Retrospective study of 151 patients with cutaneous leishmaniasis treated with meglumine antimoniate

We retrospectively analyzed a series of 151 cases of cutaneous leishmaniasis treated between 1967 and 1982. One-hundredand-thirty-nine (92%) patients presented with active lesions and were treated with daily doses of meglumine antimoniate: 81 adults received a 5-ml vial IM and 58 children received 1 to 5ml. Forty-five (32.4%) patients underwent continuous treatment with meglumine antimoniate for 25 to 116 days without rest intervals, and 94 (67.6%) intermittent treatment with 2 to 5 series of meglumine antimoniate. Intermittent series could include schedules of daily IM applications for 10 to 25 days each and intervals varying from 10 to 60 days. Antimony dose was calculated for 66 (47.5%) patients and ranged from 3.9 to 28.7 Sb/kg/day. Of these, 35 patients received >10mg and 31 patients <10mg Sb/kg/day. Median time of healing was longer for lesions on the legs and feet – 67.5 days versus 48.7 days (p < 0.001) for other sites. However, there were no significant differences in the median time of healing between adults and children, intermittent and continuous regimens or high and low antimony doses. Fifty-one patients were reassessed 5 to 14 years after treatment and showed no evidence of disease. These results support further investigation (clinical trials) on treatment using low doses of antimony. Key-words: Cutaneous Leishmaniasis. Leishmania (Viannia) braziliensis. Drug therapy. Meglumine antimoniate. Therapeutic schedules.

In Rio de Janeiro, American tegumentary leishmaniasis (ATL) is caused by Leishmania (Viannia) braziliensis, whose transmission is dependent on the adaptation of the vector Lutzomyia intermedia to the peridomiciliary environment 19 .The disease affects the skin and mucosae.Cutaneous leishmaniasis (CL) presents as skin ulcers in body sites exposed to the sandflies' bite.These ulcers may regress without any treatment after a period of several months to years 7 .The patients may remain cured or reactivation of scars or development of mucosal lesions may occur 40 .Mucosal leishmaniasis (ML) presents as chronic and destructive lesions of the oral, nasal, pharyngeal and/or laryngeal tissues.A higher risk of reactivation and development of ML is believed to be associated with incomplete or inadequate treatment 16 17 18 41 .
Pentavalent antimonials have been used in the treatment of leishmaniasis for more than 60 years 11 .Despite the broad spectrum of clinical and in vitro sensitivity to pentavalent antimonials exhibited by different species and strains of Leishmania around the world, some therapeutic guidelines have been suggested 10 13 42 .However, clinical assays continue to be performed to define the therapeutic regimen best suited to different regions of the globe 33 .The main differences between the therapeutic regimens available relate to the use of meglumine antimoniate or sodium stibogluconate, continuous or intermittent administration, total daily dose, duration of treatment, the criteria used for discontinuation or prolongation of treatment, and the Leishmania species and strains involved 4 .
Until the mid-eighties, the treatment protocol for adult ATL at Evandro Chagas Clinical Research Institute (IPEC) consisted of one daily 5-ml vial IM of meglumine antimoniate, irrespective of body weight 37 .We present here a retrospective series of CL cases treated with fixed doses of antimony independent of body weight, 51 of these were reassessed several years after treatment.The objective of this paper was to present the retrospective series of cases that encouraged prospective cohort studies and clinical trials in Rio de Janeiro (Southeast Region of Brazil) using low doses of antimony 29 30 .

MATERIAL AND METHODS
The study was approved by the Ethics Committee of the Oswaldo Cruz Foundation (Fiocruz) and was conducted according to Resolution # 1/88 of the National Health Council 24 .
Retrospective study (record review).The records and charts of patients with ATL seen at IPEC from 1967 to 1982 were reviewed.To be included, the following information had to be available: a) an epidemiologic history consistent with ATL acquired in the State of Rio de Janeiro; b) presence of cutaneous lesions suggestive of CL; c) diagnosis based on a positive Montenegro skin test (MST) and/or demonstration of the parasite in culture, by direct examination or by histopathology; and d) treatment with meglumine antimoniate.Additionally, data about Leishmania species characterization based on monoclonal antibody, and isoenzyme analysis 12 25 were obtained from the charts.Of the 333 records reviewed, only 151 (45.3%) fulfilled the inclusion criteria.
Frequency distributions and medians with percentiles 25 and 75 are presented.We performed an analysis of treatment effectiveness.The results of treatment comprised presence or absence of a good therapeutic response, defined as a written record of complete scarring (healing) of the lesions after treatment.The time in days to achieve the results of treatment with meglumine antimoniate since the beginning of treatment was compared, according to the presence or absence of the following variables: age (> or < 18 years), body site of the lesions (legs or foot versus other), dose of antimony administered (> or < 10mg/kg/day), and continuous versus intermittent treatment.The Kolmogorov Smirnov test rejected all the null hypothesis concerning the normality of continuous variables distribution.Therefore, we chose the nonparametric Mann-Whitney test to compare median times of healing between groups.
Cross-sectional study (reassessment of the patients).Between September 1986 and January 1988, an active search for these patients was conducted.Fifty-one patients were located again and reassessed after signing the informed consent form to participate in the cross-sectional study.The patients were seen at IPEC for medical history and physical, dermatologic and ENT (ears, nose and throat) examinations.The latter included anterior rhinoscopy, posterior rhinoscopy and laryngoscopy with Hopkins optics 0º and 90º.Leishmanin was provided by the Institute of Biological Sciences, Federal University of Minas Gerais 22 for MST.All tests and measurements with a ballpoint pen 38 were performed by a single observer.An indirect immunofluorescence assay (IFA) was performed for the detection of anti-Leishmania antibodies 5 .Promastigotes of the Brazilian strain MHCM/BR/76/JOF, phenotypically similar to L. major 26 , were used as antigen.

RESULTS
Retrospective study (record review).Of the 333 records reviewed, 151 fulfilled the inclusion criteria, with 137 (90.7%) of them from the metropolitan region of Rio de Janeiro.Patients were 74 men and 77 women, median age 16 years with percentiles 25 and 75 of 8 to 30.8 years for age and 1 to 10 months (median =3 months) for duration of disease.
The median number of lesions per patient was one.One-hundred-and-five (69.5%) patients had single lesions, 22 (14.5%) had two lesions and 24 (16%) had three or more lesions.Upon treatment, 12 (8%) patients had only scars suggestive of CL and 139 (92%) had active lesions.The twelve patients (8 adults and 4 children aged up to 12 years) with cicatricial lesions at the beginning of treatment were excluded from the analysis of treatment effectiveness.These patients underwent prophylactic treatment to prevent the development of ML and received 50-125 doses of meglumine antimoniate.Leishmania was isolated from the scar of one of these patients 8 years after treatment with an intermittent schedule 36 .
Forty-five (n = 139, 32.4%) patients underwent continuous treatment with meglumine antimoniate for 25 to 116 days, without rest intervals, and 94 (67.6%) underwent intermittent treatment, consisting of 2 to 5 series of meglumine antimoniate with 10 to 25 days duration each, and intervals of 10 to 60 days between each series.However, 16 patients considered to have undergone a continuous regimen were in fact patients who did not return for additional therapy, because lesions healed after a single 25-day series.
Overall, the median time to healing after the beginning of treatment was 50 days (30 -60 days).The median time (and percentiles 25 and 75) of healing was longer -67.5 days (43.8 -91.3 days) -for lesions in the legs and feet than for lesions at other sites -48.7 days (30 -60 days) (p < 0.001).
Overall, the median number of injections per patient was 66 (ranging from 25 to 125 and the median duration of treatment was 90.0 days with 50% of observations in the following interquartile interval (50 days -110 days).
Cross-sectional study (reassessment of the patients).Fifty-one patients were reassessed at a median of seven years after treatment.Thirty-three of these patients had been treated with a known dose of antimony: 17 patients with >10mg Sb 5+ /kg body weight/day and 16 with <10mg.All patients were still living in their area of origin.There were 25 men and 26 women ranging from 10 to 63 years of age (median = 23).All patients remained asymptomatic and presented atrophic cutaneous scars and no mucosal lesions.The MST was positive in 50 (n = 50, 100%) patients.The IFA was positive (IgG = 1:40) in the serum of 5 (n = 51, 10%) patients.

DISCUSSION
We studied 151 patients with CL from Rio de Janeiro who had received one ampoule or less of meglumine antimoniate intramuscularly daily.The limitations of this study are related to bias inherent in uncontrolled real settings of treatment such as: difficulties in recovering data from charts of patients seen by different physicians; irregular data recording; different therapeutic schedules and variable criteria to evaluate response to therapy.
For the treatment of CL, the World Health Organization 42 has recommended the use of 10-20mg Sb 5+ /kg body weight/day, without interruption until cure, for at least three weeks 31 .In Brazil, the same daily dose for 20 days, with a maximum of 3 ampoules daily, is recommended.Re-treatment should be considered in cases in which complete scarring is not achieved three months after the end of the initial treatment 10 .It is interesting to note that both fixed doses of antimony used in patients described in the present study and restriction of the maximum daily dose in contemporary official Brazilian guidelines can lead to the use of doses lower than 10mg Sb 5+ /kg body weight/day.
Continuous or intermittent schedules with 20mg Sb 5+ /kg body weight/day are well tolerated, and intravenous administration has been preferred because pain and discomfort at the site of injection are frequent when large volumes are injected intramuscularly 2 3 4 13 35 .Other authors have reported renal tubular dysfunction, cardiac, hepatic, pancreatic and hematological alterations 1 8 9 34 .In Rio de Janeiro, continuous schedules with 5mg Sb 5+ /kg body weight/day has been safe and effective for treatment of ATL 28 29 30 .In this study, no significant difference in the time of healing was observed between the therapeutic schedules used and high and low doses.Unfortunately, adverse effects were not recorded on a regular basis in the charts reviewed.

Median time Percentiles p value of
It was reported that pentavalent antimony is rapidly excreted in urine 6 .Miekeley et al 23 confirmed these results.However, in contrast to previous reports, this rapid excretion phase was followed by a slower one with a half-life >50 days.These authors found evidence of the in vivo conversion of meglumine antimoniate into the ionic species Sb 5+ and Sb 3+ , leading to considerable concentrations of Sb 3+ in body fluids as suggested previously 43 .This finding supports the hypothesis that the formation of Sb 3+ may be responsible for both the observed longterm toxicity of the drug and its therapeutic action 32 .
In the present study, lesion healing had occurred within the period established by Brazilian therapeutic guidelines 10 in 97.1% of the patients, despite the fact that healing time could be overestimated due to time elapsed from scarring to medical observation and recording on the chart.In the subgroup of patients who underwent continuous treatment, duration of treatment and time until healing were similar and scarring determined the interruption of antimonial administration.However some patients in this subgroup had shorter duration of treatment than time intervals until healing, suggesting that it may not been necessary to continue antimonial application until total healing of CL lesions occurs.In the sub-group of patients undergoing intermittent treatment, both the duration of treatment and the number of injections per patient were higher than time of healing, suggesting that, in these cases, one or more of the additional series were unnecessarily administered after lesion healing.Other studies have shown that cutaneous lesions which do not heal until the end of treatment could heal without the need for re-treatment 4 .Lesions located on legs and feet take longer to heal, suggesting venous stasis could be a delaying factor, as previously reported 18 .
Persistence of the parasite in one patient without signs of active disease demonstrates that treatment did not always eliminate the parasite and that this might not be necessary to establish clinical healing.
The 51 patients reassessed 5 to 14 years after treatment remained asymptomatic and fulfilled the criteria used to define clinical cure of ATL 42 , i.e., healed skin lesions, absence of mucosal lesions and a positive MST.Five (10%) patients presented positive IFA at low titers (1:40).Some investigators have suggested that a negative IFA should also be included in the criteria of cure 39 .However, the clinical value of persistent antibody levels for predicting ATL recurrence in endemic areas has been questioned 15 41 .Other authors have obtained similar results with therapeutic schemes different from the ones currently recommended 20 21 .Marsden 18 suggested that a low dose of meglumine antimoniate for the treatment of CL might prevent involvement of the mucosae.Other investigators observed cutaneous relapse and evolution to ML in 3 to 9.1% of cases followed up for a period of 6 years after treatment 14 27 41 .Walton et al 40 has suggested the need for longer periods of observation.
The present study indicates that lower doses of antimony could be as effective as higher doses.