MELISA ®(Memory Lymphocyte Immuno Stimulation Assay)

MELISA® (Memory Lymphocyte Immuno Stimulation Assay)

Provet bygger på en etablerad immunologisk kunskap. I blodet hos människor som har förvärvat allergi mot metaller eller andra kemikalier, finns en viss typ av blodkroppar, s k minnesceller. Odling av minnesceller tillsammans med allergenet medför att cellerna ökar i storlek och antal (genom celldelning). Med MELISA-testet är det möjligt att mäta denna tillväxt.

Authors
  Stejskal VD.  Forsbeck M.  Cederbrant KE.  Asteman O.
Title
  Mercury-specific lymphocytes: an indication of mercury allergy in man.
Source
  Journal of Clinical Immunology.  16(1):31-40, 1996 Jan.

In this study, 18 patients with oral lichen planus (OLP), adjacent to amalgam fillings, were tested in vitro with an optimized lymphocyte proliferation test, MELISA (memory lymphocyte immunostimulation assay) and with a patch test. Twenty subjects with amalgam fillings but without oral discomfort and 12 amalgam-free subjects served as controls. The results show that patients with OLP have significantly higher lymphocyte reactivity to inorganic mercury, a corrosion product of amalgam, compared to control groups. Removal of amalgam fillings resulted in the disappearance of oral mucosal changes, thus indicating a causal relationship. Positive responses to phenylmercury (phenyl-Hg), a bactericidal agent in root fillings and in pharmaceutical preparations, were also noted in the oral lichen group but not in the control groups. Thus, low-grade chronic exposure to mercury may induce a state of systemic sensitization as verified by Hg-specific lymphocyte reactivity in vitro.

Title
  MELISA - an *in vitro* tool for the study of metal allergy
Authors
  V.D.M Stejskal, K. Cederbrant, A. Lindvall and M. Forsbeck
Source
  Toxicology in Vitro. 8(5):991-1000, 1994

The sensitizing properties of metals widely used in medical and dental care have been studied with the help of an optimized lymphocyte proliferative assay, MELISA. MELISA (memory lymphocyte immuno-stimulation assay) was originally developed for the screening of allergenic epitopes of drugs and other chemicals of low molecular weight, but has recently been adapted for the study of metal-induced sensitization. The patients studied suffered from various oral mucosal problems which were suspected to be caused by the release of metal ions from dental restorations. They were also troubled by chronic fatigue persisting over many years. One patient was also occupationally exposed to metals while working in a dental practice. Healthy subjects without any discomfort due to metal devices served as controls. In addition to metals used in dentistry, lymphocyte responses to organic mercurials used widely as preservatives in vaccines, eye/nose drops and contact lense fluids were studied. The results indicated that mercurials, as well as other metals such as gold or palladium, induce strong lymphocyte proliferative responses in patients with oral or systemic symptoms, but not in similarly exposed unaffected subjects. The results of MELISA performed with a pair of identical twins with chronic fatigue syndrome (CFS) indicated that metal-specific responses may be dependent on the genetics of the patient. Thus, many metals that are today accepted for use in medicine and dentistry carry a definite sensitizing risk for certain genetically predisposed individuals. Therefore, the use of these metals should be limited in the future.

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