RESUMO
Cystic echinococcosis (CE) is a major neglected tropical zoonotic disease caused by the tissue-dwelling larval stage of the cestode parasite Echinococcus granulosus. For individuals suspected of CE, the diagnostic standard is imaging using ultrasonography, X rays, or computed tomography. These resource-demanding and expensive procedures are rarely available in endemic rural areas where CE is most prevalent. There is a critical need for a new approach to identify CE patients so that they can be managed early in the course of their infection. This study reports on the results of a diagnostic approach that identifies E. granulosus-derived cell-free DNA (cfDNA) in the urine of CE patients. Utilizing PCR to amplify a fragment of a major tandem repeat element found in E. granulosus nuclear DNA, urine samples from all seven imaging-confirmed CE patients who harbored active liver cysts were positive. In addition, the urine samples from 2/4 patients who presented with non-viable/calcified liver cysts were also PCR positive for the repeat fragment. To our knowledge, this is the first report of using parasite cfDNA from urine to diagnose CE. This approach provides an easy to implement and cost-effective method to survey for the prevalence of E. granulosus in humans populations.
Assuntos
Ácidos Nucleicos Livres/urina , Equinococose/diagnóstico , Echinococcus granulosus/genética , Animais , DNA de Helmintos/urina , Equinococose/epidemiologia , Echinococcus granulosus/isolamento & purificação , Humanos , Doenças Negligenciadas/diagnóstico , Doenças Negligenciadas/epidemiologia , Peru/epidemiologia , Reação em Cadeia da Polimerase/métodos , Prevalência , Zoonoses/diagnóstico , Zoonoses/epidemiologiaRESUMO
Neurocysticercosis (NCC), caused by Taenia solium larvae that reside in the central nervous system, results in serious public health and medical issues in many regions of the world. Current diagnosis of NCC is complex requiring both serology and costly neuroimaging of parasitic cysts in the brain. This diagnostic pipeline can be problematic in resource-constrained settings. There is an unmet need for a highly sensitive and clinically informative diagnostic test to complement the present diagnostic approaches. Here, we report that T. solium-derived cell-free DNA is readily detectable in the urine of patients with the subarachnoid and parenchymal forms of NCC, and discuss the potential utility of this approach in enhancing and refining T. solium diagnostics.
Assuntos
Ácidos Nucleicos Livres/genética , Disfunção Cognitiva/parasitologia , DNA de Helmintos/genética , Neurocisticercose/parasitologia , Taenia solium/genética , Animais , Ácidos Nucleicos Livres/sangue , Ácidos Nucleicos Livres/urina , Sistema Nervoso Central/parasitologia , Sistema Nervoso Central/fisiopatologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/fisiopatologia , DNA de Helmintos/sangue , DNA de Helmintos/urina , Humanos , Larva/genética , Neurocisticercose/diagnóstico por imagem , Neurocisticercose/fisiopatologia , Neuroimagem/métodos , Peru , Reação em Cadeia da Polimerase/métodos , Taenia solium/isolamento & purificaçãoRESUMO
BACKGROUND: KRAS mutations are prevalent in non-small cell lung cancer (NSCLC) but its clinical implications remain to be determined. Continual profiling of KRAS mutations in patients is challenging, and the study aims to determine the potential use of urinary DNA in disease predictions. METHODS: A total of 150 patients were recruited. To ascertain the clinical relevance of urinary DNA, matched tumor profiles were analyzed. Serial measurements were taken to gauge the reliability of the assay. These results were correlated to overall survival using the Kaplan-Meier estimate. RESULTS: A good overall concordance of 93% (consolidated results from serial measurements) was achieved between tumor tissue and urinary DNA profiling. Of the discordant KRAS cases, we observed subsequent positive detection during monitoring and very low concentrations of mutant DNA. In addition, we noted that KRAS-positive patients detected using urinary DNA have good prognostic utility. Interestingly, we also observed that the trend is highly correlative of the rate of change in KRAS mutant DNA concentrations and the period of monitoring. CONCLUSIONS: Urinary DNA offered a non-invasive approach to probe NSCLC dynamics, and in our study we showed that it had predictive capabilities for KRAS-positive patients. Serial monitoring of urinary samples showed that it had a predictive role in identifying patients with worse outcome.