RESUMO
Diphtheria is a vaccine-preventable disease, yet immunization can wane over time to non-protective levels. We have developed a low-cost, miniaturized electroanalytical biosensor to quantify anti-diphtheria toxin (DTx) immunoglobulin G (anti-DTx IgG) antibody to minimize the risk for localized outbreaks. Two epitopes specific to DTx and recognized by antibodies generated post-vaccination were selected to create a bi-epitope peptide, biEP, by synthesizing the epitopes in tandem. The biEP peptide was conjugated to the surface of a pencil-lead electrode (PLE) integrated into a portable electrode holder. Captured anti-DTx IgG was measured by square wave voltammetry from the generation of hydroquinone (HQ) from the resulting immunocomplex. The performance of the biEP reagent presented high selectivity and specificity for DTx. Under the optimized working conditions, a logarithmic calibration curve showed good linearity over the concentration range of 10-5-10-1 IU mL-1 and achieved a limit of detection of 5 × 10-6 IU mL-1. The final device proved suitable for interrogating the immunity level against DTx in actual serum samples. Results showed good agreement with those obtained from a commercial enzyme-linked immunosorbent assay. In addition, the flexibility for conjugating other capture molecules to PLEs suggests that this technology could be easily adapted to the diagnoses of other pathogens.
Assuntos
Técnicas Biossensoriais , Toxina Diftérica , Ensaio de Imunoadsorção Enzimática , Epitopos/imunologia , Imunoensaio , Imunoglobulina G/química , Imunoglobulina G/imunologiaRESUMO
O papilomavírus humano (HPV) é o principal agente etiológico do câncer do trato anogenital. A maior prevalência e incidência de desenvolvimento de câncer e doenças associadas ao HPV têm sido observadas em indivíduos infectados pelo vírus da imunodeficiência humana tipo 1 (HIV-1). A história natural da infecção pelo HPV não foi completamente elucidada, assim como a resposta imune que ocorre na coinfecção pelo HIV/ HPV, particularmente na mucosa anal. Objetivo: Analisar a prevalência de HPV, dados clínicos, epidemiológicos e comportamentais em uma coorte de indivíduos infectados pelo HIV do Instituto Nacional de Infectologia (INI), FIOCRUZ, RJ. Métodos: Foi incluído um total de 114 indivíduos com diagnóstico histopatológico de biópsia anal. A tipagem do DNA de HPV foi realizada através da secreção anal. A análise estatística foi realizada utilizando o software SPSS 15.0. Resultados: Pacientes HIV positivos com Neoplasia intraepitelial anal de alto grau (NIA II/III) apresentaram CD4+ nadir <50 células/mm³ , comparados a pacientes sem displasia anal (p=0,01). Os tipos de HPV mais prevalentes na secreção anal (pelo Papillocheck) foram HPV 16 (29,2%), seguido do HPV 52 (23,1%), ambos de alto risco oncogênico, seguido de HPV 44 e 55 (21,5%), que são baixo risco oncogênico. Um total de 53,3% dos indivíduos infectados pelo HIV já analisados foi exposto aos 4 tipos de HPV, que são alvos da vacina quadrivalente corrente (MSD HPV 6, 11, 16 e 18). Conclusão: Os dados sugerem que a vacinação contra o HPV pode ser considerada como uma medida profilática para reduzir o risco de lesões intraepiteliais anais em indivíduos infectados pelo HIV
Human Papillomavirus (HPV) is the primary etiologic agent of anogenital tract cancer. A higher prevalence and incidence of developing cancer and diseases associated with HPV have been observed in individuals infected with the human immunodeficiency virus (HIV). The natural history of HPV infection has not been completely elucidated, as well as the immune response that occurs as coinfection with HIV/HPV, particularly in the anal mucosa. Objective: To analyze the HPV prevalence and clinical, epidemiological, and behavioral data in a cohort of HIV-seropositive individuals from the National Institute of Infectious Diseases, FIOCRUZ, RJ. Methods: The study included a total of 114 individuals from the histopathological diagnosis of anal biopsy. PCR and sequencing was performed for HPV DNA identification in anal discharge. Statistical analysis was performed using SPSS 15.0 software. Results: Patients Infected with HIV with anal intraepithelial neoplasia (AIN) II/III had nadir CD4 + <50 cells/mm³ compared to normal patients (p=0.01). The most prevalent HPV types in the anal secretion (by Papillocheck) were HPV 16 (29.2%), followed by HPV 52 (23.1%), both high-risk oncogenic, followed by HPV 44 and 55 (21.5%) that are low-risk type. A total of 53.3% HIV-infected individuals analyzed have already been exposed to the four HPV types targeted by the current quadrivalent vaccine (MSDm HPV types 6, 11, 16, and 18). Conclusion: The data suggest that vaccination against HPV could be regarded as a prophylactic measure to reduce the risk of anal intraepithelial lesions in HIV-infected individuals