Complement activation in tear fluid during occupational mold challenge

Tear Fluid as a Matrix for Biomonitoring Environmental and Chemical Exposures

PURPOSE

Exposures to hazardous chemicals have been linked to many detrimental health effects and it is therefore critical to have effective biomonitoring methods to better evaluate key environmental exposures that increase the risk of chronic disease and death. Traditional biomonitoring utilizing blood and urine is limited due to the specialized skills and invasiveness of collecting these fluid samples. This systematic review focuses on tear fluid, which is largely under-researched, as a promising complementary matrix to the traditional fluids used for biomonitoring. The objective is to evaluate the practicability of using human tear fluid for biomonitoring environmental exposures, highlighting potential pitfalls and opportunities.

RECENT FINDING

Tear fluid biomonitoring represents a promising method for assessing exposures because it can be collected with minimal invasiveness and tears contain exposure markers from both the external and internal environments. Tear fluid uniquely interfaces with the external environment at the air-tear interface, providing a surface for airborne chemicals to diffuse into the ocular environment and interact with biomolecules. Tear fluid also contains molecules from the internal environment that have travelled from the blood to tears by crossing the blood-tear barrier. This review demonstrates that tear fluid can be used to identify hazardous chemicals from the external environment and differentiate exposure groups.

Ocular Surface Fluid: More than a Matrix

Although the eye can be subjected to therapeutic manipulation, some of its structures are highly inaccessible. Thus, conventional therapeutic administration pathways, such as topical or systemic routes, usually show significant limitations in the form of low ocular penetration or the appearance of side effects linked to physiology, among others. The critical feature of many xenobiotics is the drug gradient from the concentrated tear reservoir to the relatively barren corneal and conjunctival epithelia, which forces a passive route of absorption. The same is true in the opposite direction, towards the ocular surface (OS). With the premise that tears can be regarded as equivalent to or a substitute for plasma, researchers may determine drug concentrations in the OS fluid. Within this framework, a survey of scholarly sources on the topic was conducted. It provided an overview of current knowledge, allowing the identification of relevant theories, methods, and gaps in the existing research that can be employed in subsequent research. OS fluid (tears particularly) has enormous potential as a source of biological material for external drug screening and as a biomarker of various systemic diseases. Given the numerous alternate matrices, knowledge of their properties is very important in selecting the most appropriate specimens in toxicological analyses.

Indoor microbial exposure increases complement component C3a and C-reactive protein concentrations in serum

Indoor exposure to microbial growth, caused by moisture damage, has been an established health risk for several decades. It is likely that a damp indoor environment contains biological pollutants that trigger both the innate and adaptive branches of the immune system. In this study, we investigated the association between moisture damage related microbial exposure and serum C3a, C5a and CRP concentrations in Finnish adults. Serum C3a and CRP concentrations were elevated in individuals exposed to moisture damage and microbial growth in an indoor air environment. The elevated concentrations may be due to environmental factors present in moisture-damaged buildings. Complement activation and the resulting proinflammatory cleavage products may be a driving factor in inflammatory responses following exposure to indoor moisture damage and related microbial growth.

Diagnostics and new developments in the treatment of ocular allergies

About 30% of people suffer from allergic symptoms, and 40% to 80% of them have eye symptoms. Atopic conjunctivitis is divided into seasonal allergic conjunctivitis and perennial allergic conjunctivitis. The treatment of seasonal allergic conjunctivitis is simple: antihistamines, anti-inflammatory agents, or cromoglycate. Perennial allergic conjunctivitis needs longer therapy with mast cell stabilizers and sometimes local steroids. Atopic keratoconjunctivitis requires long-term treatment of the lid eczema and keratoconjunctivitis. Vernal keratoconjunctivitis mainly affects children and young people. It commonly calms down after puberty. It demands intensive therapy, often for many years, to avoid serious complicating corneal ulcers. Giant papillary conjunctivitis is a foreign body reaction in contact lens users or patients with sutures following ocular surgery. Nonallergic eosinophilic conjunctivitis affects mostly middle-aged and older women with eosinophilic conjunctivitis and dry eye. Contact allergic blepharoconjunctivitis is often caused by cosmetics and eye medication. Work-related ocular allergies should be considered as a cause of resistant ocular symptoms in workplaces.