Objective:To observe the therapeutic response and safety of rituximab in patients with anti-SRP antibody positive immune-mediated necrotizing myositis.Methods:We identified five patients with anti-SRP antibody positive immune-mediated necrotizing myositis who received rituximab treatment in the rheumatology and immunology department of China-Japan Friendship Hospital from March 2022 to October 2023, and reviewed their clinical characteristics, treatment response to rituximab and adverse reaction.Results:After 6 months of treatment with rituximab, 3 of 5 patients were effective and all were significantly effective, 1 patient showed no response, 1 patient died of "pulmonary infection" after 5 months of treatment, and 1 patient developed latent tuberculosis infection.Conclusion:Rituximab is effective in the treatment of anti-SRP antibody positive immune-mediated necrotizing myositis,with a low incidence of adverse reactions and overall benefits outweighing risks.

Nicotinamide mononucleotide (NMN) is an important precursor in conversing nicotinamide adenine dinucleotide (NAD +) in the body. By elevating NAD + level in the body, NMN enhances the hydrogen transfer function of NAD + in biological processes, promotes the synthesis of proteins and polysaccharides, improves substance transportation and regulatory efficiency, and enhances metabolic functions. Specifically, in central nervous system disease, NMN exerts neuroprotective effect through antioxidation, anti-inflammation, mitochondrial protection, and prevention of neuronal and axonal degeneration. This review focuses on the therapeutic role of NMN in common central nervous system diseases and their neuroprotective mechanisms, so as to further understand the role of NMN in central nervous system diseases, and provide references for predicting therapeutic targets and screening therapeutic drugs for central nervous system diseases.

Objective To report a pedigree with X?linked dominant protoporphyria(XLDPP), and to detect 5?aminolevulinic acid synthetase 2(ALAS2)gene mutations in this pedigree. Methods A clinical investigation was performed in a pedigree with XLDPP, and relevant data were collected from family members. A next?generation sequencing method was applied to screen possible mutation sites, and Sanger sequencing was performed to determine pathogenic gene mutations. Dermoscopy was conducted to observe skin lesions in the patients with XLDPP, and the Fotofinder system and very high frequency (VHF) ultrasound system were utilized to assess the severity of photodamage. Liver and gallbladder ultrasonography as well as blood examination were performed for all the family members. Results A deletion mutation, c.1706?1709ΔAGTG, was detected in the ALAS2 gene on the X chromosomes of all the patients in this family, which led to replacement or loss of 19-20 C?terminal residues through transcriptional frameshifting, and eventually caused an increase in ALAS2 activity. In the patients with XLDPP, skin photodamage was relatively severe;protoporphyrin?induced hepatobiliary damage was observed and aggravated with age;anemia and iron deficiency occurred sometimes. Conclusion The deletion mutation c.1706?1709ΔAGTG of the ALAS2 gene may be the underlying cause of XLDPP in this pedigree.