The Search for Reliable Biomarkers of Disease in Multiple Chemical Sensitivity and Other Environmental Intolerances

Abstract

Whilst facing a worldwide fast increase of food and environmental allergies, the medical community is also confronted with another inhomogeneous group of environment-associated disabling conditions, including multiple chemical sensitivity (MCS), fibromyalgia, chronic fatigue syndrome, electric hypersensitivity, amalgam disease and others. These share the features of poly-symptomatic multi-organ cutaneous and systemic manifestations, with postulated inherited/acquired impaired metabolism of chemical/physical/nutritional xenobiotics, triggering adverse reactions at exposure levels far below toxicologically-relevant values, often in the absence of clear-cut allergologic and/or immunologic involvement. Due to the lack of proven pathogenic mechanisms generating measurable disease biomarkers, these environmental hypersensitivities are generally ignored by sanitary and social systems, as psychogenic or “medically unexplained symptoms”. The uncontrolled application of diagnostic and treatment protocols not corresponding to acceptable levels of validation, safety, and clinical efficacy, to a steadily increasing number of patients demanding assistance, occurs in many countries in the absence of evidence-based guidelines. Here we revise available information supporting the organic nature of these clinical conditions. Following intense research on gene polymorphisms of phase I/II detoxification enzyme genes, so far statistically inconclusive, epigenetic and metabolic factors are under investigation, in particular free radical/antioxidant homeostasis disturbances. The finding of relevant alterations of catalase, glutathione-transferase and peroxidase detoxifying activities significantly correlating with clinical manifestations of MCS, has recently registered some progress towards the identification of reliable biomarkers of disease onset, progression, and treatment outcomes.

Xenobiotic Sensor- and Metabolism-Related Gene Variants in Environmental Sensitivity-Related Illnesses: A Survey on the Italian Population

“…Indeed, the World Health Organization has collectively defined these conditions as “idiopathic environmental intolerances”(IEIs), namely multiple chemical sensitivity (MCS), fibromyalgia (FM), chronic fatigue syndrome (CFS), dental amalgam disease, and others, among which the intolerances to microbial and environmental allergens or toxins, drugs, vaccines, specific foods, synthetic implants, and possibly new biomaterials are also included [5–7]. In view of the progressively increasing knowledge and awareness regarding these diseases, they are presently better described collectively as “sensitivity-related illnesses” (SRIs) [7, 8]. …”

Multiple Chemical Sensitivity and the Workplace: Current Position and Need for an Occupational Health Surveillance Protocol

“…Depending on its characteristics (i.e., the prevalence of somatic or psychological disorders) it can be confused with allergic reactions or psychiatric illness [27, 28]. …”

Multiple Chemical Sensitivity in Pregnancy: An Unclassified Rare Syndrome

“…She received an intravenous 1,200 mg/day glutathione replacement therapy in combination with fetal lung maturity induction [4]. None of the illness crises were detected during hospitalization.…”