The influence of treatment on the development of leishmaniasis recidiva cutis: a 17-year case-control study in Midwestern Brazil

A retrospective cohort study of the effectiveness and adverse events of intralesional pentavalent antimonials in the treatment of cutaneous leishmaniasis

Introduction

The standard therapy for American cutaneous leishmaniasis (ACL) is intravenous meglumine antimoniate (IV-MA). However, treatment interruptions due to adverse events (AEs) and non-adherence are frequent. Consequently, intralesional MA (IL-MA) was proposed.

Objective

This study examined the effectiveness of and AEs associated with IL-MA.

Methods

We performed a retrospective cohort study of 240 patients with ACL. We excluded patients with mucous lesions and disseminated leishmaniasis and those who received treatment in the previous 6 months. We considered protocol treatments as the main risk factors. IL-MA was performed using a subcutaneous injection of MA in a volume sufficient to elevate the lesion base (approximately 1 mL/cm² of lesion area) once weekly for 1–8 weeks. IV-MA was performed via intravenous injections of MA at a dosage of 10–20 mg Sb⁵⁺/kg/day for 20 days. The primary outcome was defined as a lesion cure 3 months after treatment, and AEs were secondary outcomes.

Results

Seventy-three patients were included. The IL-MA group consisted of 21 patients, and the IV-MA group consisted of 52 patients. The IL-MA group was older, had more comorbidities and more previous unsuccessful treatment of ACL. The antimonial dose was significantly lower in this group. The cure rate for IL-MA was 66.7%, which was lower than that in the IV-MA group (relative risk (RR) = 0.68, 95% CI: 0.50–0.92, p < 0.001), while the rate of AEs was similar. Female sex (RR = 1.16, 95% CI: 1.02–1.33), lesion diameter ≤1 cm (RR = 1.25, 95% CI: 1.00–1.56) and treatment with IV-MA (RR = 1.43, 95% CI: 1.06–1.93) were independently associated with achieving a cure. Comorbidities (RR = 1.7, 95% CI: 1.06–2.98) were independently associated with AEs.

Conclusions

Patients of IL-MA group were older, had more comorbidities and more previous unsuccessful treatment of ACL. Nevertheless, IL-MA had a cure rate of 66.7%, and it was useful in this context. A prospective randomized trial is recommended.

•

Intralesional antimonials (IL-MA) had a 66.7% lower cure compared to systemic.

•

IL-MA group was older, had more comorbidities and unsuccessful previous treatment.

•

IL-MA was useful in this group, where worse clinical responses are expected.

•

Lesions larger than 3 cm did not have more chance of failure with IL-MA.

•

There was no mucous recurrence after IL-MA in an area of New World Leishmaniasis.

The accuracy of the Montenegro skin test for leishmaniasis in PCR-negative patients

INTRODUCTION

As highly specific molecular biology-based techniques may not be sensitive enough for the diagnosis of American tegumentary leishmaniasis (ATL), clinicians frequently rely on immunological tests before treatment initiation. Hence, the correct combination of diagnostic tests is imperative for ATL diagnosis. We aimed to evaluate the accuracy of the Montenegro (Leishmanin) skin test (MST) in polymerase chain reaction (PCR)-negative patients to accurately detect ATL.

METHODS

Patients with a clinical picture compatible with ATL were divided into ATL (confirmed by lesion smear, culture indirect immunofluorescence, and/or histopathology) and no-ATL (diseases that can mimic leishmaniasis) groups. Conventional PCR for the minicircle kDNA of Leishmania was performed, and the MST was carried out for PCR-negative patients.

RESULTS

Ninety-nine patients were included in this study, including 79 diagnosed with ATL (6 with mucocutaneous leishmaniasis) and 20 without ATL (no-ATL group). The MST showed a high sensitivity of 90.0% (95% confidence interval [CI] = 69.90-97.21) in PCR-negative patients that was 10% higher than the sensitivity reported in PCR-positive population (79.66%; 95% CI = 67.73-87.96).

CONCLUSIONS

One of the most important reasons for PCR negativity among patients with active ATL is the presence of a strong cellular immunological response, especially in chronic and mucocutaneous leishmaniasis. This reinforces the considerable utility of the tests that detect cellular responses against Leishmania antigens such as the MST in PCR-negative patients when the performance in screening situations is questionable.

A randomized, open-label clinical trial comparing the long-term effects of miltefosine and meglumine antimoniate for mucosal leishmaniasis

INTRODUCTION

The treatment of mucosal leishmaniasis (ML) is difficult due to the toxicity and route of administration of standard drugs. Miltefosine is an oral agent used for leishmaniasis treatment; however, no data exist regarding its use for ML in Brazil. In this study, we aimed to evaluate the efficacy of miltefosine for ML treatment compared to that of pentavalent antimonial in a pilot study.

METHODS

We performed a randomized clinical trial with two parallel groups. The tested intervention consisted of miltefosine 1.3-2 mg/kg/day (two capsules) for 28 days or intravenous 20 mg SbV/kg/day of meglumine antimoniate (N-MA) for 30 days. The final endpoint was defined as complete healing of the lesion four years after treatment. We also analyzed an early endpoint at 90 days after treatment.

RESULTS

Forty patients were included in this study: each experimental group comprised 20 patients. Applying a multivariate model in an intention-to-treat analysis, we observed that patients treated with miltefosine had a cure probability 2.08 times greater (95% confidence interval [CI] = 1.03-4.18) than those treated with N-MA at 90 days after treatment. At the final endpoint, we observed no differences in cure probability between miltefosine and N-MA (relative risk = 0.66; 95% CI = 0.33-1.32). With respect to adverse reactions, significant differences between groups were related to gastrointestinal effects, which were more frequent in the miltefosine group.

CONCLUSIONS

Miltefosine may be an interesting alternative for treating ML because of its oral administration and cure rate after long-term follow-up.

Field validation of a Leishmania (Leishmania) mexicana exo-antigens ELISA for diagnosing tegumentary leishmaniasis in regions of Leishmania (Viannia) predominance

Background

Several tests are performed to obtain better accuracy when diagnosing American tegumentary leishmaniasis (ATL). It is believed that antigens released via secretion, excretion and metabolism are more specific than are antigens released by the lysis of Leishmania parasites. Such antigens are known as exo-antigens (exo-Ag) and are formed from products released by cultured parasites in a way that is similar to that in which they cause infections in hosts.

Objective

We attempted to validate a Leishmania mexicana ELISA exo-Ag for ATL diagnosis in Midwestern Brazil.

Methods

A total of 281 patients were included in the study. We analysed pre-treatment blood from 98 ATL patients; out of those, 85.7% and 14.3% had cutaneous and mucosal forms, respectively.

Results

The exo-Ag accuracy was 83.99% (95% CI = 79.24–87.81) with a sensitivity value of 90.82% (95% CI = 83.46–95.09) and an overall specificity value of 80.33% (95% CI = 73.97–85.44). The positive predictive value and negative predictive value were 71.20% (95% CI = 62.72–78.41) and 94.23% (95% CI = 89.40–96.94), respectively. Among healthy controls, exo-Ag had a specificity of 91.25% (95% CI = 83.02–95.70); additionally, the test had specificity rates of 66.67% (95% CI = 46.71–82.03) in Chagas disease patients, 60.61% (95% CI = 43.68–75.32) in patients with rheumatic diseases, 76.92% (95% CI = 49.74–91.82) in pemphigus foliaceus patients, 87.50% (95% CI = 52.91–97.76) in leprosy patients, 87.50% (95% CI = 63.98–96.50) in VRDL-positive patients, and 77.78 (95% CI = 45.26–93.68) in deep mycosis patients.

Conclusion

Based on the indicators of validity, we conclude that the results obtained in this study enable the recommendation of the exo-Ag ELISA for ATL diagnosis once it presented a reasonable accuracy compared to classical methods. Cost evaluations are necessary to completely define the role of this technique in large scale.