Environmental exposure to arsenic and chromium in children is associated with kidney injury molecule-1.

Environmental hazards from natural or anthropological sources are widespread, especially in the north-central region of Mexico. Children represent a susceptible population due to their unique routes of exposure and special vulnerabilities. In this study we evaluated the association of exposure to environmental kidney toxicants with kidney injury biomarkers in children living in San Luis Potosi (SLP), Mexico. A cross-sectional study was conducted with 83 children (5-12 years of age) residents of Villa de Reyes, SLP. Exposure to arsenic, cadmium, chromium, fluoride and lead was assessed in urine, blood and drinking water samples. Almost all tap and well water samples had levels of arsenic (81.5%) and fluoride (100%) above the permissible levels recommended by the World Health Organization. Mean urine arsenic (45.6ppb) and chromium (61.7ppb) were higher than the biological exposure index, a reference value in occupational settings. Using multivariate adjusted models, we found a dose-dependent association between kidney injury molecule-1 (KIM-1) across chromium exposure tertiles [(T1: reference, T2: 467pg/mL; T3: 615pg/mL) (p-trend=0.001)]. Chromium upper tertile was also associated with higher urinary miR-200c (500 copies/µl) and miR-423 (189 copies/µL). Arsenic upper tertile was also associated with higher urinary KIM-1 (372pg/mL). Other kidney injury/functional biomarkers such as serum creatinine, glomerular filtration rate, albuminuria, neutrophil gelatinase-associated lipocalin and miR-21 did not show any association with arsenic, chromium or any of the other toxicants evaluated. We conclude that KIM-1 might serve as a sensitive biomarker to screen children for kidney damage induced by environmental toxic agents.

Analysis of Th1, Th17 and regulatory T cells in tuberculosis case contacts.

We have hypothesized that individuals infected with Mycobacteriumtuberculosis that exhibit different patterns of immune reactivity in serial interferon (IFN)-γ release assays (IGRA's) correspond to different status within the immune spectrum of latent tuberculosis (TB). Accordingly, we analyzed the possible association between the consistent results (negative or positive) in an IGRA test and relevant immune parameters, mainly the levels of Th1 and Th17 lymphocytes and T regulatory (Treg) cells in the peripheral blood of TB case contacts. We found that individuals with a persistently positive IGRA showed increased levels of Th1 and Th17 lymphocytes upon in vitro stimulation with MTB antigens. In addition, a significant increase in the proportion of CD4+CTLA-4+ and CD4+Foxp3+ cells was detected in assays with blood samples from these individuals. Our data support that different immune phenotypes can be identified into the spectrum of latent TB, by combining different parameters of immune reactivity against MTB.