up, therapy was considered to have failed. Failure to respond: 1) Greater than 50% enlargement of lesion size at the end of therapy or at subsequent follow-up or 2) no clinical response at an examination done 1.5 months or more after the end of therapy. Relapse: The reappearance of the lesion at the original site after a complete clinical response or the appearance of lesions involving the mucosa. A patient was considered cured if all of the patients lesions had a complete clinical response by the third month of therapy and no relapse had occurred by the 12-month follow-up appointment. Therapy was considered to have failed if any of the patients lesions did not respond to therapy or relapsed. Evaluation of Responses Patients, study investigators, and monitors were blinded to therapy with allopurinol compared with placebo. After the end of follow-up for the last patient, three independent, blinded evaluators determined efficacy and reached a consensus for each patient. The randomization code was then broken. Toxicity was determined by one evaluator before the code was broken. Results Patient Characteristics Five of the original 187 randomly assigned patients were excluded from the study: Two patients violated the study protocol, 1 had an uncertain parasitologic diagnosis, 1 had a clinical course that could not be interpreted, and 1 had co-infection with Sporothrix schenckii. The characteristics of the 182 patients studied are shown in Table 1. The groups were well matched for age, sex, number of lesions per patient, location and characteristics of lesions, and duration of the presence of lesions before treatment. Table 1. Patient Characteristics* Study Site Characteristics and Parasitology Patients from Arma and La Mesa had disease caused by L. braziliensis. Patients from the other nine regions had disease caused by L. panamensis. Ninety-seven percent to 100% of lesions were smear positive and 61% to 75% were culture positive for Leishmania organisms. Because our study was designed to investigate the efficacy of treatment for infection with L. panamensis, we stopped entering patients into the study at Arma and La Mesa as soon as the strain present at those sites was recognized. For the 182 analyzable patients, 153 patients (84%) had documented infection with L. panamensis or were from regions in which L. panamensis was endemic; 29 patients (16%) had infection

Safety and immunogenicity of a killed Leishmania (L.) amazonensis vaccine against cutaneous leishmaniasis in Colombia: a randomized controlled trial

The safety and immunogenicity of an intramuscular (i.m.) and intradermal (ID) formulation of autoclaved Leishmania (Leishmania) amazonensis vaccine was evaluated in 296 volunteers in a randomized, placebo-controlled, double-blind trial in Colombia. There were 4 vaccination groups: i.m. vaccine, i.m. placebo, ID vaccine, and ID placebo. The ID formulations were mixed with BCG as adjuvant at the time of injection. For each group, 3 vaccinations were given with a 20-day interval between injections, and adverse events were monitored at 20 min, and at 2, 7 and 21 days after each injection. BCG-induced adverse reactions resulted in cancellation of the third vaccine administration in the ID groups. Antibody titres did not differ significantly between the groups. Montenegro skin-test conversion was achieved by 86.4% and 90% of the i.m. vaccine group and by 25% and 5% of the i.m. placebo group 80 days and 1 year after vaccination, respectively. A significant increase in mean Leishmania-antigen lymphocyte proliferation indexes was observed after i.m. vaccine immunization, but not after i.m. placebo immunization, 80 days and 1 year after vaccination. Significant levels of IFN gamma but not IL-10 were observed 1 year after vaccination in the i.m. vaccine group compared to the i.m. placebo group. The good safety profile and evidence of Th1 immune reactions due to i.m. vaccination in this phase-I/II study suggest that a population-based phase-III efficacy trial of the i.m. vaccine should be initiated.

Gender and cutaneous leishmaniasis in Colombia

Leishmaniasis in Colombia has traditionally been seen as a health risk for adult males, as they become infected when they enter the vectors biotopes to tap natural resources. National health statistics seem to confirm this theory. However, during field studies, the Program for the Study and Control of Tropical Diseases (PECET) observed both equal proportions of men and women with active leishmaniasis and delayed hypersensitivity skin tests and equal proportions of males and females having had contact with the parasite from early childhood. Several factors that have not been analyzed in depth in Colombia thus far appear to distort the diseases epidemiological pattern in the country, and gender-linked differences in access to health care appear to exist. As a consequence, no relief is provided for this source of human suffering, and socioeconomic repercussions for households are significant. Preventive measures by the Colombian Ministry of Health (MOH) systematically underestimate the magnitude of intra- and peridomiciliary transmission, and female patients are excluded from active case detection. Further research should be devoted to this phenomenon. The MOH should be encouraged to improve leishmaniasis control programs, especially with regard to active case detection, training, and teaching, so that quicker diagnosis can be performed. Meanwhile, the MOH should retrain its health personnel.

Cutaneous New World leishmaniasis-sporotrichosis coinfection: Report of 3 cases

Three cases of coinfection with Leishmania and Sporothrix spp in the same lesion are described. The patients had ulcers with erythematous borders and regional lymphadenopathy. The diagnosis of leishmaniasis was accomplished by direct visualization of the amastigotes or culture of the promastigotes, or both. The diagnosis of sporotrichosis was proved in two cases by culture of Sporothrix schenckii and by the histopathologic features in one case. All patients had a positive sporotrichin test. Two patients responded successfully to oral potassium iodide. One patient received oral itraconazole 100 mg/day because of intolerance to iodides and was cured. To our knowledge coinfection with Leishmania and Sporothrix spp has not been reported. The use of empirical treatments for leishmaniasis such as poultices or puncturing of the lesion with thorns or woods splinters might introduce Sporothrix and explain the coinfection.

The method used to sample ulcers influences the diagnosis of cutaneous leishmaniasis

Before beginning treatment for cutaneous leishmaniasis, parasitological confirmation of the disease is required. The most commonly used diagnostic procedures are microscopy and culture of samples taken from the active edge of the lesion. In this study, we compared the sensitivity of previous diagnostic procedures with the polymerase chain reaction (PCR), using smears taken from the edge of the lesion and its centre. The sensitivity was greater with smears taken from the centre of the lesion, both for microscopical examination (85%) and for PCR (81%), compared to those obtained from the edge of the lesion (69% and 58% respectively). When PCR was carried out on biopsy material from the edge of the lesion the sensitivity was 63%.

Human antibody response to a 56‐kDa purified excretory/ secretory product of Dirofilaria immitis

Summary Canine dirofilariasis is widespread in urban areas of central and northern Colombia. Previously we detected specific antibodies against complex antigens from Dirofilaria immitis adult worms in individuals from an isolated Tikuna Indian community in the Colombian Amazon. In this study a 56 kDa polypeptide from the adult D. immitis excretory/secretory (E/S) products is identified by Western blot, isolated by elution from polyacrilamide gels and applied in an ELISA‐based test for the detection of specific IgG. Eleven of 74 serum samples analysed were positive by ELISADi56. Positive individuals came from five different areas of Colombia. The highest number of positives was found in the Amazon (4), followed by Bogotà (3). The physicians of the area must be alerted regarding the existence of human D. immitis infections and include dirofilariasis in the differential diagnosis of pulmonary nodules.

Control of Taenia Solium Transmission of Taeniosis and Cysticercosis in Endemic Countries: The Roles of Continental Networks of Specialists and of Local Health Authorities

© 2013 Fleury et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Control of Taenia Solium Transmission of Taeniosis and Cysticercosis in Endemic Countries: The Roles of Continental Networks of Specialists and of Local Health Authorities