Diagnosis and Management of Seronegative Myasthenia Gravis: Lights and Shadows

Depression: A Contributing Factor to the Clinical Course in Myasthenia Gravis Patients

Background and Objectives: The association between myasthenia gravis (MG) and depression is intricate and characterized by bidirectional causality. In this regard, MG can be a contributing factor to depression and, conversely, depression may worsen the symptoms of MG. This study aimed to identify any differences in the progression of the disease among patients with MG who were also diagnosed with depression as compared to those without depression. Our hypothesis focused on the theory that patients with more severe MG symptoms may have a higher likelihood of suffering depression at the same time. Materials and Methods: One hundred twenty-two male and female patients (N = 122) aged over 18 with a confirmed diagnosis of autoimmune MG who were admitted to the Neurology II department of Myasthenia Gravis, Clinical Institute Fundeni in Bucharest between January 2019 and December 2020, were included in the study. Patients were assessed at baseline and after six months. The psychiatric assessment of the patients included the Hamilton Depression Rating Scale-17 items (HAM-D), and neurological status was determined with two outcome measures: Quantitative Myasthenia Gravis (QMG) and Myasthenia Gravis Activities of Daily Life (MG-ADL). The patients were divided into two distinct groups as follows: group MG w/dep, which comprised 49 MG patients diagnosed with depressive disorder who were also currently receiving antidepressant medication, and group MG w/o dep, which consisted of 73 patients who did not have depression. Results: In our study, 40.16% of the myasthenia gravis (MG) patients exhibited a comorbid diagnosis of depression. Among the MG patients receiving antidepressant treatment, baseline assessments revealed a mean MG-ADL score of 7.73 (SD = 5.05), an average QMG score of 18.40 (SD = 8.61), and a mean Ham-D score of 21.53 (SD = 7.49). After a six-month period, a statistically significant decrease was observed in the MG-ADL (2.92, SD = 1.82), QMG (7.15, SD = 4.46), and Ham-D scores (11.16, SD = 7.49) (p < 0.0001). These results suggest a significant correlation between MG severity and elevated HAM-D depression scores. Regarding the MG treatment in the group with depression, at baseline, the mean dose of oral corticosteroids was 45.10 mg (SD = 16.60). Regarding the treatment with pyridostigmine, patients with depression and undergoing antidepressant treatment remained with an increased need for pyridostigmine, 144.49 mg (SD = 51.84), compared to those in the group without depression, 107.67 mg (SD = 55.64, p < 0.001). Conclusions: Our investigation confirms that the occurrence of depressive symptoms is significantly widespread among individuals diagnosed with MG. Disease severity, along with younger age and higher doses of cortisone, is a significant factor associated with depression in patients with MG. Substantial reductions in MG-ADL and QMG scores were observed within each group after six months, highlighting the effectiveness of MG management. The findings suggest that addressing depressive symptoms in MG patients, in addition to standard MG management, can lead to improved clinical outcomes.

Case report: Coexistence of triple-seronegative myasthenia gravis and pathology-proven cryptogenic organizing pneumonia

Objective

Emerging evidence shows that patients with myasthenia gravis (MG) were at a higher risk for the co-occurrence of other autoimmune diseases, which reflects phenotypic heterogeneity in MG. The coexistence of MG and cryptogenic organizing pneumonia (COP) has rarely been reported. The present case is to report the coexistence of triple-seronegative MG and pathology-proven COP in a patient.

Methods

The clinical data of the patient were derived from medical records of Nanjing First Hospital, Nanjing Medical University, China. Written informed consent was obtained from the patient.

Results

We presented a 56-year-old man with acute respiratory syndrome, who was diagnosed with COP based on the intra-alveolar fibroinflammatory buds (Masson's bodies) in the pathology of bronchoscopy biopsy. Oral prednisone induced dramatic symptomatic improvement and complete resolution of previous lung lesions. After a stable course of no respiratory symptom for 2 months, he was referred to the neurology department with complaints of fluctuating generalized muscle weakness. He was diagnosed with triple-seronegative MG based on fluctuating weakness, neostigmine test-positivity and RNS-positivity. After three-month treatment with pyridostigmine in combination with tacrolimus, the symptoms gradually improved and he achieved minimal symptom expression.

Conclusions

This case highlights the rare coexistence of triple-seronegative MG and pathology-proven COP. However, a causal association between COP and MG cannot be explicitly ascertained. In future, more data are needed to clarify the relationship, taking into account the limited number of cases reported with this coexistence of the diseases.

Current Biomarker Strategies in Autoimmune Neuromuscular Diseases

Inflammatory neuromuscular disorders encompass a diverse group of immune-mediated diseases with varying clinical manifestations and treatment responses. The identification of specific biomarkers has the potential to provide valuable insights into disease pathogenesis, aid in accurate diagnosis, predict disease course, and monitor treatment efficacy. However, the rarity and heterogeneity of these disorders pose significant challenges in the identification and implementation of reliable biomarkers. Here, we aim to provide a comprehensive review of biomarkers currently established in Guillain-Barré syndrome (GBS), chronic inflammatory demyelinating polyneuropathy (CIDP), myasthenia gravis (MG), and idiopathic inflammatory myopathy (IIM). It highlights the existing biomarkers in these disorders, including diagnostic, prognostic, predictive and monitoring biomarkers, while emphasizing the unmet need for additional specific biomarkers. The limitations and challenges associated with the current biomarkers are discussed, and the potential implications for disease management and personalized treatment strategies are explored. Collectively, biomarkers have the potential to improve the management of inflammatory neuromuscular disorders. However, novel strategies and further research are needed to establish clinically meaningful biomarkers.