Prediction of generalization of ocular myasthenia gravis under immunosuppressive therapy in Northwest China

Jun Guo,Dan Dang,Jiaqi Ding,Sijia Zhao,Min Zhang,Kaixi Ren,Zhuyi Li,Hongzeng Li,Fang Wu

doi:10.1186/s12883-020-01805-1

Abstract

BackgroundIt is well demonstrated that immunosuppressants can reduce, but not eliminate the risk of generalized development in ocular myasthenia gravis (OMG). In this study, we aimed to explore the predictive factors of generalized conversion of OMG patients who received immunosuppressive treatments.MethodsOMG patients under immunosuppressive treatments in Tangdu Hospital from June 2008 to June 2012 were retrospectively reviewed. Baseline clinical characteristics were documented. Patients were followed up regularly by face-to-face interview and the main outcome measure was generalized conversion. The logistic regression analysis was performed to determine the predictive factors of generalization of OMG.ResultsTwo hundred twenty-three eligible OMG patients completed the final follow-up visit and 38 (17.0%) progressed to generalized MG (GMG) at a median time to generalization of 0.9 year. Patients with adult onset and positive repetitive nerve stimulation (RNS) of facial or axillary nerve had higher conversion rate than those with juvenile onset and negative RNS (p = 0.001; p = 0.019; p = 0.015, respectively). Adult-onset patients converted earlier than juvenile-onset OMG patients (p = 0.014). Upon multivariate logistic regression analysis, age of onset (Odds ratio [OR] 1.023, 95% confidence interval [CI] 1.006–1.041, p = 0.007) and positive facial nerve RNS (OR 2.826, 95%CI 1.045–5.460, p = 0.038) were found to be positively associated with generalized development. Moreover, an obviously negative association was found for disease duration (OR 0.603, 95%CI 0.365–0.850, p = 0.019).ConclusionsAge of onset, disease duration and facial nerve RNS test can predict generalized conversion of OMG under immunosuppressive therapy. Adult-onset, shorter disease duration and facial nerve RNS-positive OMG patients have a higher risk of generalized development.

Highlights

It is well demonstrated that immunosuppressants can reduce, but not eliminate the risk of generalized development in ocular myasthenia gravis (OMG)
It has been widely accepted that generalization of OMG is a classical phenomenon even though the conversion rate varies in different studies, and a series of predictors have been postulated to be correlated with secondary generalization
Generalized conversion is a typical feature for Myasthenia gravis (MG) patients who initially present pure ocular symptoms, and approximately 90% of OMG patients from Caucasian populations might progress to generalized MG (GMG) within the first 2– 3 years [1, 2]

Summary

Introduction

It is well demonstrated that immunosuppressants can reduce, but not eliminate the risk of generalized development in ocular myasthenia gravis (OMG). We aimed to explore the predictive factors of generalized conversion of OMG patients who received immunosuppressive treatments. Prior studies have shown that approximately 70% of MG patients initially present pure ocular symptoms and more than 90% of OMG patients undergo generalized conversion within 2–3 years [1, 2]. Previous studies have suggested that immunosuppressive therapy reduce the conversion rate of OMG to 7–23.3% [6, 7, 9], but a proportion of patients still ineluctably experience secondary generalization, and the predictors of generalization in these patients require further investigation. This study attempts to explore the potential predictors of generalized conversion in OMG patients under immunosuppressive therapy

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