Apinyawasisuk S, Chongpison Y, Thitisaksakul C, Jariyakosol S. Factors Affecting Generalization of Ocular Myasthenia Gravis in Patients With Positive Acetylcholine Receptor Antibody.
Am J Ophthalmol 2020;
209:10-17. [PMID:
31562855 DOI:
10.1016/j.ajo.2019.09.019]
[Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/18/2019] [Accepted: 09/18/2019] [Indexed: 01/22/2023]
Abstract
PURPOSE
To evaluate the associated factors of conversion of ocular myasthenia gravis (OMG) to generalized myasthenia gravis (GMG) among patients with seropositive acetylcholine receptor antibody (AchR Ab).
DESIGN
Retrospective cohort study.
METHODS
Setting: Retrospective chart review.
PATIENT
Seventy-one OMG patients with seropositive AchR Ab presented during July 2009 and December 2016. The exclusion criteria were patients who (1) first presented with GMG, (2) were unable to identify the time of onset of OMG or GMG, (3) were unable to provide information about previous treatments before the onset of GMG, and (4) had incomplete or lost medical records.
OBSERVATION PROCEDURE
We collected demographic and clinical characteristics, including onset of OMG and GMG, presence of other autoimmune disorders, history of smoking, presence of thymic abnormalities, and medications received.
MAIN OUTCOME MEASURES
Conversion to GMG and time to conversion.
RESULTS
Thirty-six patients experienced conversion to GMG. Overall incidence of GMG was 14 (95% confidence interval [CI] 10.09-19.4) per 100 patient-years. Probability of conversion at 2 years was .37 (95% CI .27-.49). Overall median conversion time was 4.97 years. Cox proportional hazard model showed that risk factors were female sex (HR 2.52, 95% CI 1.04-6.10), history of smoking (HR 3.42, 95% CI 1.40-8.45), and thymic abnormalities (HR 1.82, 95% CI 0.91-3.67). Protective factors against conversion to GMG were receiving immunosuppressive agents (HR 0.42, 95% CI 0.19-0.97) and pyridostigmine (HR 0.37, 95% CI 0.14-0.93).
CONCLUSIONS
OMG patients with seropositive AchR Ab should be informed that taking pyridostigmine and/or immunosuppressive agents as well as smoking cessation might prevent conversion to GMG.
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