Single-Nucleotide Polymorphisms in NOD1, RIPK2, MICB, PLCE1, TNF, and IKBKE Genes Associated with Symptomatic Dengue in Children from Colombia.

Functional immunological evidence supports the impact that the host genetic variability has on the susceptibility to develop asymptomatic or symptomatic dengue infection. Children are more prone to develop severe dengue. Thus, we have evaluated possible associations between single-nucleotide polymorphisms (SNPs) located in immune genes and the development of symptomatic dengue in children from two Colombian populations with differences in genetic backgrounds and geographical features. We genotyped 15 SNPs (in 12 genes) in 298 symptomatic children and 648 healthy controls. Ancestry proportions (APs) were inferred by genotyping 29 ancestry informative markers. We observed four SNPs associated with susceptibility to develop dengue in NOD1, RIPK2, MICB, or PLCE1 genes. Conversely, we found one SNP in TNF gene and two haplotypes in the IKBKE gene associated with resistance to develop dengue. These associations were adjusted by gender, APs, and the population of origin because the association of polymorphisms may be different in admixed populations like Colombian. To our knowledge, this is the first reported association study with dengue in IKBKE, RIPK2, and NOD1 genes. We have also confirmed previously reported associations in MICB and PLCE1 genes with dengue. Overall, our results contribute to the understanding of the genetic susceptibility/resistance to develop symptomatic dengue. Nevertheless, these associations must be validated through functional analysis.

Factores asociados a extravasación plasmática en pacientes con dengue de Antioquia y Chocó entre el 2000 y 2013. Colombia / Associated factors to plasma leakage in dengue patients from Antioquia and Chocó between 2000 and 2013. Colombia

Introducción: la extravasación del plasma es la manifestación más severa de la enfermedad producida por los virus del dengue y que con mayor frecuencia conduce al estado de choque. Se caracteriza por derrames serosos a nivel de diversas cavidades y aumento del hematocrito. Se realizó el presente estudio con el objetivo de determinar los factores sociodemográficos, clínicos y de laboratorio que más se asocian a la presencia de extravasación plasmática en los pacientes con dengue. Materiales y métodos: estudio observacional analítico transversal, analizado bajo la metodología de casos y controles, a partir de registros clínicos de pacientes con dengue. Se utilizaron prueba Chi cuadrado de Pearson, prueba exacta de Fisher, prueba no paramétrica U de Mann-Whitney y un modelo de regresión logística multivariado de factores asociados. Fueron calculados los Odds Ratio con su intervalo de confianza al 95 %. Se consideró un nivel de significancia de 5 %. Resultados: fueron analizados un total de 350 registros, de los cuales 128 presentaron signos de extravasación plasmática (36,6 %). Después de ajustar por factores de confusión se observó que las variables que más se asocian a presencia de extravasación plasmática en los pacientes con dengue fueron el dolor abdominal, la leucopenia y las melenas. Conclusión: estos hallazgos clínicos y de laboratorio deben ser priorizados en su vigilancia en la atención al paciente con dengue, para identificar los casos con mayor probabilidad de extravasación plasmática para su manejo oportuno y adecuado.

Introduction: Plasma leakage is the most severe complication caused by dengue virus infection and is also the mechanism that frequently leads to dengue shock syndrome. Plasma leakage is characterized by ascites, pleural and pericardial effusion and increased hematocrit level. The present study was conducted to identify socio-demographic, clinical and laboratory factors that more are associated to the presence of plasma leakage in dengue infected patients. Materials and methods: A cross sectional analytic study was performed on clinical records from dengue infected patients using the casecontrol methodology. Pearson's chi-square test or Fisher's exact test, Mann-Whitney's non-parametric U test and a multivariate logistic regression model of associated factors were used to evaluate the data. Odd Ratios with 95 % confidence intervals were calculated and significance level of 5 % was considered. Results: A total of 350 clinical records were analyzed, 128 cases (36.6 %) presented signs of plasma leakage. After adjustments by confounding factors, we observed that abdominal pain, leukopenia and melena were the variables that explain the presence of plasma leakage in dengue infected patients. Conclusion: During the follow-up of dengue infected patients priority should be given to the survey of these clinical and laboratory findings in order to identify the cases with higher probabilities of developing plasma leakage, allowing achieving more timely and appropriate management.

African genetic ancestry is associated with a protective effect on Dengue severity in colombian populations.

The wide variation in severity displayed during Dengue Virus (DENV) infection may be influenced by host susceptibility. In several epidemiological approaches, differences in disease outcomes have been found between some ethnic groups, suggesting that human genetic background has an important role in disease severity. In the Caribbean, It has been reported that populations of African descent present considerable less frequency of severe forms compared with Mestizo and White self-reported groups. Admixed populations offer advantages for genetic epidemiology studies due to variation and distribution of alleles, such as those involved in disease susceptibility, as well to provide explanations of individual variability in clinical outcomes. The current study analysed three Colombian populations, which like most of Latin American populations, are made up of the product of complex admixture processes between European, Native American and African ancestors; having as a main goal to assess the effect of genetic ancestry, estimated with 30 Ancestry Informative Markers (AIMs), on DENV infection severity. We found that African ancestry has a protective effect against severe outcomes under several systems of clinical classification: Severe Dengue (OR: 0.963 for every 1% increase in African ancestry, 95% confidence interval (0.934-0.993), p-value: 0.016), Dengue Haemorrhagic Fever (OR: 0.969, 95% CI (0.947-0.991), p-value: 0.006), and occurrence of haemorrhages (OR: 0.971, 95% CI (0.952-0.989), p-value: 0.002). Conversely, decrease from 100% to 0% African ancestry significantly increases the chance of severe outcomes: OR is 44-fold for Severe Dengue, 24-fold for Dengue Haemorrhagic Fever, and 20-fold for occurrence of haemorrhages. Furthermore, several warning signs also showed statistically significant association given more evidences in specific stages of DENV infection. These results provide consistent evidence in order to infer statistical models providing a framework for future genetic epidemiology and clinical studies.