Occupational exposure to crystalline silica and peripheral biomarkers: An update.

Peripheral biomarkers are important tools for detecting occupational exposures to prevent the onset and/or progression of diseases. Studies that reveal early peripheral biomarkers are highly important to preserve the health of workers and can potentially contribute to diagnosing and/or prognosing occupational pathologies. Exposure to crystalline silica is a problem in several workplaces because it increases the risk of chronic obstructive pulmonary disease (COPD), tuberculosis, cancer, and pulmonary fibrosis, clinically defined as silicosis. Silicosis is diagnosed by chest radiography and/or lung tomography in advanced stages when there is a severe loss of lung function. Peripheral biomarkers can help in diagnosing early changes prior to silicosis and represent a highly important technical-scientific advance that is minimally invasive. This review aimed to investigate the biomarkers studied for evaluating occupational exposure to crystalline silica and to understand the recent advances in this area. Potential oxidative, inflammatory, and immunological biomarkers were reviewed, as well as routine biomarkers such as biochemical parameters. It was found that biomarkers of effect such as serum CC16 and l-selectin levels could represent promising alternatives. Additionally, studies have shown that neopterin levels in urine and serum can be used to monitor worker exposure. However, further studies are needed that include a greater number of participants, different times of exposure to crystalline silica, and a combination of silicosis patients and healthy volunteers. Evaluating the concentration of crystalline silica in occupational environments, its impact on biomarkers of effect, and alterations in lung function could contribute to revealing early health alterations in workers in a more robust manner.

Alzheimer's disease and type 2 diabetes mellitus: A systematic review of proteomic studies.

Similar to dementia, the risk for developing type 2 diabetes mellitus (T2DM) increases with age, and T2DM also increases the risk for dementia, particularly Alzheimer's disease (AD). Although T2DM is primarily a peripheral disorder and AD is a central nervous system disease, both share some common features as they are chronic and complex diseases, and both show involvement of oxidative stress and inflammation in their progression. These characteristics suggest that T2DM may be associated with AD, which gave rise to a new term, type 3 diabetes (T3DM). In this study, we searched for matching peripheral proteomic biomarkers of AD and T2DM based in a systematic review of the available literature. We identified 17 common biomarkers that were differentially expressed in both patients with AD or T2DM when compared with healthy controls. These biomarkers could provide a useful workflow for screening T2DM patients at risk to develop AD.

Plasma Tau Variants Detected by a Novel Anti-Tau Monoclonal Antibody: A Potential Biomarker for Alzheimer's Disease.

BACKGROUND: A major drawback in Alzheimer's disease (AD) is the lack of validated biomarkers for routine clinical diagnostic. We have reported earlier a novel blood biomarker, named Alz-tau®, based on variants of platelet tau. This marker evaluates the ratio of high molecular weight tau (HMWtau) and the low molecular weight (LMWtau) tau. OBJECTIVE: To analyze a potential novel source of antigen for Alz-tau®, plasma tau, detected by immunoreactivity with the novel monoclonal antibody, tau51. METHODS: We evaluated tau variants in plasma precipitated with ammonium sulfate from 36 AD patients and 15 control subjects by western blot with this novel monoclonal antibody. RESULTS: The HMW/LMWtau ratio was statistically different between AD patients and controls. CONCLUSIONS: Plasma tau variants are suitable to be considered as a novel antigen source for the Alz-tau® biomarker for AD.

Parkinson's Disease is Accompanied by Intertwined Alterations in Iron Metabolism and Activated Immune-inflammatory and Oxidative Stress Pathways.

BACKGROUND: Parkinson's disease (PD) is a neurodegenerative disorder characterized by a complex interplay between peripheral and central inflammatory and oxidative stress pathways. OBJECTIVE: To investigate immune-inflammatory and oxidative stress pathways in relation to iron metabolism in peripheral blood of PD patients and healthy controls. METHOD: We recruited 56 healthy individuals and 56 PD patients in stages 1-3 of Hoehn and Yahr Scale. Plasma haptoglobin (Hp), homocysteine, interleukin 6, soluble interleukin 6 receptor, iron (Fe), ferritin, total iron binding capacity, transferrin (Tf), soluble transferrin receptor (sTfR), malondialdehyde (MDA) and paraoxonase 1 (PON1) were measured. RESULTS: PD was associated with significant changes in Tf (lowered), sTfR, ferritin, Hp, interleukin 6 and MDA (all increased) levels, while there was a trend towards a negative association with PON1. Logistic regression showed that the most significant biomarkers of PD were MDA, sTfR, Hp and ferritin. Moreover, Fe levels were negatively associated with Hp and positively with PON1, total iron binding capacity and Tf, while ferritin and sTfR were positively associated with MDA levels. CONCLUSION: Our study indicates a state of systemic inflammation and oxidative stress in PD patients coupled with alterations in Fe metabolism. Chronic inflammation and oxidative pathways in PD may in part determine changes in iron metabolism. New drug treatments for PD should target inflammatory and oxidative stress pathways and iron metabolism as well.