Long-term outcomes and prognostic factors in generalized myasthenia gravis

Clinical Characteristics and Outcomes of Generalized Myasthenia Gravis in Malaysia: A Single-Center Experience

BACKGROUND AND PURPOSE

Myasthenia gravis (MG) is clinically heterogeneous and can be classified into subgroups according to the clinical presentation, antibody status, age at onset, and thymic abnormalities. This study aimed to determine the clinical characteristics and outcomes of generalized MG (GMG) patients based on these subgroups.

METHODS

Medical records of MG patients from 1976 to 2023 were reviewed retrospectively. Patients with pure ocular MG were excluded. Data on demographic, clinical characteristics, laboratory features, and outcomes were analyzed.

RESULTS

This study included 120 GMG patients. There was a slight preponderance of female patients over male patients (male:female ratio=1:1.3), with the age at onset exhibiting a bimodal distribution. Female patients peaked at a lower age (21-30 years) whereas male patients peaked at a higher age (61-70 years). Most (92%, 105 of 114) patients had positive anti-acetylcholine receptor antibodies. Five patients were also tested for anti-muscle-specific tyrosine kinase antibodies, with two showing positivity. Thymectomy was performed in 62 (52%) patients, of which 30 had thymoma, 16 had thymic hyperplasia, 7 had an involuted thymus, and 6 had a normal thymus. There were significantly more female patients (68% vs. 45%, p=0.011) with early-onset disease (<50 years old) and thymic hyperplasia (33% vs. 0%, p<0.025). Most (71%) of the patients had a good outcome based on the Myasthenia Gravis Foundation of America postintervention status. GMG patients with early-onset disease had a significantly better outcome than patients with a late onset in univariate (58% vs. 37%, p=0.041) and multivariate (odds ratio=4.68, 95% confidence interval=1.17-18.64, p=0.029) analyses.

CONCLUSIONS

Female patients with early-onset MG and thymic hyperplasia had significantly better outcomes, but only early-onset disease was independently associated with a good outcome. These findings are comparable with those of other studies.

Comparative effectiveness and safety of intravenous methylprednisolone and tacrolimus monotherapy in ocular myasthenia gravis with unsatisfactory prednisone responses: a retrospective study

BACKGROUND

Oral prednisone has been recognized as the first-line therapy for the treatment of ocular myasthenia gravis (OMG). However, its long-term use is complicated by numerous adverse effects and is ineffective for some OMG patients in reaching remission. This study aimed to evaluate the effectiveness and safety of intravenous methylprednisolone (IVMP) and tacrolimus monotherapy for OMG patients with unsatisfactory responses to conventional prednisone therapy.

METHODS

We retrospectively reviewed 57 OMG patients who had not achieved satisfactory improvement after prednisone therapy and thereby received IVMP or tacrolimus monotherapy for at least 6 months. Ocular symptoms were evaluated by the ocular-quantitative MG (QMG) score at each time point. A ≥ 2-point fall in ocular QMG score was defined as the cut-off point to indicate clinical improvement. Logistic regression analysis was performed to identify factors associated with the efficacy of IVMP at discharge. Adverse events were recorded.

RESULTS

Both IVMP and tacrolimus monotherapy demonstrated significant clinical efficacy, with no statistical differences observed at the study endpoint. The proportions of patients who reached the cut-off point for efficacy evaluation were higher in the IVMP group than in the tacrolimus group (1, 3, and 6 months: 51.7% (15/29) vs 12.0% (3/25), p = 0.002; 69.0% (20/29) vs 40.0% (10/25), p = 0.033; 69.0% (20/29) vs 46.4% (13/28), p = 0.085, respectively). Multivariate logistics analysis showed that high ocular QMG scores at baseline indicated favourable responses to IVMP treatment (OR = 1.781; 95% CI 1.066-2.975; p = 0.028). All the adverse events were transient and tolerable.

CONCLUSION

Our findings suggest that both IVMP and tacrolimus monotherapy hold promise as viable treatment options for OMG patients with unsatisfactory responses to oral prednisone. The study supports the safety and effectiveness of both therapies, with IVMP exhibiting faster improvement and favourable efficacy in patients with high ocular QMG scores.

Disease-Based Prognostication: Myasthenia Gravis

Myasthenia gravis (MG) is an acquired autoimmune neuromuscular junction transmission disorder that clinically presents as fluctuating or persistent weakness in various skeletal muscle groups. Neuroprognostication in MG begins with some basic observations on the natural history of the disease and known treatment outcomes. Our objective is to provide a framework that can assist a clinician who encounters the MG patient for the first time and attempts to prognosticate probable outcomes in individual patients. In this review article, we explore clinical type, age of onset, antibody status, severity of disease, thymus pathology, autoimmune, and other comorbidities as prognostic factors in MG.

Changes in the Cath Lab in the Treatment of Adult Patients with Congenital Heart Disease: A 12-Year Experience in a Single Referral Center with the Establishment of a Dedicated Working Group

BACKGROUND

Adults with congenital heart disease (ACHD) are a growing population needing ongoing care. The aim of this study was to investigate if a dedicated ACHD team impacted the timing and indication of invasive cardiology procedures in these patients at our hospital.

METHODS

Our retrospective single-center study enrolled adult patients with moderate or complex congenital heart disease and with at least one cardiac catheterization between January 2010 and December 2021. According to the period, procedures were labeled as group A (2010 to 2015) or group B (2016 to 2021) and further divided into diagnostic (DCC) and interventional cardiac catheterizations (ICC).

RESULTS

594 patients were eligible for the study. Both DCC (p < 0.05) and ICC increased between groups A and B (p < 0.05). In group B: Fontan patients accounted for the majority of DCC (p < 0.001), while DCC decreased in arterial switch repair (p < 0.001). In Fontan patients, conduit stenting was prevalent (p < 0.001), while fenestration closures dropped (p < 0.01). In patients with tetralogy of Fallot and native outflow tract, percutaneous pulmonary valve implantations (PPVI) increased, with a concurrent reduction in pulmonary valve replacements (p < 0.001 vs. surgical series). In right ventricular conduits, ICC increased (p < 0.01), mainly due to PPVI. Among Mustard/Senning patients, baffle stenting increased from Group A to Group B (p < 0.001). In patients with pulmonary atresia and biventricular repair, ICC often increased for pulmonary artery stenting.

CONCLUSIONS

A dedicated working group could improve ACHD patients' indications for interventional procedures, leading to tailored treatment, better risk stratification and optimizing time until heart transplantation.

Effectiveness of early cycles of fast-acting treatment in generalised myasthenia gravis

BACKGROUND

Early fast-acting treatment (EFT) is the aggressive use of fast-acting therapies such as plasmapheresis, intravenous immunoglobulin and/or intravenous high-dose methylprednisolone (IVMP) from the early phases of treatment. EFT is reportedly beneficial for early achievement of minimal manifestations (MM) or better status with ≤5 mg/day prednisolone (MM5mg), a practical therapeutic target for myasthenia gravis (MG).

OBJECTIVE

The current study aimed to clarify which specific EFT regimen is efficacious and the patient characteristics that confer sensitivity to EFT.

METHODS

We recruited a total of 1710 consecutive patients with MG who enrolled in the Japan MG Registry for this large-cohort study. Among them, 1066 with generalised MG who had received immunotherapy were analysed. Prognostic background factors were matched in a 1:1 ratio using propensity score matching analysis between patients treated with EFT (n=350) and those treated without EFT (n=350). The clinical course and time to first achieve MM5mg after starting immunotherapy was analysed in relation to treatment combinations and patient characteristics.

RESULTS

Kaplan-Meier analyses showed that EFT had a significant effect on the achievement of MM5mg (p<0.0001, log-rank test; HR 1.82, p<0.0001). Notably, EFT was efficacious for any type of MG, and the inclusion of IVMP resulted in earlier and more frequent achievement of MM5mg (p=0.0352, log-rank test; HR 1.46, p=0.0380). In addition, early administration of calcineurin inhibitors also promoted MM5mg achievement.

CONCLUSION

Early cycles of intervention with EFT and early use of calcineurin inhibitors provides long-term benefits in terms of achieving therapeutic targets for generalised MG, regardless of clinical subtype.

Minimal symptom expression achievement over time in generalized myasthenia gravis

OBJECTIVES

Minimal symptom expression (MSE), defined as myasthenia gravis (MG) activities of daily living profile (MGADL) score 0 or 1, has been recently used as an indicator of treatment goal in MG. However, no study has determined when MSE is achieved. The current study aimed to investigate the timing and incidence of MSE achievement in generalized MG patients.

METHODS

Eighty-five patients with acetylcholine receptor antibody-positive generalized MG were included. They were followed-up maximum 3 years after starting immunotherapy, and we reviewed the MGADL score, prednisolone dose, and achievement of MSE and minimal manifestations (MM) or better status.

RESULTS

MSE was achieved in 37.6, 45.2, 55.8, 60.3, and 57.1% of the patients at 3, 6, 12, 24, and 36 months after treatment, respectively. Most patients who achieved MSE showed MM or better status at any phase. In addition, more than 2 years after the starting treatment, about 80% of patients who achieved MSE showed MM or better status with an oral prednisolone dose of 5 mg/day or less (MM-5 mg). Noteworthy, during the early stage of treatment, the proportion of patients who achieved MSE was higher than that who achieved MM-5 mg.

CONCLUSION

From the early phases of immunotherapy, MSE is a good marker of therapeutic goal in patients with generalized MG.

Efgartigimod for generalized myasthenia gravis with or without anti-acetylcholine receptor antibodies: a worldwide and Japanese perspective

INTRODUCTION

The management of myasthenia gravis (MG) has been improved due to immunotherapy advances, but 20% of individuals with MG are refractory to the conventional therapy, and the need for novel biological drugs remains.

AREA COVERED

The Japanese clinical guidelines for MG published in May 2022 include the concept that treatment is often lifelong and should aim to maintain a sufficient quality of life and mental health. We provide an overview of the therapeutic strategy for generalized MG in Japan, in comparison with the international consensus. We summarize the clinical efficacy, safety, and tolerability of efgartigimod, the first approved anti-neonatal Fc receptor inhibitor for MG. A phase III study showed that efgartigimod was well-tolerated and efficacious in patients with generalized MG.

EXPERT OPINION

Efgartigimod is a promising biological drug for patients with moderate to severe generalized MG with or without anti-acetylcholine receptor antibodies in Japan.

Nomogram for short-term outcome assessment in AChR subtype generalized myasthenia gravis

BACKGROUND

An accurate prediction for prognosis can help in guiding the therapeutic options and optimizing the trial design for generalized myasthenia gravis (gMG). We aimed to develop and validate a predictive nomogram to assess the short-term outcome in patients with the anti-acetylcholine receptor (AChR) subtype gMG.

METHODS

We retrospectively reviewed 165 patients with AChR subtype gMG who were immunotherapy naïve at the first visit from five tertiary centers in China. The short-term clinical outcome is defined as the achievement of minimal symptom expression (MSE) at 12 months. Of them, 120 gMG patients from Huashan Hospital were enrolled to form a derivation cohort (n = 96) and a temporal validation cohort (n = 24) for the nomogram. Then, this nomogram was externally validated using 45 immunotherapy naïve AChR subtype gMG from the other four hospitals. Multivariate logistic regression was used to screen independent factors and construct the nomogram.

RESULTS

MSE was achieved in 70 (72.9%), 20 (83.3%), and 33 (73.3%) patients in the training, temporal validation, and external validation cohort, respectively. The duration ≤ 12 months (p = 0.021), ocular score ≤ 2 (p = 0.006), QMG score > 13 (p = 0.008), and gross motor score ≤ 9 (p = 0.006) were statistically associated with MSE in AChR subtype gMG. The nomogram has good performance in predicting MSE as the concordance indexes are 0.81 (95% CI, 0.72-0.90) in the development cohort, 0.944 (95% CI, 0.83-1.00) in the temporal validation cohort, and 0.773 (95% CI, 0.63-0.92) in the external validation cohort.

CONCLUSION

The nomogram achieved an optimal prediction of MSE in AChR subtype gMG patients using the baseline clinical characters.