The significance of serum anti-titin antibodies and anti-acetylcholine receptor antibodies in patients with myasthenia gravis

Abstract

Objective To study the clinical significance of serum anti-Titin antibodies and thecorrelation between anti-Titin anbibodies and anti-acetyleholine receptor (AchR) antibodies in patientswith myasthenia gravis (MG). Methods We detected anti-Titin antibodies and anti-AchR antibodieswith enzyme linked immunosorbent assay (ELISA) in the sera from 81 cases of MG groups includingearly-onset MG, late-onset MG and MG with thymoma (MGT). The positive rates were compared amongthese groups. Results The positive rates of anti-Titin antibodies in sera of MG patients weresignificantly higher than controls (P<0.01). The mean titers and the positive rates of anti-Titin antibodieswere significantly higher in MGT (80%) and late-onset MG (69.4%) subgroups than in the early-onsetMG subgroup (25%). In contrast, the positive rates and mean titers of AchR antibodies in the early-onsetMG subgroup were higher than those in the late-onset MG subgroup. The detections of serum anti-Titinantibodies and AchR antibodies were consistent with the diagnosis of MG. Conclusion Anti-Titinantibodies are specific for MG. They often present in the sera of patients with MGT and late-onset MG.The positive rates and mean titers of AchR antibodies in early-onset MG patients sera are higher thanthose in late-onset MG patients. These features prompt fiu'ther studies on the pathogenesis of MG. Testingfor a combination of anti-Titin antibodies and AchR antibodies gives the higher sensitivity for thedetection of MG than each antibody alone. Key words: Myasthenia gravis; Anti-Titin antibodies; Anti-AchR antibodies