Increased frequency of delayed type hypersensitivity to metals in patients with connective tissue disease

• Published in: Journal of trace elements in medicine and biology Vol. 31; pp. 230 - 236
• Main Authors: Stejskal, Vera, Reynolds, Tim, Bjørklund, Geir
• Format: Journal Article
• Language: English
• Published: Germany Elsevier GmbH 01.01.2015
• Subjects: Adult; Aged; Arthritis, Rheumatoid - immunology; Case-Control Studies; Delayed type hypersensitivity; Dental Restoration, Permanent - adverse effects; Dental Restoration, Permanent - instrumentation; Female; Gold - immunology; Gold - toxicity; Humans; Hypersensitivity, Delayed - chemically induced; Hypersensitivity, Delayed - epidemiology; Lupus Erythematosus, Systemic - immunology; Male; Mercury - immunology; Mercury - toxicity; Metal allergy; Metals - immunology; Metals - toxicity; Middle Aged; Nickel - immunology; Nickel - toxicity; Palladium - immunology; Palladium - toxicity; Rheumatoid arthritis; Sjogren's syndrome; Sjogren's Syndrome - immunology; Sjögren's syndrome; Systemic lupus erythematosus; Titanium - immunology; Titanium - toxicity; Young Adult; Systemic lupus erythematosus; Delayed type hypersensitivity; Sjögren's syndrome; Rheumatoid arthritis; Metal allergy
• ISSN: 0946-672X; 1878-3252; 1878-3252
• DOI: 10.1016/j.jtemb.2015.01.001

Connective tissue disease (CTD) is a group of inflammatory disorders of unknown aetiology. Patients with CTD often report hypersensitivity to nickel. We examined the frequency of delayed type hypersensitivity (DTH) (Type IV allergy) to metals in patients with CTD. Thirty-eight patients; 9 with systemic lupus erythematosus (SLE), 16 with rheumatoid arthritis (RA), and 13 with Sjögren's syndrome (SS) and a control group of 43 healthy age- and sex-matched subjects were included in the study. A detailed metal exposure history was collected by questionnaire. Metal hypersensitivity was evaluated using the optimised lymphocyte transformation test LTT-MELISA® (Memory Lymphocyte Immuno Stimulation Assay). In all subjects, the main source of metal exposure was dental metal restorations. The majority of patients (87%) had a positive lymphocyte reaction to at least one metal and 63% reacted to two or more metals tested. Within the control group, 43% of healthy subjects reacted to one metal and only 18% reacted to two or more metals. The increased metal reactivity in the patient group compared with the control group was statistically significant (P<0.0001). The most frequent allergens were nickel, mercury, gold and palladium. Patients with SLE, RA and SS have an increased frequency of metal DTH. Metals such as nickel, mercury and gold are present in dental restorative materials, and many adults are therefore continually exposed to metal ions through corrosion of dental alloys. Metal-related DTH will cause inflammation. Since inflammation is a key process in CTDs, it is possible that metal-specific T cell reactivity is an etiological factor in their development. The role of metal-specific lymphocytes in autoimmunity remains an exciting challenge for future studies.