Clinical, imaging, muscle pathological and gene mutational features of patients with late-onset mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes / 中华神经医学杂志

Objective:To summarize the clinical, imaging, muscle pathological and gene mutational features of patients with late-onset mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS).Methods:Three patients with late-onset MELAS, admitted to Department of Neurology, Jiaozuo People's Hospital Affiliated of Xinxiang Medical University from January 1997 to December 2021 were chosen; all patients were screened for mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) mutations by second-generation gene sequencing. The clinical, imaging, muscle pathological and gene mutational features of patients with late-onset MELAS were analyzed retrospectively.Results:The main clinical manifestations of these late-onset MELAS patients included stroke-like attacks, headache, hearing and vision loss, cognitive decline and mental disorder. The muscle tension and muscle strength of both upper extremities in these 3 patients were normal. Increased muscle tension and active tendon reflexes, and positive pathological signs in both lower extremities were noted in 2 patients. Head MRI showed abnormal long T1 and long T2 signals in temporal occipital parietal cortex and subcortex in 3 patients, and CT showed calcification in bilateral globus pallidus in 1 patient. Ragged red fibers (RRF) and ragged blue fibers (RBF) were found in the muscle biopsies of 3 patients, and cytochrome oxidase (COX)-negative muscle fibers were found in 2 patients. MT-TL1 gene m.3243A>G mutation was detected in all 3 patients by genetic testing, among which mutation in the blood of 2 patients was 15% and 17%, respectively, and mutation in the muscle tissues of 1 patient was 73%. Conclusion:Muscle pathology indicates high RRF percentage in patients with late-onset MELAS; and m.3243A>G spot mutation is the most common mutation type in late-onset MELAS, and m.3243A>G mutation ratio in muscle tissues is obviously higher than that in blood.

FHL1 gene mutation related late-onset reducing body myopathy in a Chinese family / 中华神经科杂志

Objective:To summarize the characteristics of clinical, muscle pathology and gene mutation of late-onset reducing body myopathy caused by FHL1 gene mutation, in order to improve clinicians′ understanding of this disorder. Methods:The clinical, muscle pathology and muscle magnetic resonance imaging data of the proband from a family diagnosed as reducing body myopathy in Jiaozuo People′s Hospital in December 2021 were collected. Genetic tests and pedigree verification were conducted on the proband and her son.Results:The proband was a 59-year-old female with progressive, asymmetrical limb weakness and muscular atrophy. Her mother, sister and brother had similar symptoms. Electromyography showed myogenic and neurogenic damage. Muscle magnetic resonance imaging indicated that the lesion mainly involved the posterior muscles of the thigh and calf, as well as the gluteus maximus. The muscle pathology showed eosinophilic granular inclusion bodies and rimmed vacuoles in the muscle fibers of the lesion. The structure of myofibrils was disordered and abnormal protein deposition was observed. The gene sequencing showed the FHL1 gene p.C150S heterozygous variation. Conclusions:Late-onset reducing body myopathy is characterized by progressive asymmetric proximal limb muscle weakness, partially involving distal limb muscles and gluteus maximus. Muscle pathology shows the characteristic pathological changes of many kinds of myofibrillar myopathies. FHL1 gene mutation is an important basis for diagnosis.

Anti-PEG antibodies boosted in humans by SARS-CoV-2 lipid nanoparticle mRNA vaccine

Humans commonly have low level antibodies to poly(ethylene) glycol (PEG) due to environmental exposure. Lipid nanoparticle (LNP) mRNA vaccines for SARS-CoV-2 contain small amounts of PEG but it is not known whether PEG antibodies are enhanced by vaccination and what their impact is on particle-immune cell interactions in human blood. We studied plasma from 130 adults receiving either the BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) mRNA vaccines, or no SARS-CoV-2 vaccine for PEG-specific antibodies. Anti-PEG IgG was commonly detected prior to vaccination and was significantly boosted a mean of 13.1-fold (range 1.0 to 70.9) following mRNA-1273 vaccination and a mean of 1.78-fold (range 0.68 to 16.6) following BNT162b2 vaccination. Anti-PEG IgM increased 68.5-fold (range 0.9 to 377.1) and 2.64-fold (0.76 to 12.84) following mRNA-1273 and BNT162b2 vaccination, respectively. The rise in PEG-specific antibodies following mRNA-1273 vaccination was associated with a significant increase in the association of clinically relevant PEGylated LNPs with blood phagocytes ex vivo. PEG antibodies did not impact the SARS-CoV-2 specific neutralizing antibody response to vaccination. However, the elevated levels of vaccine-induced anti-PEG antibodies correlated with increased systemic reactogenicity following two doses of vaccination. We conclude that PEG-specific antibodies can be boosted by LNP mRNA-vaccination and that the rise in PEG-specific antibodies is associated with systemic reactogenicity and an increase of PEG particle-leukocyte association in human blood. The longer-term clinical impact of the increase in PEG-specific antibodies induced by lipid nanoparticle mRNA-vaccines should be monitored.