[Standard treatment for late-onset myasthenia gravis in Japan]

Clinical features of double seronegative ocular myasthenia gravis

PURPOSE

To clarify the clinical features of patients with Double seronegative (DS) ocular myasthenia gravis (OMG).

METHODS

Sixty-one patients diagnosed with DS OMG at the Department of Ophthalmology, Hyogo Medical University Hospital over a 5-year period from 2017 were included. Patients were classified into three groups based on the initial examination findings: group P (ptosis alone), group M (ocular motility disorder alone), and group PM (combination of both). We retrospectively reviewed the patients and clarified their clinical features.

RESULTS

There were 32 males and 29 females, with a mean age of 49.8 ± 20.9:1-82 years. Twenty-one patients (34.4%) were in group P, 23 (37.7%) in group M, and 17 (27.8%) in group PM. The proportion of males (73.9%) was significantly higher in group M compared with the other two groups. The diagnosis was proven by detection of neuromuscular junction (NMJ) disorder in 73.8%, oral pyridostigmine trial test in 13.1%, and eight patients (13.1%) in group M were diagnosed after surgical treatment. The clinical symptoms were resolved by oral pyridostigmine treatment in 54.1% of cases.

CONCLUSION

About 30% of patients with DS OMG had no obvious NMJ disorder, and an oral pyridostigmine trial test was necessary to diagnose these patients. Although DS OMG is often considered as the mildest form of MG, its prognosis is not optimistic and it requires aggressive therapeutic intervention.

TRIAL REGISTRATION

Trial registration number: 202104-750, "2016/4/18," retrospectively registered.

Surgical safety analysis and clinical experience sharing of myasthenia gravis patients aged 65 and over

BACKGROUND

To evaluate the surgical safety in myasthenia gravis (MG) patients aged 65 and over.

METHODS

A total of 564 patients with MG who underwent surgery in the Department of Thoracic Surgery of Beijing Hospital from November 2011 to March 2022 were included in the study and divided into two groups taking the age of 65 as the boundary. Perioperative data of patients were recorded and statistically analyzed.

RESULTS

Compared with young patients, FEV1, FEV1% and MVV in lung function of elderly MG patients were worse (p < 0.001, p < 0.001, p = 0.002). Postoperative drainage time was longer (p < 0.001), combined with more drainage volume (p = 0.002). The American Society of Anesthesiologists (ASA) score of elderly MG patients was higher (p < 0.001). Complications were more likely to occur (p = 0.008) after surgery and Clavien-Dindo classification (CDC) of postoperative complications was also higher (p = 0.003). Meanwhile, postoperative myasthenic crisis (POMC) was more likely to occur (p = 0.038). Logistic regression showed that lower DLCO% (p = 0.049) was an independent risk factor for postoperative complications.

CONCLUSIONS

Surgical indications should be considered in each elderly MG patient on an individual basis. Moreover, most elderly MG patients safely survive the perioperative period and benefit from surgery through individualized consideration.

Efficacy and safety of tacrolimus as long-term monotherapy for myasthenia gravis

The objective was to evaluate the long-term efficacy and safety of tacrolimus monotherapy in myasthenia gravis (MG) patients. Immunosuppressive drug-naïve MG patients were administered tacrolimus, followed by thymectomy in some of the cases according to the clinical guideline for MG. Additional aggressive immunosuppressive therapies were allowed if the patients without thymectomy did not achieve minimal manifestation (MM) or better status after 3 weeks of tacrolimus administration or in the thymectomized patients by 1-2 weeks after the operation (i.e., 1st evaluation). Of all 14 patients included in this study, 8 of them (57%) achieved MM or better status at the 1st evaluation, and the remaining 6 (43%), who had failed to gain MM or better status at the 1st evaluation, also achieved MM or better status with 1 course of aggressive immunosuppressive therapy. The quantitative MG (QMG) scores, MG-Activities of Daily Living (ADL) scales, and anti-acetylcholine receptor (AchR) antibody levels were significantly decreased at 6 months and maintained thereafter. At the end of the follow-up period (41-70 months), all patients were in MM or better status. None of the patients experienced severe adverse effects. Our small preliminary study indicates that long-term tacrolimus monotherapy is possibly effective and safe for MG patients.

Treatment of Myasthenia Gravis in Patients with Elderly Onset at Advanced Age

The number of patients with late-onset myasthenia gravis (MG) among patients ≥50 years has been increasing recently. We encountered three patients who developed elderly-onset MG at a particularly advanced age (≥80 years). All were female and positive for anti-acetylcholine receptor antibodies. About 4 years have passed since MG onset in all three patients and symptoms have been controlled without recurrence using a combination of oral low-dose prednisolone and tacrolimus. As many cases of elderly-onset MG do not require strong immunosuppression, we recommend minimum immunosuppressive treatment to avoid adverse events, particularly in patients at an advanced age of ≥80 years.

Perioperative management in myasthenia gravis: republication of a systematic review and a proposal by the guideline committee of the Japanese Association for Chest Surgery 2014

Thymectomy is regarded as a useful therapeutic option for myasthenia gravis (MG), though perioperative management in MG patients is largely empirical. While evidence-based medicine is limited in the perioperative management of MG patients, treatment guidelines are required as a benchmark. We selected issues faced by physicians in clinical practice in the perioperative management of extended thymectomy for MG, and examined them with a review of the literature. The present guidelines have reached the stage of consensus within the Japanese Association for Chest Surgery.