The diagnosis of American Tegumentary Leishmaniasis is a difficult but essential task when considering the high toxicity profile of the drugs available. Since the discovery of its etiologic agent, numerous diagnostic tests have been developed. None of the tests available today can be considered as the gold standard, since they do not add enough accuracy for the disease detection. Good epidemiological and clinical knowledge of the disease are fundamental precepts of the dermatology practice and precede the rational use of existing diagnostic tests. In this article we aim, through extensive literature review, to recall fundamental concepts of any diagnostic test. Subsequently, based on this information, we will weave important comments about the characteristics of existing diagnostic tests, including immunological tests such as Montenegro's skin test, serology and detection of parasites by direct examination, culture or histopathology. Finally we will discuss the new technologies and options for the diagnosis of Cutaneous Leishmaniasis. The molecular biology technique is considered a promising tool, promoting the rapid identification of the species involved. We also aim to educate dermatologists about a disease with high morbidity and assist in its difficult recognition.
BackgroundLeprosy diagnosis is mainly based on clinical evaluation, although this approach is difficult, especially for untrained physicians. We conducted a temporary campaign to detect previously unknown leprosy cases in midwestern Brazil and to compare the performance of different serological tests.MethodsA mobile clinic was stationed at the main bus terminal in Brasília, Brazil. Volunteers were quizzed and given a clinical exam to allow categorization as either patients, known contacts of patients or non-contacts, and blood was collected to determine anti-PGL-I and anti-LID-1 antibody titers by ELISA and by the NDO-LID rapid test. New cases of leprosy and the impact of performing this broad random surveillance strategy were evaluated. Accuracy values and concordance between the test results were evaluated among all groups.ResultsFour hundred thirty-four individuals were evaluated, and 44 (10.1%) were diagnosed with leprosy. Borderline forms were the most frequent presentation. Both tests presented higher positivity in those individuals with multibacillary disease. Serological tests demonstrated specificities arround 70% for anti-PGL-1 and anti-LID ELISA; and arround 40% for NDO-LID. Sensitivities ranged from 48 to 62%. A substantial agreement between NDO-LID and ELISA with concomitant positive results was found within leprosy patients (Kappa index = 0.79 CI95% 0.36–1.22).ConclusionsThe unexpectedly high leprosy prevalence in this population indicates ongoing community-based exposure to Mycobacterium leprae antigens and high rates of subclinical infection. All tests showed low specificity and sensitivity values and therefore cannot be considered for use as stand-alone diagnostics. Rather, considering their positivity among MB patients and non-patients, these tests can be considered effective tools for screening and identifying individuals at high risk who might benefit from regular monitoring.
Objectives: Owing to difficulties in the clinical diagnosis of leprosy, several complementary tests have been developed and used. The aim was to systematically summarize the accuracy of diagnostic tests for leprosy. Methods: We searched for relevant articles in Embase, Medline, and Global Health databases, until June 2017. Studies evaluating the accuracy of any diagnostic techniques for differentiating between people with and without leprosy were included. Studies solely focusing on differentiating between the separate forms of leprosy were excluded. Our protocol was registered on PROSPERO (CRD42017071803). We assessed study quality using the QUADAS-2 checklist. A bivariate random effects regression model was used for the meta-analyses. Results: We included 78 studies, most of those evaluating the detection of IgM antibodies against phenolic glycolipid I using ELISA. Sensitivity of the 39 studies evaluating ELISA was 63.8% (95% CI 55.0 e71.8); specificity 91.0% (95% CI 86.9e93.9). The lateral flow test (nine studies) and the agglutination test (five studies) had a slightly higher sensitivity and a slightly lower specificity. Sensitivity of qPCR was (five studies) 78.5% (95% CI 61.9e89.2) and specificity 89.3% (95% CI 61.4e97.8). Sensitivity of conventional PCR was (17 studies) 75.3% (95% CI 67.9e81.5) and specificity 94.5% (95% CI 91.4e96.5). Conclusions: Although the test accuracy looks reasonable, the studies suffered from heterogeneity and low methodological quality.
Tuberous Sclerosis Complex, also known as Epiloia or Bourneville-Pringle disease is an autosomal dominant neurocutaneous syndrome with variable clinical expression. It is a multisystem disorder that may be associated with hamartomas in multiple organs in an unpredictable manner. The dermatologist plays an essential role in the history of the disease, since skin manifestations represent the most prevalent clinical features, enabling early diagnosis and intervention in its natural course. This article aims to inform the scientific community about advances made in the study of genetics and molecular biology. Recent findings regarding stimulation of tumor growth have been changing the history of this condition, making therapeutic trials with topical and systemic drugs possible. Knowledge of these topics enables better management of the patients affected, since tissue replacement by tumors can result in significant morbidity and mortality. Keywords: Dermatology; Diagnosis; Neurology; Sirolimus; Tuberous sclerosis Resumo:A Esclerose Tuberosa, também conhecida como Epilóia ou Facomatose de Pringle-Bourneville, é uma síndrome neurocutânea de caráter autossômico dominante com expressões clínicas variadas. É uma doença multissistêmica que pode cursar com hamartomas em diversos órgãos, de forma imprevisível. O dermatologista tem papel essencial na história da doença, uma vez que as afecções cutâneas representam as mais prevalentes apresentações clínicas, possibilitando assim o diagnóstico precoce da sín-drome e intervenção na sua evolução natural. O presente artigo tem o objetivo de atualizar a comunidade científica sobre avanços alcançados no estudo genético e biologia molecular. Recentes descobertas sobre o estímulo do crescimento tumoral vêm mudando a evolução desta patologia, possibilitando ensaios terapêuticos com drogas tópicas e sistêmicas. O conhecimento destes aspectos possibilita melhor condução dos pacientes acometidos, dado que a substituição tumoral dos diversos tecidos pode resultar em relevante morbidade e mortalidade.
The precise diagnosis of American tegumentary leishmaniasis (ATL) is an essential task due to the disease's associated morbidity. A noninvasive, extremely sensitive, and highly specific exam is critical, particularly for mucosal leishmaniasis (ML), in which a low parasite quantity is expected. We aimed to compare the diagnostic accuracy of swab and biopsy sample analysis using SYBR Green-and TaqManbased real-time PCR (qPCR) assays with that of a composite reference standard consisting of the Montenegro skin test, serology, histopathology, smears, culture, and conventional PCR. In total, 55 patients with ATL (ML, 18 patients; cutaneous leishmaniasis [CL], 37 patients) and 36 patients without ATL were studied. qPCR analysis of swabs was more accurate when using SYBR Green (87.88%; 95% confidence interval [CI], 77.86 to 93.73 patients) than when using TaqMan (78.79%; 95% CI, 67.49 to 86.92%) (P ϭ 0.031). SYBR Green (84.72%; 95% CI, 74.68 to 91.25%) was also more accurate than TaqMan (73.61%; 95% CI, 62.42 to 82.41%) for biopsy samples (P ϭ 0.008). All qPCR methods were 100% specific. Swabs and biopsy specimens had similar sensitivity when using the same chemistry (P ϭ 0.125 for SYBR Green and P ϭ 0.625 for TaqMan). Moreover, qPCR achieved better performance than most existing techniques used for the diagnosis of ATL and also detected the Leishmania parasite in a greater proportion of patients than the associated histopathology, smear, culture, and conventional PCR techniques did. Swabs therefore represent a useful diagnostic tool because they not only are noninvasive but also can achieve an accuracy similar to that of biopsy samples. The high accuracy of SYBR Green-based qPCR may also reduce the requirement for associated parasitological tests for ATL diagnosis.
Leishmania parasites utilize adaptive evasion mechanisms in infected macrophages to overcome host defenses and proliferate. We report here that the PERK/eIF2α/ATF4 signaling branch of the integrated endoplasmic reticulum stress response (IERSR) is activated by Leishmania and this pathway is important for Leishmania amazonensis infection. Knocking down PERK or ATF4 expression or inhibiting PERK kinase activity diminished L. amazonensis infection. Knocking down ATF4 decreased NRF2 expression and its nuclear translocation, reduced HO-1 expression and increased nitric oxide production. Meanwhile, the increased expression of ATF4 and HO-1 mRNAs were observed in lesions derived from patients infected with the prevalent related species L.(V.) braziliensis. Our data demonstrates that Leishmania parasites activate the PERK/eIF2α/ATF-4 pathway in cultured macrophages and infected human tissue and that this pathway is important for parasite survival and progression of the infection.
We conclude that superficial sampling can retrieve a greater quantity of parasites. Future studies of the role of transepidermal elimination as a mechanism of host defence in ATL must be performed as there is a considerable quantity of Leishmania kDNA in the epidermis.
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