IgE-mediated allergic reactions after the first administration of glatiramer acetate in patients with multiple sclerosis.

Background: Immediate adverse reactions to glatiramer acetate (GA), a drug used in the treatment of patients with multiple sclerosis (MS), have been poorly investigated. We studied 3 MS patients who presented adverse reactions following GA administration. Two of them experienced severe anaphylactic reactions after the first administration and the other an eyelid edema upon reintroduction 6 months after GA withdrawal.

Methods: Skin prick tests (SPT) to GA and mannitol were performed on all 3 patients and in 10 atopic controls. Specific IgE (sIgE) levels to GA, myelin basic protein (MBP) and MBP fragments were assessed in all 3 patients, 6 MS patients treated with GA for more than 6 month and 10 healthy donors. Specific IgG (sIgG) to GA was also quantified in the three study groups. Both sIgE and sIgG were determined by means of the UniCAP 100 assay.

Results: SPT and sIgE to GA were positive only in the 3 patients with adverse reactions while sIgE to mannitol was negative in all. sIgE tests against MBP and its fragments were negative in all individuals. Similar levels of sIgG to GA were found in all studied subjects.

Conclusion: These results demonstrate the significance of sIgE in allergic reactions to GA presented by these patients and suggest the importance of strict surveillance during administration of the first GA doses.