Objective: Two cases of double filtration plasmapheresis (DFPp) combined with oral low-dose prednisone acetate were reported for the treatment of systemic myasthenia gravis (MG), aiming to provide ideas for the clinical treatment of MG.

Methods: The clinical symptoms, auxiliary examination results, diagnosis and treatment process and prognosis of 2 patients with systemic MG were reported. The effects of different treatment methods were analyzed by reviewing relevant literature.

Results: In case 1, the main clinical manifestations were "chest tightness and shortess of breath for more than 3 months, aggravated by drooping eyelids and coughing due to drinking water for 1 month". After admission, relevant examinations were improved, the fatigue test and neostigmine test were positive, musce strength of limbs was grade 4,serum anti acetylcholine receptor (AchR) antibody was positive, and myasthenia gravis score (QMGS) was 19 points.MG-activities of daily living profile(MG-ADL) was 13 points. Case 2 was admitted for diagnosis and treatment due to "dysphagia for one month, aggravated by weakness in the limbs for more than a week". Muscle strength in the limbs was found to be level 5, and the Wada drinking water test was level 3. The fatigue test was positive.QMGS was 6 points, MG-ADL was 11 points, blood anti-AchR antibody >80 nmol/L.Combined with the clinical manifestations and auxiliary examination results, 2 cases were diagnosed as MG moderate systemic type, acute exacerbation period. After treatment with DFPP combined with oral prednisone acetate, the clinical symptoms of 2 patients were improved. After treatment, the QMGS scores of the 2 patients were 7 and 0, respectively,and the MG-ADL scores were 5 and 0,respectively.

Conclusion:In this study, DFPPcombined with oral low-dose prednisone acetate was used for treatment, which not only gave full play to the synergistic effect between drugs,effectively improved the clinical symptoms of MG patients, and prevented the adverse reactions caused by long-term use of corticosteroids. Therefore, the treatment method of this case has certain suggestive significance for the clinical treatment of MG.