Accuracy of mucocutaneous leishmaniasis diagnosis using polymerase chain reaction: systematic literature review and meta-analysis

The diagnosis of mucocutaneous leishmaniasis (MCL) is hampered by the absence of a gold standard. An accurate diagnosis is essential because of the high toxicity of the medications for the disease. This study aimed to assess the ability of polymerase chain reaction (PCR) to identify MCL and to compare these results with clinical research recently published by the authors. A systematic literature review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses: the PRISMA Statement was performed using comprehensive search criteria and communication with the authors. A meta-analysis considering the estimates of the univariate and bivariate models was performed. Specificity near 100% was common among the papers. The primary reason for accuracy differences was sensitivity. The meta-analysis, which was only possible for PCR samples of lesion fragments, revealed a sensitivity of 71% [95% confidence interval (CI) = 0.59; 0.81] and a specificity of 93% (95% CI = 0.83; 0.98) in the bivariate model. The search for measures that could increase the sensitivity of PCR should be encouraged. The quality of the collected material and the optimisation of the amplification of genetic material should be prioritised.

Active search for leprosy cases in Midwestern Brazil: a serological evaluation of asymptomatic household contacts before and after prophylaxis with bacillus Calmette-Guérin / Busca ativa por casos de hanseníase no Centro-Oeste do Brasil: avaliação sorológica dos contatos domiciliares assintomáticos antes e após a profilaxia com Bacillus Calmette-Guérin

Leprosy is a disease caused by Mycobacterium leprae that carries a high risk of disability, making early diagnosis mandatory. This study aimed to determine the applicability of anti-PGL-1 IgM antibody detection, using the ML FLOW technique, as an assistant tool for the detection of leprosy infection in asymptomatic household contacts (AHHC) of multibacillary leprosy index cases from Midwest Brazil. Serological changes induced by the prophylaxis of these household contacts with Bacillus Calmette-Guérin (BCG) were also verified. A total of 91 AHHC were assessed, among which, 18.68% (n = 17) presented both positive bacilloscopy and positive anti-PGL-1 IgM serology. Positivity concordance between these two laboratorial exams (Kappa Index = 1; p < 0.001) was indicated, however, one case did not demonstrate concordance between the semiquantitative assessment of anti-PGL-1 IgM and the bacilloscopy index (Kappa Index = 0.96; p < 0.001). Among the 17 AHHC with positive bacilloscopy, eight were reassessed after prophylaxis with BCG and two of them presented negative anti-PGL-1 IgM serology, being these patients who had presented a bacilloscopy index of < 2[+] in the initial assessment. This study shows that anti-PGL-1 IgM detection may be used as a tool to determine the bacillary load in AHHC and to detect immune changes related to prophylaxis by nonspecific vaccination.

A hanseníase é doença causada pelo Mycobacterium leprae, apresentando elevado potencial incapacitante, o que torna indispensável seu diagnóstico precoce. O estudo visa determinar a aplicabilidade da detecção de anticorpos anti-PGL1-IgM por meio da técnica do ML FLOW como ferramenta adjuvante ao diagnóstico de hanseníase em contatos domiciliares assintomáticos (AHHC) de pacientes multibacilares procedentes da região Centro-Oeste do Brasil, bem como, documentar o comportamento sorológico após a profilaxia com a vacina Bacillus Calmette-Guérin (BCG). Foram avaliados 91 AHHC atendidos no Hospital Universitário de Brasília - Brasil, dos quais 18,68% (n = 17) apresentaram positividade para baciloscopia e anti-PGL1-IgM, totalizando uma concordância completa entre os dois grupos (Índice Kappa = 1; p < 0,001). Em apenas um dos casos não observou-se concordância entre a avaliação semi-quantitativa do anti-PGL1-IgM e índice baciloscópico (Índice Kappa = 0,96; p < 0,001). Oito dos 17 AHHC com baciloscopia positiva foram reavaliados após profilaxia com BCG e apenas dois apresentaram negativação dos títulos anti-PGL1-IgM, sendo tais casos correspondentes aos que haviam apresentado índice baciloscópico menor do que 2[+] na avaliação inicial. O estudo corrobora o potencial do anti-PGL1-IgM como ferramenta de predição da carga bacilar em AHHC da região Centro-Oeste do Brasil, e surpreende alterações imunes relacionadas à profilaxia obtida pela vacinação não específica com BCG.