Mariana Junqueira Pedras

Multi-centric prospective evaluation of rk39 rapid test and direct agglutination test for the diagnosis of visceral leishmaniasis in Brazil.

The diagnosis of visceral leishmaniasis (VL) is still a major problem in Brazil and several other countries where the disease is endemic. The use of an easy-to-use and interpret, sensitive, and specific method that requires no complex infrastructure or specialized professionals, such as direct agglutination test (DAT) and the rK39-based rapid immunochromatographic test may enhance the diagnosis of disease. This study evaluated the performance of a rapid test (DiaMed- IT-LEISH®) and the DAT for the diagnosis of VL in 213 parasitologically confirmed cases and 119 controls with clinical suspicion of VL and confirmation of another etiology. The sensitivities and specificities of the rapid test were 93% and 97%, respectively and those of the DAT were 90% and 96%, respectively. The positive predictive values of the rapid test and the DAT were 98% and 97%, respectively and the negative predictive values were 89% and 84%, respectively. The Kappa index showed agreement between both methods classified as substantial (0.77). This study showed that the DAT and the rapid test can be used to diagnose VL in Brazil, following a pilot study for implementation of the rapid test in the health services.

Antibody subclass profile against Leishmania braziliensis and Leishmania amazonensis in the diagnosis and follow-up of mucosal leishmaniasis

Sensitivities and specificities of IgG subclasses-ELISA and IgG-indirect fluorescent antibody test (IFAT) against Leishmania braziliensis (Lb) and L. amazonensis (La) antigens were determined in 17 patients with mucosal (ML) and 19 with muco-cutaneous (MCL) leishmaniasis. Using IFAT-IgG both antigens gave high sensitivities and were statistically similar, being 89.5% with La and 100% with Lb. Using ELISA, the highest sensitivity was achieved with total IgG for ML (94.7% with both antigens) and MCL (100% with both antigens). Cross-reactivity, observed with Chagas disease and malaria sera reduced the specificity of the IgG-based assays, being 50 to 70% with IFAT and 40 to 70% with ELISA. An increase in specificity was obtained with IgG1-ELISA (90% with Lb and 100% with La). Serum levels of anti-Lb-IgG and IgG3 dropped 90 days after treatment. IgG subclasses antibody detection constitute an valuable alternative to increase the efficiency of sorological diagnostics of ML/MCL.

Validação do teste imunocromatográfico rápido IT-LEISH® para o diagnóstico da leishmaniose visceral humana

The rapid immunochromatographic test IT-LEISH® (DiaMed IT-LEISH) was validated for the diagnosis of visceral leishmaniasis (VL) in four endemic areas of Brazil. The performance of the IT-LEISH® was compared with that of the indirect fluorescent antibody test, and that of enzyme-linked immunosorbent assay, using soluble antigen of Leishmania chagasi and the recombinant K39 (rK39). The study group was composed by 332 patients with clinical suspicion of VL: 213 cases confirmed by parasitological tests; and 119 with confirmation of another etiology. The sensitivity of the test IT-LEISH® was of 93% and the specificity of 97%. Immunofluorescent antibody test, ELISA L. chagasi and ELISA rK39 showed sensitivity of 88%, 92%, and 97%, and specificity of 81%, 77%, and 84%, respectively. The results confirm the validity of the test IT-LEISH® for the diagnosis of the VL in Brazil.

Improvement of direct agglutination test (DAT) for laboratory diagnosis of visceral leishmaniasis in Brazil

We previously standardized the direct agglutination test (DAT) to detect anti-Leishmania chagasi promastigote antibodies (DAT-LPC) with good sensitivity and specificity for diagnosing visceral leishmaniasis (VL). In this paper, we present a technical upgrade by introducing some modifications into the antigen preparation. This antigen was evaluated in DAT (DAT-Mod) using 61 sera samples from VL patients and 96 samples from patients with other diseases. The DAT-Mod presented a cut-off of 1:100, satisfactory reproducibility (VC <5.8), sensitivity of 93.4%, specificity of 96.9%, and diagnostic efficiency of 95.5%. The improvement in antigen preparation reduced inter-batch variations and resulted in a high test performance.

Mucosal leishmaniasis: the experience of a Brazilian referral center

INTRODUCTION Pentavalent antimonials (Sbv) are the most commonly used drugs for the treatment of mucosal leishmaniasis (ML), despite their high toxicity and only moderate efficacy. The aim of this study was to report therapeutic responses with different available options for ML. METHODS This study was based on a review of clinical records of 35 patients (24 men and 11 women) treated between 2009 and 2015. RESULTS The median age of patients was 63 years, and the median duration of the disease was 24 months. Seventeen patients received Sbv, while nine patients were treated with liposomal amphotericin B (AmB), and another nine patients were treated with fluconazole. Patients treated with AmB received a total median accumulated dose of 2550mg. The mean duration of azole use was 120 days, and the daily dose ranged from 450 to 900mg. At the three-month follow-up visit, the cure rate was 35%, 67%, and 22% for Sbv, AmB, and azole groups, respectively. At the six-month follow-up visit, the cure rates for Sbv, AmB, and azole groups were 71%, 78%, and 33%, respectively. CONCLUSIONS There is a scarcity of effective ML treatment alternatives, and based on our observations, fluconazole is not a valid treatment option.

Development and initial validation of a cutaneous leishmaniasis impact questionnaire

Background The impact of cutaneous leishmaniasis (CL) on the quality of life of patients has been neglected in research studies worldwide. The few reported studies have used non-specific questionnaires for the disease, which represents a limitation since generic instruments may not address specific aspects of the disease, compromising the evaluation of its real impact. The aim of this paper is to describe the development and the initial validation of an instrument for evaluating the impact of CL, named the Cutaneous Leishmaniasis Impact Questionnaire. Methodology The formulation and validation of the instrument consisted of the following steps: (1) literature review; (2) conceptual framework construction and initial item generation; (3) tool analysis by health professionals (experts); (4) tool evaluation performed by the patients; and (5) a pilot study with 100 patients with localized CL, evaluated at a reference ambulatory facility in Belo Horizonte, in the state of Minas Gerais, Brazil. The structure of the proposed instrument was analyzed using hierarchical cluster analysis (ICLUST). Results Twenty-seven items were initially proposed by the researchers to compose the questionnaire. Content validity (evaluates if the instrument fully assesses the construct of interest) was evaluated by the panel of experts, while face validity (evaluates how potential participants interpret the items) was evaluated by the target population. In this step, some items were excluded, reformulated and/or included. After evaluating a factorial structure of the items in accordance with the cluster analysis, we assembled a questionnaire with 25 items (alpha = 0.86), with high reliability and homogeneity, which address the following: 1) the general impact of the disease (alpha = 0.91, beta = 0.67) and 2) the evaluation of the perception about the treatment and health services (alpha = 0.72, beta = 0.51). Conclusions The Cutaneous Leishmaniasis Impact Questionnaire, developed with contributions from patients and experts, was confirmed, in this first validation, as a useful and reliable instrument.

Meglumine antimoniate intralesional infiltration for localised cutaneous leishmaniasis: a single arm, open label, phase II clinical trial

BACKGROUND Cutaneous leishmaniasis (CL) is a world-wide health problem which currently lacks effective, affordable and easy to use therapy. Recently, the meglumine antimoniate (MA) intralesional infiltration was included among the acceptable therapies for New World leishmaniasis. While this approach is attractive, there is currently little evidence to support its use in Americas. OBJECTIVES The aim of this study was to provide information about effectiveness and safety of a standardised MA intralesional infiltration technique for the treatment of CL. METHODS It is a single-arm phase II clinical trial conducted at a Brazilian referral centre. CL cases with parasitological confirmation presenting a maximum of three CL-compatible skin lesions were treated with weekly MA intralesional infiltration by using a validated technique, up to a maximum of eight infiltrations. RESULTS A total of 53 patients (62 lesions) were included. Overall, patients received a median of seven infiltrations (IQR25-75% 5-8) over a median treatment period of 43 days (IQR25-75% 28-52 days). The definitive cure rate at D180 was 87% (95% CI:77-96%). The majority of adverse events were local, with mild or moderate intensity. Bacterial secondary infection of the lesion site was observed in 13% of the treated patients, beside two intensity-three adverse events (hypersensitivity reactions).