Serum immunoglobulin G level reduction is a predictor of short-term improvement in patients with myasthenia gravis undergoing plasmapheresis.

OBJECTIVES

The aim of the study was to investigate the serological factors in predicting symptom improvement in myasthenia gravis (MG) patients who underwent plasmapheresis (PP).

METHODS

The relationship between symptom improvement and change in immunoglobin G (IgG) and acetylcholine receptor antibody (AchR-Ab) levels in 21 MG patients after PP was analyzed.

RESULTS

Patients were divided into two groups: the favorable (n = 11) or unfavorable (n = 10) response groups around the median MG composite improvement rate (50 [29, 56]%) 2 weeks after a PP course. In all patients, the IgG reduction rate before and after PP was higher in the favorable than the unfavorable response group. In AChR-Ab-positive patients, IgG and AChR-Ab reduction rates were higher in the favorable than the unfavorable response group.

CONCLUSION

IgG reduction rate is a predictor of symptom improvement in MG patients who underwent PP.