Riveting research in the world of biomarkers suggests great potential for biomarkers both in clinical and laboratory settings. Below are recent studies and articles concerning biomarkers and their emerging relevance in science.
Clara cell protein as a biomarker for ozone-induced lung injury in humans
Ozone, a component of photochemical air pollution, has been shown to induce lung-related detrimental conditions, such as increased airway resistance, altered airway permeability, perturbation of antioxidant defenses, and airway neutrophilia. Airway inflammation and epithelial lung injury assessment are both time and resource demanding, especially in cases where bronchoscopy-based lavage has been performed on the patient. Induced sputum, nasal lavage, and measurements of exhaled gases and breath condensation are current assessments of pulmonary responses to acute air pollution that are the least invasive. Although successful in demonstrating increased markers of inflammation induced by air pollutants, these methods fail to demonstrate increased permeability in studies using traditional markers of lung injury (i.e. albumin, total protein, etc. As an alternative, Clara cell protein was suggested as a biomarker for epithelial lung damage, including O3-induced damage. Clara cell protein is an anti-inflammatory protein that would be present in response to injury, able to be utilized in detecting increased epithelial permeability in a variety of clinical and experimental situations. In an experiment where cyclists were exposed to ambient air for 2 hours demonstrated increased Clara cell proteins concentrations with increased O3 concentration, suggesting a correlation.
Absorptive clearance of DTPA as an aerosol-based biomarker in the cystic fibrosis airway
Indium-111 (In-DTPA) is small, radio-labelled hydrophilic molecule. In the necessity for a viable biomarker to quantify basic elements of cystic fibrosis, a study determined whether the absorption of DTPA would be increased in CF airways. Previously, DTPA clearance had been used to assess epithelial permeability, with a possibility that it may also be useful for quantifying liquid absorption. DTPA absorptive clearance rate was quantified in 10 cystic fibrosis patient and 11 control subjects utilizing an aerosol technique containing non-absorbable technetium-99m sulfur colloid particles and In-DTPA. Differences in absorption between these two materials estimated the In-DTPA absorption. In-DTPA total absorption increased in central and peripheral zones of cystic fibrosis lungs, and the absorptive component of In-DTPA clearance increased in the airway-dominated central lung zone in cystic fibrosis. Although this study confirms the viability of In-DTPA as a potential biomarker in cystic fibrosis, further study is needed.
A urine biomarker for severe obstructive sleep apnoea patients: lipocalin-type prostaglandin D synthase
Lipocalin-type prostaglandin D synthase (L-PGDS) has been reported to have a connection with cardiovascular disease as well as sleep regulation. Because of these connections, L-PGDS was tested as a potential biomarker in identifying patients with obstructive sleep apnoea. The urinary concentration of L-PGDS was measured after slumber in 64 subjects, with 25 subjects having their urine measured every 4 hours. Hyperaemia peripheral arterial tone index was used as an assessment of endothelial function. After their measurements, it was revealed that L-PGDS concentration is highly dependent on time and circadian rhythm in its fluctuation and was displayed to be higher in subjects with severe obstructive sleep apnoea than in the control subjects and subjects of which possessed moderate obstructive sleep apnoea. L-PDS concentrations decreased significantly after a 2-day positive airway pressure treatment to the levels displayed by the control subjects. The endothelial function, however did not change significantly. As a result, urinary L-PGDS may be a moderately useful biomarker in identifying patients with severe obstructive sleep apnoea; however, L-PGDS concentrations have no indicator with sleepiness itself.
Cardiovascular biomarkers predict susceptibility to lung injury in World Trade Center dust-exposed firefighters
In an attempt to determine if other cardiovascular disease biomarkers predicted World Trade Center-related lung injuries, a case-cohort study utilized 801 firefighters of whom were present at the World Trade Center attack with normal lung functions prior to the tragedy and possessed no prior history of smoking. These subjects presented for subspecialty pulmonary evauation prior to March 2008. A subcohort of 124 out of the 801 firefighter subjects of which had their serum drawn within 6 months of 9/11 defined the cardiovascular disease biomarker distribution. Post-9/11 performed a forced expiratory volume test (FEV1) adjusted for World Trade Center exposure intensity, body mass index during subspecialty pulmonary evaluation, age during 9/11, and prior 9/11 FEV1. The susceptible World Trade Center lung injury cases displayed higher levels of apolipoprotein-All, C-reactive protein, and macrophage inflammatory protein-4. The resistant cases had significantly higher soluble vascular cell adhesion molecule and lower myeloperoxidase. In serum cardiovascular disease biomarkers post-9/11 may define pathways related to pulmonary vascular disease and associated lung function loss after irritant exposure, as they predicted either susceptibility or resistance to World Trade Center lung injury related cases.
Microalbuminuria as a potential novel cardiovascular biomarker in patients with COPD
Chronic obstructive pulmonary disease patents are more likely to have pre-existing cardiovascular disease and are at a high risk of acute events, hospitalizations from the conditions, and death, with the association independent of the degree of airflow limitation. The Global Initiative for Chronic Obstructive Lung Disease recognizes this relationship but makes no recommendation as to how to routinely look for the chronic obstructive pulmonary disease-cardiovascular disease relationship. The American College of cardiology/American Heart Association categorizes microalbuminuria assessment as a reasonable biomarker in adults with hypertension or diabetes, and may be a promising biomarker in chronic obstructive pulmonary disease-related cardiovascular risk assessment. Microabluminuria presence is associated with arterial stiffness assessed by pulse wave velocity and worse cardiovascular outcomes, especially in diabetic or hypertensive patients. Along with having this association microalbuminuria has a stronger association with cardiovascular events and death than C-reactive protein, reflecting a general state of endothelial dysfunction. The presence of microalbuminuria increases in patients with chronic obstructive lung disease and, in theory, is a viable option as a biomarker.