Survival Analysis of Myasthenia Gravis Patients at a Referral Center in Pará, Brazil (2005-2020)

Resumo

Objective: To evaluate the profile and survival of patients diagnosed with Myasthenia Gravis, by reviewing medical records of neurological consultations at a referral service in the interior of Pará (Brazil), between 2005 and 2020.

Methods: a historical, observational and retrospective cohort study. 36 participants were included. Survival analysis methods were used to identify prognostic factors for disease remission at the observation time of 36 months. The correlation between the variables and the death outcome was performed using the chi-square test.

Results: Most patients were women (66.6%) and had the generalized form of the disease (86.1%). The most prevalent symptoms were: ophthalmoparesis (97.2%), fatigability (75%) and dysphagia (72.2%). Among the complications, 19.4% had myasthenic crisis. The dosage of anti-acetylcholine receptor (AChR) antibody was positive in 58.3% and 69.4% underwent electroneuromyography, and 72% of them had electrodecrement. Most of the patients responded to the staggered standard treatment and achieved remission (83.3%), while 16.6% died. Survival analysis showed through Kaplan-Meier curves and Log-rank test that the variables related to poor control were male gender (p=0.01), thymus disease (p=0.02) and use of cyclosporine (p=0.02). The factors that influenced the death outcome were male gender, cyclosporine and thymectomy.

Conclusion: The study showed that the evolution of people with Myasthenia Gravis over 15 years and the poor prognostic factors were equivalent to the international literature.