Objective: To establish the experimental autoimmune Lewis rat model of myasthenia gravis (EAMG) specific for muscle-specific kinase (MuSK).
Methods: Lewis rats were immunized subcutaneously with a single injection of 200 µl of MuSK (50/100 µg) emulsified in complete Freund's adjuvant (CFA). And MuSK was expressed according to the murine gene of MuSK (AY360453). Control rats were immunized with CFA alone. All rats were observed every other day in a blinded fashion for fatigue characteristics. The clinical symptoms were graded between 0 and 3. And the clinical scores were recorded. The serum levels of anti-MuSK IgG at Days 7 and 57 were determined by enzyme-linked immunosorbent assay (ELISA).
Results: The clinical symptoms of myasthenia gravis (MG) appeared at Day 16 and peaked at Days 18-22. The serum levels of anti-MuSK IgG were markedly elevated in the experimental groups compared with the control group.
Conclusion: EAMG induced by MuSK is successfully established in rats. And this animal model may help us elucidate the pathogenesis of anti-MuSK myasthenia (AMM) and discover new drug therapy in the future.