Clinical outcome and peripheral CD4+ T profile in impending myasthenic crisis: A prospective cohort study.

Impending Myasthenic Crisis (MC) is defined as a rapid worsening of myasthenia gravis (MG) that can progress to respiratory failure within days to weeks. The clinical data regarding the outcome and peripheral immune profile is limited. This multicenter cohort enrolled 37 patients with impending MC who were given timely rescue therapies from six university hospitals (n = 272). The transformation rate in the impending MC cohort to manifest MC was 24.32 % (9/37). Compared with those who have transformed to MC, the untransformed patients manifested a shorter hospital stay (13.98 ± 15.22 vs. 22.00 ± 16.03 days, P = 0.004), a lower baseline MG Quality of Life 15 (QOL-15) (23.42 ± 14.32 vs. 38.44 ± 13.56, P = 0.006), and shorter disease duration (29.30 ± 46.05 vs. 88.00 ± 71.43 months, P = 0.003). Peripheral CD4+ T profiling revealed an elevated Th17 proportion in impending crisis compared with healthy controls (22.33 ± 6.58 vs. 15.06 ± 4.35, P = 0.0006). Impending MC can be effectively prevented from transforming into manifest MC with rescue therapies.