Overcoming the Negligence in Laboratory Diagnosis of Mucosal Leishmaniasis

The northern region of Brazil, which has the largest number of cases of tegumentary leishmaniasis (TL) in the country, is also the region that has the highest diversity of species of vectors and Leishmania parasites. In this region, cases of mucosal leishmaniasis (ML), a clinical form of TL, exceed the national average of cases, reaching up to 12% of the total annual TL notifications. ML is associated with multiple factors, such as the parasite species and the viral endosymbiont Leishmania RNA virus 1 (LRV1). Being a chronic parasitological disease, laboratory diagnosis of ML poses a challenge for health services. Here, we evaluated more than 700 clinical samples from patients with clinical suspicion of TL, including patients with cutaneous leishmaniasis (CL) and mucosal leishmaniasis, comparing the results of parasitological tests—direct parasitological examination by microscopy (DP) and conventional PCR (cPCR) targeting of both kDNA and hsp70. The DP was performed by collecting material from lesions through biopsies (mucosal lesions) or scarification (cutaneous lesions); for PCR, a cervical brush was used for sample collection. Blood samples were tested employing standardized real-time PCR (qPCR) protocol targeting the HSP70 gene. PCR tests showed higher sensitivity than DP for both CL and ML samples. Considering ML samples only (N = 89), DP showed a sensitivity of 49.4% (N = 44) against 98.8% (N = 88) for kDNA PCR. The qPCR hsp70 for blood samples from patients with ML (N = 14) resulted in superior sensitivity (50%; N = 7) compared to DP (21.4%; N = 3) for samples from the same patients. Our results reinforced the need to implement a molecular test for the diagnosis of ML, in addition to proposing methods less invasive for collecting material from TL patients. Sample collection using a cervical brush in lesions observed in CL and ML patients is easy to perform and less invasive, compared to scarification and biopsies. Blood samples could be a good source for qPCR diagnosis for ML patients. Thus, we propose here a standardized method for collection and for performing of molecular diagnosis of clinical samples from suspicious ML patients that can be applied in reference services for improving ML diagnosis.

Diagnostic challenges of oral leishmaniasis: unusual presentation of two cases

Leishmaniasis is a non-contagious infectious disease and has a broad spectrum of clinical forms. Isolated oral mucosal leishmaniasis is rare and challenges clinicians and pathologists. We report two cases of oral leishmaniasis manifested as ulcerative growth on the palate and tongue nodule. Histopathological analysis was performed and the final diagnosis was made with the visualization of amastigote-like structures. Both cases had unusual clinical manifestations and many differential diagnoses were considered, including syphilis, paracoccidioidomycosis and mesenchymal or epithelial neoplasms. The broad spectrum of clinical manifestations and the often-inconclusive findings in histopathology reinforce the importance of clinicopathological correlation in diagnosis of leishmaniasis.

Intravenous liposomal amphotericin B efficacy and safety for cutaneous and mucosal leishmaniasis: a systematic review and meta-analysis protocol

IntroductionTreatment of cutaneous and mucosal leishmaniasis (CL and ML, respectively) must be individualised as there is no universal therapeutic approach. Intravenous liposomal amphotericin B (L-AmB) is an accessible and relatively safe treatment that has been increasingly used for the treatment of CL and ML. While several descriptive studies have been published on the efficacy and safety of L-AmB, there are no interventional studies. Moreover, the findings from published studies have not yet been integrated and synthesised. Therefore, we aim to evaluate and consolidate the descriptive evidence on the efficacy and the safety of Intravenous L-AmB treatment for CL and ML in both the New and Old World.Methods and analysesA systematic review of all relevant study types with no restriction on date or language of publication will be conducted. Online databases including MEDLINE, The Cochrane Library, EMBASE, EBSCO, Scopus, Ovid and WHO databases were searched on 3 April 2020. The search included all study types that assess Intravenous L-AmB treatment for CL and ML in humans. The Population, Intervention, Comparison, Outcome and Study Design strategy and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines will be used to determine which studies will be selected for final inclusion. The quality of included case series and case reports will be assessed using modified quality assessment tools. A narrative synthesis of the findings will be provided and the primary outcome and secondary outcome of interest, response rate and adverse events rate, respectively, and the 95% CI will be ascertained. Estimates from individual studies will be pooled using random-effects model.Ethics and disseminationThis systematic review does not require formal ethical approval since no primary data will be collected. Findings will be disseminated through a peer-reviewed publication and relevant conferences.PROSPERO registration numberCRD42020173440.

High Anti-Leishmania IgG Antibody Levels Are Associated With Severity of Mucosal Leishmaniasis

BackgroundMucosal leishmaniasis (ML), the most inflammatory form of tegumentary leishmaniasis, is predominantly caused by Leishmania braziliensis. The disease is characterized by the development of lesions, mainly in the nasal mucosa. An exacerbated inflammatory response has been associated with the presence of destructive and disfiguring lesions, with stages of severity ranging from small nodulations to the complete destruction of the nasal pyramid architecture. As Leishmania is an intracellular parasite, most immunological studies have emphasized the cell-mediated immune response, while relatively few studies aimed to investigate the role antibodies in protection against, or the pathology of ML.MethodsPatients with a confirmed diagnosis of ML were classified according to clinical staging criteria. Serum levels of Leishmania-specific IgG, IgG1 and IgG2 antibodies were determined by ELISA before and after treatment with antimony or antimony plus pentoxifylline.ResultsPatients in stages IV and V produced higher concentrations of IgG and IgG1 antibodies when compared to those in stage I and II. Significant reductions were seen in the concentrations of IgG and IgG2 antibodies in most patients who responded well to treatment.ConclusionsOur data demonstrate an association between IgG antibody titers and the severity of mucosal disease. The observed reduction in antibody production after successful treatment in most patients preliminarily indicates that these tests can be used to aid in the assessment of therapeutic response.

PARTICIPAÇÃO DOS RECEPTORES TOLL-LIKE NA RESPOSTA A INFECÇÃO in vitro POR Leishmania (Viannia) braziliensis: UMA REVISÃO DE LITERATURA

Introdução: A Leishmania braziliensis é um protozoário da família Trypanosomatidae responsável pelo desenvolvimento de uma das formas dermotrópicas da doença denominada leishmaniose mucosa (LM). O parasito é intracelular obrigatório e se multiplica dentro dos macrófagos e monócitos de seus hospedeiros. Os receptores tolllike (TLR) são glicoproteínas transmembrana presentes nas células de defesa, principalmente Natural Killer, macrófagos e células dendríticas, que reconhecem estruturas microbianas e que promovem uma série de sinais que produzem citocinas próinflamatórias importantes para que a resposta imune inata seja efetiva, como por exemplo TNF-α, IL-10 e TGF-β. Objetivo: Realizar revisão da literatura a respeito do papel dos receptores Toll-like na resposta à infecção in vitro por L. braziliensis. Material e métodos: Realizado no formato de revisão integrativa, a pesquisa abrangeu artigos científicos das bases de dados SCIELO e PUBMED. Os descritores utilizados foram “American Cutaneous leishmaniasis”, “Leishmania braziliensis”, “mucosal leishmaniasis” e “Toll-like receptors”. Foram selecionados artigos acadêmicos originais, escritos na língua inglesa, que foram publicados no período de 2014 a 2020, obtendo -se 20 artigos. Após a leitura dos títulos e resumos e ao adotar os critérios de exclusão, foram selecionados 12 artigos originais para a presente revisão. Resultados: As pesquisas selecionadas avaliaram 147 pacientes com diagnóstico histopatológico de Leishmaniose Cutânea (LC). Os pacientes que apresentavam LM, concomitantemente possuíam uma maior expressão de células TCD4+, TCD8+, IL-10+ e TGF-β+ em comparação com aqueles que possuíam LC, que expressavam uma menor quantidades dessas citocinas. Em oposição, o TNF-α em pacientes com LC, encontrava-se aumentado se comparada a LM. Na análise relacionada a TLR-2 e TLR-4, houve uma maior expressão em monócitos nos pacientes com LC associadas a L. braziliensis e que o bloqueio dos TRL reduziu as respostas oxidativas das células de pacientes com LC. Conclusão: Diante dos resultados é possível concluir que a maior expressão de TLR-2 e TLR-4 promove a hiper-reatividade de citocinas pró-inflamatórias e consequente pré-disposição para desenvolvimento da doença. Portanto, seu bloqueio é eficaz para redução das lesões. Esse dado demonstra a relação e o papel dos TLR na infecção por L. braziliensis, trazendo importantes esclarecimentos para a resposta imune e desenho vacinal.

Squamous cell carcinoma superimposed on mucosal leishmaniasis in an HIV-positive patient

Leishmaniasis is emerging as an important problem in immunosuppressed individuals, leading to overt clinical disease, atypical presentation, chronic course, and impaired treatment response. Moreover, it can affect unexposed regions and strikingly mimic other infectious disorders and a variety of neoplastic diseases, thus being easily misdiagnosed. Here, we report the case of an HIV-patient where both clinical picture and histopathological findings were consistent with mucosal leishmaniasis (ML). However, the worsening of the clinical picture after anti-leishmania treatment led to suspect a different diagnosis, and squamous cell carcinoma superimposed on ML and Human Papilloma Virus infection was ultimately diagnosed.