An 83-year-old man with cholangiocarcinoma developed immune checkpoint inhibitor-associated myositis after two cycles of durvalumab, presenting with muscle weakness and myalgia. His serum creatine kinase (CK) level peaked at 26,329 U/L. Needle electromyography confirmed a myogenic process, and MRI revealed extensive muscle edema. Muscle biopsy indicated multifocal necrotic fibers. Following steroid treatment, his CK levels normalized and muscle strength returned. This case represents the first reported instance of durvalumab-associated myositis in Korea.

An 83-year-old man with cholangiocarcinoma developed immune checkpoint inhibitor-associated myositis after two cycles of durvalumab, presenting with muscle weakness and myalgia. His serum creatine kinase (CK) level peaked at 26,329 U/L. Needle electromyography confirmed a myogenic process, and MRI revealed extensive muscle edema. Muscle biopsy indicated multifocal necrotic fibers. Following steroid treatment, his CK levels normalized and muscle strength returned. This case represents the first reported instance of durvalumab-associated myositis in Korea.

An 83-year-old man with cholangiocarcinoma developed immune checkpoint inhibitor-associated myositis after two cycles of durvalumab, presenting with muscle weakness and myalgia. His serum creatine kinase (CK) level peaked at 26,329 U/L. Needle electromyography confirmed a myogenic process, and MRI revealed extensive muscle edema. Muscle biopsy indicated multifocal necrotic fibers. Following steroid treatment, his CK levels normalized and muscle strength returned. This case represents the first reported instance of durvalumab-associated myositis in Korea.

An 83-year-old man with cholangiocarcinoma developed immune checkpoint inhibitor-associated myositis after two cycles of durvalumab, presenting with muscle weakness and myalgia. His serum creatine kinase (CK) level peaked at 26,329 U/L. Needle electromyography confirmed a myogenic process, and MRI revealed extensive muscle edema. Muscle biopsy indicated multifocal necrotic fibers. Following steroid treatment, his CK levels normalized and muscle strength returned. This case represents the first reported instance of durvalumab-associated myositis in Korea.

An 83-year-old man with cholangiocarcinoma developed immune checkpoint inhibitor-associated myositis after two cycles of durvalumab, presenting with muscle weakness and myalgia. His serum creatine kinase (CK) level peaked at 26,329 U/L. Needle electromyography confirmed a myogenic process, and MRI revealed extensive muscle edema. Muscle biopsy indicated multifocal necrotic fibers. Following steroid treatment, his CK levels normalized and muscle strength returned. This case represents the first reported instance of durvalumab-associated myositis in Korea.

Oxidative stress contributes to the onset of chronic diseases in various organs, including muscles. Morroniside, a type of iridoid glycoside contained in Cornus officinalis, is reported to have advantages as a natural compound that prevents various diseases.However, the question of whether this phytochemical exerts any inhibitory effect against oxidative stress in muscle cells has not been well reported. Therefore, the current study aimed to evaluate whether morroniside can protect against oxidative damage induced by hydrogen peroxide (H 2O2) in murine C2C12 myoblasts. Our results demonstrate that morroniside pretreatment was able to inhibit cytotoxicity while suppressing H2O2-induced DNA damage and apoptosis. Morroniside also significantly improved the antioxidant capacity in H2O2-challenged C2C12 cells by blocking the production of cellular reactive oxygen species and mitochondrial superoxide and increasing glutathione production. In addition, H2O2-induced mitochondrial damage and endoplasmic reticulum (ER) stress were effectively attenuated by morroniside pretreatment, inhibiting cytoplasmic leakage of cytochrome c and expression of ER stress-related proteins. Furthermore, morroniside neutralized H2O2-mediated calcium (Ca2+ ) overload in mitochondria and mitigated the expression of calpains, cytosolic Ca2+ -dependent proteases. Collectively, these findings demonstrate that morroniside protected against mitochondrial impairment and Ca2+ -mediated ER stress by minimizing oxidative stress, thereby inhibiting H2O2-induced cytotoxicity in C2C12 myoblasts.

Purpose: Spinal muscular atrophy (SMA) is an autosomal recessive genetic disease characterized by the loss of motor neurons in the spinal cord and brainstem, leading to muscle atrophy and weakness. To understand the diagnostic process of Korean patients with SMA, we analyzed their clinical characteristics and challenges. Materials and Methods: We conducted a retrospective study of 38 patients with SMA (9 type II and 29 type III) between January 2000 and September 2023. Clinical, laboratory, and genetic data were reviewed. Results: The median ages at symptom onset and diagnosis were 3.0 years [interquartile range (IQR): 1.0–7.3 years] and 25.0 years (IQR: 10.5–37.3 years), respectively. The median diagnostic delay was 19.6 years (IQR: 6.4–31.0 years). A significantly longer delay was observed in SMA type III patients (median: 21.0 years, IQR: 11.0–31.0 years) compared to SMA type II patients (median: 3.0 years, IQR: 0.9–21.0 years) (p=0.021). No significant difference was observed in the number of clinic visits before diagnosis between patients with SMA type II (median: 2.0, IQR: 1.0–4.5) and those with type III (median: 2.0, IQR: 2.0–6.0, p=0.282). The number of clinic visits before diagnosis showed no significant association with the age at symptom onset and diagnosis (p=0.998 and 0.291, respectively). Conclusion Our investigation is the first examination of the diagnostic journey of Korean patients with SMA. As treatments for SMA progress, the significance of an accurate diagnosis has increased, highlighting the importance of reviewing the diagnostic advancements made thus far.