Thymectomy in myasthenia gravis: A narrative review

Immune mediated myasthenia gravis in children, current concepts and new treatments: A narrative review article

Myasthenia gravis (MG) is the most frequent transmission disease in the neuromuscular junction. Juvenile myasthenia gravis (JMG) is an autoimmune antibody-mediated disease of postsynaptic endplate defined as MG presentation in patients before the age of 18 years old. While many clinical features of JMG are identical to the adults, there are some significant differences between them regarding presentation, clinical course, antibody level, and thymus histopathology. In JMG, ocular symptoms are more frequent, the clinical course is comparably benign, and the outcome is better than adult MG. Antibodies attack the muscle endplate proteins in the postsynaptic membrane and interfere with transmission. These antibodies in most patients are against the acetylcholine receptors, but they may also be directed toward muscle-specific kinase, lipoprotein-related protein 4, and agrin. Findings show racial influences and genetic effects on the occurrence of JMG. The essential clinical symptom is fatigable weakness of muscles that can be in the form of isolated ocular type or more disseminated weakness. The diagnosis of JMG is essentially clinical, with fluctuating patterns of weakness and easy fatigability, but a series of diagnostic evaluations can confirm the diagnosis. Precise diagnostic evaluation and distinction from congenital myasthenic syndromes is critical. The treatment plan is conducted according to the clinical course (ocular or generalized), antibody type, and disease severity. The mainstay of treatment includes symptomatic therapy, long-lasting immunosuppressive treatment and treatment of myasthenic crisis. Novel medications are introduced and conducted to the specific pathophysiologic mechanisms of the disease, and they are used primarily in the refractory MG.

Physiological and pathological roles of the thymus and value of thymectomy in myasthenia gravis: a narrative review

Background and Objective

Myasthenia gravis (MG) is a well-elucidated autoimmune disorder affecting the neuromuscular junction. Given the relationship between MG and thymic pathologies, with T cell and antibody-mediated pathogenesis, surgical (i.e., thymectomy) and non-surgical approaches remain a mainstay of management of the disease. This review seeks to outline the involvement of the thymus in the development of lymphocytes leading to MG.

Methods

Different databases were searched exploring the role of thymectomy in treatment and outcomes in various MG patient subpopulations, including in ocular versus generalized disease, different age groups, and antibody status.

Key Content and Findings

Overall, the findings of multiple studies and reviews provide evidence to support the efficacy and long-term success of thymectomy in the management of MG; outcomes have included remission status, symptom severity, and need for adjunctive therapy. However, the heterogeneity in the MG population suggests that there are multiple factors that may confound the results of thymectomy and still need further examination. Separately, other autoimmune diseases develop following thymectomy, and further research is required to elucidate this susceptibility. Finally, our review will discuss the different surgical approaches for thymectomy, including their advantages, limitations, and perioperative complications.

Conclusions

Overall, in light of the known pathogenesis and association of the thymus with MG, thymectomy remains an extremely effective approach for long-term management and improved clinical outcomes.

Postoperative leukocyte counts as a surrogate for surgical stress response in matched robot- and video-assisted thoracoscopic surgery cohorts of patients: A preliminary report

The objective is to preliminary evaluated postoperative leukocyte counts as a surrogate for the surgical stress response in NSCLC patients who underwent RATS or VATS for further prospective analyses with proper assessment of surgical stress response and tissue trauma. We retrospectively analyzed patients with stageI-IIIA NSCLC who underwent RATS or VATS at a hospital between 8 May 2020 and 31 December 2021. Analysis of leukocytes (including neutrophils and lymphocytes) and albumin on postoperative days (PODs) 1 and 3 in patients with NSCLC treated with RATS or VATS after propensity score matching (PSM). In total, 1824 patients (565 RATS and 1259 VATS) were investigated. The two MIS groups differed significantly with regard to operative time (p < 0.001), chronic lung disease (p < 0.001), the type of pulmonary resection (p < 0.001), the excision site of lobectomy (p = 0.004), and histology of the tumor (p = 0.028). After PSM, leukocyte and neutrophil levels in the RATS group were lower than those in the VATS group on PODs 1 and 3, with those on POD 3 (p < 0.001) being particularly notable. While lymphocyte levels in the RATS group were significantly lower than those in the VATS group only at POD 1 (p = 0.016). There was no difference in albumin levels between the RATS and VATS groups on PODs 1 and 3. The surgical stress response and tissue trauma was less severe in NSCLC patients who underwent RATS than in those who underwent VATS, especially reflected in the neutrophils of leukocytes.

Comparison of three methods for the detection of antibodies against muscle-specific kinase

OBJECTIVES

To compare 3 different methods for the detection of antibodies against muscle-specific kinase (MuSK).

METHODS

MuSK antibody testing was performed in 237 serum samples by enzyme-linked immunosorbent assay (ELISA) and fixed cell-based assay (f-CBA-IFA). One hundred and forty-eight (148) of the sera had previously been tested by RIA during clinical testing: 47 MuSK antibody positive and 101 MuSK antibody negative. Of the MuSK RIA negative antibodies, 46 tested positive for other neural antibodies. Additionally, 89 sera were subsequently tested by all three methods: 70 healthy controls and 19 sera positive for other neural antibodies.

RESULTS

Qualitative inter-assay agreement based on tiered RIA values was 100% for results of 1.00 nmol/L or greater by both methods; 81% and 94% for results between 0.21 and 0.99 nmol/L by ELISA and f-CBA-IFA, respectively; and 0% for results of 0.04-0.20 nmol/L by both methods. Negative results showed 100% agreement between RIA and both ELISA and f-CBA-IFA (n = 55). None of the controls positive for other neural autoantibodies or healthy controls were positive in any assay.

CONCLUSION

Overall, excellent agreement was observed between the 3 methods used to detect antibodies against MuSK. Both the f-CBA-IFA and ELISA performed comparably to RIA and exhibited excellent overall accuracy for MuSK IgG detection, with the f-CBA-IFA demonstrating higher agreement between positive samples with the RIA than the ELISA without identifying false positives in the control samples. Advantages of non-radioactive methods for the detection of MuSK antibodies include reduced handling and disposal of hazardous materials, potential for automation and the reagents having a longer shelf-life, reducing costs associated with both workflow and lot validations. Thus, commercially available ELISA and transfected cell-based assays are viable alternatives to the traditional radioactive assay used for serologic determination of MuSK IgG.

The First Case of Burkholderia cepacia-Induced Myasthenic Crisis

We report the case of a 62-year-old male patient with a previous diagnosis of myasthenia gravis who experienced a myasthenic crisis due to a lower respiratory tract infection caused by Burkholderia cepacia. The patient was admitted to the neuro-intensive care unit and received ventilatory support to address respiratory insufficiency. Treatment included tigecycline and piperacillin-tazobactam for the suspected bacterial infection, as well as targeted management for the myasthenic crisis. Following a successful recovery and favorable clinical response, this case report aims to contribute to the literature by discussing the patient's presentation and exploring the incidence and characteristics of B. cepacia-related myasthenic crisis.