title: Titin antibody positive myasthenia gravis patients have a cellular immune response against the main immunogenic region of titin.
abstract: Some myasthenia gravis (MG) patients have antibodies against non-acetylcholine receptor (AChR) epitopes of skeletal muscle including titin. Peripheral blood lymphocytes from 11 MG patients and 13 blood-donors were tested for lymphocyte proliferation after stimulation with the titin peptide MGT-30, which represents the main immunogenic region. Four out of seven titin antibody positive patients had significant stimulation defined as a stimulation index (SI) above 2. Neither of the four titin antibody negative patients nor the 13 blood-donors had SI above 2 (p = 0.001). Mean SI was significantly higher for T-cells from titin antibody positive MG patients, SI = 2.2 ± 0.8, compared to titin antibody negative patients, SI = 0.9 ± 0.2 (p = 0.01), and blood-donors, SI = 0.8 ±0.3 (p > 0.0005). After MGT-30 stimulation, IL-4 was detected in the blood lymphocyte culture supernatant from four of the five MG patients examined, but from none of the eight blood-donors. Thus, MG patients with anti-titin antibodies have a T-cell mediated immune reaction against titin.
authors.affiliation: Department of Neurology, The Gade Institute, University of Bergen, Bergen, NorwayDepartment of Microbiology and Immunology, The Gade Institute, University of Bergen, Bergen, NorwayEuropean Molecular Biology Laboratory, Heidelberg, Germany.
authors.forename: G O
authors.initials: GO
authors.lastname: Skeie
authors.forename: J A
authors.initials: JA
authors.lastname: Aarli
authors.forename: R
authors.initials: R
authors.lastname: Matre
authors.forename: A
authors.initials: A
authors.lastname: Freiburg
authors.forename: N E
authors.initials: NE
authors.lastname: Gilhus